zshall

ZSHALL(1)                   General Commands Manual                  ZSHALL(1)



NAME
       zshall - the Z shell meta-man page

OVERVIEW
       Because zsh contains many features, the zsh manual has been split into
       a number of sections.  This manual page includes all the separate
       manual pages in the following order:

       zsh          Zsh overview
       zshroadmap   Informal introduction to the manual
       zshmisc      Anything not fitting into the other sections
       zshexpn      Zsh command and parameter expansion
       zshparam     Zsh parameters
       zshoptions   Zsh options
       zshbuiltins  Zsh built-in functions
       zshzle       Zsh command line editing
       zshcompwid   Zsh completion widgets
       zshcompsys   Zsh completion system
       zshcompctl   Zsh completion control
       zshmodules   Zsh loadable modules
       zshcalsys    Zsh built-in calendar functions
       zshtcpsys    Zsh built-in TCP functions
       zshzftpsys   Zsh built-in FTP client
       zshcontrib   Additional zsh functions and utilities

DESCRIPTION
       Zsh is a UNIX command interpreter (shell) usable as an interactive
       login shell and as a shell script command processor.  Of the standard
       shells, zsh most closely resembles ksh but includes many enhancements.
       It does not provide compatibility with POSIX or other shells in its
       default operating mode:  see the section Compatibility below.

       Zsh has command line editing, builtin spelling correction, programmable
       command completion, shell functions (with autoloading), a history
       mechanism, and a host of other features.

AUTHOR
       Zsh was originally written by Paul Falstad <pf@zsh.org>.  Zsh is now
       maintained by the members of the zsh-workers mailing list
       <zsh-workers@zsh.org>.  The development is currently coordinated by
       Peter Stephenson <pws@zsh.org>.  The coordinator can be contacted at
       <coordinator@zsh.org>, but matters relating to the code should
       generally go to the mailing list.

AVAILABILITY
       Zsh is available from the following HTTP and anonymous FTP site.

       ftp://ftp.zsh.org/pub/
       https://www.zsh.org/pub/
       )

       The up-to-date source code is available via Git from Sourceforge.  See
       https://sourceforge.net/projects/zsh/ for details.  A summary of
       instructions for the archive can be found at
       http://zsh.sourceforge.net/.

MAILING LISTS
       Zsh has 3 mailing lists:

       <zsh-announce@zsh.org>
              Announcements about releases, major changes in the shell and the
              monthly posting of the Zsh FAQ.  (moderated)

       <zsh-users@zsh.org>
              User discussions.

       <zsh-workers@zsh.org>
              Hacking, development, bug reports and patches.

       To subscribe or unsubscribe, send mail to the associated administrative
       address for the mailing list.

       <zsh-announce-subscribe@zsh.org>
       <zsh-users-subscribe@zsh.org>
       <zsh-workers-subscribe@zsh.org>
       <zsh-announce-unsubscribe@zsh.org>
       <zsh-users-unsubscribe@zsh.org>
       <zsh-workers-unsubscribe@zsh.org>

       YOU ONLY NEED TO JOIN ONE OF THE MAILING LISTS AS THEY ARE NESTED.  All
       submissions to zsh-announce are automatically forwarded to zsh-users.
       All submissions to zsh-users are automatically forwarded to
       zsh-workers.

       If you have problems subscribing/unsubscribing to any of the mailing
       lists, send mail to <listmaster@zsh.org>.  The mailing lists are
       maintained by Karsten Thygesen <karthy@kom.auc.dk>.

       The mailing lists are archived; the archives can be accessed via the
       administrative addresses listed above.  There is also a hypertext
       archive, maintained by Geoff Wing <gcw@zsh.org>, available at
       https://www.zsh.org/mla/.

THE ZSH FAQ
       Zsh has a list of Frequently Asked Questions (FAQ), maintained by Peter
       Stephenson <pws@zsh.org>.  It is regularly posted to the newsgroup
       comp.unix.shell and the zsh-announce mailing list.  The latest version
       can be found at any of the Zsh FTP sites, or at
       http://www.zsh.org/FAQ/.  The contact address for FAQ-related matters
       is <faqmaster@zsh.org>.

THE ZSH WEB PAGE
       Zsh has a web page which is located at https://www.zsh.org/.  This is
       maintained by Karsten Thygesen <karthy@zsh.org>, of SunSITE Denmark.
       The contact address for web-related matters is <webmaster@zsh.org>.

THE ZSH USERGUIDE
       A userguide is currently in preparation.  It is intended to complement
       the manual, with explanations and hints on issues where the manual can
       be cabbalistic, hierographic, or downright mystifying (for example, the
       word `hierographic' does not exist).  It can be viewed in its current
       state at http://zsh.sourceforge.net/Guide/.  At the time of writing,
       chapters dealing with startup files and their contents and the new
       completion system were essentially complete.

INVOCATION
       The following flags are interpreted by the shell when invoked to
       determine where the shell will read commands from:

       -c     Take the first argument as a command to execute, rather than
              reading commands from a script or standard input.  If any
              further arguments are given, the first one is assigned to $0,
              rather than being used as a positional parameter.

       -i     Force shell to be interactive.  It is still possible to specify
              a script to execute.

       -s     Force shell to read commands from the standard input.  If the -s
              flag is not present and an argument is given, the first argument
              is taken to be the pathname of a script to execute.

       If there are any remaining arguments after option processing, and
       neither of the options -c or -s was supplied, the first argument is
       taken as the file name of a script containing shell commands to be
       executed.  If the option PATH_SCRIPT is set, and the file name does not
       contain a directory path (i.e. there is no `/' in the name), first the
       current directory and then the command path given by the variable PATH
       are searched for the script.  If the option is not set or the file name
       contains a `/' it is used directly.

       After the first one or two arguments have been appropriated as
       described above, the remaining arguments are assigned to the positional
       parameters.

       For further options, which are common to invocation and the set
       builtin, see zshoptions(1).

       The long option `--emulate' followed (in a separate word) by an
       emulation mode may be passed to the shell.  The emulation modes are
       those described for the emulate builtin, see zshbuiltins(1).  The
       `--emulate' option must precede any other options (which might
       otherwise be overridden), but following options are honoured, so may be
       used to modify the requested emulation mode.  Note that certain extra
       steps are taken to ensure a smooth emulation when this option is used
       compared with the emulate command within the shell: for example,
       variables that conflict with POSIX usage such as path are not defined
       within the shell.

       Options may be specified by name using the -o option.  -o acts like a
       single-letter option, but takes a following string as the option name.
       For example,

              zsh -x -o shwordsplit scr

       runs the script scr, setting the XTRACE option by the corresponding
       letter `-x' and the SH_WORD_SPLIT option by name.  Options may be
       turned off by name by using +o instead of -o.  -o can be stacked up
       with preceding single-letter options, so for example `-xo shwordsplit'
       or `-xoshwordsplit' is equivalent to `-x -o shwordsplit'.

       Options may also be specified by name in GNU long option style,
       `--option-name'.  When this is done, `-' characters in the option name
       are permitted: they are translated into `_', and thus ignored.  So, for
       example, `zsh --sh-word-split' invokes zsh with the SH_WORD_SPLIT
       option turned on.  Like other option syntaxes, options can be turned
       off by replacing the initial `-' with a `+'; thus `+-sh-word-split' is
       equivalent to `--no-sh-word-split'.  Unlike other option syntaxes,
       GNU-style long options cannot be stacked with any other options, so for
       example `-x-shwordsplit' is an error, rather than being treated like
       `-x --shwordsplit'.

       The special GNU-style option `--version' is handled; it sends to
       standard output the shell's version information, then exits
       successfully.  `--help' is also handled; it sends to standard output a
       list of options that can be used when invoking the shell, then exits
       successfully.

       Option processing may be finished, allowing following arguments that
       start with `-' or `+' to be treated as normal arguments, in two ways.
       Firstly, a lone `-' (or `+') as an argument by itself ends option
       processing.  Secondly, a special option `--' (or `+-'), which may be
       specified on its own (which is the standard POSIX usage) or may be
       stacked with preceding options (so `-x-' is equivalent to `-x --').
       Options are not permitted to be stacked after `--' (so `-x-f' is an
       error), but note the GNU-style option form discussed above, where
       `--shwordsplit' is permitted and does not end option processing.

       Except when the sh/ksh emulation single-letter options are in effect,
       the option `-b' (or `+b') ends option processing.  `-b' is like `--',
       except that further single-letter options can be stacked after the `-b'
       and will take effect as normal.

COMPATIBILITY
       Zsh tries to emulate sh or ksh when it is invoked as sh or ksh
       respectively; more precisely, it looks at the first letter of the name
       by which it was invoked, excluding any initial `r' (assumed to stand
       for `restricted'), and if that is `b', `s' or `k' it will emulate sh or
       ksh.  Furthermore, if invoked as su (which happens on certain systems
       when the shell is executed by the su command), the shell will try to
       find an alternative name from the SHELL environment variable and
       perform emulation based on that.

       In sh and ksh compatibility modes the following parameters are not
       special and not initialized by the shell: ARGC, argv, cdpath, fignore,
       fpath, HISTCHARS, mailpath, MANPATH, manpath, path, prompt, PROMPT,
       PROMPT2, PROMPT3, PROMPT4, psvar, status, watch.

       The usual zsh startup/shutdown scripts are not executed.  Login shells
       source /etc/profile followed by $HOME/.profile.  If the ENV environment
       variable is set on invocation, $ENV is sourced after the profile
       scripts.  The value of ENV is subjected to parameter expansion, command
       substitution, and arithmetic expansion before being interpreted as a
       pathname.  Note that the PRIVILEGED option also affects the execution
       of startup files.

       The following options are set if the shell is invoked as sh or ksh:
       NO_BAD_PATTERN, NO_BANG_HIST, NO_BG_NICE, NO_EQUALS,
       NO_FUNCTION_ARGZERO, GLOB_SUBST, NO_GLOBAL_EXPORT, NO_HUP,
       INTERACTIVE_COMMENTS, KSH_ARRAYS, NO_MULTIOS, NO_NOMATCH, NO_NOTIFY,
       POSIX_BUILTINS, NO_PROMPT_PERCENT, RM_STAR_SILENT, SH_FILE_EXPANSION,
       SH_GLOB, SH_OPTION_LETTERS, SH_WORD_SPLIT.  Additionally the BSD_ECHO
       and IGNORE_BRACES options are set if zsh is invoked as sh.  Also, the
       KSH_OPTION_PRINT, LOCAL_OPTIONS, PROMPT_BANG, PROMPT_SUBST and
       SINGLE_LINE_ZLE options are set if zsh is invoked as ksh.

RESTRICTED SHELL
       When the basename of the command used to invoke zsh starts with the
       letter `r' or the `-r' command line option is supplied at invocation,
       the shell becomes restricted.  Emulation mode is determined after
       stripping the letter `r' from the invocation name.  The following are
       disabled in restricted mode:

       ·      changing directories with the cd builtin

       ·      changing or unsetting the EGID, EUID, GID, HISTFILE, HISTSIZE,
              IFS, LD_AOUT_LIBRARY_PATH, LD_AOUT_PRELOAD, LD_LIBRARY_PATH,
              LD_PRELOAD, MODULE_PATH, module_path, PATH, path, SHELL, UID and
              USERNAME parameters

       ·      specifying command names containing /

       ·      specifying command pathnames using hash

       ·      redirecting output to files

       ·      using the exec builtin command to replace the shell with another
              command

       ·      using jobs -Z to overwrite the shell process' argument and
              environment space

       ·      using the ARGV0 parameter to override argv[0] for external
              commands

       ·      turning off restricted mode with set +r or unsetopt RESTRICTED

       These restrictions are enforced after processing the startup files.
       The startup files should set up PATH to point to a directory of
       commands which can be safely invoked in the restricted environment.
       They may also add further restrictions by disabling selected builtins.

       Restricted mode can also be activated any time by setting the
       RESTRICTED option.  This immediately enables all the restrictions
       described above even if the shell still has not processed all startup
       files.

       A shell Restricted Mode is an outdated way to restrict what users may
       do:  modern systems have better, safer and more reliable ways to
       confine user actions, such as chroot jails, containers and zones.

       A restricted shell is very difficult to implement safely.  The feature
       may be removed in a future version of zsh.

       It is important to realise that the restrictions only apply to the
       shell, not to the commands it runs (except for some shell builtins).
       While a restricted shell can only run the restricted list of commands
       accessible via the predefined `PATH' variable, it does not prevent
       those commands from running any other command.

       As an example, if `env' is among the list of allowed commands, then it
       allows the user to run any command as `env' is not a shell builtin
       command and can run arbitrary executables.

       So when implementing a restricted shell framework it is important to be
       fully aware of what actions each of the allowed commands or features
       (which may be regarded as modules) can perform.

       Many commands can have their behaviour affected by environment
       variables.  Except for the few listed above, zsh does not restrict the
       setting of environment variables.

       If a `perl', `python', `bash', or other general purpose interpreted
       script it treated as a restricted command, the user can work around the
       restriction by setting specially crafted `PERL5LIB', `PYTHONPATH',
       `BASHENV' (etc.) environment variables. On GNU systems, any command can
       be made to run arbitrary code when performing character set conversion
       (including zsh itself) by setting a `GCONV_PATH' environment variable.
       Those are only a few examples.

       Bear in mind that, contrary to some other shells, `readonly' is not a
       security feature in zsh as it can be undone and so cannot be used to
       mitigate the above.

       A restricted shell only works if the allowed commands are few and
       carefully written so as not to grant more access to users than
       intended.  It is also important to restrict what zsh module the user
       may load as some of them, such as `zsh/system', `zsh/mapfile' and
       `zsh/files', allow bypassing most of the restrictions.

STARTUP/SHUTDOWN FILES
       Commands are first read from /etc/zshenv; this cannot be overridden.
       Subsequent behaviour is modified by the RCS and GLOBAL_RCS options; the
       former affects all startup files, while the second only affects global
       startup files (those shown here with an path starting with a /).  If
       one of the options is unset at any point, any subsequent startup
       file(s) of the corresponding type will not be read.  It is also
       possible for a file in $ZDOTDIR to re-enable GLOBAL_RCS. Both RCS and
       GLOBAL_RCS are set by default.

       Commands are then read from $ZDOTDIR/.zshenv.  If the shell is a login
       shell, commands are read from /etc/zprofile and then
       $ZDOTDIR/.zprofile.  Then, if the shell is interactive, commands are
       read from /etc/zshrc and then $ZDOTDIR/.zshrc.  Finally, if the shell
       is a login shell, /etc/zlogin and $ZDOTDIR/.zlogin are read.

       When a login shell exits, the files $ZDOTDIR/.zlogout and then
       /etc/zlogout are read.  This happens with either an explicit exit via
       the exit or logout commands, or an implicit exit by reading end-of-file
       from the terminal.  However, if the shell terminates due to exec'ing
       another process, the logout files are not read.  These are also
       affected by the RCS and GLOBAL_RCS options.  Note also that the RCS
       option affects the saving of history files, i.e. if RCS is unset when
       the shell exits, no history file will be saved.

       If ZDOTDIR is unset, HOME is used instead.  Files listed above as being
       in /etc may be in another directory, depending on the installation.

       As /etc/zshenv is run for all instances of zsh, it is important that it
       be kept as small as possible.  In particular, it is a good idea to put
       code that does not need to be run for every single shell behind a test
       of the form `if [[ -o rcs ]]; then ...' so that it will not be executed
       when zsh is invoked with the `-f' option.

       Any of these files may be pre-compiled with the zcompile builtin
       command (see zshbuiltins(1)).  If a compiled file exists (named for the
       original file plus the .zwc extension) and it is newer than the
       original file, the compiled file will be used instead.



ZSHROADMAP(1)               General Commands Manual              ZSHROADMAP(1)



NAME
       zshroadmap - informal introduction to the zsh manual The Zsh Manual,
       like the shell itself, is large and often complicated.  This section of
       the manual provides some pointers to areas of the shell that are likely
       to be of particular interest to new users, and indicates where in the
       rest of the manual the documentation is to be found.

WHEN THE SHELL STARTS
       When it starts, the shell reads commands from various files.  These can
       be created or edited to customize the shell.  See the section
       Startup/Shutdown Files in zsh(1).

       If no personal initialization files exist for the current user, a
       function is run to help you change some of the most common settings.
       It won't appear if your administrator has disabled the zsh/newuser
       module.  The function is designed to be self-explanatory.  You can run
       it by hand with `autoload -Uz zsh-newuser-install; zsh-newuser-install
       -f'.  See also the section User Configuration Functions in
       zshcontrib(1).

INTERACTIVE USE
       Interaction with the shell uses the builtin Zsh Line Editor, ZLE.  This
       is described in detail in zshzle(1).

       The first decision a user must make is whether to use the Emacs or Vi
       editing mode as the keys for editing are substantially different.
       Emacs editing mode is probably more natural for beginners and can be
       selected explicitly with the command bindkey -e.

       A history mechanism for retrieving previously typed lines (most simply
       with the Up or Down arrow keys) is available; note that, unlike other
       shells, zsh will not save these lines when the shell exits unless you
       set appropriate variables, and the number of history lines retained by
       default is quite small (30 lines).  See the description of the shell
       variables (referred to in the documentation as parameters) HISTFILE,
       HISTSIZE and SAVEHIST in zshparam(1).  Note that it's currently only
       possible to read and write files saving history when the shell is
       interactive, i.e. it does not work from scripts.

       The shell now supports the UTF-8 character set (and also others if
       supported by the operating system).  This is (mostly) handled
       transparently by the shell, but the degree of support in terminal
       emulators is variable.  There is some discussion of this in the shell
       FAQ, http://www.zsh.org/FAQ/.  Note in particular that for combining
       characters to be handled the option COMBINING_CHARS needs to be set.
       Because the shell is now more sensitive to the definition of the
       character set, note that if you are upgrading from an older version of
       the shell you should ensure that the appropriate variable, either LANG
       (to affect all aspects of the shell's operation) or LC_CTYPE (to affect
       only the handling of character sets) is set to an appropriate value.
       This is true even if you are using a single-byte character set
       including extensions of ASCII such as ISO-8859-1 or ISO-8859-15.  See
       the description of LC_CTYPE in zshparam(1).

   Completion
       Completion is a feature present in many shells. It allows the user to
       type only a part (usually the prefix) of a word and have the shell fill
       in the rest.  The completion system in zsh is programmable.  For
       example, the shell can be set to complete email addresses in arguments
       to the mail command from your ~/.abook/addressbook; usernames,
       hostnames, and even remote paths in arguments to scp, and so on.
       Anything that can be written in or glued together with zsh can be the
       source of what the line editor offers as possible completions.

       Zsh has two completion systems, an old, so called compctl completion
       (named after the builtin command that serves as its complete and only
       user interface), and a new one, referred to as compsys, organized as
       library of builtin and user-defined functions.  The two systems differ
       in their interface for specifying the completion behavior.  The new
       system is more customizable and is supplied with completions for many
       commonly used commands; it is therefore to be preferred.

       The completion system must be enabled explicitly when the shell starts.
       For more information see zshcompsys(1).

   Extending the line editor
       Apart from completion, the line editor is highly extensible by means of
       shell functions.  Some useful functions are provided with the shell;
       they provide facilities such as:

       insert-composed-char
              composing characters not found on the keyboard

       match-words-by-style
              configuring what the line editor considers a word when moving or
              deleting by word

       history-beginning-search-backward-end, etc.
              alternative ways of searching the shell history

       replace-string, replace-pattern
              functions for replacing strings or patterns globally in the
              command line

       edit-command-line
              edit the command line with an external editor.

       See the section `ZLE Functions' in zshcontrib(1) for descriptions of
       these.

OPTIONS
       The shell has a large number of options for changing its behaviour.
       These cover all aspects of the shell; browsing the full documentation
       is the only good way to become acquainted with the many possibilities.
       See zshoptions(1).

PATTERN MATCHING
       The shell has a rich set of patterns which are available for file
       matching (described in the documentation as `filename generation' and
       also known for historical reasons as `globbing') and for use when
       programming.  These are described in the section `Filename Generation'
       in zshexpn(1).

       Of particular interest are the following patterns that are not commonly
       supported by other systems of pattern matching:

       **     for matching over multiple directories

       |      for matching either of two alternatives

       ~, ^   the ability to exclude patterns from matching when the
              EXTENDED_GLOB option is set

       (...)  glob qualifiers, included in parentheses at the end of the
              pattern, which select files by type (such as directories) or
              attribute (such as size).

GENERAL COMMENTS ON SYNTAX
       Although the syntax of zsh is in ways similar to the Korn shell, and
       therefore more remotely to the original UNIX shell, the Bourne shell,
       its default behaviour does not entirely correspond to those shells.
       General shell syntax is introduced in the section `Shell Grammar' in
       zshmisc(1).

       One commonly encountered difference is that variables substituted onto
       the command line are not split into words.  See the description of the
       shell option SH_WORD_SPLIT in the section `Parameter Expansion' in
       zshexpn(1).  In zsh, you can either explicitly request the splitting
       (e.g. ${=foo}) or use an array when you want a variable to expand to
       more than one word.  See the section `Array Parameters' in zshparam(1).

PROGRAMMING
       The most convenient way of adding enhancements to the shell is
       typically by writing a shell function and arranging for it to be
       autoloaded.  Functions are described in the section `Functions' in
       zshmisc(1).  Users changing from the C shell and its relatives should
       notice that aliases are less used in zsh as they don't perform argument
       substitution, only simple text replacement.

       A few general functions, other than those for the line editor described
       above, are provided with the shell and are described in zshcontrib(1).
       Features include:

       promptinit
              a prompt theme system for changing prompts easily, see the
              section `Prompt Themes'


       zsh-mime-setup
              a MIME-handling system which dispatches commands according to
              the suffix of a file as done by graphical file managers

       zcalc  a calculator

       zargs  a version of xargs that makes the find command redundant

       zmv    a command for renaming files by means of shell patterns.




ZSHMISC(1)                  General Commands Manual                 ZSHMISC(1)



NAME
       zshmisc - everything and then some

SIMPLE COMMANDS & PIPELINES
       A simple command is a sequence of optional parameter assignments
       followed by blank-separated words, with optional redirections
       interspersed.  For a description of assignment, see the beginning of
       zshparam(1).

       The first word is the command to be executed, and the remaining words,
       if any, are arguments to the command.  If a command name is given, the
       parameter assignments modify the environment of the command when it is
       executed.  The value of a simple command is its exit status, or 128
       plus the signal number if terminated by a signal.  For example,

              echo foo

       is a simple command with arguments.

       A pipeline is either a simple command, or a sequence of two or more
       simple commands where each command is separated from the next by `|' or
       `|&'.  Where commands are separated by `|', the standard output of the
       first command is connected to the standard input of the next.  `|&' is
       shorthand for `2>&1 |', which connects both the standard output and the
       standard error of the command to the standard input of the next.  The
       value of a pipeline is the value of the last command, unless the
       pipeline is preceded by `!' in which case the value is the logical
       inverse of the value of the last command.  For example,

              echo foo | sed 's/foo/bar/'

       is a pipeline, where the output (`foo' plus a newline) of the first
       command will be passed to the input of the second.

       If a pipeline is preceded by `coproc', it is executed as a coprocess; a
       two-way pipe is established between it and the parent shell.  The shell
       can read from or write to the coprocess by means of the `>&p' and `<&p'
       redirection operators or with `print -p' and `read -p'.  A pipeline
       cannot be preceded by both `coproc' and `!'.  If job control is active,
       the coprocess can be treated in other than input and output as an
       ordinary background job.

       A sublist is either a single pipeline, or a sequence of two or more
       pipelines separated by `&&' or `||'.  If two pipelines are separated by
       `&&', the second pipeline is executed only if the first succeeds
       (returns a zero status).  If two pipelines are separated by `||', the
       second is executed only if the first fails (returns a nonzero status).
       Both operators have equal precedence and are left associative.  The
       value of the sublist is the value of the last pipeline executed.  For
       example,

              dmesg | grep panic && print yes

       is a sublist consisting of two pipelines, the second just a simple
       command which will be executed if and only if the grep command returns
       a zero status.  If it does not, the value of the sublist is that return
       status, else it is the status returned by the print (almost certainly
       zero).

       A list is a sequence of zero or more sublists, in which each sublist is
       terminated by `;', `&', `&|', `&!', or a newline.  This terminator may
       optionally be omitted from the last sublist in the list when the list
       appears as a complex command inside `(...)' or `{...}'.  When a sublist
       is terminated by `;' or newline, the shell waits for it to finish
       before executing the next sublist.  If a sublist is terminated by a
       `&', `&|', or `&!', the shell executes the last pipeline in it in the
       background, and does not wait for it to finish (note the difference
       from other shells which execute the whole sublist in the background).
       A backgrounded pipeline returns a status of zero.

       More generally, a list can be seen as a set of any shell commands
       whatsoever, including the complex commands below; this is implied
       wherever the word `list' appears in later descriptions.  For example,
       the commands in a shell function form a special sort of list.

PRECOMMAND MODIFIERS
       A simple command may be preceded by a precommand modifier, which will
       alter how the command is interpreted.  These modifiers are shell
       builtin commands with the exception of nocorrect which is a reserved
       word.

       -      The command is executed with a `-' prepended to its argv[0]
              string.

       builtin
              The command word is taken to be the name of a builtin command,
              rather than a shell function or external command.

       command [ -pvV ]
              The command word is taken to be the name of an external command,
              rather than a shell function or builtin.   If the POSIX_BUILTINS
              option is set, builtins will also be executed but certain
              special properties of them are suppressed. The -p flag causes a
              default path to be searched instead of that in $path. With the
              -v flag, command is similar to whence and with -V, it is
              equivalent to whence -v.

       exec [ -cl ] [ -a argv0 ]
              The following command together with any arguments is run in
              place of the current process, rather than as a sub-process.  The
              shell does not fork and is replaced.  The shell does not invoke
              TRAPEXIT, nor does it source zlogout files.  The options are
              provided for compatibility with other shells.

              The -c option clears the environment.

              The -l option is equivalent to the - precommand modifier, to
              treat the replacement command as a login shell; the command is
              executed with a - prepended to its argv[0] string.  This flag
              has no effect if used together with the -a option.

              The -a option is used to specify explicitly the argv[0] string
              (the name of the command as seen by the process itself) to be
              used by the replacement command and is directly equivalent to
              setting a value for the ARGV0 environment variable.

       nocorrect
              Spelling correction is not done on any of the words.  This must
              appear before any other precommand modifier, as it is
              interpreted immediately, before any parsing is done.  It has no
              effect in non-interactive shells.

       noglob Filename generation (globbing) is not performed on any of the
              words.

COMPLEX COMMANDS
       A complex command in zsh is one of the following:

       if list then list [ elif list then list ] ... [ else list ] fi
              The if list is executed, and if it returns a zero exit status,
              the then list is executed.  Otherwise, the elif list is executed
              and if its status is zero, the then list is executed.  If each
              elif list returns nonzero status, the else list is executed.

       for name ... [ in word ... ] term do list done
              Expand the list of words, and set the parameter name to each of
              them in turn, executing list each time.  If the `in word' is
              omitted, use the positional parameters instead of the words.

              The term consists of one or more newline or ; which terminate
              the words, and are optional when the `in word' is omitted.

              More than one parameter name can appear before the list of
              words.  If N names are given, then on each execution of the loop
              the next N words are assigned to the corresponding parameters.
              If there are more names than remaining words, the remaining
              parameters are each set to the empty string.  Execution of the
              loop ends when there is no remaining word to assign to the first
              name.  It is only possible for in to appear as the first name in
              the list, else it will be treated as marking the end of the
              list.

       for (( [expr1] ; [expr2] ; [expr3] )) do list done
              The arithmetic expression expr1 is evaluated first (see the
              section `Arithmetic Evaluation').  The arithmetic expression
              expr2 is repeatedly evaluated until it evaluates to zero and
              when non-zero, list is executed and the arithmetic expression
              expr3 evaluated.  If any expression is omitted, then it behaves
              as if it evaluated to 1.

       while list do list done
              Execute the do list as long as the while list returns a zero
              exit status.

       until list do list done
              Execute the do list as long as until list returns a nonzero exit
              status.

       repeat word do list done
              word is expanded and treated as an arithmetic expression, which
              must evaluate to a number n.  list is then executed n times.

              The repeat syntax is disabled by default when the shell starts
              in a mode emulating another shell.  It can be enabled with the
              command `enable -r repeat'

       case word in [ [(] pattern [ | pattern ] ... ) list (;;|;&|;|) ] ...
       esac
              Execute the list associated with the first pattern that matches
              word, if any.  The form of the patterns is the same as that used
              for filename generation.  See the section `Filename Generation'.

              Note further that, unless the SH_GLOB option is set, the whole
              pattern with alternatives is treated by the shell as equivalent
              to a group of patterns within parentheses, although white space
              may appear about the parentheses and the vertical bar and will
              be stripped from the pattern at those points.  White space may
              appear elsewhere in the pattern; this is not stripped.  If the
              SH_GLOB option is set, so that an opening parenthesis can be
              unambiguously treated as part of the case syntax, the expression
              is parsed into separate words and these are treated as strict
              alternatives (as in other shells).

              If the list that is executed is terminated with ;& rather than
              ;;, the following list is also executed.  The rule for the
              terminator of the following list ;;, ;& or ;| is applied unless
              the esac is reached.

              If the list that is executed is terminated with ;| the shell
              continues to scan the patterns looking for the next match,
              executing the corresponding list, and applying the rule for the
              corresponding terminator ;;, ;& or ;|.  Note that word is not
              re-expanded; all applicable patterns are tested with the same
              word.

       select name [ in word ... term ] do list done
              where term is one or more newline or ; to terminate the words.
              Print the set of words, each preceded by a number.  If the in
              word is omitted, use the positional parameters.  The PROMPT3
              prompt is printed and a line is read from the line editor if the
              shell is interactive and that is active, or else standard input.
              If this line consists of the number of one of the listed words,
              then the parameter name is set to the word corresponding to this
              number.  If this line is empty, the selection list is printed
              again.  Otherwise, the value of the parameter name is set to
              null.  The contents of the line read from standard input is
              saved in the parameter REPLY.  list is executed for each
              selection until a break or end-of-file is encountered.

       ( list )
              Execute list in a subshell.  Traps set by the trap builtin are
              reset to their default values while executing list.

       { list }
              Execute list.

       { try-list } always { always-list }
              First execute try-list.  Regardless of errors, or break or
              continue commands encountered within try-list, execute
              always-list.  Execution then continues from the result of the
              execution of try-list; in other words, any error, or break or
              continue command is treated in the normal way, as if always-list
              were not present.  The two chunks of code are referred to as the
              `try block' and the `always block'.

              Optional newlines or semicolons may appear after the always;
              note, however, that they may not appear between the preceding
              closing brace and the always.

              An `error' in this context is a condition such as a syntax error
              which causes the shell to abort execution of the current
              function, script, or list.  Syntax errors encountered while the
              shell is parsing the code do not cause the always-list to be
              executed.  For example, an erroneously constructed if block in
              try-list would cause the shell to abort during parsing, so that
              always-list would not be executed, while an erroneous
              substitution such as ${*foo*} would cause a run-time error,
              after which always-list would be executed.

              An error condition can be tested and reset with the special
              integer variable TRY_BLOCK_ERROR.  Outside an always-list the
              value is irrelevant, but it is initialised to -1.  Inside
              always-list, the value is 1 if an error occurred in the
              try-list, else 0.  If TRY_BLOCK_ERROR is set to 0 during the
              always-list, the error condition caused by the try-list is
              reset, and shell execution continues normally after the end of
              always-list.  Altering the value during the try-list is not
              useful (unless this forms part of an enclosing always block).

              Regardless of TRY_BLOCK_ERROR, after the end of always-list the
              normal shell status $? is the value returned from try-list.
              This will be non-zero if there was an error, even if
              TRY_BLOCK_ERROR was set to zero.

              The following executes the given code, ignoring any errors it
              causes.  This is an alternative to the usual convention of
              protecting code by executing it in a subshell.

                     {
                         # code which may cause an error
                       } always {
                         # This code is executed regardless of the error.
                         (( TRY_BLOCK_ERROR = 0 ))
                     }
                     # The error condition has been reset.

              When a try block occurs outside of any function, a return or a
              exit encountered in try-list does not cause the execution of
              always-list.  Instead, the shell exits immediately after any
              EXIT trap has been executed.  Otherwise, a return command
              encountered in try-list will cause the execution of always-list,
              just like break and continue.

       function word ... [ () ] [ term ] { list }
       word ... () [ term ] { list }
       word ... () [ term ] command
              where term is one or more newline or ;.  Define a function which
              is referenced by any one of word.  Normally, only one word is
              provided; multiple words are usually only useful for setting
              traps.  The body of the function is the list between the { and
              }.  See the section `Functions'.

              If the option SH_GLOB is set for compatibility with other
              shells, then whitespace may appear between the left and right
              parentheses when there is a single word;  otherwise, the
              parentheses will be treated as forming a globbing pattern in
              that case.

              In any of the forms above, a redirection may appear outside the
              function body, for example

                     func() { ... } 2>&1

              The redirection is stored with the function and applied whenever
              the function is executed.  Any variables in the redirection are
              expanded at the point the function is executed, but outside the
              function scope.

       time [ pipeline ]
              The pipeline is executed, and timing statistics are reported on
              the standard error in the form specified by the TIMEFMT
              parameter.  If pipeline is omitted, print statistics about the
              shell process and its children.

       [[ exp ]]
              Evaluates the conditional expression exp and return a zero exit
              status if it is true.  See the section `Conditional Expressions'
              for a description of exp.

ALTERNATE FORMS FOR COMPLEX COMMANDS
       Many of zsh's complex commands have alternate forms.  These are
       non-standard and are likely not to be obvious even to seasoned shell
       programmers; they should not be used anywhere that portability of shell
       code is a concern.

       The short versions below only work if sublist is of the form `{ list }'
       or if the SHORT_LOOPS option is set.  For the if, while and until
       commands, in both these cases the test part of the loop must also be
       suitably delimited, such as by `[[ ... ]]' or `(( ... ))', else the end
       of the test will not be recognized.  For the for, repeat, case and
       select commands no such special form for the arguments is necessary,
       but the other condition (the special form of sublist or use of the
       SHORT_LOOPS option) still applies.

       if list { list } [ elif list { list } ] ... [ else { list } ]
              An alternate form of if.  The rules mean that

                     if [[ -o ignorebraces ]] {
                       print yes
                     }

              works, but

                     if true {  # Does not work!
                       print yes
                     }

              does not, since the test is not suitably delimited.

       if list sublist
              A short form of the alternate if.  The same limitations on the
              form of list apply as for the previous form.

       for name ... ( word ... ) sublist
              A short form of for.

       for name ... [ in word ... ] term sublist
              where term is at least one newline or ;.  Another short form of
              for.

       for (( [expr1] ; [expr2] ; [expr3] )) sublist
              A short form of the arithmetic for command.

       foreach name ... ( word ... ) list end
              Another form of for.

       while list { list }
              An alternative form of while.  Note the limitations on the form
              of list mentioned above.

       until list { list }
              An alternative form of until.  Note the limitations on the form
              of list mentioned above.

       repeat word sublist
              This is a short form of repeat.

       case word { [ [(] pattern [ | pattern ] ... ) list (;;|;&|;|) ] ... }
              An alternative form of case.

       select name [ in word ... term ] sublist
              where term is at least one newline or ;.  A short form of
              select.

       function word ... [ () ] [ term ] sublist
              This is a short form of function.

RESERVED WORDS
       The following words are recognized as reserved words when used as the
       first word of a command unless quoted or disabled using disable -r:

       do done esac then elif else fi for case if while function repeat time
       until select coproc nocorrect foreach end ! [[ { } declare export float
       integer local readonly typeset

       Additionally, `}' is recognized in any position if neither the
       IGNORE_BRACES option nor the IGNORE_CLOSE_BRACES option is set.

ERRORS
       Certain errors are treated as fatal by the shell: in an interactive
       shell, they cause control to return to the command line, and in a
       non-interactive shell they cause the shell to be aborted.  In older
       versions of zsh, a non-interactive shell running a script would not
       abort completely, but would resume execution at the next command to be
       read from the script, skipping the remainder of any functions or shell
       constructs such as loops or conditions; this somewhat illogical
       behaviour can be recovered by setting the option CONTINUE_ON_ERROR.

       Fatal errors found in non-interactive shells include:

       ·      Failure to parse shell options passed when invoking the shell

       ·      Failure to change options with the set builtin

       ·      Parse errors of all sorts, including failures to parse
              mathematical expressions

       ·      Failures to set or modify variable behaviour with typeset,
              local, declare, export, integer, float

       ·      Execution of incorrectly positioned loop control structures
              (continue, break)

       ·      Attempts to use regular expression with no regular expression
              module available

       ·      Disallowed operations when the RESTRICTED options is set

       ·      Failure to create a pipe needed for a pipeline

       ·      Failure to create a multio

       ·      Failure to autoload a module needed for a declared shell feature

       ·      Errors creating command or process substitutions

       ·      Syntax errors in glob qualifiers

       ·      File generation errors where not caught by the option
              BAD_PATTERN

       ·      All bad patterns used for matching within case statements

       ·      File generation failures where not caused by NO_MATCH or similar
              options

       ·      All file generation errors where the pattern was used to create
              a multio

       ·      Memory errors where detected by the shell

       ·      Invalid subscripts to shell variables

       ·      Attempts to assign read-only variables

       ·      Logical errors with variables such as assignment to the wrong
              type

       ·      Use of invalid variable names

       ·      Errors in variable substitution syntax

       ·      Failure to convert characters in $'...' expressions

       If the POSIX_BUILTINS option is set, more errors associated with shell
       builtin commands are treated as fatal, as specified by the POSIX
       standard.

COMMENTS
       In non-interactive shells, or in interactive shells with the
       INTERACTIVE_COMMENTS option set, a word beginning with the third
       character of the histchars parameter (`#' by default) causes that word
       and all the following characters up to a newline to be ignored.

ALIASING
       Every eligible word in the shell input is checked to see if there is an
       alias defined for it.  If so, it is replaced by the text of the alias
       if it is in command position (if it could be the first word of a simple
       command), or if the alias is global.  If the replacement text ends with
       a space, the next word in the shell input is always eligible for
       purposes of alias expansion.  An alias is defined using the alias
       builtin; global aliases may be defined using the -g option to that
       builtin.

       A word is defined as:

       ·      Any plain string or glob pattern

       ·      Any quoted string, using any quoting method (note that the
              quotes must be part of the alias definition for this to be
              eligible)

       ·      Any parameter reference or command substitution

       ·      Any series of the foregoing, concatenated without whitespace or
              other tokens between them

       ·      Any reserved word (case, do, else, etc.)

       ·      With global aliasing, any command separator, any redirection
              operator, and `(' or `)' when not part of a glob pattern

       Alias expansion is done on the shell input before any other expansion
       except history expansion.  Therefore, if an alias is defined for the
       word foo, alias expansion may be avoided by quoting part of the word,
       e.g. \foo.  Any form of quoting works, although there is nothing to
       prevent an alias being defined for the quoted form such as \foo as
       well.

       When POSIX_ALIASES is set, only plain unquoted strings are eligible for
       aliasing.  The alias builtin does not reject ineligible aliases, but
       they are not expanded.

       For use with completion, which would remove an initial backslash
       followed by a character that isn't special, it may be more convenient
       to quote the word by starting with a single quote, i.e. 'foo;
       completion will automatically add the trailing single quote.

   Alias difficulties
       Although aliases can be used in ways that bend normal shell syntax, not
       every string of non-white-space characters can be used as an alias.

       Any set of characters not listed as a word above is not a word, hence
       no attempt is made to expand it as an alias, no matter how it is
       defined (i.e. via the builtin or the special parameter aliases
       described in the section THE ZSH/PARAMETER MODULE in zshmodules(1)).
       However, as noted in the case of POSIX_ALIASES above, the shell does
       not attempt to deduce whether the string corresponds to a word at the
       time the alias is created.

       For example, an expression containing an = at the start of a command
       line is an assignment and cannot be expanded as an alias; a lone = is
       not an assignment but can only be set as an alias using the parameter,
       as otherwise the = is taken part of the syntax of the builtin command.

       It is not presently possible to alias the `((' token that introduces
       arithmetic expressions, because until a full statement has been parsed,
       it cannot be distinguished from two consecutive `(' tokens introducing
       nested subshells.  Also, if a separator such as && is aliased, \&&
       turns into the two tokens \& and &, each of which may have been aliased
       separately.  Similarly for \<<, \>|, etc.

       There is a commonly encountered problem with aliases illustrated by the
       following code:

              alias echobar='echo bar'; echobar

       This prints a message that the command echobar could not be found.
       This happens because aliases are expanded when the code is read in; the
       entire line is read in one go, so that when echobar is executed it is
       too late to expand the newly defined alias.  This is often a problem in
       shell scripts, functions, and code executed with `source' or `.'.
       Consequently, use of functions rather than aliases is recommended in
       non-interactive code.

       Note also the unhelpful interaction of aliases and function
       definitions:

              alias func='noglob func'
              func() {
                  echo Do something with $*
              }

       Because aliases are expanded in function definitions, this causes the
       following command to be executed:

              noglob func() {
                  echo Do something with $*
              }

       which defines noglob as well as func as functions with the body given.
       To avoid this, either quote the name func or use the alternative
       function definition form `function func'.  Ensuring the alias is
       defined after the function works but is problematic if the code
       fragment might be re-executed.

QUOTING
       A character may be quoted (that is, made to stand for itself) by
       preceding it with a `\'.  `\' followed by a newline is ignored.

       A string enclosed between `$'' and `'' is processed the same way as the
       string arguments of the print builtin, and the resulting string is
       considered to be entirely quoted.  A literal `'' character can be
       included in the string by using the `\'' escape.

       All characters enclosed between a pair of single quotes ('') that is
       not preceded by a `$' are quoted.  A single quote cannot appear within
       single quotes unless the option RC_QUOTES is set, in which case a pair
       of single quotes are turned into a single quote.  For example,

              print ''''

       outputs nothing apart from a newline if RC_QUOTES is not set, but one
       single quote if it is set.

       Inside double quotes (""), parameter and command substitution occur,
       and `\' quotes the characters `\', ``', `"', `$', and the first
       character of $histchars (default `!').

REDIRECTION
       If a command is followed by & and job control is not active, then the
       default standard input for the command is the empty file /dev/null.
       Otherwise, the environment for the execution of a command contains the
       file descriptors of the invoking shell as modified by input/output
       specifications.

       The following may appear anywhere in a simple command or may precede or
       follow a complex command.  Expansion occurs before word or digit is
       used except as noted below.  If the result of substitution on word
       produces more than one filename, redirection occurs for each separate
       filename in turn.

       < word Open file word for reading as standard input.  It is an error to
              open a file in this fashion if it does not exist.

       <> word
              Open file word for reading and writing as standard input.  If
              the file does not exist then it is created.

       > word Open file word for writing as standard output.  If the file does
              not exist then it is created.  If the file exists, and the
              CLOBBER option is unset, this causes an error; otherwise, it is
              truncated to zero length.

       >| word
       >! word
              Same as >, except that the file is truncated to zero length if
              it exists, regardless of CLOBBER.

       >> word
              Open file word for writing in append mode as standard output.
              If the file does not exist, and the CLOBBER and APPEND_CREATE
              options are both unset, this causes an error; otherwise, the
              file is created.

       >>| word
       >>! word
              Same as >>, except that the file is created if it does not
              exist, regardless of CLOBBER and APPEND_CREATE.

       <<[-] word
              The shell input is read up to a line that is the same as word,
              or to an end-of-file.  No parameter expansion, command
              substitution or filename generation is performed on word.  The
              resulting document, called a here-document, becomes the standard
              input.

              If any character of word is quoted with single or double quotes
              or a `\', no interpretation is placed upon the characters of the
              document.  Otherwise, parameter and command substitution occurs,
              `\' followed by a newline is removed, and `\' must be used to
              quote the characters `\', `$', ``' and the first character of
              word.

              Note that word itself does not undergo shell expansion.
              Backquotes in word do not have their usual effect; instead they
              behave similarly to double quotes, except that the backquotes
              themselves are passed through unchanged.  (This information is
              given for completeness and it is not recommended that backquotes
              be used.)  Quotes in the form $'...' have their standard effect
              of expanding backslashed references to special characters.

              If <<- is used, then all leading tabs are stripped from word and
              from the document.

       <<< word
              Perform shell expansion on word and pass the result to standard
              input.  This is known as a here-string.  Compare the use of word
              in here-documents above, where word does not undergo shell
              expansion.

       <& number
       >& number
              The standard input/output is duplicated from file descriptor
              number (see dup2(2)).

       <& -
       >& -   Close the standard input/output.

       <& p
       >& p   The input/output from/to the coprocess is moved to the standard
              input/output.

       >& word
       &> word
              (Except where `>& word' matches one of the above syntaxes; `&>'
              can always be used to avoid this ambiguity.)  Redirects both
              standard output and standard error (file descriptor 2) in the
              manner of `> word'.  Note that this does not have the same
              effect as `> word 2>&1' in the presence of multios (see the
              section below).

       >&| word
       >&! word
       &>| word
       &>! word
              Redirects both standard output and standard error (file
              descriptor 2) in the manner of `>| word'.

       >>& word
       &>> word
              Redirects both standard output and standard error (file
              descriptor 2) in the manner of `>> word'.

       >>&| word
       >>&! word
       &>>| word
       &>>! word
              Redirects both standard output and standard error (file
              descriptor 2) in the manner of `>>| word'.

       If one of the above is preceded by a digit, then the file descriptor
       referred to is that specified by the digit instead of the default 0 or
       1.  The order in which redirections are specified is significant.  The
       shell evaluates each redirection in terms of the (file descriptor,
       file) association at the time of evaluation.  For example:

              ... 1>fname 2>&1

       first associates file descriptor 1 with file fname.  It then associates
       file descriptor 2 with the file associated with file descriptor 1 (that
       is, fname).  If the order of redirections were reversed, file
       descriptor 2 would be associated with the terminal (assuming file
       descriptor 1 had been) and then file descriptor 1 would be associated
       with file fname.

       The `|&' command separator described in Simple Commands & Pipelines in
       zshmisc(1) is a shorthand for `2>&1 |'.

       The various forms of process substitution, `<(list)', and `=(list)' for
       input and `>(list)' for output, are often used together with
       redirection.  For example, if word in an output redirection is of the
       form `>(list)' then the output is piped to the command represented by
       list.  See Process Substitution in zshexpn(1).

OPENING FILE DESCRIPTORS USING PARAMETERS
       When the shell is parsing arguments to a command, and the shell option
       IGNORE_BRACES is not set, a different form of redirection is allowed:
       instead of a digit before the operator there is a valid shell
       identifier enclosed in braces.  The shell will open a new file
       descriptor that is guaranteed to be at least 10 and set the parameter
       named by the identifier to the file descriptor opened.  No whitespace
       is allowed between the closing brace and the redirection character.
       For example:

              ... {myfd}>&1

       This opens a new file descriptor that is a duplicate of file descriptor
       1 and sets the parameter myfd to the number of the file descriptor,
       which will be at least 10.  The new file descriptor can be written to
       using the syntax >&$myfd.  The file descriptor remains open in
       subshells and forked external executables.

       The syntax {varid}>&-, for example {myfd}>&-, may be used to close a
       file descriptor opened in this fashion.  Note that the parameter given
       by varid must previously be set to a file descriptor in this case.

       It is an error to open or close a file descriptor in this fashion when
       the parameter is readonly.  However, it is not an error to read or
       write a file descriptor using <&$param or >&$param if param is
       readonly.

       If the option CLOBBER is unset, it is an error to open a file
       descriptor using a parameter that is already set to an open file
       descriptor previously allocated by this mechanism.  Unsetting the
       parameter before using it for allocating a file descriptor avoids the
       error.

       Note that this mechanism merely allocates or closes a file descriptor;
       it does not perform any redirections from or to it.  It is usually
       convenient to allocate a file descriptor prior to use as an argument to
       exec.  The syntax does not in any case work when used around complex
       commands such as parenthesised subshells or loops, where the opening
       brace is interpreted as part of a command list to be executed in the
       current shell.

       The following shows a typical sequence of allocation, use, and closing
       of a file descriptor:

              integer myfd
              exec {myfd}>~/logs/mylogfile.txt
              print This is a log message. >&$myfd
              exec {myfd}>&-

       Note that the expansion of the variable in the expression >&$myfd
       occurs at the point the redirection is opened.  This is after the
       expansion of command arguments and after any redirections to the left
       on the command line have been processed.

MULTIOS
       If the user tries to open a file descriptor for writing more than once,
       the shell opens the file descriptor as a pipe to a process that copies
       its input to all the specified outputs, similar to tee, provided the
       MULTIOS option is set, as it is by default.  Thus:

              date >foo >bar

       writes the date to two files, named `foo' and `bar'.  Note that a pipe
       is an implicit redirection; thus

              date >foo | cat

       writes the date to the file `foo', and also pipes it to cat.

       Note that the shell opens all the files to be used in the multio
       process immediately, not at the point they are about to be written.

       Note also that redirections are always expanded in order.  This happens
       regardless of the setting of the MULTIOS option, but with the option in
       effect there are additional consequences. For example, the meaning of
       the expression >&1 will change after a previous redirection:

              date >&1 >output

       In the case above, the >&1 refers to the standard output at the start
       of the line; the result is similar to the tee command.  However,
       consider:

              date >output >&1

       As redirections are evaluated in order, when the >&1 is encountered the
       standard output is set to the file output and another copy of the
       output is therefore sent to that file.  This is unlikely to be what is
       intended.

       If the MULTIOS option is set, the word after a redirection operator is
       also subjected to filename generation (globbing).  Thus

              : > *

       will truncate all files in the current directory, assuming there's at
       least one.  (Without the MULTIOS option, it would create an empty file
       called `*'.)  Similarly, you can do

              echo exit 0 >> *.sh

       If the user tries to open a file descriptor for reading more than once,
       the shell opens the file descriptor as a pipe to a process that copies
       all the specified inputs to its output in the order specified, provided
       the MULTIOS option is set.  It should be noted that each file is opened
       immediately, not at the point where it is about to be read: this
       behaviour differs from cat, so if strictly standard behaviour is
       needed, cat should be used instead.

       Thus

              sort <foo <fubar

       or even

              sort <f{oo,ubar}

       is equivalent to `cat foo fubar | sort'.

       Expansion of the redirection argument occurs at the point the
       redirection is opened, at the point described above for the expansion
       of the variable in >&$myfd.

       Note that a pipe is an implicit redirection; thus

              cat bar | sort <foo

       is equivalent to `cat bar foo | sort' (note the order of the inputs).

       If the MULTIOS option is unset, each redirection replaces the previous
       redirection for that file descriptor.  However, all files redirected to
       are actually opened, so

              echo Hello > bar > baz

       when MULTIOS is unset will truncate `bar', and write `Hello' into
       `baz'.

       There is a problem when an output multio is attached to an external
       program.  A simple example shows this:

              cat file >file1 >file2
              cat file1 file2

       Here, it is possible that the second `cat' will not display the full
       contents of file1 and file2 (i.e. the original contents of file
       repeated twice).

       The reason for this is that the multios are spawned after the cat
       process is forked from the parent shell, so the parent shell does not
       wait for the multios to finish writing data.  This means the command as
       shown can exit before file1 and file2 are completely written.  As a
       workaround, it is possible to run the cat process as part of a job in
       the current shell:

              { cat file } >file >file2

       Here, the {...} job will pause to wait for both files to be written.

REDIRECTIONS WITH NO COMMAND
       When a simple command consists of one or more redirection operators and
       zero or more parameter assignments, but no command name, zsh can behave
       in several ways.

       If the parameter NULLCMD is not set or the option CSH_NULLCMD is set,
       an error is caused.  This is the csh behavior and CSH_NULLCMD is set by
       default when emulating csh.

       If the option SH_NULLCMD is set, the builtin `:' is inserted as a
       command with the given redirections.  This is the default when
       emulating sh or ksh.

       Otherwise, if the parameter NULLCMD is set, its value will be used as a
       command with the given redirections.  If both NULLCMD and READNULLCMD
       are set, then the value of the latter will be used instead of that of
       the former when the redirection is an input.  The default for NULLCMD
       is `cat' and for READNULLCMD is `more'. Thus

              < file

       shows the contents of file on standard output, with paging if that is a
       terminal.  NULLCMD and READNULLCMD may refer to shell functions.

COMMAND EXECUTION
       If a command name contains no slashes, the shell attempts to locate it.
       If there exists a shell function by that name, the function is invoked
       as described in the section `Functions'.  If there exists a shell
       builtin by that name, the builtin is invoked.

       Otherwise, the shell searches each element of $path for a directory
       containing an executable file by that name.  If the search is
       unsuccessful, the shell prints an error message and returns a nonzero
       exit status.

       If execution fails because the file is not in executable format, and
       the file is not a directory, it is assumed to be a shell script.
       /bin/sh is spawned to execute it.  If the program is a file beginning
       with `#!', the remainder of the first line specifies an interpreter for
       the program.  The shell will execute the specified interpreter on
       operating systems that do not handle this executable format in the
       kernel.

       If no external command is found but a function
       command_not_found_handler exists the shell executes this function with
       all command line arguments.  The return status of the function becomes
       the status of the command.  If the function wishes to mimic the
       behaviour of the shell when the command is not found, it should print
       the message `command not found: cmd' to standard error and return
       status 127.  Note that the handler is executed in a subshell forked to
       execute an external command, hence changes to directories, shell
       parameters, etc. have no effect on the main shell.

FUNCTIONS
       Shell functions are defined with the function reserved word or the
       special syntax `funcname ()'.  Shell functions are read in and stored
       internally.  Alias names are resolved when the function is read.
       Functions are executed like commands with the arguments passed as
       positional parameters.  (See the section `Command Execution'.)

       Functions execute in the same process as the caller and share all files
       and present working directory with the caller.  A trap on EXIT set
       inside a function is executed after the function completes in the
       environment of the caller.

       The return builtin is used to return from function calls.

       Function identifiers can be listed with the functions builtin.
       Functions can be undefined with the unfunction builtin.

AUTOLOADING FUNCTIONS
       A function can be marked as undefined using the autoload builtin (or
       `functions -u' or `typeset -fu').  Such a function has no body.  When
       the function is first executed, the shell searches for its definition
       using the elements of the fpath variable.  Thus to define functions for
       autoloading, a typical sequence is:

              fpath=(~/myfuncs $fpath)
              autoload myfunc1 myfunc2 ...

       The usual alias expansion during reading will be suppressed if the
       autoload builtin or its equivalent is given the option -U. This is
       recommended for the use of functions supplied with the zsh
       distribution.  Note that for functions precompiled with the zcompile
       builtin command the flag -U must be provided when the .zwc file is
       created, as the corresponding information is compiled into the latter.

       For each element in fpath, the shell looks for three possible files,
       the newest of which is used to load the definition for the function:

       element.zwc
              A file created with the zcompile builtin command, which is
              expected to contain the definitions for all functions in the
              directory named element.  The file is treated in the same manner
              as a directory containing files for functions and is searched
              for the definition of the function.   If the definition is not
              found, the search for a definition proceeds with the other two
              possibilities described below.

              If element already includes a .zwc extension (i.e. the extension
              was explicitly given by the user), element is searched for the
              definition of the function without comparing its age to that of
              other files; in fact, there does not need to be any directory
              named element without the suffix.  Thus including an element
              such as `/usr/local/funcs.zwc' in fpath will speed up the search
              for functions, with the disadvantage that functions included
              must be explicitly recompiled by hand before the shell notices
              any changes.

       element/function.zwc
              A file created with zcompile, which is expected to contain the
              definition for function.  It may include other function
              definitions as well, but those are neither loaded nor executed;
              a file found in this way is searched only for the definition of
              function.

       element/function
              A file of zsh command text, taken to be the definition for
              function.

       In summary, the order of searching is, first, in the parents of
       directories in fpath for the newer of either a compiled directory or a
       directory in fpath; second, if more than one of these contains a
       definition for the function that is sought, the leftmost in the fpath
       is chosen; and third, within a directory, the newer of either a
       compiled function or an ordinary function definition is used.

       If the KSH_AUTOLOAD option is set, or the file contains only a simple
       definition of the function, the file's contents will be executed.  This
       will normally define the function in question, but may also perform
       initialization, which is executed in the context of the function
       execution, and may therefore define local parameters.  It is an error
       if the function is not defined by loading the file.

       Otherwise, the function body (with no surrounding `funcname() {...}')
       is taken to be the complete contents of the file.  This form allows the
       file to be used directly as an executable shell script.  If processing
       of the file results in the function being re-defined, the function
       itself is not re-executed.  To force the shell to perform
       initialization and then call the function defined, the file should
       contain initialization code (which will be executed then discarded) in
       addition to a complete function definition (which will be retained for
       subsequent calls to the function), and a call to the shell function,
       including any arguments, at the end.

       For example, suppose the autoload file func contains

              func() { print This is func; }
              print func is initialized

       then `func; func' with KSH_AUTOLOAD set will produce both messages on
       the first call, but only the message `This is func' on the second and
       subsequent calls.  Without KSH_AUTOLOAD set, it will produce the
       initialization message on the first call, and the other message on the
       second and subsequent calls.

       It is also possible to create a function that is not marked as
       autoloaded, but which loads its own definition by searching fpath, by
       using `autoload -X' within a shell function.  For example, the
       following are equivalent:

              myfunc() {
                autoload -X
              }
              myfunc args...

       and

              unfunction myfunc   # if myfunc was defined
              autoload myfunc
              myfunc args...

       In fact, the functions command outputs `builtin autoload -X' as the
       body of an autoloaded function.  This is done so that

              eval "$(functions)"

       produces a reasonable result.  A true autoloaded function can be
       identified by the presence of the comment `# undefined' in the body,
       because all comments are discarded from defined functions.

       To load the definition of an autoloaded function myfunc without
       executing myfunc, use:

              autoload +X myfunc

ANONYMOUS FUNCTIONS
       If no name is given for a function, it is `anonymous' and is handled
       specially.  Either form of function definition may be used: a `()' with
       no preceding name, or a `function' with an immediately following open
       brace.  The function is executed immediately at the point of definition
       and is not stored for future use.  The function name is set to
       `(anon)'.

       Arguments to the function may be specified as words following the
       closing brace defining the function, hence if there are none no
       arguments (other than $0) are set.  This is a difference from the way
       other functions are parsed: normal function definitions may be followed
       by certain keywords such as `else' or `fi', which will be treated as
       arguments to anonymous functions, so that a newline or semicolon is
       needed to force keyword interpretation.

       Note also that the argument list of any enclosing script or function is
       hidden (as would be the case for any other function called at this
       point).

       Redirections may be applied to the anonymous function in the same
       manner as to a current-shell structure enclosed in braces.  The main
       use of anonymous functions is to provide a scope for local variables.
       This is particularly convenient in start-up files as these do not
       provide their own local variable scope.

       For example,

              variable=outside
              function {
                local variable=inside
                print "I am $variable with arguments $*"
              } this and that
              print "I am $variable"

       outputs the following:

              I am inside with arguments this and that
              I am outside

       Note that function definitions with arguments that expand to nothing,
       for example `name=; function $name { ... }', are not treated as
       anonymous functions.  Instead, they are treated as normal function
       definitions where the definition is silently discarded.

SPECIAL FUNCTIONS
       Certain functions, if defined, have special meaning to the shell.

   Hook Functions
       For the functions below, it is possible to define an array that has the
       same name as the function with `_functions' appended.  Any element in
       such an array is taken as the name of a function to execute; it is
       executed in the same context and with the same arguments as the basic
       function.  For example, if $chpwd_functions is an array containing the
       values `mychpwd', `chpwd_save_dirstack', then the shell attempts to
       execute the functions `chpwd', `mychpwd' and `chpwd_save_dirstack', in
       that order.  Any function that does not exist is silently ignored.  A
       function found by this mechanism is referred to elsewhere as a `hook
       function'.  An error in any function causes subsequent functions not to
       be run.  Note further that an error in a precmd hook causes an
       immediately following periodic function not to run (though it may run
       at the next opportunity).

       chpwd  Executed whenever the current working directory is changed.

       periodic
              If the parameter PERIOD is set, this function is executed every
              $PERIOD seconds, just before a prompt.  Note that if multiple
              functions are defined using the array periodic_functions only
              one period is applied to the complete set of functions, and the
              scheduled time is not reset if the list of functions is altered.
              Hence the set of functions is always called together.

       precmd Executed before each prompt.  Note that precommand functions are
              not re-executed simply because the command line is redrawn, as
              happens, for example, when a notification about an exiting job
              is displayed.

       preexec
              Executed just after a command has been read and is about to be
              executed.  If the history mechanism is active (regardless of
              whether the line was discarded from the history buffer), the
              string that the user typed is passed as the first argument,
              otherwise it is an empty string.  The actual command that will
              be executed (including expanded aliases) is passed in two
              different forms: the second argument is a single-line,
              size-limited version of the command (with things like function
              bodies elided); the third argument contains the full text that
              is being executed.

       zshaddhistory
              Executed when a history line has been read interactively, but
              before it is executed.  The sole argument is the complete
              history line (so that any terminating newline will still be
              present).

              If any of the hook functions returns status 1 (or any non-zero
              value other than 2, though this is not guaranteed for future
              versions of the shell) the history line will not be saved,
              although it lingers in the history until the next line is
              executed, allowing you to reuse or edit it immediately.

              If any of the hook functions returns status 2 the history line
              will be saved on the internal history list, but not written to
              the history file.  In case of a conflict, the first non-zero
              status value is taken.

              A hook function may call `fc -p ...' to switch the history
              context so that the history is saved in a different file from
              the that in the global HISTFILE parameter.  This is handled
              specially: the history context is automatically restored after
              the processing of the history line is finished.

              The following example function works with one of the options
              INC_APPEND_HISTORY or SHARE_HISTORY set, in order that the line
              is written out immediately after the history entry is added.  It
              first adds the history line to the normal history with the
              newline stripped, which is usually the correct behaviour.  Then
              it switches the history context so that the line will be written
              to a history file in the current directory.

                     zshaddhistory() {
                       print -sr -- ${1%%$'\n'}
                       fc -p .zsh_local_history
                     }

       zshexit
              Executed at the point where the main shell is about to exit
              normally.  This is not called by exiting subshells, nor when the
              exec precommand modifier is used before an external command.
              Also, unlike TRAPEXIT, it is not called when functions exit.

   Trap Functions
       The functions below are treated specially but do not have corresponding
       hook arrays.

       TRAPNAL
              If defined and non-null, this function will be executed whenever
              the shell catches a signal SIGNAL, where NAL is a signal name as
              specified for the kill builtin.  The signal number will be
              passed as the first parameter to the function.

              If a function of this form is defined and null, the shell and
              processes spawned by it will ignore SIGNAL.

              The return status from the function is handled specially.  If it
              is zero, the signal is assumed to have been handled, and
              execution continues normally.  Otherwise, the shell will behave
              as interrupted except that the return status of the trap is
              retained.

              Programs terminated by uncaught signals typically return the
              status 128 plus the signal number.  Hence the following causes
              the handler for SIGINT to print a message, then mimic the usual
              effect of the signal.

                     TRAPINT() {
                       print "Caught SIGINT, aborting."
                       return $(( 128 + $1 ))
                     }

              The functions TRAPZERR, TRAPDEBUG and TRAPEXIT are never
              executed inside other traps.

       TRAPDEBUG
              If the option DEBUG_BEFORE_CMD is set (as it is by default),
              executed before each command; otherwise executed after each
              command.  See the description of the trap builtin in
              zshbuiltins(1) for details of additional features provided in
              debug traps.

       TRAPEXIT
              Executed when the shell exits, or when the current function
              exits if defined inside a function.  The value of $? at the
              start of execution is the exit status of the shell or the return
              status of the function exiting.

       TRAPZERR
              Executed whenever a command has a non-zero exit status.
              However, the function is not executed if the command occurred in
              a sublist followed by `&&' or `||'; only the final command in a
              sublist of this type causes the trap to be executed.  The
              function TRAPERR acts the same as TRAPZERR on systems where
              there is no SIGERR (this is the usual case).

       The functions beginning `TRAP' may alternatively be defined with the
       trap builtin:  this may be preferable for some uses.  Setting a trap
       with one form removes any trap of the other form for the same signal;
       removing a trap in either form removes all traps for the same signal.
       The forms

              TRAPNAL() {
               # code
              }

       ('function traps') and

              trap '
               # code
              ' NAL

       ('list traps') are equivalent in most ways, the exceptions being the
       following:

       ·      Function traps have all the properties of normal functions,
              appearing in the list of functions and being called with their
              own function context rather than the context where the trap was
              triggered.

       ·      The return status from function traps is special, whereas a
              return from a list trap causes the surrounding context to return
              with the given status.

       ·      Function traps are not reset within subshells, in accordance
              with zsh behaviour; list traps are reset, in accordance with
              POSIX behaviour.

JOBS
       If the MONITOR option is set, an interactive shell associates a job
       with each pipeline.  It keeps a table of current jobs, printed by the
       jobs command, and assigns them small integer numbers.  When a job is
       started asynchronously with `&', the shell prints a line to standard
       error which looks like:

              [1] 1234

       indicating that the job which was started asynchronously was job number
       1 and had one (top-level) process, whose process ID was 1234.

       If a job is started with `&|' or `&!', then that job is immediately
       disowned.  After startup, it does not have a place in the job table,
       and is not subject to the job control features described here.

       If you are running a job and wish to do something else you may hit the
       key ^Z (control-Z) which sends a TSTP signal to the current job:  this
       key may be redefined by the susp option of the external stty command.
       The shell will then normally indicate that the job has been
       `suspended', and print another prompt.  You can then manipulate the
       state of this job, putting it in the background with the bg command, or
       run some other commands and then eventually bring the job back into the
       foreground with the foreground command fg.  A ^Z takes effect
       immediately and is like an interrupt in that pending output and unread
       input are discarded when it is typed.

       A job being run in the background will suspend if it tries to read from
       the terminal.

       Note that if the job running in the foreground is a shell function,
       then suspending it will have the effect of causing the shell to fork.
       This is necessary to separate the function's state from that of the
       parent shell performing the job control, so that the latter can return
       to the command line prompt.  As a result, even if fg is used to
       continue the job the function will no longer be part of the parent
       shell, and any variables set by the function will not be visible in the
       parent shell.  Thus the behaviour is different from the case where the
       function was never suspended.  Zsh is different from many other shells
       in this regard.

       One additional side effect is that use of disown with a job created by
       suspending shell code in this fashion is delayed: the job can only be
       disowned once any process started from the parent shell has terminated.
       At that point, the disowned job disappears silently from the job list.

       The same behaviour is found when the shell is executing code as the
       right hand side of a pipeline or any complex shell construct such as
       if, for, etc., in order that the entire block of code can be managed as
       a single job.  Background jobs are normally allowed to produce output,
       but this can be disabled by giving the command `stty tostop'.  If you
       set this tty option, then background jobs will suspend when they try to
       produce output like they do when they try to read input.

       When a command is suspended and continued later with the fg or wait
       builtins, zsh restores tty modes that were in effect when it was
       suspended.  This (intentionally) does not apply if the command is
       continued via `kill -CONT', nor when it is continued with bg.

       There are several ways to refer to jobs in the shell.  A job can be
       referred to by the process ID of any process of the job or by one of
       the following:

       %number
              The job with the given number.
       %string
              The last job whose command line begins with string.
       %?string
              The last job whose command line contains string.
       %%     Current job.
       %+     Equivalent to `%%'.
       %-     Previous job.

       The shell learns immediately whenever a process changes state.  It
       normally informs you whenever a job becomes blocked so that no further
       progress is possible.  If the NOTIFY option is not set, it waits until
       just before it prints a prompt before it informs you.  All such
       notifications are sent directly to the terminal, not to the standard
       output or standard error.

       When the monitor mode is on, each background job that completes
       triggers any trap set for CHLD.

       When you try to leave the shell while jobs are running or suspended,
       you will be warned that `You have suspended (running) jobs'.  You may
       use the jobs command to see what they are.  If you do this or
       immediately try to exit again, the shell will not warn you a second
       time; the suspended jobs will be terminated, and the running jobs will
       be sent a SIGHUP signal, if the HUP option is set.

       To avoid having the shell terminate the running jobs, either use the
       nohup command (see nohup(1)) or the disown builtin.

SIGNALS
       The INT and QUIT signals for an invoked command are ignored if the
       command is followed by `&' and the MONITOR option is not active.  The
       shell itself always ignores the QUIT signal.  Otherwise, signals have
       the values inherited by the shell from its parent (but see the TRAPNAL
       special functions in the section `Functions').

       Certain jobs are run asynchronously by the shell other than those
       explicitly put into the background; even in cases where the shell would
       usually wait for such jobs, an explicit exit command or exit due to the
       option ERR_EXIT will cause the shell to exit without waiting.  Examples
       of such asynchronous jobs are process substitution, see the section
       PROCESS SUBSTITUTION in the zshexpn(1) manual page, and the handler
       processes for multios, see the section MULTIOS in the zshmisc(1) manual
       page.

ARITHMETIC EVALUATION
       The shell can perform integer and floating point arithmetic, either
       using the builtin let, or via a substitution of the form $((...)).  For
       integers, the shell is usually compiled to use 8-byte precision where
       this is available, otherwise precision is 4 bytes.  This can be tested,
       for example, by giving the command `print - $(( 12345678901 ))'; if the
       number appears unchanged, the precision is at least 8 bytes.  Floating
       point arithmetic always uses the `double' type with whatever
       corresponding precision is provided by the compiler and the library.

       The let builtin command takes arithmetic expressions as arguments; each
       is evaluated separately.  Since many of the arithmetic operators, as
       well as spaces, require quoting, an alternative form is provided: for
       any command which begins with a `((', all the characters until a
       matching `))' are treated as a quoted expression and arithmetic
       expansion performed as for an argument of let.  More precisely,
       `((...))' is equivalent to `let "..."'.  The return status is 0 if the
       arithmetic value of the expression is non-zero, 1 if it is zero, and 2
       if an error occurred.

       For example, the following statement

              (( val = 2 + 1 ))

       is equivalent to

              let "val = 2 + 1"

       both assigning the value 3 to the shell variable val and returning a
       zero status.

       Integers can be in bases other than 10.  A leading `0x' or `0X' denotes
       hexadecimal and a leading `0b' or `0B' binary.  Integers may also be of
       the form `base#n', where base is a decimal number between two and
       thirty-six representing the arithmetic base and n is a number in that
       base (for example, `16#ff' is 255 in hexadecimal).  The base# may also
       be omitted, in which case base 10 is used.  For backwards compatibility
       the form `[base]n' is also accepted.

       An integer expression or a base given in the form `base#n' may contain
       underscores (`_') after the leading digit for visual guidance; these
       are ignored in computation.  Examples are 1_000_000 or 0xffff_ffff
       which are equivalent to 1000000 and 0xffffffff respectively.

       It is also possible to specify a base to be used for output in the form
       `[#base]', for example `[#16]'.  This is used when outputting
       arithmetical substitutions or when assigning to scalar parameters, but
       an explicitly defined integer or floating point parameter will not be
       affected.  If an integer variable is implicitly defined by an
       arithmetic expression, any base specified in this way will be set as
       the variable's output arithmetic base as if the option `-i base' to the
       typeset builtin had been used.  The expression has no precedence and if
       it occurs more than once in a mathematical expression, the last
       encountered is used.  For clarity it is recommended that it appear at
       the beginning of an expression.  As an example:

              typeset -i 16 y
              print $(( [#8] x = 32, y = 32 ))
              print $x $y

       outputs first `8#40', the rightmost value in the given output base, and
       then `8#40 16#20', because y has been explicitly declared to have
       output base 16, while x (assuming it does not already exist) is
       implicitly typed by the arithmetic evaluation, where it acquires the
       output base 8.

       The base may be replaced or followed by an underscore, which may itself
       be followed by a positive integer (if it is missing the value 3 is
       used).  This indicates that underscores should be inserted into the
       output string, grouping the number for visual clarity.  The following
       integer specifies the number of digits to group together.  For example:

              setopt cbases
              print $(( [#16_4] 65536 ** 2 ))

       outputs `0x1_0000_0000'.

       The feature can be used with floating point numbers, in which case the
       base must be omitted; grouping is away from the decimal point.  For
       example,

              zmodload zsh/mathfunc
              print $(( [#_] sqrt(1e7) ))

       outputs `3_162.277_660_168_379_5' (the number of decimal places shown
       may vary).

       If the C_BASES option is set, hexadecimal numbers are output in the
       standard C format, for example `0xFF' instead of the usual `16#FF'.  If
       the option OCTAL_ZEROES is also set (it is not by default), octal
       numbers will be treated similarly and hence appear as `077' instead of
       `8#77'.  This option has no effect on the output of bases other than
       hexadecimal and octal, and these formats are always understood on
       input.

       When an output base is specified using the `[#base]' syntax, an
       appropriate base prefix will be output if necessary, so that the value
       output is valid syntax for input.  If the # is doubled, for example
       `[##16]', then no base prefix is output.

       Floating point constants are recognized by the presence of a decimal
       point or an exponent.  The decimal point may be the first character of
       the constant, but the exponent character e or E may not, as it will be
       taken for a parameter name.  All numeric parts (before and after the
       decimal point and in the exponent) may contain underscores after the
       leading digit for visual guidance; these are ignored in computation.

       An arithmetic expression uses nearly the same syntax and associativity
       of expressions as in C.

       In the native mode of operation, the following operators are supported
       (listed in decreasing order of precedence):

       + - ! ~ ++ --
              unary plus/minus, logical NOT, complement,
              {pre,post}{in,de}crement
       << >>  bitwise shift left, right
       &      bitwise AND
       ^      bitwise XOR
       |      bitwise OR
       **     exponentiation
       * / %  multiplication, division, modulus (remainder)
       + -    addition, subtraction
       < > <= >=
              comparison
       == !=  equality and inequality
       &&     logical AND
       || ^^  logical OR, XOR
       ? :    ternary operator
       = += -= *= /= %= &= ^= |= <<= >>= &&= ||= ^^= **=
              assignment
       ,      comma operator

       The operators `&&', `||', `&&=', and `||=' are short-circuiting, and
       only one of the latter two expressions in a ternary operator is
       evaluated.  Note the precedence of the bitwise AND, OR, and XOR
       operators.

       With the option C_PRECEDENCES the precedences (but no other properties)
       of the operators are altered to be the same as those in most other
       languages that support the relevant operators:

       + - ! ~ ++ --
              unary plus/minus, logical NOT, complement,
              {pre,post}{in,de}crement
       **     exponentiation
       * / %  multiplication, division, modulus (remainder)
       + -    addition, subtraction
       << >>  bitwise shift left, right
       < > <= >=
              comparison
       == !=  equality and inequality
       &      bitwise AND
       ^      bitwise XOR
       |      bitwise OR
       &&     logical AND
       ^^     logical XOR
       ||     logical OR
       ? :    ternary operator
       = += -= *= /= %= &= ^= |= <<= >>= &&= ||= ^^= **=
              assignment
       ,      comma operator

       Note the precedence of exponentiation in both cases is below that of
       unary operators, hence `-3**2' evaluates as `9', not `-9'.  Use
       parentheses where necessary: `-(3**2)'.  This is for compatibility with
       other shells.

       Mathematical functions can be called with the syntax `func(args)',
       where the function decides if the args is used as a string or a
       comma-separated list of arithmetic expressions. The shell currently
       defines no mathematical functions by default, but the module
       zsh/mathfunc may be loaded with the zmodload builtin to provide
       standard floating point mathematical functions.

       An expression of the form `##x' where x is any character sequence such
       as `a', `^A', or `\M-\C-x' gives the value of this character and an
       expression of the form `#name' gives the value of the first character
       of the contents of the parameter name.  Character values are according
       to the character set used in the current locale; for multibyte
       character handling the option MULTIBYTE must be set.  Note that this
       form is different from `$#name', a standard parameter substitution
       which gives the length of the parameter name.  `#\' is accepted instead
       of `##', but its use is deprecated.

       Named parameters and subscripted arrays can be referenced by name
       within an arithmetic expression without using the parameter expansion
       syntax.  For example,

              ((val2 = val1 * 2))

       assigns twice the value of $val1 to the parameter named val2.

       An internal integer representation of a named parameter can be
       specified with the integer builtin.  Arithmetic evaluation is performed
       on the value of each assignment to a named parameter declared integer
       in this manner.  Assigning a floating point number to an integer
       results in rounding towards zero.

       Likewise, floating point numbers can be declared with the float
       builtin; there are two types, differing only in their output format, as
       described for the typeset builtin.  The output format can be bypassed
       by using arithmetic substitution instead of the parameter substitution,
       i.e. `${float}' uses the defined format, but `$((float))' uses a
       generic floating point format.

       Promotion of integer to floating point values is performed where
       necessary.  In addition, if any operator which requires an integer
       (`&', `|', `^', `<<', `>>' and their equivalents with assignment) is
       given a floating point argument, it will be silently rounded towards
       zero except for `~' which rounds down.

       Users should beware that, in common with many other programming
       languages but not software designed for calculation, the evaluation of
       an expression in zsh is taken a term at a time and promotion of
       integers to floating point does not occur in terms only containing
       integers.  A typical result of this is that a division such as 6/8 is
       truncated, in this being rounded towards 0.  The FORCE_FLOAT shell
       option can be used in scripts or functions where floating point
       evaluation is required throughout.

       Scalar variables can hold integer or floating point values at different
       times; there is no memory of the numeric type in this case.

       If a variable is first assigned in a numeric context without previously
       being declared, it will be implicitly typed as integer or float and
       retain that type either until the type is explicitly changed or until
       the end of the scope.  This can have unforeseen consequences.  For
       example, in the loop

              for (( f = 0; f < 1; f += 0.1 )); do
              # use $f
              done

       if f has not already been declared, the first assignment will cause it
       to be created as an integer, and consequently the operation `f += 0.1'
       will always cause the result to be truncated to zero, so that the loop
       will fail.  A simple fix would be to turn the initialization into `f =
       0.0'.  It is therefore best to declare numeric variables with explicit
       types.

CONDITIONAL EXPRESSIONS
       A conditional expression is used with the [[ compound command to test
       attributes of files and to compare strings.  Each expression can be
       constructed from one or more of the following unary or binary
       expressions:

       -a file
              true if file exists.

       -b file
              true if file exists and is a block special file.

       -c file
              true if file exists and is a character special file.

       -d file
              true if file exists and is a directory.

       -e file
              true if file exists.

       -f file
              true if file exists and is a regular file.

       -g file
              true if file exists and has its setgid bit set.

       -h file
              true if file exists and is a symbolic link.

       -k file
              true if file exists and has its sticky bit set.

       -n string
              true if length of string is non-zero.

       -o option
              true if option named option is on.  option may be a single
              character, in which case it is a single letter option name.
              (See the section `Specifying Options'.)

              When no option named option exists, and the POSIX_BUILTINS
              option hasn't been set, return 3 with a warning.  If that option
              is set, return 1 with no warning.

       -p file
              true if file exists and is a FIFO special file (named pipe).

       -r file
              true if file exists and is readable by current process.

       -s file
              true if file exists and has size greater than zero.

       -t fd  true if file descriptor number fd is open and associated with a
              terminal device.  (note: fd is not optional)

       -u file
              true if file exists and has its setuid bit set.

       -v varname
              true if shell variable varname is set.

       -w file
              true if file exists and is writable by current process.

       -x file
              true if file exists and is executable by current process.  If
              file exists and is a directory, then the current process has
              permission to search in the directory.

       -z string
              true if length of string is zero.

       -L file
              true if file exists and is a symbolic link.

       -O file
              true if file exists and is owned by the effective user ID of
              this process.

       -G file
              true if file exists and its group matches the effective group ID
              of this process.

       -S file
              true if file exists and is a socket.

       -N file
              true if file exists and its access time is not newer than its
              modification time.

       file1 -nt file2
              true if file1 exists and is newer than file2.

       file1 -ot file2
              true if file1 exists and is older than file2.

       file1 -ef file2
              true if file1 and file2 exist and refer to the same file.

       string = pattern
       string == pattern
              true if string matches pattern.  The two forms are exactly
              equivalent.  The `=' form is the traditional shell syntax (and
              hence the only one generally used with the test and [ builtins);
              the `==' form provides compatibility with other sorts of
              computer language.

       string != pattern
              true if string does not match pattern.

       string =~ regexp
              true if string matches the regular expression regexp.  If the
              option RE_MATCH_PCRE is set regexp is tested as a PCRE regular
              expression using the zsh/pcre module, else it is tested as a
              POSIX extended regular expression using the zsh/regex module.
              Upon successful match, some variables will be updated; no
              variables are changed if the matching fails.

              If the option BASH_REMATCH is not set the scalar parameter MATCH
              is set to the substring that matched the pattern and the integer
              parameters MBEGIN and MEND to the index of the start and end,
              respectively, of the match in string, such that if string is
              contained in variable var the expression `${var[$MBEGIN,$MEND]}'
              is identical to `$MATCH'.  The setting of the option KSH_ARRAYS
              is respected.  Likewise, the array match is set to the
              substrings that matched parenthesised subexpressions and the
              arrays mbegin and mend to the indices of the start and end
              positions, respectively, of the substrings within string.  The
              arrays are not set if there were no parenthesised
              subexpressions.  For example, if the string `a short string' is
              matched against the regular expression `s(...)t', then (assuming
              the option KSH_ARRAYS is not set) MATCH, MBEGIN and MEND are
              `short', 3 and 7, respectively, while match, mbegin and mend are
              single entry arrays containing the strings `hor', `4' and `6',
              respectively.

              If the option BASH_REMATCH is set the array BASH_REMATCH is set
              to the substring that matched the pattern followed by the
              substrings that matched parenthesised subexpressions within the
              pattern.

       string1 < string2
              true if string1 comes before string2 based on ASCII value of
              their characters.

       string1 > string2
              true if string1 comes after string2 based on ASCII value of
              their characters.

       exp1 -eq exp2
              true if exp1 is numerically equal to exp2.  Note that for purely
              numeric comparisons use of the ((...)) builtin described in the
              section `ARITHMETIC EVALUATION' is more convenient than
              conditional expressions.

       exp1 -ne exp2
              true if exp1 is numerically not equal to exp2.

       exp1 -lt exp2
              true if exp1 is numerically less than exp2.

       exp1 -gt exp2
              true if exp1 is numerically greater than exp2.

       exp1 -le exp2
              true if exp1 is numerically less than or equal to exp2.

       exp1 -ge exp2
              true if exp1 is numerically greater than or equal to exp2.

       ( exp )
              true if exp is true.

       ! exp  true if exp is false.

       exp1 && exp2
              true if exp1 and exp2 are both true.

       exp1 || exp2
              true if either exp1 or exp2 is true.

       For compatibility, if there is a single argument that is not
       syntactically significant, typically a variable, the condition is
       treated as a test for whether the expression expands as a string of
       non-zero length.  In other words, [[ $var ]] is the same as [[ -n $var
       ]].  It is recommended that the second, explicit, form be used where
       possible.

       Normal shell expansion is performed on the file, string and pattern
       arguments, but the result of each expansion is constrained to be a
       single word, similar to the effect of double quotes.

       Filename generation is not performed on any form of argument to
       conditions.  However, it can be forced in any case where normal shell
       expansion is valid and when the option EXTENDED_GLOB is in effect by
       using an explicit glob qualifier of the form (#q) at the end of the
       string.  A normal glob qualifier expression may appear between the `q'
       and the closing parenthesis; if none appears the expression has no
       effect beyond causing filename generation.  The results of filename
       generation are joined together to form a single word, as with the
       results of other forms of expansion.

       This special use of filename generation is only available with the [[
       syntax.  If the condition occurs within the [ or test builtin commands
       then globbing occurs instead as part of normal command line expansion
       before the condition is evaluated.  In this case it may generate
       multiple words which are likely to confuse the syntax of the test
       command.

       For example,

              [[ -n file*(#qN) ]]

       produces status zero if and only if there is at least one file in the
       current directory beginning with the string `file'.  The globbing
       qualifier N ensures that the expression is empty if there is no
       matching file.

       Pattern metacharacters are active for the pattern arguments; the
       patterns are the same as those used for filename generation, see
       zshexpn(1), but there is no special behaviour of `/' nor initial dots,
       and no glob qualifiers are allowed.

       In each of the above expressions, if file is of the form `/dev/fd/n',
       where n is an integer, then the test applied to the open file whose
       descriptor number is n, even if the underlying system does not support
       the /dev/fd directory.

       In the forms which do numeric comparison, the expressions exp undergo
       arithmetic expansion as if they were enclosed in $((...)).

       For example, the following:

              [[ ( -f foo || -f bar ) && $report = y* ]] && print File exists.

       tests if either file foo or file bar exists, and if so, if the value of
       the parameter report begins with `y'; if the complete condition is
       true, the message `File exists.' is printed.

EXPANSION OF PROMPT SEQUENCES
       Prompt sequences undergo a special form of expansion.  This type of
       expansion is also available using the -P option to the print builtin.

       If the PROMPT_SUBST option is set, the prompt string is first subjected
       to parameter expansion, command substitution and arithmetic expansion.
       See zshexpn(1).

       Certain escape sequences may be recognised in the prompt string.

       If the PROMPT_BANG option is set, a `!' in the prompt is replaced by
       the current history event number.  A literal `!' may then be
       represented as `!!'.

       If the PROMPT_PERCENT option is set, certain escape sequences that
       start with `%' are expanded.  Many escapes are followed by a single
       character, although some of these take an optional integer argument
       that should appear between the `%' and the next character of the
       sequence.  More complicated escape sequences are available to provide
       conditional expansion.

SIMPLE PROMPT ESCAPES
   Special characters
       %%     A `%'.

       %)     A `)'.

   Login information
       %l     The line (tty) the user is logged in on, without `/dev/' prefix.
              If the name starts with `/dev/tty', that prefix is stripped.

       %M     The full machine hostname.

       %m     The hostname up to the first `.'.  An integer may follow the `%'
              to specify how many components of the hostname are desired.
              With a negative integer, trailing components of the hostname are
              shown.

       %n     $USERNAME.

       %y     The line (tty) the user is logged in on, without `/dev/' prefix.
              This does not treat `/dev/tty' names specially.

   Shell state
       %#     A `#' if the shell is running with privileges, a `%' if not.
              Equivalent to `%(!.#.%%)'.  The definition of `privileged', for
              these purposes, is that either the effective user ID is zero,
              or, if POSIX.1e capabilities are supported, that at least one
              capability is raised in either the Effective or Inheritable
              capability vectors.

       %?     The return status of the last command executed just before the
              prompt.

       %_     The status of the parser, i.e. the shell constructs (like `if'
              and `for') that have been started on the command line. If given
              an integer number that many strings will be printed; zero or
              negative or no integer means print as many as there are.  This
              is most useful in prompts PS2 for continuation lines and PS4 for
              debugging with the XTRACE option; in the latter case it will
              also work non-interactively.

       %^     The status of the parser in reverse. This is the same as `%_'
              other than the order of strings.  It is often used in RPS2.

       %d
       %/     Current working directory.  If an integer follows the `%', it
              specifies a number of trailing components of the current working
              directory to show; zero means the whole path.  A negative
              integer specifies leading components, i.e. %-1d specifies the
              first component.

       %~     As %d and %/, but if the current working directory starts with
              $HOME, that part is replaced by a `~'. Furthermore, if it has a
              named directory as its prefix, that part is replaced by a `~'
              followed by the name of the directory, but only if the result is
              shorter than the full path; see Dynamic and Static named
              directories in zshexpn(1).

       %e     Evaluation depth of the current sourced file, shell function, or
              eval.  This is incremented or decremented every time the value
              of %N is set or reverted to a previous value, respectively.
              This is most useful for debugging as part of $PS4.

       %h
       %!     Current history event number.

       %i     The line number currently being executed in the script, sourced
              file, or shell function given by %N.  This is most useful for
              debugging as part of $PS4.

       %I     The line number currently being executed in the file %x.  This
              is similar to %i, but the line number is always a line number in
              the file where the code was defined, even if the code is a shell
              function.

       %j     The number of jobs.

       %L     The current value of $SHLVL.

       %N     The name of the script, sourced file, or shell function that zsh
              is currently executing, whichever was started most recently.  If
              there is none, this is equivalent to the parameter $0.  An
              integer may follow the `%' to specify a number of trailing path
              components to show; zero means the full path.  A negative
              integer specifies leading components.

       %x     The name of the file containing the source code currently being
              executed.  This behaves as %N except that function and eval
              command names are not shown, instead the file where they were
              defined.

       %c
       %.
       %C     Trailing component of the current working directory.  An integer
              may follow the `%' to get more than one component.  Unless `%C'
              is used, tilde contraction is performed first.  These are
              deprecated as %c and %C are equivalent to %1~ and %1/,
              respectively, while explicit positive integers have the same
              effect as for the latter two sequences.

   Date and time
       %D     The date in yy-mm-dd format.

       %T     Current time of day, in 24-hour format.

       %t
       %@     Current time of day, in 12-hour, am/pm format.

       %*     Current time of day in 24-hour format, with seconds.

       %w     The date in day-dd format.

       %W     The date in mm/dd/yy format.

       %D{string}
              string is formatted using the strftime function.  See
              strftime(3) for more details.  Various zsh extensions provide
              numbers with no leading zero or space if the number is a single
              digit:

              %f     a day of the month
              %K     the hour of the day on the 24-hour clock
              %L     the hour of the day on the 12-hour clock

              In addition, if the system supports the POSIX gettimeofday
              system call, %. provides decimal fractions of a second since the
              epoch with leading zeroes.  By default three decimal places are
              provided, but a number of digits up to 9 may be given following
              the %; hence %6.  outputs microseconds, and %9. outputs
              nanoseconds.  (The latter requires a nanosecond-precision
              clock_gettime; systems lacking this will return a value
              multiplied by the appropriate power of 10.)  A typical example
              of this is the format `%D{%H:%M:%S.%.}'.

              The GNU extension %N is handled as a synonym for %9..

              Additionally, the GNU extension that a `-' between the % and the
              format character causes a leading zero or space to be stripped
              is handled directly by the shell for the format characters d, f,
              H, k, l, m, M, S and y; any other format characters are provided
              to the system's strftime(3) with any leading `-' present, so the
              handling is system dependent.  Further GNU (or other) extensions
              are also passed to strftime(3) and may work if the system
              supports them.

   Visual effects
       %B (%b)
              Start (stop) boldface mode.

       %E     Clear to end of line.

       %U (%u)
              Start (stop) underline mode.

       %S (%s)
              Start (stop) standout mode.

       %F (%f)
              Start (stop) using a different foreground colour, if supported
              by the terminal.  The colour may be specified two ways: either
              as a numeric argument, as normal, or by a sequence in braces
              following the %F, for example %F{red}.  In the latter case the
              values allowed are as described for the fg zle_highlight
              attribute; see Character Highlighting in zshzle(1).  This means
              that numeric colours are allowed in the second format also.

       %K (%k)
              Start (stop) using a different bacKground colour.  The syntax is
              identical to that for %F and %f.

       %{...%}
              Include a string as a literal escape sequence.  The string
              within the braces should not change the cursor position.  Brace
              pairs can nest.

              A positive numeric argument between the % and the { is treated
              as described for %G below.

       %G     Within a %{...%} sequence, include a `glitch': that is, assume
              that a single character width will be output.  This is useful
              when outputting characters that otherwise cannot be correctly
              handled by the shell, such as the alternate character set on
              some terminals.  The characters in question can be included
              within a %{...%} sequence together with the appropriate number
              of %G sequences to indicate the correct width.  An integer
              between the `%' and `G' indicates a character width other than
              one.  Hence %{seq%2G%} outputs seq and assumes it takes up the
              width of two standard characters.

              Multiple uses of %G accumulate in the obvious fashion; the
              position of the %G is unimportant.  Negative integers are not
              handled.

              Note that when prompt truncation is in use it is advisable to
              divide up output into single characters within each %{...%}
              group so that the correct truncation point can be found.

CONDITIONAL SUBSTRINGS IN PROMPTS
       %v     The value of the first element of the psvar array parameter.
              Following the `%' with an integer gives that element of the
              array.  Negative integers count from the end of the array.

       %(x.true-text.false-text)
              Specifies a ternary expression.  The character following the x
              is arbitrary; the same character is used to separate the text
              for the `true' result from that for the `false' result.  This
              separator may not appear in the true-text, except as part of a
              %-escape sequence.  A `)' may appear in the false-text as `%)'.
              true-text and false-text may both contain arbitrarily-nested
              escape sequences, including further ternary expressions.

              The left parenthesis may be preceded or followed by a positive
              integer n, which defaults to zero.  A negative integer will be
              multiplied by -1, except as noted below for `l'.  The test
              character x may be any of the following:

              !      True if the shell is running with privileges.
              #      True if the effective uid of the current process is n.
              ?      True if the exit status of the last command was n.
              _      True if at least n shell constructs were started.
              C
              /      True if the current absolute path has at least n elements
                     relative to the root directory, hence / is counted as 0
                     elements.
              c
              .
              ~      True if the current path, with prefix replacement, has at
                     least n elements relative to the root directory, hence /
                     is counted as 0 elements.
              D      True if the month is equal to n (January = 0).
              d      True if the day of the month is equal to n.
              e      True if the evaluation depth is at least n.
              g      True if the effective gid of the current process is n.
              j      True if the number of jobs is at least n.
              L      True if the SHLVL parameter is at least n.
              l      True if at least n characters have already been printed
                     on the current line.  When n is negative, true if at
                     least abs(n) characters remain before the opposite margin
                     (thus the left margin for RPROMPT).
              S      True if the SECONDS parameter is at least n.
              T      True if the time in hours is equal to n.
              t      True if the time in minutes is equal to n.
              v      True if the array psvar has at least n elements.
              V      True if element n of the array psvar is set and
                     non-empty.
              w      True if the day of the week is equal to n (Sunday = 0).

       %<string<
       %>string>
       %[xstring]
              Specifies truncation behaviour for the remainder of the prompt
              string.  The third, deprecated, form is equivalent to
              `%xstringx', i.e. x may be `<' or `>'.  The string will be
              displayed in place of the truncated portion of any string; note
              this does not undergo prompt expansion.

              The numeric argument, which in the third form may appear
              immediately after the `[', specifies the maximum permitted
              length of the various strings that can be displayed in the
              prompt.  In the first two forms, this numeric argument may be
              negative, in which case the truncation length is determined by
              subtracting the absolute value of the numeric argument from the
              number of character positions remaining on the current prompt
              line.  If this results in a zero or negative length, a length of
              1 is used.  In other words, a negative argument arranges that
              after truncation at least n characters remain before the right
              margin (left margin for RPROMPT).

              The forms with `<' truncate at the left of the string, and the
              forms with `>' truncate at the right of the string.  For
              example, if the current directory is `/home/pike', the prompt
              `%8<..<%/' will expand to `..e/pike'.  In this string, the
              terminating character (`<', `>' or `]'), or in fact any
              character, may be quoted by a preceding `\'; note when using
              print -P, however, that this must be doubled as the string is
              also subject to standard print processing, in addition to any
              backslashes removed by a double quoted string:  the worst case
              is therefore `print -P "%<\\\\<<..."'.

              If the string is longer than the specified truncation length, it
              will appear in full, completely replacing the truncated string.

              The part of the prompt string to be truncated runs to the end of
              the string, or to the end of the next enclosing group of the
              `%(' construct, or to the next truncation encountered at the
              same grouping level (i.e. truncations inside a `%(' are
              separate), which ever comes first.  In particular, a truncation
              with argument zero (e.g., `%<<') marks the end of the range of
              the string to be truncated while turning off truncation from
              there on. For example, the prompt `%10<...<%~%<<%# ' will print
              a truncated representation of the current directory, followed by
              a `%' or `#', followed by a space.  Without the `%<<', those two
              characters would be included in the string to be truncated.
              Note that `%-0<<' is not equivalent to `%<<' but specifies that
              the prompt is truncated at the right margin.

              Truncation applies only within each individual line of the
              prompt, as delimited by embedded newlines (if any).  If the
              total length of any line of the prompt after truncation is
              greater than the terminal width, or if the part to be truncated
              contains embedded newlines, truncation behavior is undefined and
              may change in a future version of the shell.  Use
              `%-n(l.true-text.false-text)' to remove parts of the prompt when
              the available space is less than n.




ZSHEXPN(1)                  General Commands Manual                 ZSHEXPN(1)



NAME
       zshexpn - zsh expansion and substitution

DESCRIPTION
       The following types of expansions are performed in the indicated order
       in five steps:

       History Expansion
              This is performed only in interactive shells.

       Alias Expansion
              Aliases are expanded immediately before the command line is
              parsed as explained under Aliasing in zshmisc(1).

       Process Substitution
       Parameter Expansion
       Command Substitution
       Arithmetic Expansion
       Brace Expansion
              These five are performed in left-to-right fashion.  On each
              argument, any of the five steps that are needed are performed
              one after the other.  Hence, for example, all the parts of
              parameter expansion are completed before command substitution is
              started.  After these expansions, all unquoted occurrences of
              the characters `\',`'' and `"' are removed.

       Filename Expansion
              If the SH_FILE_EXPANSION option is set, the order of expansion
              is modified for compatibility with sh and ksh.  In that case
              filename expansion is performed immediately after alias
              expansion, preceding the set of five expansions mentioned above.

       Filename Generation
              This expansion, commonly referred to as globbing, is always done
              last.

       The following sections explain the types of expansion in detail.

HISTORY EXPANSION
       History expansion allows you to use words from previous command lines
       in the command line you are typing.  This simplifies spelling
       corrections and the repetition of complicated commands or arguments.

       Immediately before execution, each command is saved in the history
       list, the size of which is controlled by the HISTSIZE parameter.  The
       one most recent command is always retained in any case.  Each saved
       command in the history list is called a history event and is assigned a
       number, beginning with 1 (one) when the shell starts up.  The history
       number that you may see in your prompt (see EXPANSION OF PROMPT
       SEQUENCES in zshmisc(1)) is the number that is to be assigned to the
       next command.

   Overview
       A history expansion begins with the first character of the histchars
       parameter, which is `!' by default, and may occur anywhere on the
       command line, including inside double quotes (but not inside single
       quotes '...' or C-style quotes $'...' nor when escaped with a
       backslash).

       The first character is followed by an optional event designator (see
       the section `Event Designators') and then an optional word designator
       (the section `Word Designators'); if neither of these designators is
       present, no history expansion occurs.

       Input lines containing history expansions are echoed after being
       expanded, but before any other expansions take place and before the
       command is executed.  It is this expanded form that is recorded as the
       history event for later references.

       History expansions do not nest.

       By default, a history reference with no event designator refers to the
       same event as any preceding history reference on that command line; if
       it is the only history reference in a command, it refers to the
       previous command.  However, if the option CSH_JUNKIE_HISTORY is set,
       then every history reference with no event specification always refers
       to the previous command.

       For example, `!' is the event designator for the previous command, so
       `!!:1' always refers to the first word of the previous command, and
       `!!$' always refers to the last word of the previous command.  With
       CSH_JUNKIE_HISTORY set, then `!:1' and `!$' function in the same manner
       as `!!:1' and `!!$', respectively.  Conversely, if CSH_JUNKIE_HISTORY
       is unset, then `!:1' and `!$' refer to the first and last words,
       respectively, of the same event referenced by the nearest other history
       reference preceding them on the current command line, or to the
       previous command if there is no preceding reference.

       The character sequence `^foo^bar' (where `^' is actually the second
       character of the histchars parameter) repeats the last command,
       replacing the string foo with bar.  More precisely, the sequence
       `^foo^bar^' is synonymous with `!!:s^foo^bar^', hence other modifiers
       (see the section `Modifiers') may follow the final `^'.  In particular,
       `^foo^bar^:G' performs a global substitution.

       If the shell encounters the character sequence `!"' in the input, the
       history mechanism is temporarily disabled until the current list (see
       zshmisc(1)) is fully parsed.  The `!"' is removed from the input, and
       any subsequent `!' characters have no special significance.

       A less convenient but more comprehensible form of command history
       support is provided by the fc builtin.

   Event Designators
       An event designator is a reference to a command-line entry in the
       history list.  In the list below, remember that the initial `!' in each
       item may be changed to another character by setting the histchars
       parameter.

       !      Start a history expansion, except when followed by a blank,
              newline, `=' or `('.  If followed immediately by a word
              designator (see the section `Word Designators'), this forms a
              history reference with no event designator (see the section
              `Overview').

       !!     Refer to the previous command.  By itself, this expansion
              repeats the previous command.

       !n     Refer to command-line n.

       !-n    Refer to the current command-line minus n.

       !str   Refer to the most recent command starting with str.

       !?str[?]
              Refer to the most recent command containing str.  The trailing
              `?' is necessary if this reference is to be followed by a
              modifier or followed by any text that is not to be considered
              part of str.

       !#     Refer to the current command line typed in so far.  The line is
              treated as if it were complete up to and including the word
              before the one with the `!#' reference.

       !{...} Insulate a history reference from adjacent characters (if
              necessary).

   Word Designators
       A word designator indicates which word or words of a given command line
       are to be included in a history reference.  A `:' usually separates the
       event specification from the word designator.  It may be omitted only
       if the word designator begins with a `^', `$', `*', `-' or `%'.  Word
       designators include:

       0      The first input word (command).
       n      The nth argument.
       ^      The first argument.  That is, 1.
       $      The last argument.
       %      The word matched by (the most recent) ?str search.
       x-y    A range of words; x defaults to 0.
       *      All the arguments, or a null value if there are none.
       x*     Abbreviates `x-$'.
       x-     Like `x*' but omitting word $.

       Note that a `%' word designator works only when used in one of `!%',
       `!:%' or `!?str?:%', and only when used after a !? expansion (possibly
       in an earlier command).  Anything else results in an error, although
       the error may not be the most obvious one.

   Modifiers
       After the optional word designator, you can add a sequence of one or
       more of the following modifiers, each preceded by a `:'.  These
       modifiers also work on the result of filename generation and parameter
       expansion, except where noted.

       a      Turn a file name into an absolute path:  prepends the current
              directory, if necessary; remove `.' path segments; and remove
              `..' path segments and the segments that immediately precede
              them.

              This transformation is agnostic about what is in the filesystem,
              i.e. is on the logical, not the physical directory.  It takes
              place in the same manner as when changing directories when
              neither of the options CHASE_DOTS or CHASE_LINKS is set.  For
              example, `/before/here/../after' is always transformed to
              `/before/after', regardless of whether `/before/here' exists or
              what kind of object (dir, file, symlink, etc.) it is.

       A      Turn a file name into an absolute path as the `a' modifier does,
              and then pass the result through the realpath(3) library
              function to resolve symbolic links.

              Note: on systems that do not have a realpath(3) library
              function, symbolic links are not resolved, so on those systems
              `a' and `A' are equivalent.

              Note: foo:A and realpath(foo) are different on some inputs.  For
              realpath(foo) semantics, see the `P` modifier.

       c      Resolve a command name into an absolute path by searching the
              command path given by the PATH variable.  This does not work for
              commands containing directory parts.  Note also that this does
              not usually work as a glob qualifier unless a file of the same
              name is found in the current directory.

       e      Remove all but the part of the filename extension following the
              `.'; see the definition of the filename extension in the
              description of the r modifier below.  Note that according to
              that definition the result will be empty if the string ends with
              a `.'.

       h [ digits ]
              Remove a trailing pathname component, shortening the path by one
              directory level: this is the `head' of the pathname.  This works
              like `dirname'.  If the h is followed immediately (with no
              spaces or other separator) by any number of decimal digits, and
              the value of the resulting number is non-zero, that number of
              leading components is preserved instead of the final component
              being removed.  In an absolute path the leading `/' is the first
              component, so, for example, if var=/my/path/to/something, then
              ${var:h3} substitutes /my/path.  Consecutive `/'s are treated
              the same as a single `/'.  In parameter substitution, digits may
              only be used if the expression is in braces, so for example the
              short form substitution $var:h2 is treated as ${var:h}2, not as
              ${var:h2}.  No restriction applies to the use of digits in
              history substitution or globbing qualifiers.  If more components
              are requested than are present, the entire path is substituted
              (so this does not trigger a `failed modifier' error in history
              expansion).

       l      Convert the words to all lowercase.

       p      Print the new command but do not execute it.  Only works with
              history expansion.

       P      Turn a file name into an absolute path, like realpath(3).  The
              resulting path will be absolute, have neither `.' nor `..'
              components, and refer to the same directory entry as the input
              filename.

              Unlike realpath(3), non-existent trailing components are
              permitted and preserved.

       q      Quote the substituted words, escaping further substitutions.
              Works with history expansion and parameter expansion, though for
              parameters it is only useful if the resulting text is to be
              re-evaluated such as by eval.

       Q      Remove one level of quotes from the substituted words.

       r      Remove a filename extension leaving the root name.  Strings with
              no filename extension are not altered.  A filename extension is
              a `.' followed by any number of characters (including zero) that
              are neither `.' nor `/' and that continue to the end of the
              string.  For example, the extension of `foo.orig.c' is `.c', and
              `dir.c/foo' has no extension.

       s/l/r[/]
              Substitute r for l as described below.  The substitution is done
              only for the first string that matches l.  For arrays and for
              filename generation, this applies to each word of the expanded
              text.  See below for further notes on substitutions.

              The forms `gs/l/r' and `s/l/r/:G' perform global substitution,
              i.e. substitute every occurrence of r for l.  Note that the g or
              :G must appear in exactly the position shown.

              See further notes on this form of substitution below.

       &      Repeat the previous s substitution.  Like s, may be preceded
              immediately by a g.  In parameter expansion the & must appear
              inside braces, and in filename generation it must be quoted with
              a backslash.

       t [ digits ]
              Remove all leading pathname components, leaving the final
              component (tail).  This works like `basename'.  Any trailing
              slashes are first removed.  Decimal digits are handled as
              described above for (h), but in this case that number of
              trailing components is preserved instead of the default 1; 0 is
              treated the same as 1.

       u      Convert the words to all uppercase.

       x      Like q, but break into words at whitespace.  Does not work with
              parameter expansion.

       The s/l/r/ substitution works as follows.  By default the left-hand
       side of substitutions are not patterns, but character strings.  Any
       character can be used as the delimiter in place of `/'.  A backslash
       quotes the delimiter character.  The character `&', in the
       right-hand-side r, is replaced by the text from the left-hand-side l.
       The `&' can be quoted with a backslash.  A null l uses the previous
       string either from the previous l or from the contextual scan string s
       from `!?s'.  You can omit the rightmost delimiter if a newline
       immediately follows r; the rightmost `?' in a context scan can
       similarly be omitted.  Note the same record of the last l and r is
       maintained across all forms of expansion.

       Note that if a `&' is used within glob qualifiers an extra backslash is
       needed as a & is a special character in this case.

       Also note that the order of expansions affects the interpretation of l
       and r.  When used in a history expansion, which occurs before any other
       expansions, l and r are treated as literal strings (except as explained
       for HIST_SUBST_PATTERN below).  When used in parameter expansion, the
       replacement of r into the parameter's value is done first, and then any
       additional process, parameter, command, arithmetic, or brace references
       are applied, which may evaluate those substitutions and expansions more
       than once if l appears more than once in the starting value.  When used
       in a glob qualifier, any substitutions or expansions are performed once
       at the time the qualifier is parsed, even before the `:s' expression
       itself is divided into l and r sides.

       If the option HIST_SUBST_PATTERN is set, l is treated as a pattern of
       the usual form described in the section FILENAME GENERATION below.
       This can be used in all the places where modifiers are available; note,
       however, that in globbing qualifiers parameter substitution has already
       taken place, so parameters in the replacement string should be quoted
       to ensure they are replaced at the correct time.  Note also that
       complicated patterns used in globbing qualifiers may need the extended
       glob qualifier notation (#q:s/.../.../) in order for the shell to
       recognize the expression as a glob qualifier.  Further, note that bad
       patterns in the substitution are not subject to the NO_BAD_PATTERN
       option so will cause an error.

       When HIST_SUBST_PATTERN is set, l may start with a # to indicate that
       the pattern must match at the start of the string to be substituted,
       and a % may appear at the start or after an # to indicate that the
       pattern must match at the end of the string to be substituted.  The %
       or # may be quoted with two backslashes.

       For example, the following piece of filename generation code with the
       EXTENDED_GLOB option:

              print -r -- *.c(#q:s/#%(#b)s(*).c/'S${match[1]}.C'/)

       takes the expansion of *.c and applies the glob qualifiers in the
       (#q...) expression, which consists of a substitution modifier anchored
       to the start and end of each word (#%).  This turns on backreferences
       ((#b)), so that the parenthesised subexpression is available in the
       replacement string as ${match[1]}.  The replacement string is quoted so
       that the parameter is not substituted before the start of filename
       generation.

       The following f, F, w and W modifiers work only with parameter
       expansion and filename generation.  They are listed here to provide a
       single point of reference for all modifiers.

       f      Repeats the immediately (without a colon) following modifier
              until the resulting word doesn't change any more.

       F:expr:
              Like f, but repeats only n times if the expression expr
              evaluates to n.  Any character can be used instead of the `:';
              if `(', `[', or `{' is used as the opening delimiter, the
              closing delimiter should be ')', `]', or `}', respectively.

       w      Makes the immediately following modifier work on each word in
              the string.

       W:sep: Like w but words are considered to be the parts of the string
              that are separated by sep. Any character can be used instead of
              the `:'; opening parentheses are handled specially, see above.

PROCESS SUBSTITUTION
       Each part of a command argument that takes the form `<(list)',
       `>(list)' or `=(list)' is subject to process substitution.  The
       expression may be preceded or followed by other strings except that, to
       prevent clashes with commonly occurring strings and patterns, the last
       form must occur at the start of a command argument, and the forms are
       only expanded when first parsing command or assignment arguments.
       Process substitutions may be used following redirection operators; in
       this case, the substitution must appear with no trailing string.

       Note that `<<(list)' is not a special syntax; it is equivalent to `<
       <(list)', redirecting standard input from the result of process
       substitution.  Hence all the following documentation applies.  The
       second form (with the space) is recommended for clarity.

       In the case of the < or > forms, the shell runs the commands in list as
       a subprocess of the job executing the shell command line.  If the
       system supports the /dev/fd mechanism, the command argument is the name
       of the device file corresponding to a file descriptor; otherwise, if
       the system supports named pipes (FIFOs), the command argument will be a
       named pipe.  If the form with > is selected then writing on this
       special file will provide input for list.  If < is used, then the file
       passed as an argument will be connected to the output of the list
       process.  For example,

              paste <(cut -f1 file1) <(cut -f3 file2) |
              tee >(process1) >(process2) >/dev/null

       cuts fields 1 and 3 from the files file1 and file2 respectively, pastes
       the results together, and sends it to the processes process1 and
       process2.

       If =(...) is used instead of <(...), then the file passed as an
       argument will be the name of a temporary file containing the output of
       the list process.  This may be used instead of the < form for a program
       that expects to lseek (see lseek(2)) on the input file.

       There is an optimisation for substitutions of the form =(<<<arg), where
       arg is a single-word argument to the here-string redirection <<<.  This
       form produces a file name containing the value of arg after any
       substitutions have been performed.  This is handled entirely within the
       current shell.  This is effectively the reverse of the special form
       $(<arg) which treats arg as a file name and replaces it with the file's
       contents.

       The = form is useful as both the /dev/fd and the named pipe
       implementation of <(...) have drawbacks.  In the former case, some
       programmes may automatically close the file descriptor in question
       before examining the file on the command line, particularly if this is
       necessary for security reasons such as when the programme is running
       setuid.  In the second case, if the programme does not actually open
       the file, the subshell attempting to read from or write to the pipe
       will (in a typical implementation, different operating systems may have
       different behaviour) block for ever and have to be killed explicitly.
       In both cases, the shell actually supplies the information using a
       pipe, so that programmes that expect to lseek (see lseek(2)) on the
       file will not work.

       Also note that the previous example can be more compactly and
       efficiently written (provided the MULTIOS option is set) as:

              paste <(cut -f1 file1) <(cut -f3 file2) \
              > >(process1) > >(process2)

       The shell uses pipes instead of FIFOs to implement the latter two
       process substitutions in the above example.

       There is an additional problem with >(process); when this is attached
       to an external command, the parent shell does not wait for process to
       finish and hence an immediately following command cannot rely on the
       results being complete.  The problem and solution are the same as
       described in the section MULTIOS in zshmisc(1).  Hence in a simplified
       version of the example above:

              paste <(cut -f1 file1) <(cut -f3 file2) > >(process)

       (note that no MULTIOS are involved), process will be run asynchronously
       as far as the parent shell is concerned.  The workaround is:

              { paste <(cut -f1 file1) <(cut -f3 file2) } > >(process)

       The extra processes here are spawned from the parent shell which will
       wait for their completion.

       Another problem arises any time a job with a substitution that requires
       a temporary file is disowned by the shell, including the case where
       `&!' or `&|' appears at the end of a command containing a substitution.
       In that case the temporary file will not be cleaned up as the shell no
       longer has any memory of the job.  A workaround is to use a subshell,
       for example,

              (mycmd =(myoutput)) &!

       as the forked subshell will wait for the command to finish then remove
       the temporary file.

       A general workaround to ensure a process substitution endures for an
       appropriate length of time is to pass it as a parameter to an anonymous
       shell function (a piece of shell code that is run immediately with
       function scope).  For example, this code:

              () {
                 print File $1:
                 cat $1
              } =(print This be the verse)

       outputs something resembling the following

              File /tmp/zsh6nU0kS:
              This be the verse

       The temporary file created by the process substitution will be deleted
       when the function exits.

PARAMETER EXPANSION
       The character `$' is used to introduce parameter expansions.  See
       zshparam(1) for a description of parameters, including arrays,
       associative arrays, and subscript notation to access individual array
       elements.

       Note in particular the fact that words of unquoted parameters are not
       automatically split on whitespace unless the option SH_WORD_SPLIT is
       set; see references to this option below for more details.  This is an
       important difference from other shells.  However, as in other shells,
       null words are elided from unquoted parameters' expansions.

       With default options, after the assignments:

              array=("first word" "" "third word")
              scalar="only word"

       then $array substitutes two words, `first word' and `third word', and
       $scalar substitutes a single word `only word'.  Note that second
       element of array was elided.  Scalar parameters can be elided too if
       their value is null (empty).  To avoid elision, use quoting as follows:
       "$scalar" for scalars and "${array[@]}" or "${(@)array}" for arrays.
       (The last two forms are equivalent.)

       Parameter expansions can involve flags, as in `${(@kv)aliases}', and
       other operators, such as `${PREFIX:-"/usr/local"}'.  Parameter
       expansions can also be nested.  These topics will be introduced below.
       The full rules are complicated and are noted at the end.

       In the expansions discussed below that require a pattern, the form of
       the pattern is the same as that used for filename generation; see the
       section `Filename Generation'.  Note that these patterns, along with
       the replacement text of any substitutions, are themselves subject to
       parameter expansion, command substitution, and arithmetic expansion.
       In addition to the following operations, the colon modifiers described
       in the section `Modifiers' in the section `History Expansion' can be
       applied:  for example, ${i:s/foo/bar/} performs string substitution on
       the expansion of parameter $i.

       In the following descriptions, `word' refers to a single word
       substituted on the command line, not necessarily a space delimited
       word.

       ${name}
              The value, if any, of the parameter name is substituted.  The
              braces are required if the expansion is to be followed by a
              letter, digit, or underscore that is not to be interpreted as
              part of name.  In addition, more complicated forms of
              substitution usually require the braces to be present;
              exceptions, which only apply if the option KSH_ARRAYS is not
              set, are a single subscript or any colon modifiers appearing
              after the name, or any of the characters `^', `=', `~', `#' or
              `+' appearing before the name, all of which work with or without
              braces.

              If name is an array parameter, and the KSH_ARRAYS option is not
              set, then the value of each element of name is substituted, one
              element per word.  Otherwise, the expansion results in one word
              only; with KSH_ARRAYS, this is the first element of an array.
              No field splitting is done on the result unless the
              SH_WORD_SPLIT option is set.  See also the flags = and
              s:string:.

       ${+name}
              If name is the name of a set parameter `1' is substituted,
              otherwise `0' is substituted.

       ${name-word}
       ${name:-word}
              If name is set, or in the second form is non-null, then
              substitute its value; otherwise substitute word.  In the second
              form name may be omitted, in which case word is always
              substituted.

       ${name+word}
       ${name:+word}
              If name is set, or in the second form is non-null, then
              substitute word; otherwise substitute nothing.

       ${name=word}
       ${name:=word}
       ${name::=word}
              In the first form, if name is unset then set it to word; in the
              second form, if name is unset or null then set it to word; and
              in the third form, unconditionally set name to word.  In all
              forms, the value of the parameter is then substituted.

       ${name?word}
       ${name:?word}
              In the first form, if name is set, or in the second form if name
              is both set and non-null, then substitute its value; otherwise,
              print word and exit from the shell.  Interactive shells instead
              return to the prompt.  If word is omitted, then a standard
              message is printed.

       In any of the above expressions that test a variable and substitute an
       alternate word, note that you can use standard shell quoting in the
       word value to selectively override the splitting done by the
       SH_WORD_SPLIT option and the = flag, but not splitting by the s:string:
       flag.

       In the following expressions, when name is an array and the
       substitution is not quoted, or if the `(@)' flag or the name[@] syntax
       is used, matching and replacement is performed on each array element
       separately.

       ${name#pattern}
       ${name##pattern}
              If the pattern matches the beginning of the value of name, then
              substitute the value of name with the matched portion deleted;
              otherwise, just substitute the value of name.  In the first
              form, the smallest matching pattern is preferred; in the second
              form, the largest matching pattern is preferred.

       ${name%pattern}
       ${name%%pattern}
              If the pattern matches the end of the value of name, then
              substitute the value of name with the matched portion deleted;
              otherwise, just substitute the value of name.  In the first
              form, the smallest matching pattern is preferred; in the second
              form, the largest matching pattern is preferred.

       ${name:#pattern}
              If the pattern matches the value of name, then substitute the
              empty string; otherwise, just substitute the value of name.  If
              name is an array the matching array elements are removed (use
              the `(M)' flag to remove the non-matched elements).

       ${name:|arrayname}
              If arrayname is the name (N.B., not contents) of an array
              variable, then any elements contained in arrayname are removed
              from the substitution of name.  If the substitution is scalar,
              either because name is a scalar variable or the expression is
              quoted, the elements of arrayname are instead tested against the
              entire expression.

       ${name:*arrayname}
              Similar to the preceding substitution, but in the opposite
              sense, so that entries present in both the original substitution
              and as elements of arrayname are retained and others removed.

       ${name:^arrayname}
       ${name:^^arrayname}
              Zips two arrays, such that the output array is twice as long as
              the shortest (longest for `:^^') of name and arrayname, with the
              elements alternatingly being picked from them. For `:^', if one
              of the input arrays is longer, the output will stop when the end
              of the shorter array is reached.  Thus,

                     a=(1 2 3 4); b=(a b); print ${a:^b}

              will output `1 a 2 b'.  For `:^^', then the input is repeated
              until all of the longer array has been used up and the above
              will output `1 a 2 b 3 a 4 b'.

              Either or both inputs may be a scalar, they will be treated as
              an array of length 1 with the scalar as the only element. If
              either array is empty, the other array is output with no extra
              elements inserted.

              Currently the following code will output `a b' and `1' as two
              separate elements, which can be unexpected. The second print
              provides a workaround which should continue to work if this is
              changed.

                     a=(a b); b=(1 2); print -l "${a:^b}"; print -l "${${a:^b}}"

       ${name:offset}
       ${name:offset:length}
              This syntax gives effects similar to parameter subscripting in
              the form $name[start,end], but is compatible with other shells;
              note that both offset and length are interpreted differently
              from the components of a subscript.

              If offset is non-negative, then if the variable name is a scalar
              substitute the contents starting offset characters from the
              first character of the string, and if name is an array
              substitute elements starting offset elements from the first
              element.  If length is given, substitute that many characters or
              elements, otherwise the entire rest of the scalar or array.

              A positive offset is always treated as the offset of a character
              or element in name from the first character or element of the
              array (this is different from native zsh subscript notation).
              Hence 0 refers to the first character or element regardless of
              the setting of the option KSH_ARRAYS.

              A negative offset counts backwards from the end of the scalar or
              array, so that -1 corresponds to the last character or element,
              and so on.

              When positive, length counts from the offset position toward the
              end of the scalar or array.  When negative, length counts back
              from the end.  If this results in a position smaller than
              offset, a diagnostic is printed and nothing is substituted.

              The option MULTIBYTE is obeyed, i.e. the offset and length count
              multibyte characters where appropriate.

              offset and length undergo the same set of shell substitutions as
              for scalar assignment; in addition, they are then subject to
              arithmetic evaluation.  Hence, for example

                     print ${foo:3}
                     print ${foo: 1 + 2}
                     print ${foo:$(( 1 + 2))}
                     print ${foo:$(echo 1 + 2)}

              all have the same effect, extracting the string starting at the
              fourth character of $foo if the substitution would otherwise
              return a scalar, or the array starting at the fourth element if
              $foo would return an array.  Note that with the option
              KSH_ARRAYS $foo always returns a scalar (regardless of the use
              of the offset syntax) and a form such as ${foo[*]:3} is required
              to extract elements of an array named foo.

              If offset is negative, the - may not appear immediately after
              the : as this indicates the ${name:-word} form of substitution.
              Instead, a space may be inserted before the -.  Furthermore,
              neither offset nor length may begin with an alphabetic character
              or & as these are used to indicate history-style modifiers.  To
              substitute a value from a variable, the recommended approach is
              to precede it with a $ as this signifies the intention
              (parameter substitution can easily be rendered unreadable);
              however, as arithmetic substitution is performed, the expression
              ${var: offs} does work, retrieving the offset from $offs.

              For further compatibility with other shells there is a special
              case for array offset 0.  This usually accesses the first
              element of the array.  However, if the substitution refers to
              the positional parameter array, e.g. $@ or $*, then offset 0
              instead refers to $0, offset 1 refers to $1, and so on.  In
              other words, the positional parameter array is effectively
              extended by prepending $0.  Hence ${*:0:1} substitutes $0 and
              ${*:1:1} substitutes $1.

       ${name/pattern/repl}
       ${name//pattern/repl}
       ${name:/pattern/repl}
              Replace the longest possible match of pattern in the expansion
              of parameter name by string repl.  The first form replaces just
              the first occurrence, the second form all occurrences, and the
              third form replaces only if pattern matches the entire string.
              Both pattern and repl are subject to double-quoted substitution,
              so that expressions like ${name/$opat/$npat} will work, but obey
              the usual rule that pattern characters in $opat are not treated
              specially unless either the option GLOB_SUBST is set, or $opat
              is instead substituted as ${~opat}.

              The pattern may begin with a `#', in which case the pattern must
              match at the start of the string, or `%', in which case it must
              match at the end of the string, or `#%' in which case the
              pattern must match the entire string.  The repl may be an empty
              string, in which case the final `/' may also be omitted.  To
              quote the final `/' in other cases it should be preceded by a
              single backslash; this is not necessary if the `/' occurs inside
              a substituted parameter.  Note also that the `#', `%' and `#%
              are not active if they occur inside a substituted parameter,
              even at the start.

              If, after quoting rules apply, ${name} expands to an array, the
              replacements act on each element individually.  Note also the
              effect of the I and S parameter expansion flags below; however,
              the flags M, R, B, E and N are not useful.

              For example,

                     foo="twinkle twinkle little star" sub="t*e" rep="spy"
                     print ${foo//${~sub}/$rep}
                     print ${(S)foo//${~sub}/$rep}

              Here, the `~' ensures that the text of $sub is treated as a
              pattern rather than a plain string.  In the first case, the
              longest match for t*e is substituted and the result is `spy
              star', while in the second case, the shortest matches are taken
              and the result is `spy spy lispy star'.

       ${#spec}
              If spec is one of the above substitutions, substitute the length
              in characters of the result instead of the result itself.  If
              spec is an array expression, substitute the number of elements
              of the result.  This has the side-effect that joining is skipped
              even in quoted forms, which may affect other sub-expressions in
              spec.  Note that `^', `=', and `~', below, must appear to the
              left of `#' when these forms are combined.

              If the option POSIX_IDENTIFIERS is not set, and spec is a simple
              name, then the braces are optional; this is true even for
              special parameters so e.g. $#- and $#* take the length of the
              string $- and the array $* respectively.  If POSIX_IDENTIFIERS
              is set, then braces are required for the # to be treated in this
              fashion.

       ${^spec}
              Turn on the RC_EXPAND_PARAM option for the evaluation of spec;
              if the `^' is doubled, turn it off.  When this option is set,
              array expansions of the form foo${xx}bar, where the parameter xx
              is set to (a b c), are substituted with `fooabar foobbar
              foocbar' instead of the default `fooa b cbar'.  Note that an
              empty array will therefore cause all arguments to be removed.

              Internally, each such expansion is converted into the equivalent
              list for brace expansion.  E.g., ${^var} becomes
              {$var[1],$var[2],...}, and is processed as described in the
              section `Brace Expansion' below: note, however, the expansion
              happens immediately, with any explicit brace expansion happening
              later.  If word splitting is also in effect the $var[N] may
              themselves be split into different list elements.

       ${=spec}
              Perform word splitting using the rules for SH_WORD_SPLIT during
              the evaluation of spec, but regardless of whether the parameter
              appears in double quotes; if the `=' is doubled, turn it off.
              This forces parameter expansions to be split into separate words
              before substitution, using IFS as a delimiter.  This is done by
              default in most other shells.

              Note that splitting is applied to word in the assignment forms
              of spec before the assignment to name is performed.  This
              affects the result of array assignments with the A flag.

       ${~spec}
              Turn on the GLOB_SUBST option for the evaluation of spec; if the
              `~' is doubled, turn it off.  When this option is set, the
              string resulting from the expansion will be interpreted as a
              pattern anywhere that is possible, such as in filename expansion
              and filename generation and pattern-matching contexts like the
              right hand side of the `=' and `!=' operators in conditions.

              In nested substitutions, note that the effect of the ~ applies
              to the result of the current level of substitution.  A
              surrounding pattern operation on the result may cancel it.
              Hence, for example, if the parameter foo is set to *,
              ${~foo//\*/*.c} is substituted by the pattern *.c, which may be
              expanded by filename generation, but ${${~foo}//\*/*.c}
              substitutes to the string *.c, which will not be further
              expanded.

       If a ${...} type parameter expression or a $(...) type command
       substitution is used in place of name above, it is expanded first and
       the result is used as if it were the value of name.  Thus it is
       possible to perform nested operations:  ${${foo#head}%tail} substitutes
       the value of $foo with both `head' and `tail' deleted.  The form with
       $(...) is often useful in combination with the flags described next;
       see the examples below.  Each name or nested ${...} in a parameter
       expansion may also be followed by a subscript expression as described
       in Array Parameters in zshparam(1).

       Note that double quotes may appear around nested expressions, in which
       case only the part inside is treated as quoted; for example,
       ${(f)"$(foo)"} quotes the result of $(foo), but the flag `(f)' (see
       below) is applied using the rules for unquoted expansions.  Note
       further that quotes are themselves nested in this context; for example,
       in "${(@f)"$(foo)"}", there are two sets of quotes, one surrounding the
       whole expression, the other (redundant) surrounding the $(foo) as
       before.

   Parameter Expansion Flags
       If the opening brace is directly followed by an opening parenthesis,
       the string up to the matching closing parenthesis will be taken as a
       list of flags.  In cases where repeating a flag is meaningful, the
       repetitions need not be consecutive; for example, `(q%q%q)' means the
       same thing as the more readable `(%%qqq)'.  The following flags are
       supported:

       #      Evaluate the resulting words as numeric expressions and output
              the characters corresponding to the resulting integer.  Note
              that this form is entirely distinct from use of the # without
              parentheses.

              If the MULTIBYTE option is set and the number is greater than
              127 (i.e. not an ASCII character) it is treated as a Unicode
              character.

       %      Expand all % escapes in the resulting words in the same way as
              in prompts (see EXPANSION OF PROMPT SEQUENCES in zshmisc(1)). If
              this flag is given twice, full prompt expansion is done on the
              resulting words, depending on the setting of the PROMPT_PERCENT,
              PROMPT_SUBST and PROMPT_BANG options.

       @      In double quotes, array elements are put into separate words.
              E.g., `"${(@)foo}"' is equivalent to `"${foo[@]}"' and
              `"${(@)foo[1,2]}"' is the same as `"$foo[1]" "$foo[2]"'.  This
              is distinct from field splitting by the f, s or z flags, which
              still applies within each array element.

       A      Convert the substitution into an array expression, even if it
              otherwise would be scalar.  This has lower precedence than
              subscripting, so one level of nested expansion is required in
              order that subscripts apply to array elements.  Thus
              ${${(A)name}[1]} yields the full value of name when name is
              scalar.

              This assigns an array parameter with `${...=...}', `${...:=...}'
              or `${...::=...}'.  If this flag is repeated (as in `AA'),
              assigns an associative array parameter.  Assignment is made
              before sorting or padding; if field splitting is active, the
              word part is split before assignment.  The name part may be a
              subscripted range for ordinary arrays; when assigning an
              associative array, the word part must be converted to an array,
              for example by using `${(AA)=name=...}' to activate field
              splitting.

              Surrounding context such as additional nesting or use of the
              value in a scalar assignment may cause the array to be joined
              back into a single string again.

       a      Sort in array index order; when combined with `O' sort in
              reverse array index order.  Note that `a' is therefore
              equivalent to the default but `Oa' is useful for obtaining an
              array's elements in reverse order.

       b      Quote with backslashes only characters that are special to
              pattern matching. This is useful when the contents of the
              variable are to be tested using GLOB_SUBST, including the
              ${~...} switch.

              Quoting using one of the q family of flags does not work for
              this purpose since quotes are not stripped from non-pattern
              characters by GLOB_SUBST.  In other words,

                     pattern=${(q)str}
                     [[ $str = ${~pattern} ]]

              works if $str is `a*b' but not if it is `a b', whereas

                     pattern=${(b)str}
                     [[ $str = ${~pattern} ]]

              is always true for any possible value of $str.

       c      With ${#name}, count the total number of characters in an array,
              as if the elements were concatenated with spaces between them.
              This is not a true join of the array, so other expressions used
              with this flag may have an effect on the elements of the array
              before it is counted.

       C      Capitalize the resulting words.  `Words' in this case refers to
              sequences of alphanumeric characters separated by
              non-alphanumerics, not to words that result from field
              splitting.

       D      Assume the string or array elements contain directories and
              attempt to substitute the leading part of these by names.  The
              remainder of the path (the whole of it if the leading part was
              not substituted) is then quoted so that the whole string can be
              used as a shell argument.  This is the reverse of `~'
              substitution:  see the section FILENAME EXPANSION below.

       e      Perform single word shell expansions, namely parameter
              expansion, command substitution and arithmetic expansion, on the
              result. Such expansions can be nested but too deep recursion may
              have unpredictable effects.

       f      Split the result of the expansion at newlines. This is a
              shorthand for `ps:\n:'.

       F      Join the words of arrays together using newline as a separator.
              This is a shorthand for `pj:\n:'.

       g:opts:
              Process escape sequences like the echo builtin when no options
              are given (g::).  With the o option, octal escapes don't take a
              leading zero.  With the c option, sequences like `^X' are also
              processed.  With the e option, processes `\M-t' and similar
              sequences like the print builtin.  With both of the o and e
              options, behaves like the print builtin except that in none of
              these modes is `\c' interpreted.

       i      Sort case-insensitively.  May be combined with `n' or `O'.

       k      If name refers to an associative array, substitute the keys
              (element names) rather than the values of the elements.  Used
              with subscripts (including ordinary arrays), force indices or
              keys to be substituted even if the subscript form refers to
              values.  However, this flag may not be combined with subscript
              ranges.  With the KSH_ARRAYS option a subscript `[*]' or `[@]'
              is needed to operate on the whole array, as usual.

       L      Convert all letters in the result to lower case.

       n      Sort decimal integers numerically; if the first differing
              characters of two test strings are not digits, sorting is
              lexical.   Integers with more initial zeroes are sorted before
              those with fewer or none.  Hence the array `foo1 foo02 foo2 foo3
              foo20 foo23' is sorted into the order shown.  May be combined
              with `i' or `O'.

       o      Sort the resulting words in ascending order; if this appears on
              its own the sorting is lexical and case-sensitive (unless the
              locale renders it case-insensitive).  Sorting in ascending order
              is the default for other forms of sorting, so this is ignored if
              combined with `a', `i' or `n'.

       O      Sort the resulting words in descending order; `O' without `a',
              `i' or `n' sorts in reverse lexical order.  May be combined with
              `a', `i' or `n' to reverse the order of sorting.

       P      This forces the value of the parameter name to be interpreted as
              a further parameter name, whose value will be used where
              appropriate.  Note that flags set with one of the typeset family
              of commands (in particular case transformations) are not applied
              to the value of name used in this fashion.

              If used with a nested parameter or command substitution, the
              result of that will be taken as a parameter name in the same
              way.  For example, if you have `foo=bar' and `bar=baz', the
              strings ${(P)foo}, ${(P)${foo}}, and ${(P)$(echo bar)} will be
              expanded to `baz'.

              Likewise, if the reference is itself nested, the expression with
              the flag is treated as if it were directly replaced by the
              parameter name.  It is an error if this nested substitution
              produces an array with more than one word.  For example, if
              `name=assoc' where the parameter assoc is an associative array,
              then `${${(P)name}[elt]}' refers to the element of the
              associative subscripted `elt'.

       q      Quote characters that are special to the shell in the resulting
              words with backslashes; unprintable or invalid characters are
              quoted using the $'\NNN' form, with separate quotes for each
              octet.

              If this flag is given twice, the resulting words are quoted in
              single quotes and if it is given three times, the words are
              quoted in double quotes; in these forms no special handling of
              unprintable or invalid characters is attempted.  If the flag is
              given four times, the words are quoted in single quotes preceded
              by a $.  Note that in all three of these forms quoting is done
              unconditionally, even if this does not change the way the
              resulting string would be interpreted by the shell.

              If a q- is given (only a single q may appear), a minimal form of
              single quoting is used that only quotes the string if needed to
              protect special characters.  Typically this form gives the most
              readable output.

              If a q+ is given, an extended form of minimal quoting is used
              that causes unprintable characters to be rendered using $'...'.
              This quoting is similar to that used by the output of values by
              the typeset family of commands.

       Q      Remove one level of quotes from the resulting words.

       t      Use a string describing the type of the parameter where the
              value of the parameter would usually appear. This string
              consists of keywords separated by hyphens (`-'). The first
              keyword in the string describes the main type, it can be one of
              `scalar', `array', `integer', `float' or `association'. The
              other keywords describe the type in more detail:

              local  for local parameters

              left   for left justified parameters

              right_blanks
                     for right justified parameters with leading blanks

              right_zeros
                     for right justified parameters with leading zeros

              lower  for parameters whose value is converted to all lower case
                     when it is expanded

              upper  for parameters whose value is converted to all upper case
                     when it is expanded

              readonly
                     for readonly parameters

              tag    for tagged parameters

              export for exported parameters

              unique for arrays which keep only the first occurrence of
                     duplicated values

              hide   for parameters with the `hide' flag

              hideval
                     for parameters with the `hideval' flag

              special
                     for special parameters defined by the shell

       u      Expand only the first occurrence of each unique word.

       U      Convert all letters in the result to upper case.

       v      Used with k, substitute (as two consecutive words) both the key
              and the value of each associative array element.  Used with
              subscripts, force values to be substituted even if the subscript
              form refers to indices or keys.

       V      Make any special characters in the resulting words visible.

       w      With ${#name}, count words in arrays or strings; the s flag may
              be used to set a word delimiter.

       W      Similar to w with the difference that empty words between
              repeated delimiters are also counted.

       X      With this flag, parsing errors occurring with the Q, e and #
              flags or the pattern matching forms such as `${name#pattern}'
              are reported.  Without the flag, errors are silently ignored.

       z      Split the result of the expansion into words using shell parsing
              to find the words, i.e. taking into account any quoting in the
              value.  Comments are not treated specially but as ordinary
              strings, similar to interactive shells with the
              INTERACTIVE_COMMENTS option unset (however, see the Z flag below
              for related options)

              Note that this is done very late, even later than the `(s)'
              flag. So to access single words in the result use nested
              expansions as in `${${(z)foo}[2]}'. Likewise, to remove the
              quotes in the resulting words use `${(Q)${(z)foo}}'.

       0      Split the result of the expansion on null bytes.  This is a
              shorthand for `ps:\0:'.

       The following flags (except p) are followed by one or more arguments as
       shown.  Any character, or the matching pairs `(...)', `{...}', `[...]',
       or `<...>', may be used in place of a colon as delimiters, but note
       that when a flag takes more than one argument, a matched pair of
       delimiters must surround each argument.

       p      Recognize the same escape sequences as the print builtin in
              string arguments to any of the flags described below that follow
              this argument.

              Alternatively, with this option string arguments may be in the
              form $var in which case the value of the variable is
              substituted.  Note this form is strict; the string argument does
              not undergo general parameter expansion.

              For example,

                     sep=:
                     val=a:b:c
                     print ${(ps.$sep.)val}

              splits the variable on a :.

       ~      Strings inserted into the expansion by any of the flags below
              are to be treated as patterns.  This applies to the string
              arguments of flags that follow ~ within the same set of
              parentheses.  Compare with ~ outside parentheses, which forces
              the entire substituted string to be treated as a pattern.
              Hence, for example,

                     [[ "?" = ${(~j.|.)array} ]]

              treats `|' as a pattern and succeeds if and only if $array
              contains the string `?' as an element.  The ~ may be repeated to
              toggle the behaviour; its effect only lasts to the end of the
              parenthesised group.

       j:string:
              Join the words of arrays together using string as a separator.
              Note that this occurs before field splitting by the s:string:
              flag or the SH_WORD_SPLIT option.

       l:expr::string1::string2:
              Pad the resulting words on the left.  Each word will be
              truncated if required and placed in a field expr characters
              wide.

              The arguments :string1: and :string2: are optional; neither, the
              first, or both may be given.  Note that the same pairs of
              delimiters must be used for each of the three arguments.  The
              space to the left will be filled with string1 (concatenated as
              often as needed) or spaces if string1 is not given.  If both
              string1 and string2 are given, string2 is inserted once directly
              to the left of each word, truncated if necessary, before string1
              is used to produce any remaining padding.

              If either of string1 or string2 is present but empty, i.e. there
              are two delimiters together at that point, the first character
              of $IFS is used instead.

              If the MULTIBYTE option is in effect, the flag m may also be
              given, in which case widths will be used for the calculation of
              padding; otherwise individual multibyte characters are treated
              as occupying one unit of width.

              If the MULTIBYTE option is not in effect, each byte in the
              string is treated as occupying one unit of width.

              Control characters are always assumed to be one unit wide; this
              allows the mechanism to be used for generating repetitions of
              control characters.

       m      Only useful together with one of the flags l or r or with the #
              length operator when the MULTIBYTE option is in effect.  Use the
              character width reported by the system in calculating how much
              of the string it occupies or the overall length of the string.
              Most printable characters have a width of one unit, however
              certain Asian character sets and certain special effects use
              wider characters; combining characters have zero width.
              Non-printable characters are arbitrarily counted as zero width;
              how they would actually be displayed will vary.

              If the m is repeated, the character either counts zero (if it
              has zero width), else one.  For printable character strings this
              has the effect of counting the number of glyphs (visibly
              separate characters), except for the case where combining
              characters themselves have non-zero width (true in certain
              alphabets).

       r:expr::string1::string2:
              As l, but pad the words on the right and insert string2
              immediately to the right of the string to be padded.

              Left and right padding may be used together.  In this case the
              strategy is to apply left padding to the first half width of
              each of the resulting words, and right padding to the second
              half.  If the string to be padded has odd width the extra
              padding is applied on the left.

       s:string:
              Force field splitting at the separator string.  Note that a
              string of two or more characters means that all of them must
              match in sequence; this differs from the treatment of two or
              more characters in the IFS parameter.  See also the = flag and
              the SH_WORD_SPLIT option.  An empty string may also be given in
              which case every character will be a separate element.

              For historical reasons, the usual behaviour that empty array
              elements are retained inside double quotes is disabled for
              arrays generated by splitting; hence the following:

                     line="one::three"
                     print -l "${(s.:.)line}"

              produces two lines of output for one and three and elides the
              empty field.  To override this behaviour, supply the `(@)' flag
              as well, i.e.  "${(@s.:.)line}".

       Z:opts:
              As z but takes a combination of option letters between a
              following pair of delimiter characters.  With no options the
              effect is identical to z.  (Z+c+) causes comments to be parsed
              as a string and retained; any field in the resulting array
              beginning with an unquoted comment character is a comment.
              (Z+C+) causes comments to be parsed and removed.  The rule for
              comments is standard: anything between a word starting with the
              third character of $HISTCHARS, default #, up to the next newline
              is a comment.  (Z+n+) causes unquoted newlines to be treated as
              ordinary whitespace, else they are treated as if they are shell
              code delimiters and converted to semicolons.  Options are
              combined within the same set of delimiters, e.g. (Z+Cn+).

       _:flags:
              The underscore (_) flag is reserved for future use.  As of this
              revision of zsh, there are no valid flags; anything following an
              underscore, other than an empty pair of delimiters, is treated
              as an error, and the flag itself has no effect.

       The following flags are meaningful with the ${...#...} or ${...%...}
       forms.  The S and I flags may also be used with the ${.../...} forms.

       S      With # or ##, search for the match that starts closest to the
              start of the string (a `substring match'). Of all matches at a
              particular position, # selects the shortest and ## the longest:

                     % str="aXbXc"
                     % echo ${(S)str#X*}
                     abXc
                     % echo ${(S)str##X*}
                     a
                     %

              With % or %%, search for the match that starts closest to the
              end of the string:

                     % str="aXbXc"
                     % echo ${(S)str%X*}
                     aXbc
                     % echo ${(S)str%%X*}
                     aXb
                     %

              (Note that % and %% don't search for the match that ends closest
              to the end of the string, as one might expect.)

              With substitution via ${.../...} or ${...//...}, specifies
              non-greedy matching, i.e. that the shortest instead of the
              longest match should be replaced:

                     % str="abab"
                     % echo ${str/*b/_}
                     _
                     % echo ${(S)str/*b/_}
                     _ab
                     %

       I:expr:
              Search the exprth match (where expr evaluates to a number).
              This only applies when searching for substrings, either with the
              S flag, or with ${.../...} (only the exprth match is
              substituted) or ${...//...} (all matches from the exprth on are
              substituted).  The default is to take the first match.

              The exprth match is counted such that there is either one or
              zero matches from each starting position in the string, although
              for global substitution matches overlapping previous
              replacements are ignored.  With the ${...%...} and ${...%%...}
              forms, the starting position for the match moves backwards from
              the end as the index increases, while with the other forms it
              moves forward from the start.

              Hence with the string
                     which switch is the right switch for Ipswich?
              substitutions of the form ${(SI:N:)string#w*ch} as N increases
              from 1 will match and remove `which', `witch', `witch' and
              `wich'; the form using `##' will match and remove `which switch
              is the right switch for Ipswich', `witch is the right switch for
              Ipswich', `witch for Ipswich' and `wich'. The form using `%'
              will remove the same matches as for `#', but in reverse order,
              and the form using `%%' will remove the same matches as for `##'
              in reverse order.

       B      Include the index of the beginning of the match in the result.

       E      Include the index one character past the end of the match in the
              result (note this is inconsistent with other uses of parameter
              index).

       M      Include the matched portion in the result.

       N      Include the length of the match in the result.

       R      Include the unmatched portion in the result (the Rest).

   Rules
       Here is a summary of the rules for substitution; this assumes that
       braces are present around the substitution, i.e. ${...}.  Some
       particular examples are given below.  Note that the Zsh Development
       Group accepts no responsibility for any brain damage which may occur
       during the reading of the following rules.

       1. Nested substitution
              If multiple nested ${...} forms are present, substitution is
              performed from the inside outwards.  At each level, the
              substitution takes account of whether the current value is a
              scalar or an array, whether the whole substitution is in double
              quotes, and what flags are supplied to the current level of
              substitution, just as if the nested substitution were the
              outermost.  The flags are not propagated up to enclosing
              substitutions; the nested substitution will return either a
              scalar or an array as determined by the flags, possibly adjusted
              for quoting.  All the following steps take place where
              applicable at all levels of substitution.

              Note that, unless the `(P)' flag is present, the flags and any
              subscripts apply directly to the value of the nested
              substitution; for example, the expansion ${${foo}} behaves
              exactly the same as ${foo}.  When the `(P)' flag is present in a
              nested substitution, the other substitution rules are applied to
              the value before it is interpreted as a name, so ${${(P)foo}}
              may differ from ${(P)foo}.

              At each nested level of substitution, the substituted words
              undergo all forms of single-word substitution (i.e. not filename
              generation), including command substitution, arithmetic
              expansion and filename expansion (i.e. leading ~ and =).  Thus,
              for example, ${${:-=cat}:h} expands to the directory where the
              cat program resides.  (Explanation: the internal substitution
              has no parameter but a default value =cat, which is expanded by
              filename expansion to a full path; the outer substitution then
              applies the modifier :h and takes the directory part of the
              path.)

       2. Internal parameter flags
              Any parameter flags set by one of the typeset family of
              commands, in particular the -L, -R, -Z, -u and -l options for
              padding and capitalization, are applied directly to the
              parameter value.  Note these flags are options to the command,
              e.g. `typeset -Z'; they are not the same as the flags used
              within parameter substitutions.

              At the outermost level of substitution, the `(P)' flag (rule 4.)
              ignores these transformations and uses the unmodified value of
              the parameter as the name to be replaced.  This is usually the
              desired behavior because padding may make the value
              syntactically illegal as a parameter name, but if capitalization
              changes are desired, use the ${${(P)foo}} form (rule 25.).

       3. Parameter subscripting
              If the value is a raw parameter reference with a subscript, such
              as ${var[3]}, the effect of subscripting is applied directly to
              the parameter.  Subscripts are evaluated left to right;
              subsequent subscripts apply to the scalar or array value yielded
              by the previous subscript.  Thus if var is an array,
              ${var[1][2]} is the second character of the first word, but
              ${var[2,4][2]} is the entire third word (the second word of the
              range of words two through four of the original array).  Any
              number of subscripts may appear.  Flags such as `(k)' and `(v)'
              which alter the result of subscripting are applied.

       4. Parameter name replacement
              At the outermost level of nesting only, the `(P)' flag is
              applied.  This treats the value so far as a parameter name
              (which may include a subscript expression) and replaces that
              with the corresponding value.  This replacement occurs later if
              the `(P)' flag appears in a nested substitution.

              If the value so far names a parameter that has internal flags
              (rule 2.), those internal flags are applied to the new value
              after replacement.

       5. Double-quoted joining
              If the value after this process is an array, and the
              substitution appears in double quotes, and neither an `(@)' flag
              nor a `#' length operator is present at the current level, then
              words of the value are joined with the first character of the
              parameter $IFS, by default a space, between each word (single
              word arrays are not modified).  If the `(j)' flag is present,
              that is used for joining instead of $IFS.

       6. Nested subscripting
              Any remaining subscripts (i.e. of a nested substitution) are
              evaluated at this point, based on whether the value is an array
              or a scalar.  As with 3., multiple subscripts can appear.  Note
              that ${foo[2,4][2]} is thus equivalent to ${${foo[2,4]}[2]} and
              also to "${${(@)foo[2,4]}[2]}" (the nested substitution returns
              an array in both cases), but not to "${${foo[2,4]}[2]}" (the
              nested substitution returns a scalar because of the quotes).

       7. Modifiers
              Any modifiers, as specified by a trailing `#', `%', `/'
              (possibly doubled) or by a set of modifiers of the form `:...'
              (see the section `Modifiers' in the section `History
              Expansion'), are applied to the words of the value at this
              level.

       8. Character evaluation
              Any `(#)' flag is applied, evaluating the result so far
              numerically as a character.

       9. Length
              Any initial `#' modifier, i.e. in the form ${#var}, is used to
              evaluate the length of the expression so far.

       10. Forced joining
              If the `(j)' flag is present, or no `(j)' flag is present but
              the string is to be split as given by rule 11., and joining did
              not take place at rule 5., any words in the value are joined
              together using the given string or the first character of $IFS
              if none.  Note that the `(F)' flag implicitly supplies a string
              for joining in this manner.

       11. Simple word splitting
              If one of the `(s)' or `(f)' flags are present, or the `='
              specifier was present (e.g. ${=var}), the word is split on
              occurrences of the specified string, or (for = with neither of
              the two flags present) any of the characters in $IFS.

              If no `(s)', `(f)' or `=' was given, but the word is not quoted
              and the option SH_WORD_SPLIT is set, the word is split on
              occurrences of any of the characters in $IFS.  Note this step,
              too, takes place at all levels of a nested substitution.

       12. Case modification
              Any case modification from one of the flags `(L)', `(U)' or
              `(C)' is applied.

       13. Escape sequence replacement
              First any replacements from the `(g)' flag are performed, then
              any prompt-style formatting from the `(%)' family of flags is
              applied.

       14. Quote application
              Any quoting or unquoting using `(q)' and `(Q)' and related flags
              is applied.

       15. Directory naming
              Any directory name substitution using `(D)' flag is applied.

       16. Visibility enhancement
              Any modifications to make characters visible using the `(V)'
              flag are applied.

       17. Lexical word splitting
              If the '(z)' flag or one of the forms of the '(Z)' flag is
              present, the word is split as if it were a shell command line,
              so that quotation marks and other metacharacters are used to
              decide what constitutes a word.  Note this form of splitting is
              entirely distinct from that described by rule 11.: it does not
              use $IFS, and does not cause forced joining.

       18. Uniqueness
              If the result is an array and the `(u)' flag was present,
              duplicate elements are removed from the array.

       19. Ordering
              If the result is still an array and one of the `(o)' or `(O)'
              flags was present, the array is reordered.

       20. RC_EXPAND_PARAM
              At this point the decision is made whether any resulting array
              elements are to be combined element by element with surrounding
              text, as given by either the RC_EXPAND_PARAM option or the `^'
              flag.

       21. Re-evaluation
              Any `(e)' flag is applied to the value, forcing it to be
              re-examined for new parameter substitutions, but also for
              command and arithmetic substitutions.

       22. Padding
              Any padding of the value by the `(l.fill.)' or `(r.fill.)' flags
              is applied.

       23. Semantic joining
              In contexts where expansion semantics requires a single word to
              result, all words are rejoined with the first character of IFS
              between.  So in `${(P)${(f)lines}}' the value of ${lines} is
              split at newlines, but then must be joined again before the
              `(P)' flag can be applied.

              If a single word is not required, this rule is skipped.

       24. Empty argument removal
              If the substitution does not appear in double quotes, any
              resulting zero-length argument, whether from a scalar or an
              element of an array, is elided from the list of arguments
              inserted into the command line.

              Strictly speaking, the removal happens later as the same happens
              with other forms of substitution; the point to note here is
              simply that it occurs after any of the above parameter
              operations.

       25. Nested parameter name replacement
              If the `(P)' flag is present and rule 4. has not applied, the
              value so far is treated as a parameter name (which may include a
              subscript expression) and replaced with the corresponding value,
              with internal flags (rule 2.) applied to the new value.

   Examples
       The flag f is useful to split a double-quoted substitution line by
       line.  For example, ${(f)"$(<file)"} substitutes the contents of file
       divided so that each line is an element of the resulting array.
       Compare this with the effect of $(<file) alone, which divides the file
       up by words, or the same inside double quotes, which makes the entire
       content of the file a single string.

       The following illustrates the rules for nested parameter expansions.
       Suppose that $foo contains the array (bar baz):

       "${(@)${foo}[1]}"
              This produces the result b.  First, the inner substitution
              "${foo}", which has no array (@) flag, produces a single word
              result "bar baz".  The outer substitution "${(@)...[1]}" detects
              that this is a scalar, so that (despite the `(@)' flag) the
              subscript picks the first character.

       "${${(@)foo}[1]}"
              This produces the result `bar'.  In this case, the inner
              substitution "${(@)foo}" produces the array `(bar baz)'.  The
              outer substitution "${...[1]}" detects that this is an array and
              picks the first word.  This is similar to the simple case
              "${foo[1]}".

       As an example of the rules for word splitting and joining, suppose $foo
       contains the array `(ax1 bx1)'.  Then

       ${(s/x/)foo}
              produces the words `a', `1 b' and `1'.

       ${(j/x/s/x/)foo}
              produces `a', `1', `b' and `1'.

       ${(s/x/)foo%%1*}
              produces `a' and ` b' (note the extra space).  As substitution
              occurs before either joining or splitting, the operation  first
              generates the modified array (ax bx), which is joined to give
              "ax bx", and then split to give `a', ` b' and `'.  The final
              empty string will then be elided, as it is not in double quotes.

COMMAND SUBSTITUTION
       A command enclosed in parentheses preceded by a dollar sign, like
       `$(...)', or quoted with grave accents, like ``...`', is replaced with
       its standard output, with any trailing newlines deleted.  If the
       substitution is not enclosed in double quotes, the output is broken
       into words using the IFS parameter.

       The substitution `$(cat foo)' may be replaced by the faster `$(<foo)'.
       In this case foo undergoes single word shell expansions (parameter
       expansion, command substitution and arithmetic expansion), but not
       filename generation.

       If the option GLOB_SUBST is set, the result of any unquoted command
       substitution, including the special form just mentioned, is eligible
       for filename generation.

ARITHMETIC EXPANSION
       A string of the form `$[exp]' or `$((exp))' is substituted with the
       value of the arithmetic expression exp.  exp is subjected to parameter
       expansion, command substitution and arithmetic expansion before it is
       evaluated.  See the section `Arithmetic Evaluation'.

BRACE EXPANSION
       A string of the form `foo{xx,yy,zz}bar' is expanded to the individual
       words `fooxxbar', `fooyybar' and `foozzbar'.  Left-to-right order is
       preserved.  This construct may be nested.  Commas may be quoted in
       order to include them literally in a word.

       An expression of the form `{n1..n2}', where n1 and n2 are integers, is
       expanded to every number between n1 and n2 inclusive.  If either number
       begins with a zero, all the resulting numbers will be padded with
       leading zeroes to that minimum width, but for negative numbers the -
       character is also included in the width.  If the numbers are in
       decreasing order the resulting sequence will also be in decreasing
       order.

       An expression of the form `{n1..n2..n3}', where n1, n2, and n3 are
       integers, is expanded as above, but only every n3th number starting
       from n1 is output.  If n3 is negative the numbers are output in reverse
       order, this is slightly different from simply swapping n1 and n2 in the
       case that the step n3 doesn't evenly divide the range.  Zero padding
       can be specified in any of the three numbers, specifying it in the
       third can be useful to pad for example `{-99..100..01}' which is not
       possible to specify by putting a 0 on either of the first two numbers
       (i.e. pad to two characters).

       An expression of the form `{c1..c2}', where c1 and c2 are single
       characters (which may be multibyte characters), is expanded to every
       character in the range from c1 to c2 in whatever character sequence is
       used internally.  For characters with code points below 128 this is US
       ASCII (this is the only case most users will need).  If any intervening
       character is not printable, appropriate quotation is used to render it
       printable.  If the character sequence is reversed, the output is in
       reverse order, e.g. `{d..a}' is substituted as `d c b a'.

       If a brace expression matches none of the above forms, it is left
       unchanged, unless the option BRACE_CCL (an abbreviation for `brace
       character class') is set.  In that case, it is expanded to a list of
       the individual characters between the braces sorted into the order of
       the characters in the ASCII character set (multibyte characters are not
       currently handled).  The syntax is similar to a [...] expression in
       filename generation: `-' is treated specially to denote a range of
       characters, but `^' or `!' as the first character is treated normally.
       For example, `{abcdef0-9}' expands to 16 words 0 1 2 3 4 5 6 7 8 9 a b
       c d e f.

       Note that brace expansion is not part of filename generation
       (globbing); an expression such as */{foo,bar} is split into two
       separate words */foo and */bar before filename generation takes place.
       In particular, note that this is liable to produce a `no match' error
       if either of the two expressions does not match; this is to be
       contrasted with */(foo|bar), which is treated as a single pattern but
       otherwise has similar effects.

       To combine brace expansion with array expansion, see the ${^spec} form
       described in the section Parameter Expansion above.

FILENAME EXPANSION
       Each word is checked to see if it begins with an unquoted `~'.  If it
       does, then the word up to a `/', or the end of the word if there is no
       `/', is checked to see if it can be substituted in one of the ways
       described here.  If so, then the `~' and the checked portion are
       replaced with the appropriate substitute value.

       A `~' by itself is replaced by the value of $HOME.  A `~' followed by a
       `+' or a `-' is replaced by current or previous working directory,
       respectively.

       A `~' followed by a number is replaced by the directory at that
       position in the directory stack.  `~0' is equivalent to `~+', and `~1'
       is the top of the stack.  `~+' followed by a number is replaced by the
       directory at that position in the directory stack.  `~+0' is equivalent
       to `~+', and `~+1' is the top of the stack.  `~-' followed by a number
       is replaced by the directory that many positions from the bottom of the
       stack.  `~-0' is the bottom of the stack.  The PUSHD_MINUS option
       exchanges the effects of `~+' and `~-' where they are followed by a
       number.

   Dynamic named directories
       If the function zsh_directory_name exists, or the shell variable
       zsh_directory_name_functions exists and contains an array of function
       names, then the functions are used to implement dynamic directory
       naming.  The functions are tried in order until one returns status
       zero, so it is important that functions test whether they can handle
       the case in question and return an appropriate status.

       A `~' followed by a string namstr in unquoted square brackets is
       treated specially as a dynamic directory name.  Note that the first
       unquoted closing square bracket always terminates namstr.  The shell
       function is passed two arguments: the string n (for name) and namstr.
       It should either set the array reply to a single element which is the
       directory corresponding to the name and return status zero (executing
       an assignment as the last statement is usually sufficient), or it
       should return status non-zero.  In the former case the element of reply
       is used as the directory; in the latter case the substitution is deemed
       to have failed.  If all functions fail and the option NOMATCH is set,
       an error results.

       The functions defined as above are also used to see if a directory can
       be turned into a name, for example when printing the directory stack or
       when expanding %~ in prompts.  In this case each function is passed two
       arguments: the string d (for directory) and the candidate for dynamic
       naming.  The function should either return non-zero status, if the
       directory cannot be named by the function, or it should set the array
       reply to consist of two elements: the first is the dynamic name for the
       directory (as would appear within `~[...]'), and the second is the
       prefix length of the directory to be replaced.  For example, if the
       trial directory is /home/myname/src/zsh and the dynamic name for
       /home/myname/src (which has 16 characters) is s, then the function sets

              reply=(s 16)

       The directory name so returned is compared with possible static names
       for parts of the directory path, as described below; it is used if the
       prefix length matched (16 in the example) is longer than that matched
       by any static name.

       It is not a requirement that a function implements both n and d calls;
       for example, it might be appropriate for certain dynamic forms of
       expansion not to be contracted to names.  In that case any call with
       the first argument d should cause a non-zero status to be returned.

       The completion system calls `zsh_directory_name c' followed by
       equivalent calls to elements of the array zsh_directory_name_functions,
       if it exists, in order to complete dynamic names for directories.  The
       code for this should be as for any other completion function as
       described in zshcompsys(1).

       As a working example, here is a function that expands any dynamic names
       beginning with the string p: to directories below /home/pws/perforce.
       In this simple case a static name for the directory would be just as
       effective.

              zsh_directory_name() {
                emulate -L zsh
                setopt extendedglob
                local -a match mbegin mend
                if [[ $1 = d ]]; then
                  # turn the directory into a name
                  if [[ $2 = (#b)(/home/pws/perforce/)([^/]##)* ]]; then
                    typeset -ga reply
                    reply=(p:$match[2] $(( ${#match[1]} + ${#match[2]} )) )
                  else
                    return 1
                  fi
                elif [[ $1 = n ]]; then
                  # turn the name into a directory
                  [[ $2 != (#b)p:(?*) ]] && return 1
                  typeset -ga reply
                  reply=(/home/pws/perforce/$match[1])
                elif [[ $1 = c ]]; then
                  # complete names
                  local expl
                  local -a dirs
                  dirs=(/home/pws/perforce/*(/:t))
                  dirs=(p:${^dirs})
                  _wanted dynamic-dirs expl 'dynamic directory' compadd -S\] -a dirs
                  return
                else
                  return 1
                fi
                return 0
              }

   Static named directories
       A `~' followed by anything not already covered consisting of any number
       of alphanumeric characters or underscore (`_'), hyphen (`-'), or dot
       (`.') is looked up as a named directory, and replaced by the value of
       that named directory if found.  Named directories are typically home
       directories for users on the system.  They may also be defined if the
       text after the `~' is the name of a string shell parameter whose value
       begins with a `/'.  Note that trailing slashes will be removed from the
       path to the directory (though the original parameter is not modified).

       It is also possible to define directory names using the -d option to
       the hash builtin.

       When the shell prints a path (e.g. when expanding %~ in prompts or when
       printing the directory stack), the path is checked to see if it has a
       named directory as its prefix.  If so, then the prefix portion is
       replaced with a `~' followed by the name of the directory.  The shorter
       of the two ways of referring to the directory is used, i.e. either the
       directory name or the full path; the name is used if they are the same
       length.  The parameters $PWD and $OLDPWD are never abbreviated in this
       fashion.

   `=' expansion
       If a word begins with an unquoted `=' and the EQUALS option is set, the
       remainder of the word is taken as the name of a command.  If a command
       exists by that name, the word is replaced by the full pathname of the
       command.

   Notes
       Filename expansion is performed on the right hand side of a parameter
       assignment, including those appearing after commands of the typeset
       family.  In this case, the right hand side will be treated as a
       colon-separated list in the manner of the PATH parameter, so that a `~'
       or an `=' following a `:' is eligible for expansion.  All such
       behaviour can be disabled by quoting the `~', the `=', or the whole
       expression (but not simply the colon); the EQUALS option is also
       respected.

       If the option MAGIC_EQUAL_SUBST is set, any unquoted shell argument in
       the form `identifier=expression' becomes eligible for file expansion as
       described in the previous paragraph.  Quoting the first `=' also
       inhibits this.

FILENAME GENERATION
       If a word contains an unquoted instance of one of the characters `*',
       `(', `|', `<', `[', or `?', it is regarded as a pattern for filename
       generation, unless the GLOB option is unset.  If the EXTENDED_GLOB
       option is set, the `^' and `#' characters also denote a pattern;
       otherwise they are not treated specially by the shell.

       The word is replaced with a list of sorted filenames that match the
       pattern.  If no matching pattern is found, the shell gives an error
       message, unless the NULL_GLOB option is set, in which case the word is
       deleted; or unless the NOMATCH option is unset, in which case the word
       is left unchanged.

       In filename generation, the character `/' must be matched explicitly;
       also, a `.' must be matched explicitly at the beginning of a pattern or
       after a `/', unless the GLOB_DOTS option is set.  No filename
       generation pattern matches the files `.' or `..'.  In other instances
       of pattern matching, the `/' and `.' are not treated specially.

   Glob Operators
       *      Matches any string, including the null string.

       ?      Matches any character.

       [...]  Matches any of the enclosed characters.  Ranges of characters
              can be specified by separating two characters by a `-'.  A `-'
              or `]' may be matched by including it as the first character in
              the list.  There are also several named classes of characters,
              in the form `[:name:]' with the following meanings.  The first
              set use the macros provided by the operating system to test for
              the given character combinations, including any modifications
              due to local language settings, see ctype(3):

              [:alnum:]
                     The character is alphanumeric

              [:alpha:]
                     The character is alphabetic

              [:ascii:]
                     The character is 7-bit, i.e. is a single-byte character
                     without the top bit set.

              [:blank:]
                     The character is a blank character

              [:cntrl:]
                     The character is a control character

              [:digit:]
                     The character is a decimal digit

              [:graph:]
                     The character is a printable character other than
                     whitespace

              [:lower:]
                     The character is a lowercase letter

              [:print:]
                     The character is printable

              [:punct:]
                     The character is printable but neither alphanumeric nor
                     whitespace

              [:space:]
                     The character is whitespace

              [:upper:]
                     The character is an uppercase letter

              [:xdigit:]
                     The character is a hexadecimal digit

              Another set of named classes is handled internally by the shell
              and is not sensitive to the locale:

              [:IDENT:]
                     The character is allowed to form part of a shell
                     identifier, such as a parameter name

              [:IFS:]
                     The character is used as an input field separator, i.e.
                     is contained in the IFS parameter

              [:IFSSPACE:]
                     The character is an IFS white space character; see the
                     documentation for IFS in the zshparam(1) manual page.

              [:INCOMPLETE:]
                     Matches a byte that starts an incomplete multibyte
                     character.  Note that there may be a sequence of more
                     than one bytes that taken together form the prefix of a
                     multibyte character.  To test for a potentially
                     incomplete byte sequence, use the pattern
                     `[[:INCOMPLETE:]]*'.  This will never match a sequence
                     starting with a valid multibyte character.

              [:INVALID:]
                     Matches a byte that does not start a valid multibyte
                     character.  Note this may be a continuation byte of an
                     incomplete multibyte character as any part of a multibyte
                     string consisting of invalid and incomplete multibyte
                     characters is treated as single bytes.

              [:WORD:]
                     The character is treated as part of a word; this test is
                     sensitive to the value of the WORDCHARS parameter

              Note that the square brackets are additional to those enclosing
              the whole set of characters, so to test for a single
              alphanumeric character you need `[[:alnum:]]'.  Named character
              sets can be used alongside other types, e.g. `[[:alpha:]0-9]'.

       [^...]
       [!...] Like [...], except that it matches any character which is not in
              the given set.

       <[x]-[y]>
              Matches any number in the range x to y, inclusive.  Either of
              the numbers may be omitted to make the range open-ended; hence
              `<->' matches any number.  To match individual digits, the [...]
              form is more efficient.

              Be careful when using other wildcards adjacent to patterns of
              this form; for example, <0-9>* will actually match any number
              whatsoever at the start of the string, since the `<0-9>' will
              match the first digit, and the `*' will match any others.  This
              is a trap for the unwary, but is in fact an inevitable
              consequence of the rule that the longest possible match always
              succeeds.  Expressions such as `<0-9>[^[:digit:]]*' can be used
              instead.

       (...)  Matches the enclosed pattern.  This is used for grouping.  If
              the KSH_GLOB option is set, then a `@', `*', `+', `?' or `!'
              immediately preceding the `(' is treated specially, as detailed
              below. The option SH_GLOB prevents bare parentheses from being
              used in this way, though the KSH_GLOB option is still available.

              Note that grouping cannot extend over multiple directories: it
              is an error to have a `/' within a group (this only applies for
              patterns used in filename generation).  There is one exception:
              a group of the form (pat/)# appearing as a complete path segment
              can match a sequence of directories.  For example, foo/(a*/)#bar
              matches foo/bar, foo/any/bar, foo/any/anyother/bar, and so on.

       x|y    Matches either x or y.  This operator has lower precedence than
              any other.  The `|' character must be within parentheses, to
              avoid interpretation as a pipeline.  The alternatives are tried
              in order from left to right.

       ^x     (Requires EXTENDED_GLOB to be set.)  Matches anything except the
              pattern x.  This has a higher precedence than `/', so `^foo/bar'
              will search directories in `.' except `./foo' for a file named
              `bar'.

       x~y    (Requires EXTENDED_GLOB to be set.)  Match anything that matches
              the pattern x but does not match y.  This has lower precedence
              than any operator except `|', so `*/*~foo/bar' will search for
              all files in all directories in `.'  and then exclude `foo/bar'
              if there was such a match.  Multiple patterns can be excluded by
              `foo~bar~baz'.  In the exclusion pattern (y), `/' and `.' are
              not treated specially the way they usually are in globbing.

       x#     (Requires EXTENDED_GLOB to be set.)  Matches zero or more
              occurrences of the pattern x.  This operator has high
              precedence; `12#' is equivalent to `1(2#)', rather than `(12)#'.
              It is an error for an unquoted `#' to follow something which
              cannot be repeated; this includes an empty string, a pattern
              already followed by `##', or parentheses when part of a KSH_GLOB
              pattern (for example, `!(foo)#' is invalid and must be replaced
              by `*(!(foo))').

       x##    (Requires EXTENDED_GLOB to be set.)  Matches one or more
              occurrences of the pattern x.  This operator has high
              precedence; `12##' is equivalent to `1(2##)', rather than
              `(12)##'.  No more than two active `#' characters may appear
              together.  (Note the potential clash with glob qualifiers in the
              form `1(2##)' which should therefore be avoided.)

   ksh-like Glob Operators
       If the KSH_GLOB option is set, the effects of parentheses can be
       modified by a preceding `@', `*', `+', `?' or `!'.  This character need
       not be unquoted to have special effects, but the `(' must be.

       @(...) Match the pattern in the parentheses.  (Like `(...)'.)

       *(...) Match any number of occurrences.  (Like `(...)#', except that
              recursive directory searching is not supported.)

       +(...) Match at least one occurrence.  (Like `(...)##', except that
              recursive directory searching is not supported.)

       ?(...) Match zero or one occurrence.  (Like `(|...)'.)

       !(...) Match anything but the expression in parentheses.  (Like
              `(^(...))'.)

   Precedence
       The precedence of the operators given above is (highest) `^', `/', `~',
       `|' (lowest); the remaining operators are simply treated from left to
       right as part of a string, with `#' and `##' applying to the shortest
       possible preceding unit (i.e. a character, `?', `[...]', `<...>', or a
       parenthesised expression).  As mentioned above, a `/' used as a
       directory separator may not appear inside parentheses, while a `|' must
       do so; in patterns used in other contexts than filename generation (for
       example, in case statements and tests within `[[...]]'), a `/' is not
       special; and `/' is also not special after a `~' appearing outside
       parentheses in a filename pattern.

   Globbing Flags
       There are various flags which affect any text to their right up to the
       end of the enclosing group or to the end of the pattern; they require
       the EXTENDED_GLOB option. All take the form (#X) where X may have one
       of the following forms:

       i      Case insensitive:  upper or lower case characters in the pattern
              match upper or lower case characters.

       l      Lower case characters in the pattern match upper or lower case
              characters; upper case characters in the pattern still only
              match upper case characters.

       I      Case sensitive:  locally negates the effect of i or l from that
              point on.

       b      Activate backreferences for parenthesised groups in the pattern;
              this does not work in filename generation.  When a pattern with
              a set of active parentheses is matched, the strings matched by
              the groups are stored in the array $match, the indices of the
              beginning of the matched parentheses in the array $mbegin, and
              the indices of the end in the array $mend, with the first
              element of each array corresponding to the first parenthesised
              group, and so on.  These arrays are not otherwise special to the
              shell.  The indices use the same convention as does parameter
              substitution, so that elements of $mend and $mbegin may be used
              in subscripts; the KSH_ARRAYS option is respected.  Sets of
              globbing flags are not considered parenthesised groups; only the
              first nine active parentheses can be referenced.

              For example,

                     foo="a_string_with_a_message"
                     if [[ $foo = (a|an)_(#b)(*) ]]; then
                       print ${foo[$mbegin[1],$mend[1]]}
                     fi

              prints `string_with_a_message'.  Note that the first set of
              parentheses is before the (#b) and does not create a
              backreference.

              Backreferences work with all forms of pattern matching other
              than filename generation, but note that when performing matches
              on an entire array, such as ${array#pattern}, or a global
              substitution, such as ${param//pat/repl}, only the data for the
              last match remains available.  In the case of global
              replacements this may still be useful.  See the example for the
              m flag below.

              The numbering of backreferences strictly follows the order of
              the opening parentheses from left to right in the pattern
              string, although sets of parentheses may be nested.  There are
              special rules for parentheses followed by `#' or `##'.  Only the
              last match of the parenthesis is remembered: for example, in `[[
              abab = (#b)([ab])# ]]', only the final `b' is stored in
              match[1].  Thus extra parentheses may be necessary to match the
              complete segment: for example, use `X((ab|cd)#)Y' to match a
              whole string of either `ab' or `cd' between `X' and `Y', using
              the value of $match[1] rather than $match[2].

              If the match fails none of the parameters is altered, so in some
              cases it may be necessary to initialise them beforehand.  If
              some of the backreferences fail to match -- which happens if
              they are in an alternate branch which fails to match, or if they
              are followed by # and matched zero times -- then the matched
              string is set to the empty string, and the start and end indices
              are set to -1.

              Pattern matching with backreferences is slightly slower than
              without.

       B      Deactivate backreferences, negating the effect of the b flag
              from that point on.

       cN,M   The flag (#cN,M) can be used anywhere that the # or ## operators
              can be used except in the expressions `(*/)#' and `(*/)##' in
              filename generation, where `/' has special meaning; it cannot be
              combined with other globbing flags and a bad pattern error
              occurs if it is misplaced.  It is equivalent to the form {N,M}
              in regular expressions.  The previous character or group is
              required to match between N and M times, inclusive.  The form
              (#cN) requires exactly N matches; (#c,M) is equivalent to
              specifying N as 0; (#cN,) specifies that there is no maximum
              limit on the number of matches.

       m      Set references to the match data for the entire string matched;
              this is similar to backreferencing and does not work in filename
              generation.  The flag must be in effect at the end of the
              pattern, i.e. not local to a group. The parameters $MATCH,
              $MBEGIN and $MEND will be set to the string matched and to the
              indices of the beginning and end of the string, respectively.
              This is most useful in parameter substitutions, as otherwise the
              string matched is obvious.

              For example,

                     arr=(veldt jynx grimps waqf zho buck)
                     print ${arr//(#m)[aeiou]/${(U)MATCH}}

              forces all the matches (i.e. all vowels) into uppercase,
              printing `vEldt jynx grImps wAqf zhO bUck'.

              Unlike backreferences, there is no speed penalty for using match
              references, other than the extra substitutions required for the
              replacement strings in cases such as the example shown.

       M      Deactivate the m flag, hence no references to match data will be
              created.

       anum   Approximate matching: num errors are allowed in the string
              matched by the pattern.  The rules for this are described in the
              next subsection.

       s, e   Unlike the other flags, these have only a local effect, and each
              must appear on its own:  `(#s)' and `(#e)' are the only valid
              forms.  The `(#s)' flag succeeds only at the start of the test
              string, and the `(#e)' flag succeeds only at the end of the test
              string; they correspond to `^' and `$' in standard regular
              expressions.  They are useful for matching path segments in
              patterns other than those in filename generation (where path
              segments are in any case treated separately).  For example,
              `*((#s)|/)test((#e)|/)*' matches a path segment `test' in any of
              the following strings: test, test/at/start, at/end/test,
              in/test/middle.

              Another use is in parameter substitution; for example
              `${array/(#s)A*Z(#e)}' will remove only elements of an array
              which match the complete pattern `A*Z'.  There are other ways of
              performing many operations of this type, however the combination
              of the substitution operations `/' and `//' with the `(#s)' and
              `(#e)' flags provides a single simple and memorable method.

              Note that assertions of the form `(^(#s))' also work, i.e. match
              anywhere except at the start of the string, although this
              actually means `anything except a zero-length portion at the
              start of the string'; you need to use `(""~(#s))' to match a
              zero-length portion of the string not at the start.

       q      A `q' and everything up to the closing parenthesis of the
              globbing flags are ignored by the pattern matching code.  This
              is intended to support the use of glob qualifiers, see below.
              The result is that the pattern `(#b)(*).c(#q.)' can be used both
              for globbing and for matching against a string.  In the former
              case, the `(#q.)' will be treated as a glob qualifier and the
              `(#b)' will not be useful, while in the latter case the `(#b)'
              is useful for backreferences and the `(#q.)' will be ignored.
              Note that colon modifiers in the glob qualifiers are also not
              applied in ordinary pattern matching.

       u      Respect the current locale in determining the presence of
              multibyte characters in a pattern, provided the shell was
              compiled with MULTIBYTE_SUPPORT.  This overrides the MULTIBYTE
              option; the default behaviour is taken from the option.  Compare
              U.  (Mnemonic: typically multibyte characters are from Unicode
              in the UTF-8 encoding, although any extension of ASCII supported
              by the system library may be used.)

       U      All characters are considered to be a single byte long.  The
              opposite of u.  This overrides the MULTIBYTE option.

       For example, the test string fooxx can be matched by the pattern
       (#i)FOOXX, but not by (#l)FOOXX, (#i)FOO(#I)XX or ((#i)FOOX)X.  The
       string (#ia2)readme specifies case-insensitive matching of readme with
       up to two errors.

       When using the ksh syntax for grouping both KSH_GLOB and EXTENDED_GLOB
       must be set and the left parenthesis should be preceded by @.  Note
       also that the flags do not affect letters inside [...] groups, in other
       words (#i)[a-z] still matches only lowercase letters.  Finally, note
       that when examining whole paths case-insensitively every directory must
       be searched for all files which match, so that a pattern of the form
       (#i)/foo/bar/... is potentially slow.

   Approximate Matching
       When matching approximately, the shell keeps a count of the errors
       found, which cannot exceed the number specified in the (#anum) flags.
       Four types of error are recognised:

       1.     Different characters, as in fooxbar and fooybar.

       2.     Transposition of characters, as in banana and abnana.

       3.     A character missing in the target string, as with the pattern
              road and target string rod.

       4.     An extra character appearing in the target string, as with stove
              and strove.

       Thus, the pattern (#a3)abcd matches dcba, with the errors occurring by
       using the first rule twice and the second once, grouping the string as
       [d][cb][a] and [a][bc][d].

       Non-literal parts of the pattern must match exactly, including
       characters in character ranges: hence (#a1)???  matches strings of
       length four, by applying rule 4 to an empty part of the pattern, but
       not strings of length two, since all the ? must match.  Other
       characters which must match exactly are initial dots in filenames
       (unless the GLOB_DOTS option is set), and all slashes in filenames, so
       that a/bc is two errors from ab/c (the slash cannot be transposed with
       another character).  Similarly, errors are counted separately for
       non-contiguous strings in the pattern, so that (ab|cd)ef is two errors
       from aebf.

       When using exclusion via the ~ operator, approximate matching is
       treated entirely separately for the excluded part and must be activated
       separately.  Thus, (#a1)README~READ_ME matches READ.ME but not READ_ME,
       as the trailing READ_ME is matched without approximation.  However,
       (#a1)README~(#a1)READ_ME does not match any pattern of the form READ?ME
       as all such forms are now excluded.

       Apart from exclusions, there is only one overall error count; however,
       the maximum errors allowed may be altered locally, and this can be
       delimited by grouping.  For example, (#a1)cat((#a0)dog)fox allows one
       error in total, which may not occur in the dog section, and the pattern
       (#a1)cat(#a0)dog(#a1)fox is equivalent.  Note that the point at which
       an error is first found is the crucial one for establishing whether to
       use approximation; for example, (#a1)abc(#a0)xyz will not match
       abcdxyz, because the error occurs at the `x', where approximation is
       turned off.

       Entire path segments may be matched approximately, so that
       `(#a1)/foo/d/is/available/at/the/bar' allows one error in any path
       segment.  This is much less efficient than without the (#a1), however,
       since every directory in the path must be scanned for a possible
       approximate match.  It is best to place the (#a1) after any path
       segments which are known to be correct.

   Recursive Globbing
       A pathname component of the form `(foo/)#' matches a path consisting of
       zero or more directories matching the pattern foo.

       As a shorthand, `**/' is equivalent to `(*/)#'; note that this
       therefore matches files in the current directory as well as
       subdirectories.  Thus:

              ls -ld -- (*/)#bar

       or

              ls -ld -- **/bar

       does a recursive directory search for files named `bar' (potentially
       including the file `bar' in the current directory).  This form does not
       follow symbolic links; the alternative form `***/' does, but is
       otherwise identical.  Neither of these can be combined with other forms
       of globbing within the same path segment; in that case, the `*'
       operators revert to their usual effect.

       Even shorter forms are available when the option GLOB_STAR_SHORT is
       set.  In that case if no / immediately follows a ** or *** they are
       treated as if both a / plus a further * are present.  Hence:

              setopt GLOBSTARSHORT
              ls -ld -- **.c

       is equivalent to

              ls -ld -- **/*.c

   Glob Qualifiers
       Patterns used for filename generation may end in a list of qualifiers
       enclosed in parentheses.  The qualifiers specify which filenames that
       otherwise match the given pattern will be inserted in the argument
       list.

       If the option BARE_GLOB_QUAL is set, then a trailing set of parentheses
       containing no `|' or `(' characters (or `~' if it is special) is taken
       as a set of glob qualifiers.  A glob subexpression that would normally
       be taken as glob qualifiers, for example `(^x)', can be forced to be
       treated as part of the glob pattern by doubling the parentheses, in
       this case producing `((^x))'.

       If the option EXTENDED_GLOB is set, a different syntax for glob
       qualifiers is available, namely `(#qx)' where x is any of the same glob
       qualifiers used in the other format.  The qualifiers must still appear
       at the end of the pattern.  However, with this syntax multiple glob
       qualifiers may be chained together.  They are treated as a logical AND
       of the individual sets of flags.  Also, as the syntax is unambiguous,
       the expression will be treated as glob qualifiers just as long any
       parentheses contained within it are balanced; appearance of `|', `(' or
       `~' does not negate the effect.  Note that qualifiers will be
       recognised in this form even if a bare glob qualifier exists at the end
       of the pattern, for example `*(#q*)(.)' will recognise executable
       regular files if both options are set; however, mixed syntax should
       probably be avoided for the sake of clarity.  Note that within
       conditions using the `[[' form the presence of a parenthesised
       expression (#q...) at the end of a string indicates that globbing
       should be performed; the expression may include glob qualifiers, but it
       is also valid if it is simply (#q).  This does not apply to the right
       hand side of pattern match operators as the syntax already has special
       significance.

       A qualifier may be any one of the following:

       /      directories

       F      `full' (i.e. non-empty) directories.  Note that the opposite
              sense (^F) expands to empty directories and all non-directories.
              Use (/^F) for empty directories.

       .      plain files

       @      symbolic links

       =      sockets

       p      named pipes (FIFOs)

       *      executable plain files (0100 or 0010 or 0001)

       %      device files (character or block special)

       %b     block special files

       %c     character special files

       r      owner-readable files (0400)

       w      owner-writable files (0200)

       x      owner-executable files (0100)

       A      group-readable files (0040)

       I      group-writable files (0020)

       E      group-executable files (0010)

       R      world-readable files (0004)

       W      world-writable files (0002)

       X      world-executable files (0001)

       s      setuid files (04000)

       S      setgid files (02000)

       t      files with the sticky bit (01000)

       fspec  files with access rights matching spec. This spec may be a octal
              number optionally preceded by a `=', a `+', or a `-'. If none of
              these characters is given, the behavior is the same as for `='.
              The octal number describes the mode bits to be expected, if
              combined with a `=', the value given must match the file-modes
              exactly, with a `+', at least the bits in the given number must
              be set in the file-modes, and with a `-', the bits in the number
              must not be set. Giving a `?' instead of a octal digit anywhere
              in the number ensures that the corresponding bits in the
              file-modes are not checked, this is only useful in combination
              with `='.

              If the qualifier `f' is followed by any other character anything
              up to the next matching character (`[', `{', and `<' match `]',
              `}', and `>' respectively, any other character matches itself)
              is taken as a list of comma-separated sub-specs. Each sub-spec
              may be either an octal number as described above or a list of
              any of the characters `u', `g', `o', and `a', followed by a `=',
              a `+', or a `-', followed by a list of any of the characters
              `r', `w', `x', `s', and `t', or an octal digit. The first list
              of characters specify which access rights are to be checked. If
              a `u' is given, those for the owner of the file are used, if a
              `g' is given, those of the group are checked, a `o' means to
              test those of other users, and the `a' says to test all three
              groups. The `=', `+', and `-' again says how the modes are to be
              checked and have the same meaning as described for the first
              form above. The second list of characters finally says which
              access rights are to be expected: `r' for read access, `w' for
              write access, `x' for the right to execute the file (or to
              search a directory), `s' for the setuid and setgid bits, and `t'
              for the sticky bit.

              Thus, `*(f70?)' gives the files for which the owner has read,
              write, and execute permission, and for which other group members
              have no rights, independent of the permissions for other users.
              The pattern `*(f-100)' gives all files for which the owner does
              not have execute permission, and `*(f:gu+w,o-rx:)' gives the
              files for which the owner and the other members of the group
              have at least write permission, and for which other users don't
              have read or execute permission.

       estring
       +cmd   The string will be executed as shell code.  The filename will be
              included in the list if and only if the code returns a zero
              status (usually the status of the last command).

              In the first form, the first character after the `e' will be
              used as a separator and anything up to the next matching
              separator will be taken  as the string; `[', `{', and `<' match
              `]', `}', and `>', respectively, while any other character
              matches itself. Note that expansions must be quoted in the
              string to prevent them from being expanded before globbing is
              done.  string is then executed as shell code.  The string
              globqual is appended to the array zsh_eval_context the duration
              of execution.

              During the execution of string the filename currently being
              tested is available in the parameter REPLY; the parameter may be
              altered to a string to be inserted into the list instead of the
              original filename.  In addition, the parameter reply may be set
              to an array or a string, which overrides the value of REPLY.  If
              set to an array, the latter is inserted into the command line
              word by word.

              For example, suppose a directory contains a single file
              `lonely'.  Then the expression `*(e:'reply=(${REPLY}{1,2})':)'
              will cause the words `lonely1' and `lonely2' to be inserted into
              the command line.  Note the quoting of string.

              The form +cmd has the same effect, but no delimiters appear
              around cmd.  Instead, cmd is taken as the longest sequence of
              characters following the + that are alphanumeric or underscore.
              Typically cmd will be the name of a shell function that contains
              the appropriate test.  For example,

                     nt() { [[ $REPLY -nt $NTREF ]] }
                     NTREF=reffile
                     ls -ld -- *(+nt)

              lists all files in the directory that have been modified more
              recently than reffile.

       ddev   files on the device dev

       l[-|+]ct
              files having a link count less than ct (-), greater than ct (+),
              or equal to ct

       U      files owned by the effective user ID

       G      files owned by the effective group ID

       uid    files owned by user ID id if that is a number.  Otherwise, id
              specifies a user name: the character after the `u' will be taken
              as a separator and the string between it and the next matching
              separator will be taken as a user name.  The starting separators
              `[', `{', and `<' match the final separators `]', `}', and `>',
              respectively; any other character matches itself.  The selected
              files are those owned by this user.  For example, `u:foo:' or
              `u[foo]' selects files owned by user `foo'.

       gid    like uid but with group IDs or names

       a[Mwhms][-|+]n
              files accessed exactly n days ago.  Files accessed within the
              last n days are selected using a negative value for n (-n).
              Files accessed more than n days ago are selected by a positive n
              value (+n).  Optional unit specifiers `M', `w', `h', `m' or `s'
              (e.g. `ah5') cause the check to be performed with months (of 30
              days), weeks, hours, minutes or seconds instead of days,
              respectively.  An explicit `d' for days is also allowed.

              Any fractional part of the difference between the access time
              and the current part in the appropriate units is ignored in the
              comparison.  For instance, `echo *(ah-5)' would echo files
              accessed within the last five hours, while `echo *(ah+5)' would
              echo files accessed at least six hours ago, as times strictly
              between five and six hours are treated as five hours.

       m[Mwhms][-|+]n
              like the file access qualifier, except that it uses the file
              modification time.

       c[Mwhms][-|+]n
              like the file access qualifier, except that it uses the file
              inode change time.

       L[+|-]n
              files less than n bytes (-), more than n bytes (+), or exactly n
              bytes in length.

              If this flag is directly followed by a size specifier `k' (`K'),
              `m' (`M'), or `p' (`P') (e.g. `Lk-50') the check is performed
              with kilobytes, megabytes, or blocks (of 512 bytes) instead.
              (On some systems additional specifiers are available for
              gigabytes, `g' or `G', and terabytes, `t' or `T'.) If a size
              specifier is used a file is regarded as "exactly" the size if
              the file size rounded up to the next unit is equal to the test
              size.  Hence `*(Lm1)' matches files from 1 byte up to 1 Megabyte
              inclusive.  Note also that the set of files "less than" the test
              size only includes files that would not match the equality test;
              hence `*(Lm-1)' only matches files of zero size.

       ^      negates all qualifiers following it

       -      toggles between making the qualifiers work on symbolic links
              (the default) and the files they point to

       M      sets the MARK_DIRS option for the current pattern

       T      appends a trailing qualifier mark to the filenames, analogous to
              the LIST_TYPES option, for the current pattern (overrides M)

       N      sets the NULL_GLOB option for the current pattern

       D      sets the GLOB_DOTS option for the current pattern

       n      sets the NUMERIC_GLOB_SORT option for the current pattern

       Yn     enables short-circuit mode: the pattern will expand to at most n
              filenames.  If more than n matches exist, only the first n
              matches in directory traversal order will be considered.

              Implies oN when no oc qualifier is used.

       oc     specifies how the names of the files should be sorted. If c is n
              they are sorted by name; if it is L they are sorted depending on
              the size (length) of the files; if l they are sorted by the
              number of links; if a, m, or c they are sorted by the time of
              the last access, modification, or inode change respectively; if
              d, files in subdirectories appear before those in the current
              directory at each level of the search -- this is best combined
              with other criteria, for example `odon' to sort on names for
              files within the same directory; if N, no sorting is performed.
              Note that a, m, and c compare the age against the current time,
              hence the first name in the list is the youngest file. Also note
              that the modifiers ^ and - are used, so `*(^-oL)' gives a list
              of all files sorted by file size in descending order, following
              any symbolic links.  Unless oN is used, multiple order
              specifiers may occur to resolve ties.

              The default sorting is n (by name) unless the Y glob qualifier
              is used, in which case it is N (unsorted).

              oe and o+ are special cases; they are each followed by shell
              code, delimited as for the e glob qualifier and the + glob
              qualifier respectively (see above).  The code is executed for
              each matched file with the parameter REPLY set to the name of
              the file on entry and globsort appended to zsh_eval_context.
              The code should modify the parameter REPLY in some fashion.  On
              return, the value of the parameter is used instead of the file
              name as the string on which to sort.  Unlike other sort
              operators, oe and o+ may be repeated, but note that the maximum
              number of sort operators of any kind that may appear in any glob
              expression is 12.

       Oc     like `o', but sorts in descending order; i.e. `*(^oc)' is the
              same as `*(Oc)' and `*(^Oc)' is the same as `*(oc)'; `Od' puts
              files in the current directory before those in subdirectories at
              each level of the search.

       [beg[,end]]
              specifies which of the matched filenames should be included in
              the returned list. The syntax is the same as for array
              subscripts. beg and the optional end may be mathematical
              expressions. As in parameter subscripting they may be negative
              to make them count from the last match backward. E.g.:
              `*(-OL[1,3])' gives a list of the names of the three largest
              files.

       Pstring
              The string will be prepended to each glob match as a separate
              word.  string is delimited in the same way as arguments to the e
              glob qualifier described above.  The qualifier can be repeated;
              the words are prepended separately so that the resulting command
              line contains the words in the same order they were given in the
              list of glob qualifiers.

              A typical use for this is to prepend an option before all
              occurrences of a file name; for example, the pattern `*(P:-f:)'
              produces the command line arguments `-f file1 -f file2 ...'

              If the modifier ^ is active, then string will be appended
              instead of prepended.  Prepending and appending is done
              independently so both can be used on the same glob expression;
              for example by writing `*(P:foo:^P:bar:^P:baz:)' which produces
              the command line arguments `foo baz file1 bar ...'

       More than one of these lists can be combined, separated by commas. The
       whole list matches if at least one of the sublists matches (they are
       `or'ed, the qualifiers in the sublists are `and'ed).  Some qualifiers,
       however, affect all matches generated, independent of the sublist in
       which they are given.  These are the qualifiers `M', `T', `N', `D',
       `n', `o', `O' and the subscripts given in brackets (`[...]').

       If a `:' appears in a qualifier list, the remainder of the expression
       in parenthesis is interpreted as a modifier (see the section
       `Modifiers' in the section `History Expansion').  Each modifier must be
       introduced by a separate `:'.  Note also that the result after
       modification does not have to be an existing file.  The name of any
       existing file can be followed by a modifier of the form `(:...)' even
       if no actual filename generation is performed, although note that the
       presence of the parentheses causes the entire expression to be
       subjected to any global pattern matching options such as NULL_GLOB.
       Thus:

              ls -ld -- *(-/)

       lists all directories and symbolic links that point to directories, and

              ls -ld -- *(-@)

       lists all broken symbolic links, and

              ls -ld -- *(%W)

       lists all world-writable device files in the current directory, and

              ls -ld -- *(W,X)

       lists all files in the current directory that are world-writable or
       world-executable, and

              print -rC1 /tmp/foo*(u0^@:t)

       outputs the basename of all root-owned files beginning with the string
       `foo' in /tmp, ignoring symlinks, and

              ls -ld -- *.*~(lex|parse).[ch](^D^l1)

       lists all files having a link count of one whose names contain a dot
       (but not those starting with a dot, since GLOB_DOTS is explicitly
       switched off) except for lex.c, lex.h, parse.c and parse.h.

              print -rC1 b*.pro(#q:s/pro/shmo/)(#q.:s/builtin/shmiltin/)

       demonstrates how colon modifiers and other qualifiers may be chained
       together.  The ordinary qualifier `.' is applied first, then the colon
       modifiers in order from left to right.  So if EXTENDED_GLOB is set and
       the base pattern matches the regular file builtin.pro, the shell will
       print `shmiltin.shmo'.




ZSHPARAM(1)                 General Commands Manual                ZSHPARAM(1)



NAME
       zshparam - zsh parameters

DESCRIPTION
       A parameter has a name, a value, and a number of attributes.  A name
       may be any sequence of alphanumeric characters and underscores, or the
       single characters `*', `@', `#', `?', `-', `$', or `!'.  A parameter
       whose name begins with an alphanumeric or underscore is also referred
       to as a variable.

       The attributes of a parameter determine the type of its value, often
       referred to as the parameter type or variable type, and also control
       other processing that may be applied to the value when it is
       referenced.  The value type may be a scalar (a string, an integer, or a
       floating point number), an array (indexed numerically), or an
       associative array (an unordered set of name-value pairs, indexed by
       name, also referred to as a hash).

       Named scalar parameters may have the exported, -x, attribute, to copy
       them into the process environment, which is then passed from the shell
       to any new processes that it starts.  Exported parameters are called
       environment variables. The shell also imports environment variables at
       startup time and automatically marks the corresponding parameters as
       exported.  Some environment variables are not imported for reasons of
       security or because they would interfere with the correct operation of
       other shell features.

       Parameters may also be special, that is, they have a predetermined
       meaning to the shell.  Special parameters cannot have their type
       changed or their readonly attribute turned off, and if a special
       parameter is unset, then later recreated, the special properties will
       be retained.

       To declare the type of a parameter, or to assign a string or numeric
       value to a scalar parameter, use the typeset builtin.

       The value of a scalar parameter may also be assigned by writing:

              name=value

       In scalar assignment, value is expanded as a single string, in which
       the elements of arrays are joined together; filename expansion is not
       performed unless the option GLOB_ASSIGN is set.

       When the integer attribute, -i, or a floating point attribute, -E or
       -F, is set for name, the value is subject to arithmetic evaluation.
       Furthermore, by replacing `=' with `+=', a parameter can be incremented
       or appended to.  See the section `Array Parameters' and Arithmetic
       Evaluation (in zshmisc(1)) for additional forms of assignment.

       Note that assignment may implicitly change the attributes of a
       parameter.  For example, assigning a number to a variable in arithmetic
       evaluation may change its type to integer or float, and with
       GLOB_ASSIGN assigning a pattern to a variable may change its type to an
       array.

       To reference the value of a parameter, write `$name' or `${name}'.  See
       Parameter Expansion in zshexpn(1) for complete details.  That section
       also explains the effect of the difference between scalar and array
       assignment on parameter expansion.

ARRAY PARAMETERS
       To assign an array value, write one of:

              set -A name value ...
              name=(value ...)
              name=([key]=value ...)

       If no parameter name exists, an ordinary array parameter is created.
       If the parameter name exists and is a scalar, it is replaced by a new
       array.

       In the third form, key is an expression that will be evaluated in
       arithmetic context (in its simplest form, an integer) that gives the
       index of the element to be assigned with value.  In this form any
       elements not explicitly mentioned that come before the largest index to
       which a value is assigned are assigned an empty string.  The indices
       may be in any order.  Note that this syntax is strict: [ and ]= must
       not be quoted, and key may not consist of the unquoted string ]=, but
       is otherwise treated as a simple string.  The enhanced forms of
       subscript expression that may be used when directly subscripting a
       variable name, described in the section Array Subscripts below, are not
       available.

       The syntaxes with and without the explicit key may be mixed.  An
       implicit key is deduced by incrementing the index from the previously
       assigned element.  Note that it is not treated as an error if latter
       assignments in this form overwrite earlier assignments.

       For example, assuming the option KSH_ARRAYS is not set, the following:

              array=(one [3]=three four)

       causes the array variable array to contain four elements one, an empty
       string, three and four, in that order.

       In the forms where only value is specified, full command line expansion
       is performed.

       In the [key]=value form, both key and value undergo all forms of
       expansion allowed for single word shell expansions (this does not
       include filename generation); these are as performed by the parameter
       expansion flag (e) as described in zshexpn(1).  Nested parentheses may
       surround value and are included as part of the value, which is joined
       into a plain string; this differs from ksh which allows the values
       themselves to be arrays.  A future version of zsh may support that.  To
       cause the brackets to be interpreted as a character class for filename
       generation, and therefore to treat the resulting list of files as a set
       of values, quote the equal sign using any form of quoting.  Example:

              name=([a-z]'='*)

       To append to an array without changing the existing values, use one of
       the following:

              name+=(value ...)
              name+=([key]=value ...)

       In the second form key may specify an existing index as well as an
       index off the end of the old array; any existing value is overwritten
       by value.  Also, it is possible to use [key]+=value to append to the
       existing value at that index.

       Within the parentheses on the right hand side of either form of the
       assignment, newlines and semicolons are treated the same as white
       space, separating individual values.  Any consecutive sequence of such
       characters has the same effect.

       Ordinary array parameters may also be explicitly declared with:

              typeset -a name

       Associative arrays must be declared before assignment, by using:

              typeset -A name

       When name refers to an associative array, the list in an assignment is
       interpreted as alternating keys and values:

              set -A name key value ...
              name=(key value ...)
              name=([key]=value ...)

       Note that only one of the two syntaxes above may be used in any given
       assignment; the forms may not be mixed.  This is unlike the case of
       numerically indexed arrays.

       Every key must have a value in this case.  Note that this assigns to
       the entire array, deleting any elements that do not appear in the list.
       The append syntax may also be used with an associative array:

              name+=(key value ...)
              name+=([key]=value ...)

       This adds a new key/value pair if the key is not already present, and
       replaces the value for the existing key if it is.  In the second form
       it is also possible to use [key]+=value to append to the existing value
       at that key.  Expansion is performed identically to the corresponding
       forms for normal arrays, as described above.

       To create an empty array (including associative arrays), use one of:

              set -A name
              name=()

   Array Subscripts
       Individual elements of an array may be selected using a subscript.  A
       subscript of the form `[exp]' selects the single element exp, where exp
       is an arithmetic expression which will be subject to arithmetic
       expansion as if it were surrounded by `$((...))'.  The elements are
       numbered beginning with 1, unless the KSH_ARRAYS option is set in which
       case they are numbered from zero.

       Subscripts may be used inside braces used to delimit a parameter name,
       thus `${foo[2]}' is equivalent to `$foo[2]'.  If the KSH_ARRAYS option
       is set, the braced form is the only one that works, as bracketed
       expressions otherwise are not treated as subscripts.

       If the KSH_ARRAYS option is not set, then by default accesses to an
       array element with a subscript that evaluates to zero return an empty
       string, while an attempt to write such an element is treated as an
       error.  For backward compatibility the KSH_ZERO_SUBSCRIPT option can be
       set to cause subscript values 0 and 1 to be equivalent; see the
       description of the option in zshoptions(1).

       The same subscripting syntax is used for associative arrays, except
       that no arithmetic expansion is applied to exp.  However, the parsing
       rules for arithmetic expressions still apply, which affects the way
       that certain special characters must be protected from interpretation.
       See Subscript Parsing below for details.

       A subscript of the form `[*]' or `[@]' evaluates to all elements of an
       array; there is no difference between the two except when they appear
       within double quotes.  `"$foo[*]"' evaluates to `"$foo[1] $foo[2]
       ..."', whereas `"$foo[@]"' evaluates to `"$foo[1]" "$foo[2]" ...'.  For
       associative arrays, `[*]' or `[@]' evaluate to all the values, in no
       particular order.  Note that this does not substitute the keys; see the
       documentation for the `k' flag under Parameter Expansion Flags in
       zshexpn(1) for complete details.  When an array parameter is referenced
       as `$name' (with no subscript) it evaluates to `$name[*]', unless the
       KSH_ARRAYS option is set in which case it evaluates to `${name[0]}'
       (for an associative array, this means the value of the key `0', which
       may not exist even if there are values for other keys).

       A subscript of the form `[exp1,exp2]' selects all elements in the range
       exp1 to exp2, inclusive. (Associative arrays are unordered, and so do
       not support ranges.) If one of the subscripts evaluates to a negative
       number, say -n, then the nth element from the end of the array is used.
       Thus `$foo[-3]' is the third element from the end of the array foo, and
       `$foo[1,-1]' is the same as `$foo[*]'.

       Subscripting may also be performed on non-array values, in which case
       the subscripts specify a substring to be extracted.  For example, if
       FOO is set to `foobar', then `echo $FOO[2,5]' prints `ooba'.  Note that
       some forms of subscripting described below perform pattern matching,
       and in that case the substring extends from the start of the match of
       the first subscript to the end of the match of the second subscript.
       For example,

              string="abcdefghijklm"
              print ${string[(r)d?,(r)h?]}

       prints `defghi'.  This is an obvious generalisation of the rule for
       single-character matches.  For a single subscript, only a single
       character is referenced (not the range of characters covered by the
       match).

       Note that in substring operations the second subscript is handled
       differently by the r and R subscript flags: the former takes the
       shortest match as the length and the latter the longest match.  Hence
       in the former case a * at the end is redundant while in the latter case
       it matches the whole remainder of the string.  This does not affect the
       result of the single subscript case as here the length of the match is
       irrelevant.

   Array Element Assignment
       A subscript may be used on the left side of an assignment like so:

              name[exp]=value

       In this form of assignment the element or range specified by exp is
       replaced by the expression on the right side.  An array (but not an
       associative array) may be created by assignment to a range or element.
       Arrays do not nest, so assigning a parenthesized list of values to an
       element or range changes the number of elements in the array, shifting
       the other elements to accommodate the new values.  (This is not
       supported for associative arrays.)

       This syntax also works as an argument to the typeset command:

              typeset "name[exp]"=value

       The value may not be a parenthesized list in this case; only
       single-element assignments may be made with typeset.  Note that quotes
       are necessary in this case to prevent the brackets from being
       interpreted as filename generation operators.  The noglob precommand
       modifier could be used instead.

       To delete an element of an ordinary array, assign `()' to that element.
       To delete an element of an associative array, use the unset command:

              unset "name[exp]"

   Subscript Flags
       If the opening bracket, or the comma in a range, in any subscript
       expression is directly followed by an opening parenthesis, the string
       up to the matching closing one is considered to be a list of flags, as
       in `name[(flags)exp]'.

       The flags s, n and b take an argument; the delimiter is shown below as
       `:', but any character, or the matching pairs `(...)', `{...}',
       `[...]', or `<...>', may be used, but note that `<...>' can only be
       used if the subscript is inside a double quoted expression or a
       parameter substitution enclosed in braces as otherwise the expression
       is interpreted as a redirection.

       The flags currently understood are:

       w      If the parameter subscripted is a scalar then this flag makes
              subscripting work on words instead of characters.  The default
              word separator is whitespace.  When combined with the i or I
              flag, the effect is to produce the index of the first character
              of the first/last word which matches the given pattern; note
              that a failed match in this case always yields 0.

       s:string:
              This gives the string that separates words (for use with the w
              flag).  The delimiter character : is arbitrary; see above.

       p      Recognize the same escape sequences as the print builtin in the
              string argument of a subsequent `s' flag.

       f      If the parameter subscripted is a scalar then this flag makes
              subscripting work on lines instead of characters, i.e. with
              elements separated by newlines.  This is a shorthand for
              `pws:\n:'.

       r      Reverse subscripting: if this flag is given, the exp is taken as
              a pattern and the result is the first matching array element,
              substring or word (if the parameter is an array, if it is a
              scalar, or if it is a scalar and the `w' flag is given,
              respectively).  The subscript used is the number of the matching
              element, so that pairs of subscripts such as `$foo[(r)??,3]' and
              `$foo[(r)??,(r)f*]' are possible if the parameter is not an
              associative array.  If the parameter is an associative array,
              only the value part of each pair is compared to the pattern, and
              the result is that value.

              If a search through an ordinary array failed, the search sets
              the subscript to one past the end of the array, and hence
              ${array[(r)pattern]} will substitute the empty string.  Thus the
              success of a search can be tested by using the (i) flag, for
              example (assuming the option KSH_ARRAYS is not in effect):

                     [[ ${array[(i)pattern]} -le ${#array} ]]

              If KSH_ARRAYS is in effect, the -le should be replaced by -lt.

       R      Like `r', but gives the last match.  For associative arrays,
              gives all possible matches. May be used for assigning to
              ordinary array elements, but not for assigning to associative
              arrays.  On failure, for normal arrays this has the effect of
              returning the element corresponding to subscript 0; this is
              empty unless one of the options KSH_ARRAYS or KSH_ZERO_SUBSCRIPT
              is in effect.

              Note that in subscripts with both `r' and `R' pattern characters
              are active even if they were substituted for a parameter
              (regardless of the setting of GLOB_SUBST which controls this
              feature in normal pattern matching).  The flag `e' can be added
              to inhibit pattern matching.  As this flag does not inhibit
              other forms of substitution, care is still required; using a
              parameter to hold the key has the desired effect:

                     key2='original key'
                     print ${array[(Re)$key2]}

       i      Like `r', but gives the index of the match instead; this may not
              be combined with a second argument.  On the left side of an
              assignment, behaves like `r'.  For associative arrays, the key
              part of each pair is compared to the pattern, and the first
              matching key found is the result.  On failure substitutes the
              length of the array plus one, as discussed under the description
              of `r', or the empty string for an associative array.

       I      Like `i', but gives the index of the last match, or all possible
              matching keys in an associative array.  On failure substitutes
              0, or the empty string for an associative array.  This flag is
              best when testing for values or keys that do not exist.

       k      If used in a subscript on an associative array, this flag causes
              the keys to be interpreted as patterns, and returns the value
              for the first key found where exp is matched by the key.  Note
              this could be any such key as no ordering of associative arrays
              is defined.  This flag does not work on the left side of an
              assignment to an associative array element.  If used on another
              type of parameter, this behaves like `r'.

       K      On an associative array this is like `k' but returns all values
              where exp is matched by the keys.  On other types of parameters
              this has the same effect as `R'.

       n:expr:
              If combined with `r', `R', `i' or `I', makes them give the nth
              or nth last match (if expr evaluates to n).  This flag is
              ignored when the array is associative.  The delimiter character
              : is arbitrary; see above.

       b:expr:
              If combined with `r', `R', `i' or `I', makes them begin at the
              nth or nth last element, word, or character (if expr evaluates
              to n).  This flag is ignored when the array is associative.  The
              delimiter character : is arbitrary; see above.

       e      This flag causes any pattern matching that would be performed on
              the subscript to use plain string matching instead.  Hence
              `${array[(re)*]}' matches only the array element whose value is
              *.  Note that other forms of substitution such as parameter
              substitution are not inhibited.

              This flag can also be used to force * or @ to be interpreted as
              a single key rather than as a reference to all values.  It may
              be used for either purpose on the left side of an assignment.

       See Parameter Expansion Flags (zshexpn(1)) for additional ways to
       manipulate the results of array subscripting.

   Subscript Parsing
       This discussion applies mainly to associative array key strings and to
       patterns used for reverse subscripting (the `r', `R', `i', etc. flags),
       but it may also affect parameter substitutions that appear as part of
       an arithmetic expression in an ordinary subscript.

       To avoid subscript parsing limitations in assignments to associative
       array elements, use the append syntax:

              aa+=('key with "*strange*" characters' 'value string')

       The basic rule to remember when writing a subscript expression is that
       all text between the opening `[' and the closing `]' is interpreted as
       if it were in double quotes (see zshmisc(1)).  However, unlike double
       quotes which normally cannot nest, subscript expressions may appear
       inside double-quoted strings or inside other subscript expressions (or
       both!), so the rules have two important differences.

       The first difference is that brackets (`[' and `]') must appear as
       balanced pairs in a subscript expression unless they are preceded by a
       backslash (`\').  Therefore, within a subscript expression (and unlike
       true double-quoting) the sequence `\[' becomes `[', and similarly `\]'
       becomes `]'.  This applies even in cases where a backslash is not
       normally required; for example, the pattern `[^[]' (to match any
       character other than an open bracket) should be written `[^\[]' in a
       reverse-subscript pattern.  However, note that `\[^\[\]' and even
       `\[^[]' mean the same thing, because backslashes are always stripped
       when they appear before brackets!

       The same rule applies to parentheses (`(' and `)') and braces (`{' and
       `}'): they must appear either in balanced pairs or preceded by a
       backslash, and backslashes that protect parentheses or braces are
       removed during parsing.  This is because parameter expansions may be
       surrounded by balanced braces, and subscript flags are introduced by
       balanced parentheses.

       The second difference is that a double-quote (`"') may appear as part
       of a subscript expression without being preceded by a backslash, and
       therefore that the two characters `\"' remain as two characters in the
       subscript (in true double-quoting, `\"' becomes `"').  However, because
       of the standard shell quoting rules, any double-quotes that appear must
       occur in balanced pairs unless preceded by a backslash.  This makes it
       more difficult to write a subscript expression that contains an odd
       number of double-quote characters, but the reason for this difference
       is so that when a subscript expression appears inside true
       double-quotes, one can still write `\"' (rather than `\\\"') for `"'.

       To use an odd number of double quotes as a key in an assignment, use
       the typeset builtin and an enclosing pair of double quotes; to refer to
       the value of that key, again use double quotes:

              typeset -A aa
              typeset "aa[one\"two\"three\"quotes]"=QQQ
              print "$aa[one\"two\"three\"quotes]"

       It is important to note that the quoting rules do not change when a
       parameter expansion with a subscript is nested inside another subscript
       expression.  That is, it is not necessary to use additional backslashes
       within the inner subscript expression; they are removed only once, from
       the innermost subscript outwards.  Parameters are also expanded from
       the innermost subscript first, as each expansion is encountered left to
       right in the outer expression.

       A further complication arises from a way in which subscript parsing is
       not different from double quote parsing.  As in true double-quoting,
       the sequences `\*', and `\@' remain as two characters when they appear
       in a subscript expression.  To use a literal `*' or `@' as an
       associative array key, the `e' flag must be used:

              typeset -A aa
              aa[(e)*]=star
              print $aa[(e)*]

       A last detail must be considered when reverse subscripting is
       performed.  Parameters appearing in the subscript expression are first
       expanded and then the complete expression is interpreted as a pattern.
       This has two effects: first, parameters behave as if GLOB_SUBST were on
       (and it cannot be turned off); second, backslashes are interpreted
       twice, once when parsing the array subscript and again when parsing the
       pattern.  In a reverse subscript, it's necessary to use four
       backslashes to cause a single backslash to match literally in the
       pattern.  For complex patterns, it is often easiest to assign the
       desired pattern to a parameter and then refer to that parameter in the
       subscript, because then the backslashes, brackets, parentheses, etc.,
       are seen only when the complete expression is converted to a pattern.
       To match the value of a parameter literally in a reverse subscript,
       rather than as a pattern, use `${(q)name}' (see zshexpn(1)) to quote
       the expanded value.

       Note that the `k' and `K' flags are reverse subscripting for an
       ordinary array, but are not reverse subscripting for an associative
       array!  (For an associative array, the keys in the array itself are
       interpreted as patterns by those flags; the subscript is a plain string
       in that case.)

       One final note, not directly related to subscripting: the numeric names
       of positional parameters (described below) are parsed specially, so for
       example `$2foo' is equivalent to `${2}foo'.  Therefore, to use
       subscript syntax to extract a substring from a positional parameter,
       the expansion must be surrounded by braces; for example, `${2[3,5]}'
       evaluates to the third through fifth characters of the second
       positional parameter, but `$2[3,5]' is the entire second parameter
       concatenated with the filename generation pattern `[3,5]'.

POSITIONAL PARAMETERS
       The positional parameters provide access to the command-line arguments
       of a shell function, shell script, or the shell itself; see the section
       `Invocation', and also the section `Functions'.  The parameter n, where
       n is a number, is the nth positional parameter.  The parameter `$0' is
       a special case, see the section `Parameters Set By The Shell'.

       The parameters *, @ and argv are arrays containing all the positional
       parameters; thus `$argv[n]', etc., is equivalent to simply `$n'.  Note
       that the options KSH_ARRAYS or KSH_ZERO_SUBSCRIPT apply to these arrays
       as well, so with either of those options set, `${argv[0]}' is
       equivalent to `$1' and so on.

       Positional parameters may be changed after the shell or function starts
       by using the set builtin, by assigning to the argv array, or by direct
       assignment of the form `n=value' where n is the number of the
       positional parameter to be changed.  This also creates (with empty
       values) any of the positions from 1 to n that do not already have
       values.  Note that, because the positional parameters form an array, an
       array assignment of the form `n=(value ...)' is allowed, and has the
       effect of shifting all the values at positions greater than n by as
       many positions as necessary to accommodate the new values.

LOCAL PARAMETERS
       Shell function executions delimit scopes for shell parameters.
       (Parameters are dynamically scoped.)  The typeset builtin, and its
       alternative forms declare, integer, local and readonly (but not
       export), can be used to declare a parameter as being local to the
       innermost scope.

       When a parameter is read or assigned to, the innermost existing
       parameter of that name is used.  (That is, the local parameter hides
       any less-local parameter.)  However, assigning to a non-existent
       parameter, or declaring a new parameter with export, causes it to be
       created in the outermost scope.

       Local parameters disappear when their scope ends.  unset can be used to
       delete a parameter while it is still in scope; any outer parameter of
       the same name remains hidden.

       Special parameters may also be made local; they retain their special
       attributes unless either the existing or the newly-created parameter
       has the -h (hide) attribute.  This may have unexpected effects: there
       is no default value, so if there is no assignment at the point the
       variable is made local, it will be set to an empty value (or zero in
       the case of integers).  The following:

              typeset PATH=/new/directory:$PATH

       is valid for temporarily allowing the shell or programmes called from
       it to find the programs in /new/directory inside a function.

       Note that the restriction in older versions of zsh that local
       parameters were never exported has been removed.

PARAMETERS SET BY THE SHELL
       In the parameter lists that follow, the mark `<S>' indicates that the
       parameter is special.  `<Z>' indicates that the parameter does not
       exist when the shell initializes in sh or ksh emulation mode.

       The following parameters are automatically set by the shell:

       ! <S>  The process ID of the last command started in the background
              with &, put into the background with the bg builtin, or spawned
              with coproc.

       # <S>  The number of positional parameters in decimal.  Note that some
              confusion may occur with the syntax $#param which substitutes
              the length of param.  Use ${#} to resolve ambiguities.  In
              particular, the sequence `$#-...' in an arithmetic expression is
              interpreted as the length of the parameter -, q.v.

       ARGC <S> <Z>
              Same as #.

       $ <S>  The process ID of this shell.  Note that this indicates the
              original shell started by invoking zsh; all processes forked
              from the shells without executing a new program, such as
              subshells started by (...), substitute the same value.

       - <S>  Flags supplied to the shell on invocation or by the set or
              setopt commands.

       * <S>  An array containing the positional parameters.

       argv <S> <Z>
              Same as *.  Assigning to argv changes the local positional
              parameters, but argv is not itself a local parameter.  Deleting
              argv with unset in any function deletes it everywhere, although
              only the innermost positional parameter array is deleted (so *
              and @ in other scopes are not affected).

       @ <S>  Same as argv[@], even when argv is not set.

       ? <S>  The exit status returned by the last command.

       0 <S>  The name used to invoke the current shell, or as set by the -c
              command line option upon invocation.  If the FUNCTION_ARGZERO
              option is set, $0 is set upon entry to a shell function to the
              name of the function, and upon entry to a sourced script to the
              name of the script, and reset to its previous value when the
              function or script returns.

       status <S> <Z>
              Same as ?.

       pipestatus <S> <Z>
              An array containing the exit statuses returned by all commands
              in the last pipeline.

       _ <S>  The last argument of the previous command.  Also, this parameter
              is set in the environment of every command executed to the full
              pathname of the command.

       CPUTYPE
              The machine type (microprocessor class or machine model), as
              determined at run time.

       EGID <S>
              The effective group ID of the shell process.  If you have
              sufficient privileges, you may change the effective group ID of
              the shell process by assigning to this parameter.  Also
              (assuming sufficient privileges), you may start a single command
              with a different effective group ID by `(EGID=gid; command)'

              If this is made local, it is not implicitly set to 0, but may be
              explicitly set locally.

       EUID <S>
              The effective user ID of the shell process.  If you have
              sufficient privileges, you may change the effective user ID of
              the shell process by assigning to this parameter.  Also
              (assuming sufficient privileges), you may start a single command
              with a different effective user ID by `(EUID=uid; command)'

              If this is made local, it is not implicitly set to 0, but may be
              explicitly set locally.

       ERRNO <S>
              The value of errno (see errno(3)) as set by the most recently
              failed system call.  This value is system dependent and is
              intended for debugging purposes.  It is also useful with the
              zsh/system module which allows the number to be turned into a
              name or message.

       FUNCNEST <S>
              Integer.  If greater than or equal to zero, the maximum nesting
              depth of shell functions.  When it is exceeded, an error is
              raised at the point where a function is called.  The default
              value is determined when the shell is configured, but is
              typically 500.  Increasing the value increases the danger of a
              runaway function recursion causing the shell to crash.  Setting
              a negative value turns off the check.

       GID <S>
              The real group ID of the shell process.  If you have sufficient
              privileges, you may change the group ID of the shell process by
              assigning to this parameter.  Also (assuming sufficient
              privileges), you may start a single command under a different
              group ID by `(GID=gid; command)'

              If this is made local, it is not implicitly set to 0, but may be
              explicitly set locally.

       HISTCMD
              The current history event number in an interactive shell, in
              other words the event number for the command that caused
              $HISTCMD to be read.  If the current history event modifies the
              history, HISTCMD changes to the new maximum history event
              number.

       HOST   The current hostname.

       LINENO <S>
              The line number of the current line within the current script,
              sourced file, or shell function being executed, whichever was
              started most recently.  Note that in the case of shell functions
              the line number refers to the function as it appeared in the
              original definition, not necessarily as displayed by the
              functions builtin.

       LOGNAME
              If the corresponding variable is not set in the environment of
              the shell, it is initialized to the login name corresponding to
              the current login session. This parameter is exported by default
              but this can be disabled using the typeset builtin.  The value
              is set to the string returned by the getlogin(3) system call if
              that is available.

       MACHTYPE
              The machine type (microprocessor class or machine model), as
              determined at compile time.

       OLDPWD The previous working directory.  This is set when the shell
              initializes and whenever the directory changes.

       OPTARG <S>
              The value of the last option argument processed by the getopts
              command.

       OPTIND <S>
              The index of the last option argument processed by the getopts
              command.

       OSTYPE The operating system, as determined at compile time.

       PPID <S>
              The process ID of the parent of the shell.  As for $$, the value
              indicates the parent of the original shell and does not change
              in subshells.

       PWD    The present working directory.  This is set when the shell
              initializes and whenever the directory changes.

       RANDOM <S>
              A pseudo-random integer from 0 to 32767, newly generated each
              time this parameter is referenced.  The random number generator
              can be seeded by assigning a numeric value to RANDOM.

              The values of RANDOM form an intentionally-repeatable
              pseudo-random sequence; subshells that reference RANDOM will
              result in identical pseudo-random values unless the value of
              RANDOM is referenced or seeded in the parent shell in between
              subshell invocations.

       SECONDS <S>
              The number of seconds since shell invocation.  If this parameter
              is assigned a value, then the value returned upon reference will
              be the value that was assigned plus the number of seconds since
              the assignment.

              Unlike other special parameters, the type of the SECONDS
              parameter can be changed using the typeset command.  Only
              integer and one of the floating point types are allowed.  For
              example, `typeset -F SECONDS' causes the value to be reported as
              a floating point number.  The value is available to microsecond
              accuracy, although the shell may show more or fewer digits
              depending on the use of typeset.  See the documentation for the
              builtin typeset in zshbuiltins(1) for more details.

       SHLVL <S>
              Incremented by one each time a new shell is started.

       signals
              An array containing the names of the signals.  Note that with
              the standard zsh numbering of array indices, where the first
              element has index 1, the signals are offset by 1 from the signal
              number used by the operating system.  For example, on typical
              Unix-like systems HUP is signal number 1, but is referred to as
              $signals[2].  This is because of EXIT at position 1 in the
              array, which is used internally by zsh but is not known to the
              operating system.

       TRY_BLOCK_ERROR <S>
              In an always block, indicates whether the preceding list of code
              caused an error.  The value is 1 to indicate an error, 0
              otherwise.  It may be reset, clearing the error condition.  See
              Complex Commands in zshmisc(1)

       TRY_BLOCK_INTERRUPT <S>
              This variable works in a similar way to TRY_BLOCK_ERROR, but
              represents the status of an interrupt from the signal SIGINT,
              which typically comes from the keyboard when the user types ^C.
              If set to 0, any such interrupt will be reset; otherwise, the
              interrupt is propagated after the always block.

              Note that it is possible that an interrupt arrives during the
              execution of the always block; this interrupt is also
              propagated.

       TTY    The name of the tty associated with the shell, if any.

       TTYIDLE <S>
              The idle time of the tty associated with the shell in seconds or
              -1 if there is no such tty.

       UID <S>
              The real user ID of the shell process.  If you have sufficient
              privileges, you may change the user ID of the shell by assigning
              to this parameter.  Also (assuming sufficient privileges), you
              may start a single command under a different user ID by
              `(UID=uid; command)'

              If this is made local, it is not implicitly set to 0, but may be
              explicitly set locally.

       USERNAME <S>
              The username corresponding to the real user ID of the shell
              process.  If you have sufficient privileges, you may change the
              username (and also the user ID and group ID) of the shell by
              assigning to this parameter.  Also (assuming sufficient
              privileges), you may start a single command under a different
              username (and user ID and group ID) by `(USERNAME=username;
              command)'

       VENDOR The vendor, as determined at compile time.

       zsh_eval_context <S> <Z> (ZSH_EVAL_CONTEXT <S>)
              An array (colon-separated list) indicating the context of shell
              code that is being run.  Each time a piece of shell code that is
              stored within the shell is executed a string is temporarily
              appended to the array to indicate the type of operation that is
              being performed.  Read in order the array gives an indication of
              the stack of operations being performed with the most immediate
              context last.

              Note that the variable does not give information on syntactic
              context such as pipelines or subshells.  Use $ZSH_SUBSHELL to
              detect subshells.

              The context is one of the following:
              cmdarg Code specified by the -c option to the command line that
                     invoked the shell.

              cmdsubst
                     Command substitution using the `...` or $(...) construct.

              equalsubst
                     File substitution using the =(...) construct.

              eval   Code executed by the eval builtin.

              evalautofunc
                     Code executed with the KSH_AUTOLOAD mechanism in order to
                     define an autoloaded function.

              fc     Code from the shell history executed by the -e option to
                     the fc builtin.

              file   Lines of code being read directly from a file, for
                     example by the source builtin.

              filecode
                     Lines of code being read from a .zwc file instead of
                     directly from the source file.

              globqual
                     Code executed by the e or + glob qualifier.

              globsort
                     Code executed to order files by the o glob qualifier.

              insubst
                     File substitution using the <(...) construct.

              loadautofunc
                     Code read directly from a file to define an autoloaded
                     function.

              outsubst
                     File substitution using the >(...) construct.

              sched  Code executed by the sched builtin.

              shfunc A shell function.

              stty   Code passed to stty by the STTY environment variable.
                     Normally this is passed directly to the system's stty
                     command, so this value is unlikely to be seen in
                     practice.

              style  Code executed as part of a style retrieved by the zstyle
                     builtin from the zsh/zutil module.

              toplevel
                     The highest execution level of a script or interactive
                     shell.

              trap   Code executed as a trap defined by the trap builtin.
                     Traps defined as functions have the context shfunc.  As
                     traps are asynchronous they may have a different
                     hierarchy from other code.

              zpty   Code executed by the zpty builtin from the zsh/zpty
                     module.

              zregexparse-guard
                     Code executed as a guard by the zregexparse command from
                     the zsh/zutil module.

              zregexparse-action
                     Code executed as an action by the zregexparse command
                     from the zsh/zutil module.

       ZSH_ARGZERO
              If zsh was invoked to run a script, this is the name of the
              script.  Otherwise, it is the name used to invoke the current
              shell.  This is the same as the value of $0 when the
              POSIX_ARGZERO option is set, but is always available.

       ZSH_EXECUTION_STRING
              If the shell was started with the option -c, this contains the
              argument passed to the option.  Otherwise it is not set.

       ZSH_NAME
              Expands to the basename of the command used to invoke this
              instance of zsh.

       ZSH_PATCHLEVEL
              The output of `git describe --tags --long' for the zsh
              repository used to build the shell.  This is most useful in
              order to keep track of versions of the shell during development
              between releases; hence most users should not use it and should
              instead rely on $ZSH_VERSION.

       zsh_scheduled_events
              See the section `The zsh/sched Module' in zshmodules(1).

       ZSH_SCRIPT
              If zsh was invoked to run a script, this is the name of the
              script, otherwise it is unset.

       ZSH_SUBSHELL
              Readonly integer.  Initially zero, incremented each time the
              shell forks to create a subshell for executing code.  Hence
              `(print $ZSH_SUBSHELL)' and `print $(print $ZSH_SUBSHELL)'
              output 1, while `( (print $ZSH_SUBSHELL) )' outputs 2.

       ZSH_VERSION
              The version number of the release of zsh.

PARAMETERS USED BY THE SHELL
       The following parameters are used by the shell.  Again, `<S>' indicates
       that the parameter is special and `<Z>' indicates that the parameter
       does not exist when the shell initializes in sh or ksh emulation mode.

       In cases where there are two parameters with an upper- and lowercase
       form of the same name, such as path and PATH, the lowercase form is an
       array and the uppercase form is a scalar with the elements of the array
       joined together by colons.  These are similar to tied parameters
       created via `typeset -T'.  The normal use for the colon-separated form
       is for exporting to the environment, while the array form is easier to
       manipulate within the shell.  Note that unsetting either of the pair
       will unset the other; they retain their special properties when
       recreated, and recreating one of the pair will recreate the other.

       ARGV0  If exported, its value is used as the argv[0] of external
              commands.  Usually used in constructs like `ARGV0=emacs
              nethack'.

       BAUD   The rate in bits per second at which data reaches the terminal.
              The line editor will use this value in order to compensate for a
              slow terminal by delaying updates to the display until
              necessary.  If the parameter is unset or the value is zero the
              compensation mechanism is turned off.  The parameter is not set
              by default.

              This parameter may be profitably set in some circumstances, e.g.
              for slow modems dialing into a communications server, or on a
              slow wide area network.  It should be set to the baud rate of
              the slowest part of the link for best performance.

       cdpath <S> <Z> (CDPATH <S>)
              An array (colon-separated list) of directories specifying the
              search path for the cd command.

       COLUMNS <S>
              The number of columns for this terminal session.  Used for
              printing select lists and for the line editor.

       CORRECT_IGNORE
              If set, is treated as a pattern during spelling correction.  Any
              potential correction that matches the pattern is ignored.  For
              example, if the value is `_*' then completion functions (which,
              by convention, have names beginning with `_') will never be
              offered as spelling corrections.  The pattern does not apply to
              the correction of file names, as applied by the CORRECT_ALL
              option (so with the example just given files beginning with `_'
              in the current directory would still be completed).

       CORRECT_IGNORE_FILE
              If set, is treated as a pattern during spelling correction of
              file names.  Any file name that matches the pattern is never
              offered as a correction.  For example, if the value is `.*' then
              dot file names will never be offered as spelling corrections.
              This is useful with the CORRECT_ALL option.

       DIRSTACKSIZE
              The maximum size of the directory stack, by default there is no
              limit.  If the stack gets larger than this, it will be truncated
              automatically.  This is useful with the AUTO_PUSHD option.

       ENV    If the ENV environment variable is set when zsh is invoked as sh
              or ksh, $ENV is sourced after the profile scripts.  The value of
              ENV is subjected to parameter expansion, command substitution,
              and arithmetic expansion before being interpreted as a pathname.
              Note that ENV is not used unless the shell is interactive and
              zsh is emulating sh or ksh.

       FCEDIT The default editor for the fc builtin.  If FCEDIT is not set,
              the parameter EDITOR is used; if that is not set either, a
              builtin default, usually vi, is used.

       fignore <S> <Z> (FIGNORE <S>)
              An array (colon separated list) containing the suffixes of files
              to be ignored during filename completion.  However, if
              completion only generates files with suffixes in this list, then
              these files are completed anyway.

       fpath <S> <Z> (FPATH <S>)
              An array (colon separated list) of directories specifying the
              search path for function definitions.  This path is searched
              when a function with the -u attribute is referenced.  If an
              executable file is found, then it is read and executed in the
              current environment.

       histchars <S>
              Three characters used by the shell's history and lexical
              analysis mechanism.  The first character signals the start of a
              history expansion (default `!').  The second character signals
              the start of a quick history substitution (default `^').  The
              third character is the comment character (default `#').

              The characters must be in the ASCII character set; any attempt
              to set histchars to characters with a locale-dependent meaning
              will be rejected with an error message.

       HISTCHARS <S> <Z>
              Same as histchars.  (Deprecated.)

       HISTFILE
              The file to save the history in when an interactive shell exits.
              If unset, the history is not saved.

       HISTORY_IGNORE
              If set, is treated as a pattern at the time history files are
              written.  Any potential history entry that matches the pattern
              is skipped.  For example, if the value is `fc *' then commands
              that invoke the interactive history editor are never written to
              the history file.

              Note that HISTORY_IGNORE defines a single pattern: to specify
              alternatives use the `(first|second|...)' syntax.

              Compare the HIST_NO_STORE option or the zshaddhistory hook,
              either of which would prevent such commands from being added to
              the interactive history at all.  If you wish to use
              HISTORY_IGNORE to stop history being added in the first place,
              you can define the following hook:

                     zshaddhistory() {
                       emulate -L zsh
                       ## uncomment if HISTORY_IGNORE
                       ## should use EXTENDED_GLOB syntax
                       # setopt extendedglob
                       [[ $1 != ${~HISTORY_IGNORE} ]]
                     }

       HISTSIZE <S>
              The maximum number of events stored in the internal history
              list.  If you use the HIST_EXPIRE_DUPS_FIRST option, setting
              this value larger than the SAVEHIST size will give you the
              difference as a cushion for saving duplicated history events.

              If this is made local, it is not implicitly set to 0, but may be
              explicitly set locally.

       HOME <S>
              The default argument for the cd command.  This is not set
              automatically by the shell in sh, ksh or csh emulation, but it
              is typically present in the environment anyway, and if it
              becomes set it has its usual special behaviour.

       IFS <S>
              Internal field separators (by default space, tab, newline and
              NUL), that are used to separate words which result from command
              or parameter expansion and words read by the read builtin.  Any
              characters from the set space, tab and newline that appear in
              the IFS are called IFS white space.  One or more IFS white space
              characters or one non-IFS white space character together with
              any adjacent IFS white space character delimit a field.  If an
              IFS white space character appears twice consecutively in the
              IFS, this character is treated as if it were not an IFS white
              space character.

              If the parameter is unset, the default is used.  Note this has a
              different effect from setting the parameter to an empty string.

       KEYBOARD_HACK
              This variable defines a character to be removed from the end of
              the command line before interpreting it (interactive shells
              only). It is intended to fix the problem with keys placed
              annoyingly close to return and replaces the SUNKEYBOARDHACK
              option which did this for backquotes only.  Should the chosen
              character be one of singlequote, doublequote or backquote, there
              must also be an odd number of them on the command line for the
              last one to be removed.

              For backward compatibility, if the SUNKEYBOARDHACK option is
              explicitly set, the value of KEYBOARD_HACK reverts to backquote.
              If the option is explicitly unset, this variable is set to
              empty.

       KEYTIMEOUT
              The time the shell waits, in hundredths of seconds, for another
              key to be pressed when reading bound multi-character sequences.

       LANG <S>
              This variable determines the locale category for any category
              not specifically selected via a variable starting with `LC_'.

       LC_ALL <S>
              This variable overrides the value of the `LANG' variable and the
              value of any of the other variables starting with `LC_'.

       LC_COLLATE <S>
              This variable determines the locale category for character
              collation information within ranges in glob brackets and for
              sorting.

       LC_CTYPE <S>
              This variable determines the locale category for character
              handling functions.  If the MULTIBYTE option is in effect this
              variable or LANG should contain a value that reflects the
              character set in use, even if it is a single-byte character set,
              unless only the 7-bit subset (ASCII) is used.  For example, if
              the character set is ISO-8859-1, a suitable value might be
              en_US.iso88591 (certain Linux distributions) or en_US.ISO8859-1
              (MacOS).

       LC_MESSAGES <S>
              This variable determines the language in which messages should
              be written.  Note that zsh does not use message catalogs.

       LC_NUMERIC <S>
              This variable affects the decimal point character and thousands
              separator character for the formatted input/output functions and
              string conversion functions.  Note that zsh ignores this setting
              when parsing floating point mathematical expressions.

       LC_TIME <S>
              This variable determines the locale category for date and time
              formatting in prompt escape sequences.

       LINES <S>
              The number of lines for this terminal session.  Used for
              printing select lists and for the line editor.

       LISTMAX
              In the line editor, the number of matches to list without asking
              first. If the value is negative, the list will be shown if it
              spans at most as many lines as given by the absolute value.  If
              set to zero, the shell asks only if the top of the listing would
              scroll off the screen.

       LOGCHECK
              The interval in seconds between checks for login/logout activity
              using the watch parameter.

       MAIL   If this parameter is set and mailpath is not set, the shell
              looks for mail in the specified file.

       MAILCHECK
              The interval in seconds between checks for new mail.

       mailpath <S> <Z> (MAILPATH <S>)
              An array (colon-separated list) of filenames to check for new
              mail.  Each filename can be followed by a `?' and a message that
              will be printed.  The message will undergo parameter expansion,
              command substitution and arithmetic expansion with the variable
              $_ defined as the name of the file that has changed.  The
              default message is `You have new mail'.  If an element is a
              directory instead of a file the shell will recursively check
              every file in every subdirectory of the element.

       manpath <S> <Z> (MANPATH <S> <Z>)
              An array (colon-separated list) whose value is not used by the
              shell.  The manpath array can be useful, however, since setting
              it also sets MANPATH, and vice versa.

       match
       mbegin
       mend   Arrays set by the shell when the b globbing flag is used in
              pattern matches.  See the subsection Globbing flags in the
              documentation for Filename Generation in zshexpn(1).

       MATCH
       MBEGIN
       MEND   Set by the shell when the m globbing flag is used in pattern
              matches.  See the subsection Globbing flags in the documentation
              for Filename Generation in zshexpn(1).

       module_path <S> <Z> (MODULE_PATH <S>)
              An array (colon-separated list) of directories that zmodload
              searches for dynamically loadable modules.  This is initialized
              to a standard pathname, usually
              `/usr/local/lib/zsh/$ZSH_VERSION'.  (The `/usr/local/lib' part
              varies from installation to installation.)  For security
              reasons, any value set in the environment when the shell is
              started will be ignored.

              These parameters only exist if the installation supports dynamic
              module loading.

       NULLCMD <S>
              The command name to assume if a redirection is specified with no
              command.  Defaults to cat.  For sh/ksh behavior, change this to
              :.  For csh-like behavior, unset this parameter; the shell will
              print an error message if null commands are entered.

       path <S> <Z> (PATH <S>)
              An array (colon-separated list) of directories to search for
              commands.  When this parameter is set, each directory is scanned
              and all files found are put in a hash table.

       POSTEDIT <S>
              This string is output whenever the line editor exits.  It
              usually contains termcap strings to reset the terminal.

       PROMPT <S> <Z>
       PROMPT2 <S> <Z>
       PROMPT3 <S> <Z>
       PROMPT4 <S> <Z>
              Same as PS1, PS2, PS3 and PS4, respectively.

       prompt <S> <Z>
              Same as PS1.

       PROMPT_EOL_MARK
              When the PROMPT_CR and PROMPT_SP options are set, the
              PROMPT_EOL_MARK parameter can be used to customize how the end
              of partial lines are shown.  This parameter undergoes prompt
              expansion, with the PROMPT_PERCENT option set.  If not set, the
              default behavior is equivalent to the value `%B%S%#%s%b'.

       PS1 <S>
              The primary prompt string, printed before a command is read.  It
              undergoes a special form of expansion before being displayed;
              see EXPANSION OF PROMPT SEQUENCES in zshmisc(1).  The default is
              `%m%# '.

       PS2 <S>
              The secondary prompt, printed when the shell needs more
              information to complete a command.  It is expanded in the same
              way as PS1.  The default is `%_> ', which displays any shell
              constructs or quotation marks which are currently being
              processed.

       PS3 <S>
              Selection prompt used within a select loop.  It is expanded in
              the same way as PS1.  The default is `?# '.

       PS4 <S>
              The execution trace prompt.  Default is `+%N:%i> ', which
              displays the name of the current shell structure and the line
              number within it.  In sh or ksh emulation, the default is `+ '.

       psvar <S> <Z> (PSVAR <S>)
              An array (colon-separated list) whose elements can be used in
              PROMPT strings.  Setting psvar also sets PSVAR, and vice versa.

       READNULLCMD <S>
              The command name to assume if a single input redirection is
              specified with no command.  Defaults to more.

       REPORTMEMORY
              If nonnegative, commands whose maximum resident set size
              (roughly speaking, main memory usage) in kilobytes is greater
              than this value have timing statistics reported.  The format
              used to output statistics is the value of the TIMEFMT parameter,
              which is the same as for the REPORTTIME variable and the time
              builtin; note that by default this does not output memory usage.
              Appending " max RSS %M" to the value of TIMEFMT causes it to
              output the value that triggered the report.  If REPORTTIME is
              also in use, at most a single report is printed for both
              triggers.  This feature requires the getrusage() system call,
              commonly supported by modern Unix-like systems.

       REPORTTIME
              If nonnegative, commands whose combined user and system
              execution times (measured in seconds) are greater than this
              value have timing statistics printed for them.  Output is
              suppressed for commands executed within the line editor,
              including completion; commands explicitly marked with the time
              keyword still cause the summary to be printed in this case.

       REPLY  This parameter is reserved by convention to pass string values
              between shell scripts and shell builtins in situations where a
              function call or redirection are impossible or undesirable.  The
              read builtin and the select complex command may set REPLY, and
              filename generation both sets and examines its value when
              evaluating certain expressions.  Some modules also employ REPLY
              for similar purposes.

       reply  As REPLY, but for array values rather than strings.

       RPROMPT <S>
       RPS1 <S>
              This prompt is displayed on the right-hand side of the screen
              when the primary prompt is being displayed on the left.  This
              does not work if the SINGLE_LINE_ZLE option is set.  It is
              expanded in the same way as PS1.

       RPROMPT2 <S>
       RPS2 <S>
              This prompt is displayed on the right-hand side of the screen
              when the secondary prompt is being displayed on the left.  This
              does not work if the SINGLE_LINE_ZLE option is set.  It is
              expanded in the same way as PS2.

       SAVEHIST
              The maximum number of history events to save in the history
              file.

              If this is made local, it is not implicitly set to 0, but may be
              explicitly set locally.

       SPROMPT <S>
              The prompt used for spelling correction.  The sequence `%R'
              expands to the string which presumably needs spelling
              correction, and `%r' expands to the proposed correction.  All
              other prompt escapes are also allowed.

              The actions available at the prompt are [nyae]:
              n (`no') (default)
                     Discard the correction and run the command.
              y (`yes')
                     Make the correction and run the command.
              a (`abort')
                     Discard the entire command line without running it.
              e (`edit')
                     Resume editing the command line.

       STTY   If this parameter is set in a command's environment, the shell
              runs the stty command with the value of this parameter as
              arguments in order to set up the terminal before executing the
              command. The modes apply only to the command, and are reset when
              it finishes or is suspended. If the command is suspended and
              continued later with the fg or wait builtins it will see the
              modes specified by STTY, as if it were not suspended.  This
              (intentionally) does not apply if the command is continued via
              `kill -CONT'.  STTY is ignored if the command is run in the
              background, or if it is in the environment of the shell but not
              explicitly assigned to in the input line. This avoids running
              stty at every external command by accidentally exporting it.
              Also note that STTY should not be used for window size
              specifications; these will not be local to the command.

       TERM <S>
              The type of terminal in use.  This is used when looking up
              termcap sequences.  An assignment to TERM causes zsh to
              re-initialize the terminal, even if the value does not change
              (e.g., `TERM=$TERM').  It is necessary to make such an
              assignment upon any change to the terminal definition database
              or terminal type in order for the new settings to take effect.

       TERMINFO <S>
              A reference to your terminfo database, used by the `terminfo'
              library when the system has it; see terminfo(5).  If set, this
              causes the shell to reinitialise the terminal, making the
              workaround `TERM=$TERM' unnecessary.

       TERMINFO_DIRS <S>
              A colon-seprarated list of terminfo databases, used by the
              `terminfo' library when the system has it; see terminfo(5). This
              variable is only used by certain terminal libraries, in
              particular ncurses; see terminfo(5) to check support on your
              system.  If set, this causes the shell to reinitialise the
              terminal, making the workaround `TERM=$TERM' unnecessary.  Note
              that unlike other colon-separated arrays this is not tied to a
              zsh array.

       TIMEFMT
              The format of process time reports with the time keyword.  The
              default is `%J  %U user %S system %P cpu %*E total'.  Recognizes
              the following escape sequences, although not all may be
              available on all systems, and some that are available may not be
              useful:

              %%     A `%'.
              %U     CPU seconds spent in user mode.
              %S     CPU seconds spent in kernel mode.
              %E     Elapsed time in seconds.
              %P     The CPU percentage, computed as 100*(%U+%S)/%E.
              %W     Number of times the process was swapped.
              %X     The average amount in (shared) text space used in
                     kilobytes.
              %D     The average amount in (unshared) data/stack space used in
                     kilobytes.
              %K     The total space used (%X+%D) in kilobytes.
              %M     The  maximum memory the process had in use at any time in
                     kilobytes.
              %F     The number of major page faults (page needed to be
                     brought from disk).
              %R     The number of minor page faults.
              %I     The number of input operations.
              %O     The number of output operations.
              %r     The number of socket messages received.
              %s     The number of socket messages sent.
              %k     The number of signals received.
              %w     Number of voluntary context switches (waits).
              %c     Number of involuntary context switches.
              %J     The name of this job.

              A star may be inserted between the percent sign and flags
              printing time (e.g., `%*E'); this causes the time to be printed
              in `hh:mm:ss.ttt' format (hours and minutes are only printed if
              they are not zero).  Alternatively, `m' or `u' may be used
              (e.g., `%mE') to produce time output in milliseconds or
              microseconds, respectively.

       TMOUT  If this parameter is nonzero, the shell will receive an ALRM
              signal if a command is not entered within the specified number
              of seconds after issuing a prompt. If there is a trap on
              SIGALRM, it will be executed and a new alarm is scheduled using
              the value of the TMOUT parameter after executing the trap.  If
              no trap is set, and the idle time of the terminal is not less
              than the value of the TMOUT parameter, zsh terminates.
              Otherwise a new alarm is scheduled to TMOUT seconds after the
              last keypress.

       TMPPREFIX
              A pathname prefix which the shell will use for all temporary
              files.  Note that this should include an initial part for the
              file name as well as any directory names.  The default is
              `/tmp/zsh'.

       TMPSUFFIX
              A filename suffix which the shell will use for temporary files
              created by process substitutions (e.g., `=(list)').  Note that
              the value should include a leading dot `.' if intended to be
              interpreted as a file extension.  The default is not to append
              any suffix, thus this parameter should be assigned only when
              needed and then unset again.

       watch <S> <Z> (WATCH <S>)
              An array (colon-separated list) of login/logout events to
              report.

              If it contains the single word `all', then all login/logout
              events are reported.  If it contains the single word `notme',
              then all events are reported as with `all' except $USERNAME.

              An entry in this list may consist of a username, an `@' followed
              by a remote hostname, and a `%' followed by a line (tty).  Any
              of these may be a pattern (be sure to quote this during the
              assignment to watch so that it does not immediately perform file
              generation); the setting of the EXTENDED_GLOB option is
              respected.  Any or all of these components may be present in an
              entry; if a login/logout event matches all of them, it is
              reported.

              For example, with the EXTENDED_GLOB option set, the following:

                     watch=('^(pws|barts)')

              causes reports for activity associated with any user other than
              pws or barts.

       WATCHFMT
              The format of login/logout reports if the watch parameter is
              set.  Default is `%n has %a %l from %m'.  Recognizes the
              following escape sequences:

              %n     The name of the user that logged in/out.

              %a     The observed action, i.e. "logged on" or "logged off".

              %l     The line (tty) the user is logged in on.

              %M     The full hostname of the remote host.

              %m     The hostname up to the first `.'.  If only the IP address
                     is available or the utmp field contains the name of an
                     X-windows display, the whole name is printed.

                     NOTE: The `%m' and `%M' escapes will work only if there
                     is a host name field in the utmp on your machine.
                     Otherwise they are treated as ordinary strings.

              %S (%s)
                     Start (stop) standout mode.

              %U (%u)
                     Start (stop) underline mode.

              %B (%b)
                     Start (stop) boldface mode.

              %t
              %@     The time, in 12-hour, am/pm format.

              %T     The time, in 24-hour format.

              %w     The date in `day-dd' format.

              %W     The date in `mm/dd/yy' format.

              %D     The date in `yy-mm-dd' format.

              %D{string}
                     The date formatted as string using the strftime function,
                     with zsh extensions as described by EXPANSION OF PROMPT
                     SEQUENCES in zshmisc(1).

              %(x:true-text:false-text)
                     Specifies a ternary expression.  The character following
                     the x is arbitrary; the same character is used to
                     separate the text for the "true" result from that for the
                     "false" result.  Both the separator and the right
                     parenthesis may be escaped with a backslash.  Ternary
                     expressions may be nested.

                     The test character x may be any one of `l', `n', `m' or
                     `M', which indicate a `true' result if the corresponding
                     escape sequence would return a non-empty value; or it may
                     be `a', which indicates a `true' result if the watched
                     user has logged in, or `false' if he has logged out.
                     Other characters evaluate to neither true nor false; the
                     entire expression is omitted in this case.

                     If the result is `true', then the true-text is formatted
                     according to the rules above and printed, and the
                     false-text is skipped.  If `false', the true-text is
                     skipped and the false-text is formatted and printed.
                     Either or both of the branches may be empty, but both
                     separators must be present in any case.

       WORDCHARS <S>
              A list of non-alphanumeric characters considered part of a word
              by the line editor.

       ZBEEP  If set, this gives a string of characters, which can use all the
              same codes as the bindkey command as described in the zsh/zle
              module entry in zshmodules(1), that will be output to the
              terminal instead of beeping.  This may have a visible instead of
              an audible effect; for example, the string `\e[?5h\e[?5l' on a
              vt100 or xterm will have the effect of flashing reverse video on
              and off (if you usually use reverse video, you should use the
              string `\e[?5l\e[?5h' instead).  This takes precedence over the
              NOBEEP option.

       ZDOTDIR
              The directory to search for shell startup files (.zshrc, etc),
              if not $HOME.

       zle_bracketed_paste
              Many terminal emulators have a feature that allows applications
              to identify when text is pasted into the terminal rather than
              being typed normally. For ZLE, this means that special
              characters such as tabs and newlines can be inserted instead of
              invoking editor commands.  Furthermore, pasted text forms a
              single undo event and if the region is active, pasted text will
              replace the region.

              This two-element array contains the terminal escape sequences
              for enabling and disabling the feature. These escape sequences
              are used to enable bracketed paste when ZLE is active and
              disable it at other times.  Unsetting the parameter has the
              effect of ensuring that bracketed paste remains disabled.

       zle_highlight
              An array describing contexts in which ZLE should highlight the
              input text.  See Character Highlighting in zshzle(1).

       ZLE_LINE_ABORTED
              This parameter is set by the line editor when an error occurs.
              It contains the line that was being edited at the point of the
              error.  `print -zr -- $ZLE_LINE_ABORTED' can be used to recover
              the line.  Only the most recent line of this kind is remembered.

       ZLE_REMOVE_SUFFIX_CHARS
       ZLE_SPACE_SUFFIX_CHARS
              These parameters are used by the line editor.  In certain
              circumstances suffixes (typically space or slash) added by the
              completion system will be removed automatically, either because
              the next editing command was not an insertable character, or
              because the character was marked as requiring the suffix to be
              removed.

              These variables can contain the sets of characters that will
              cause the suffix to be removed.  If ZLE_REMOVE_SUFFIX_CHARS is
              set, those characters will cause the suffix to be removed; if
              ZLE_SPACE_SUFFIX_CHARS is set, those characters will cause the
              suffix to be removed and replaced by a space.

              If ZLE_REMOVE_SUFFIX_CHARS is not set, the default behaviour is
              equivalent to:

                     ZLE_REMOVE_SUFFIX_CHARS=$' \t\n;&|'

              If ZLE_REMOVE_SUFFIX_CHARS is set but is empty, no characters
              have this behaviour.  ZLE_SPACE_SUFFIX_CHARS takes precedence,
              so that the following:

                     ZLE_SPACE_SUFFIX_CHARS=$'&|'

              causes the characters `&' and `|' to remove the suffix but to
              replace it with a space.

              To illustrate the difference, suppose that the option
              AUTO_REMOVE_SLASH is in effect and the directory DIR has just
              been completed, with an appended /, following which the user
              types `&'.  The default result is `DIR&'.  With
              ZLE_REMOVE_SUFFIX_CHARS set but without including `&' the result
              is `DIR/&'.  With ZLE_SPACE_SUFFIX_CHARS set to include `&' the
              result is `DIR &'.

              Note that certain completions may provide their own suffix
              removal or replacement behaviour which overrides the values
              described here.  See the completion system documentation in
              zshcompsys(1).

       ZLE_RPROMPT_INDENT <S>
              If set, used to give the indentation between the right hand side
              of the right prompt in the line editor as given by RPS1 or
              RPROMPT and the right hand side of the screen.  If not set, the
              value 1 is used.

              Typically this will be used to set the value to 0 so that the
              prompt appears flush with the right hand side of the screen.
              This is not the default as many terminals do not handle this
              correctly, in particular when the prompt appears at the extreme
              bottom right of the screen.  Recent virtual terminals are more
              likely to handle this case correctly.  Some experimentation is
              necessary.




ZSHOPTIONS(1)               General Commands Manual              ZSHOPTIONS(1)



NAME
       zshoptions - zsh options

SPECIFYING OPTIONS
       Options are primarily referred to by name.  These names are case
       insensitive and underscores are ignored.  For example, `allexport' is
       equivalent to `A__lleXP_ort'.

       The sense of an option name may be inverted by preceding it with `no',
       so `setopt No_Beep' is equivalent to `unsetopt beep'.  This inversion
       can only be done once, so `nonobeep' is not a synonym for `beep'.
       Similarly, `tify' is not a synonym for `nonotify' (the inversion of
       `notify').

       Some options also have one or more single letter names.  There are two
       sets of single letter options: one used by default, and another used to
       emulate sh/ksh (used when the SH_OPTION_LETTERS option is set).  The
       single letter options can be used on the shell command line, or with
       the set, setopt and unsetopt builtins, as normal Unix options preceded
       by `-'.

       The sense of the single letter options may be inverted by using `+'
       instead of `-'.  Some of the single letter option names refer to an
       option being off, in which case the inversion of that name refers to
       the option being on.  For example, `+n' is the short name of `exec',
       and `-n' is the short name of its inversion, `noexec'.

       In strings of single letter options supplied to the shell at startup,
       trailing whitespace will be ignored; for example the string `-f    '
       will be treated just as `-f', but the string `-f i' is an error.  This
       is because many systems which implement the `#!' mechanism for calling
       scripts do not strip trailing whitespace.

DESCRIPTION OF OPTIONS
       In the following list, options set by default in all emulations are
       marked <D>; those set by default only in csh, ksh, sh, or zsh
       emulations are marked <C>, <K>, <S>, <Z> as appropriate.  When listing
       options (by `setopt', `unsetopt', `set -o' or `set +o'), those turned
       on by default appear in the list prefixed with `no'.  Hence (unless
       KSH_OPTION_PRINT is set), `setopt' shows all options whose settings are
       changed from the default.

   Changing Directories
       AUTO_CD (-J)
              If a command is issued that can't be executed as a normal
              command, and the command is the name of a directory, perform the
              cd command to that directory.  This option is only applicable if
              the option SHIN_STDIN is set, i.e. if commands are being read
              from standard input.  The option is designed for interactive
              use; it is recommended that cd be used explicitly in scripts to
              avoid ambiguity.

       AUTO_PUSHD (-N)
              Make cd push the old directory onto the directory stack.

       CDABLE_VARS (-T)
              If the argument to a cd command (or an implied cd with the
              AUTO_CD option set) is not a directory, and does not begin with
              a slash, try to expand the expression as if it were preceded by
              a `~' (see the section `Filename Expansion').

       CD_SILENT
              Never print the working directory after a cd (whether explicit
              or implied with the AUTO_CD option set). cd normally prints the
              working directory when the argument given to it was -, a stack
              entry, or the name of a directory found under CDPATH. Note that
              this is distinct from pushd's stack-printing behaviour, which is
              controlled by PUSHD_SILENT. This option overrides the
              printing-related effects of POSIX_CD.

       CHASE_DOTS
              When changing to a directory containing a path segment `..'
              which would otherwise be treated as canceling the previous
              segment in the path (in other words, `foo/..' would be removed
              from the path, or if `..' is the first part of the path, the
              last part of the current working directory would be removed),
              instead resolve the path to the physical directory.  This option
              is overridden by CHASE_LINKS.

              For example, suppose /foo/bar is a link to the directory
              /alt/rod.  Without this option set, `cd /foo/bar/..' changes to
              /foo; with it set, it changes to /alt.  The same applies if the
              current directory is /foo/bar and `cd ..' is used.  Note that
              all other symbolic links in the path will also be resolved.

       CHASE_LINKS (-w)
              Resolve symbolic links to their true values when changing
              directory.  This also has the effect of CHASE_DOTS, i.e. a `..'
              path segment will be treated as referring to the physical
              parent, even if the preceding path segment is a symbolic link.

       POSIX_CD <K> <S>
              Modifies the behaviour of cd, chdir and pushd commands to make
              them more compatible with the POSIX standard. The behaviour with
              the option unset is described in the documentation for the cd
              builtin in zshbuiltins(1).  If the option is set, the shell does
              not test for directories beneath the local directory (`.') until
              after all directories in cdpath have been tested, and the cd and
              chdir commands do not recognise arguments of the form `{+|-}n'
              as directory stack entries.

              Also, if the option is set, the conditions under which the shell
              prints the new directory after changing to it are modified.  It
              is no longer restricted to interactive shells (although printing
              of the directory stack with pushd is still limited to
              interactive shells); and any use of a component of CDPATH,
              including a `.' but excluding an empty component that is
              otherwise treated as `.', causes the directory to be printed.

       PUSHD_IGNORE_DUPS
              Don't push multiple copies of the same directory onto the
              directory stack.

       PUSHD_MINUS
              Exchanges the meanings of `+' and `-' when used with a number to
              specify a directory in the stack.

       PUSHD_SILENT (-E)
              Do not print the directory stack after pushd or popd.

       PUSHD_TO_HOME (-D)
              Have pushd with no arguments act like `pushd $HOME'.

   Completion
       ALWAYS_LAST_PROMPT <D>
              If unset, key functions that list completions try to return to
              the last prompt if given a numeric argument. If set these
              functions try to return to the last prompt if given no numeric
              argument.

       ALWAYS_TO_END
              If a completion is performed with the cursor within a word, and
              a full completion is inserted, the cursor is moved to the end of
              the word.  That is, the cursor is moved to the end of the word
              if either a single match is inserted or menu completion is
              performed.

       AUTO_LIST (-9) <D>
              Automatically list choices on an ambiguous completion.

       AUTO_MENU <D>
              Automatically use menu completion after the second consecutive
              request for completion, for example by pressing the tab key
              repeatedly. This option is overridden by MENU_COMPLETE.

       AUTO_NAME_DIRS
              Any parameter that is set to the absolute name of a directory
              immediately becomes a name for that directory, that will be used
              by the `%~' and related prompt sequences, and will be available
              when completion is performed on a word starting with `~'.
              (Otherwise, the parameter must be used in the form `~param'
              first.)

       AUTO_PARAM_KEYS <D>
              If a parameter name was completed and a following character
              (normally a space) automatically inserted, and the next
              character typed is one of those that have to come directly after
              the name (like `}', `:', etc.), the automatically added
              character is deleted, so that the character typed comes
              immediately after the parameter name.  Completion in a brace
              expansion is affected similarly: the added character is a `,',
              which will be removed if `}' is typed next.

       AUTO_PARAM_SLASH <D>
              If a parameter is completed whose content is the name of a
              directory, then add a trailing slash instead of a space.

       AUTO_REMOVE_SLASH <D>
              When the last character resulting from a completion is a slash
              and the next character typed is a word delimiter, a slash, or a
              character that ends a command (such as a semicolon or an
              ampersand), remove the slash.

       BASH_AUTO_LIST
              On an ambiguous completion, automatically list choices when the
              completion function is called twice in succession.  This takes
              precedence over AUTO_LIST.  The setting of LIST_AMBIGUOUS is
              respected.  If AUTO_MENU is set, the menu behaviour will then
              start with the third press.  Note that this will not work with
              MENU_COMPLETE, since repeated completion calls immediately cycle
              through the list in that case.

       COMPLETE_ALIASES
              Prevents aliases on the command line from being internally
              substituted before completion is attempted.  The effect is to
              make the alias a distinct command for completion purposes.

       COMPLETE_IN_WORD
              If unset, the cursor is set to the end of the word if completion
              is started. Otherwise it stays there and completion is done from
              both ends.

       GLOB_COMPLETE
              When the current word has a glob pattern, do not insert all the
              words resulting from the expansion but generate matches as for
              completion and cycle through them like MENU_COMPLETE. The
              matches are generated as if a `*' was added to the end of the
              word, or inserted at the cursor when COMPLETE_IN_WORD is set.
              This actually uses pattern matching, not globbing, so it works
              not only for files but for any completion, such as options, user
              names, etc.

              Note that when the pattern matcher is used, matching control
              (for example, case-insensitive or anchored matching) cannot be
              used.  This limitation only applies when the current word
              contains a pattern; simply turning on the GLOB_COMPLETE option
              does not have this effect.

       HASH_LIST_ALL <D>
              Whenever a command completion or spelling correction is
              attempted, make sure the entire command path is hashed first.
              This makes the first completion slower but avoids false reports
              of spelling errors.

       LIST_AMBIGUOUS <D>
              This option works when AUTO_LIST or BASH_AUTO_LIST is also set.
              If there is an unambiguous prefix to insert on the command line,
              that is done without a completion list being displayed; in other
              words, auto-listing behaviour only takes place when nothing
              would be inserted.  In the case of BASH_AUTO_LIST, this means
              that the list will be delayed to the third call of the function.

       LIST_BEEP <D>
              Beep on an ambiguous completion.  More accurately, this forces
              the completion widgets to return status 1 on an ambiguous
              completion, which causes the shell to beep if the option BEEP is
              also set; this may be modified if completion is called from a
              user-defined widget.

       LIST_PACKED
              Try to make the completion list smaller (occupying less lines)
              by printing the matches in columns with different widths.

       LIST_ROWS_FIRST
              Lay out the matches in completion lists sorted horizontally,
              that is, the second match is to the right of the first one, not
              under it as usual.

       LIST_TYPES (-X) <D>
              When listing files that are possible completions, show the type
              of each file with a trailing identifying mark.

       MENU_COMPLETE (-Y)
              On an ambiguous completion, instead of listing possibilities or
              beeping, insert the first match immediately.  Then when
              completion is requested again, remove the first match and insert
              the second match, etc.  When there are no more matches, go back
              to the first one again.  reverse-menu-complete may be used to
              loop through the list in the other direction. This option
              overrides AUTO_MENU.

       REC_EXACT (-S)
              If the string on the command line exactly matches one of the
              possible completions, it is accepted, even if there is another
              completion (i.e. that string with something else added) that
              also matches.

   Expansion and Globbing
       BAD_PATTERN (+2) <C> <Z>
              If a pattern for filename generation is badly formed, print an
              error message.  (If this option is unset, the pattern will be
              left unchanged.)

       BARE_GLOB_QUAL <Z>
              In a glob pattern, treat a trailing set of parentheses as a
              qualifier list, if it contains no `|', `(' or (if special) `~'
              characters.  See the section `Filename Generation'.

       BRACE_CCL
              Expand expressions in braces which would not otherwise undergo
              brace expansion to a lexically ordered list of all the
              characters.  See the section `Brace Expansion'.

       CASE_GLOB <D>
              Make globbing (filename generation) sensitive to case.  Note
              that other uses of patterns are always sensitive to case.  If
              the option is unset, the presence of any character which is
              special to filename generation will cause case-insensitive
              matching.  For example, cvs(/) can match the directory CVS owing
              to the presence of the globbing flag (unless the option
              BARE_GLOB_QUAL is unset).

       CASE_MATCH <D>
              Make regular expressions using the zsh/regex module (including
              matches with =~) sensitive to case.

       CSH_NULL_GLOB <C>
              If a pattern for filename generation has no matches, delete the
              pattern from the argument list; do not report an error unless
              all the patterns in a command have no matches.  Overrides
              NOMATCH.

       EQUALS <Z>
              Perform = filename expansion.  (See the section `Filename
              Expansion'.)

       EXTENDED_GLOB
              Treat the `#', `~' and `^' characters as part of patterns for
              filename generation, etc.  (An initial unquoted `~' always
              produces named directory expansion.)

       FORCE_FLOAT
              Constants in arithmetic evaluation will be treated as floating
              point even without the use of a decimal point; the values of
              integer variables will be converted to floating point when used
              in arithmetic expressions.  Integers in any base will be
              converted.

       GLOB (+F, ksh: +f) <D>
              Perform filename generation (globbing).  (See the section
              `Filename Generation'.)

       GLOB_ASSIGN <C>
              If this option is set, filename generation (globbing) is
              performed on the right hand side of scalar parameter assignments
              of the form `name=pattern (e.g. `foo=*').  If the result has
              more than one word the parameter will become an array with those
              words as arguments. This option is provided for backwards
              compatibility only: globbing is always performed on the right
              hand side of array assignments of the form `name=(value)' (e.g.
              `foo=(*)') and this form is recommended for clarity; with this
              option set, it is not possible to predict whether the result
              will be an array or a scalar.

       GLOB_DOTS (-4)
              Do not require a leading `.' in a filename to be matched
              explicitly.

       GLOB_STAR_SHORT
              When this option is set and the default zsh-style globbing is in
              effect, the pattern `**/*' can be abbreviated to `**' and the
              pattern `***/*' can be abbreviated to ***.  Hence `**.c' finds a
              file ending in .c in any subdirectory, and `***.c' does the same
              while also following symbolic links.  A / immediately after the
              `**' or `***' forces the pattern to be treated as the
              unabbreviated form.

       GLOB_SUBST <C> <K> <S>
              Treat any characters resulting from parameter expansion as being
              eligible for filename expansion and filename generation, and any
              characters resulting from command substitution as being eligible
              for filename generation.  Braces (and commas in between) do not
              become eligible for expansion.

       HIST_SUBST_PATTERN
              Substitutions using the :s and :& history modifiers are
              performed with pattern matching instead of string matching.
              This occurs wherever history modifiers are valid, including glob
              qualifiers and parameters.  See the section Modifiers in
              zshexpn(1).

       IGNORE_BRACES (-I) <S>
              Do not perform brace expansion.  For historical reasons this
              also includes the effect of the IGNORE_CLOSE_BRACES option.

       IGNORE_CLOSE_BRACES
              When neither this option nor IGNORE_BRACES is set, a sole close
              brace character `}' is syntactically significant at any point on
              a command line.  This has the effect that no semicolon or
              newline is necessary before the brace terminating a function or
              current shell construct.  When either option is set, a closing
              brace is syntactically significant only in command position.
              Unlike IGNORE_BRACES, this option does not disable brace
              expansion.

              For example, with both options unset a function may be defined
              in the following fashion:

                     args() { echo $# }

              while if either option is set, this does not work and something
              equivalent to the following is required:

                     args() { echo $#; }

       KSH_GLOB <K>
              In pattern matching, the interpretation of parentheses is
              affected by a preceding `@', `*', `+', `?' or `!'.  See the
              section `Filename Generation'.

       MAGIC_EQUAL_SUBST
              All unquoted arguments of the form `anything=expression'
              appearing after the command name have filename expansion (that
              is, where expression has a leading `~' or `=') performed on
              expression as if it were a parameter assignment.  The argument
              is not otherwise treated specially; it is passed to the command
              as a single argument, and not used as an actual parameter
              assignment.  For example, in echo foo=~/bar:~/rod, both
              occurrences of ~ would be replaced.  Note that this happens
              anyway with typeset and similar statements.

              This option respects the setting of the KSH_TYPESET option.  In
              other words, if both options are in effect, arguments looking
              like assignments will not undergo word splitting.

       MARK_DIRS (-8, ksh: -X)
              Append a trailing `/' to all directory names resulting from
              filename generation (globbing).

       MULTIBYTE <D>
              Respect multibyte characters when found in strings.  When this
              option is set, strings are examined using the system library to
              determine how many bytes form a character, depending on the
              current locale.  This affects the way characters are counted in
              pattern matching, parameter values and various delimiters.

              The option is on by default if the shell was compiled with
              MULTIBYTE_SUPPORT; otherwise it is off by default and has no
              effect if turned on.

              If the option is off a single byte is always treated as a single
              character.  This setting is designed purely for examining
              strings known to contain raw bytes or other values that may not
              be characters in the current locale.  It is not necessary to
              unset the option merely because the character set for the
              current locale does not contain multibyte characters.

              The option does not affect the shell's editor,  which always
              uses the locale to determine multibyte characters.  This is
              because the character set displayed by the terminal emulator is
              independent of shell settings.

       NOMATCH (+3) <C> <Z>
              If a pattern for filename generation has no matches, print an
              error, instead of leaving it unchanged in the argument list.
              This also applies to file expansion of an initial `~' or `='.

       NULL_GLOB (-G)
              If a pattern for filename generation has no matches, delete the
              pattern from the argument list instead of reporting an error.
              Overrides NOMATCH.

       NUMERIC_GLOB_SORT
              If numeric filenames are matched by a filename generation
              pattern, sort the filenames numerically rather than
              lexicographically.

       RC_EXPAND_PARAM (-P)
              Array expansions of the form `foo${xx}bar', where the parameter
              xx is set to (a b c), are substituted with `fooabar foobbar
              foocbar' instead of the default `fooa b cbar'.  Note that an
              empty array will therefore cause all arguments to be removed.

       REMATCH_PCRE
              If set, regular expression matching with the =~ operator will
              use Perl-Compatible Regular Expressions from the PCRE library.
              (The zsh/pcre module must be available.)  If not set, regular
              expressions will use the extended regexp syntax provided by the
              system libraries.

       SH_GLOB <K> <S>
              Disables the special meaning of `(', `|', `)' and '<' for
              globbing the result of parameter and command substitutions, and
              in some other places where the shell accepts patterns.  If
              SH_GLOB is set but KSH_GLOB is not, the shell allows the
              interpretation of subshell expressions enclosed in parentheses
              in some cases where there is no space before the opening
              parenthesis, e.g. !(true) is interpreted as if there were a
              space after the !.  This option is set by default if zsh is
              invoked as sh or ksh.

       UNSET (+u, ksh: +u) <K> <S> <Z>
              Treat unset parameters as if they were empty when substituting,
              and as if they were zero when reading their values in arithmetic
              expansion and arithmetic commands.  Otherwise they are treated
              as an error.

       WARN_CREATE_GLOBAL
              Print a warning message when a global parameter is created in a
              function by an assignment or in math context.  This often
              indicates that a parameter has not been declared local when it
              should have been.  Parameters explicitly declared global from
              within a function using typeset -g do not cause a warning.  Note
              that there is no warning when a local parameter is assigned to
              in a nested function, which may also indicate an error.

       WARN_NESTED_VAR
              Print a warning message when an existing parameter from an
              enclosing function scope, or global, is set in a function by an
              assignment or in math context.  Assignment to shell special
              parameters does not cause a warning.  This is the companion to
              WARN_CREATE_GLOBAL as in this case the warning is only printed
              when a parameter is not created.  Where possible, use of typeset
              -g to set the parameter suppresses the error, but note that this
              needs to be used every time the parameter is set.  To restrict
              the effect of this option to a single function scope, use
              `functions -W'.

              For example, the following code produces a warning for the
              assignment inside the function nested as that overrides the
              value within toplevel

                     toplevel() {
                       local foo="in fn"
                       nested
                     }
                     nested() {
                          foo="in nested"
                     }
                     setopt warn_nested_var
                     toplevel

   History
       APPEND_HISTORY <D>
              If this is set, zsh sessions will append their history list to
              the history file, rather than replace it. Thus, multiple
              parallel zsh sessions will all have the new entries from their
              history lists added to the history file, in the order that they
              exit.  The file will still be periodically re-written to trim it
              when the number of lines grows 20% beyond the value specified by
              $SAVEHIST (see also the HIST_SAVE_BY_COPY option).

       BANG_HIST (+K) <C> <Z>
              Perform textual history expansion, csh-style, treating the
              character `!' specially.

       EXTENDED_HISTORY <C>
              Save each command's beginning timestamp (in seconds since the
              epoch) and the duration (in seconds) to the history file.  The
              format of this prefixed data is:

              `: <beginning time>:<elapsed seconds>;<command>'.

       HIST_ALLOW_CLOBBER
              Add `|' to output redirections in the history.  This allows
              history references to clobber files even when CLOBBER is unset.

       HIST_BEEP <D>
              Beep in ZLE when a widget attempts to access a history entry
              which isn't there.

       HIST_EXPIRE_DUPS_FIRST
              If the internal history needs to be trimmed to add the current
              command line, setting this option will cause the oldest history
              event that has a duplicate to be lost before losing a unique
              event from the list.  You should be sure to set the value of
              HISTSIZE to a larger number than SAVEHIST in order to give you
              some room for the duplicated events, otherwise this option will
              behave just like HIST_IGNORE_ALL_DUPS once the history fills up
              with unique events.

       HIST_FCNTL_LOCK
              When writing out the history file, by default zsh uses ad-hoc
              file locking to avoid known problems with locking on some
              operating systems.  With this option locking is done by means of
              the system's fcntl call, where this method is available.  On
              recent operating systems this may provide better performance, in
              particular avoiding history corruption when files are stored on
              NFS.

       HIST_FIND_NO_DUPS
              When searching for history entries in the line editor, do not
              display duplicates of a line previously found, even if the
              duplicates are not contiguous.

       HIST_IGNORE_ALL_DUPS
              If a new command line being added to the history list duplicates
              an older one, the older command is removed from the list (even
              if it is not the previous event).

       HIST_IGNORE_DUPS (-h)
              Do not enter command lines into the history list if they are
              duplicates of the previous event.

       HIST_IGNORE_SPACE (-g)
              Remove command lines from the history list when the first
              character on the line is a space, or when one of the expanded
              aliases contains a leading space.  Only normal aliases (not
              global or suffix aliases) have this behaviour.  Note that the
              command lingers in the internal history until the next command
              is entered before it vanishes, allowing you to briefly reuse or
              edit the line.  If you want to make it vanish right away without
              entering another command, type a space and press return.

       HIST_LEX_WORDS
              By default, shell history that is read in from files is split
              into words on all white space.  This means that arguments with
              quoted whitespace are not correctly handled, with the
              consequence that references to words in history lines that have
              been read from a file may be inaccurate.  When this option is
              set, words read in from a history file are divided up in a
              similar fashion to normal shell command line handling.  Although
              this produces more accurately delimited words, if the size of
              the history file is large this can be slow.  Trial and error is
              necessary to decide.

       HIST_NO_FUNCTIONS
              Remove function definitions from the history list.  Note that
              the function lingers in the internal history until the next
              command is entered before it vanishes, allowing you to briefly
              reuse or edit the definition.

       HIST_NO_STORE
              Remove the history (fc -l) command from the history list when
              invoked.  Note that the command lingers in the internal history
              until the next command is entered before it vanishes, allowing
              you to briefly reuse or edit the line.

       HIST_REDUCE_BLANKS
              Remove superfluous blanks from each command line being added to
              the history list.

       HIST_SAVE_BY_COPY <D>
              When the history file is re-written, we normally write out a
              copy of the file named $HISTFILE.new and then rename it over the
              old one.  However, if this option is unset, we instead truncate
              the old history file and write out the new version in-place.  If
              one of the history-appending options is enabled, this option
              only has an effect when the enlarged history file needs to be
              re-written to trim it down to size.  Disable this only if you
              have special needs, as doing so makes it possible to lose
              history entries if zsh gets interrupted during the save.

              When writing out a copy of the history file, zsh preserves the
              old file's permissions and group information, but will refuse to
              write out a new file if it would change the history file's
              owner.

       HIST_SAVE_NO_DUPS
              When writing out the history file, older commands that duplicate
              newer ones are omitted.

       HIST_VERIFY
              Whenever the user enters a line with history expansion, don't
              execute the line directly; instead, perform history expansion
              and reload the line into the editing buffer.

       INC_APPEND_HISTORY
              This option works like APPEND_HISTORY except that new history
              lines are added to the $HISTFILE incrementally (as soon as they
              are entered), rather than waiting until the shell exits.  The
              file will still be periodically re-written to trim it when the
              number of lines grows 20% beyond the value specified by
              $SAVEHIST (see also the HIST_SAVE_BY_COPY option).

       INC_APPEND_HISTORY_TIME
              This option is a variant of INC_APPEND_HISTORY in which, where
              possible, the history entry is written out to the file after the
              command is finished, so that the time taken by the command is
              recorded correctly in the history file in EXTENDED_HISTORY
              format.  This means that the history entry will not be available
              immediately from other instances of the shell that are using the
              same history file.

              This option is only useful if INC_APPEND_HISTORY and
              SHARE_HISTORY are turned off.  The three options should be
              considered mutually exclusive.

       SHARE_HISTORY <K>

              This option both imports new commands from the history file, and
              also causes your typed commands to be appended to the history
              file (the latter is like specifying INC_APPEND_HISTORY, which
              should be turned off if this option is in effect).  The history
              lines are also output with timestamps ala EXTENDED_HISTORY
              (which makes it easier to find the spot where we left off
              reading the file after it gets re-written).

              By default, history movement commands visit the imported lines
              as well as the local lines, but you can toggle this on and off
              with the set-local-history zle binding.  It is also possible to
              create a zle widget that will make some commands ignore imported
              commands, and some include them.

              If you find that you want more control over when commands get
              imported, you may wish to turn SHARE_HISTORY off,
              INC_APPEND_HISTORY or INC_APPEND_HISTORY_TIME (see above) on,
              and then manually import commands whenever you need them using
              `fc -RI'.

   Initialisation
       ALL_EXPORT (-a, ksh: -a)
              All parameters subsequently defined are automatically exported.

       GLOBAL_EXPORT <Z>
              If this option is set, passing the -x flag to the builtins
              declare, float, integer, readonly and typeset (but not local)
              will also set the -g flag;  hence parameters exported to the
              environment will not be made local to the enclosing function,
              unless they were already or the flag +g is given explicitly.  If
              the option is unset, exported parameters will be made local in
              just the same way as any other parameter.

              This option is set by default for backward compatibility; it is
              not recommended that its behaviour be relied upon.  Note that
              the builtin export always sets both the -x and -g flags, and
              hence its effect extends beyond the scope of the enclosing
              function; this is the most portable way to achieve this
              behaviour.

       GLOBAL_RCS (-d) <D>
              If this option is unset, the startup files /etc/zprofile,
              /etc/zshrc, /etc/zlogin and /etc/zlogout will not be run.  It
              can be disabled and re-enabled at any time, including inside
              local startup files (.zshrc, etc.).

       RCS (+f) <D>
              After /etc/zshenv is sourced on startup, source the .zshenv,
              /etc/zprofile, .zprofile, /etc/zshrc, .zshrc, /etc/zlogin,
              .zlogin, and .zlogout files, as described in the section
              `Files'.  If this option is unset, the /etc/zshenv file is still
              sourced, but any of the others will not be; it can be set at any
              time to prevent the remaining startup files after the currently
              executing one from being sourced.

   Input/Output
       ALIASES <D>
              Expand aliases.

       CLOBBER (+C, ksh: +C) <D>
              Allows `>' redirection to truncate existing files.  Otherwise
              `>!' or `>|' must be used to truncate a file.

              If the option is not set, and the option APPEND_CREATE is also
              not set, `>>!' or `>>|' must be used to create a file.  If
              either option is set, `>>' may be used.

       CORRECT (-0)
              Try to correct the spelling of commands.  Note that, when the
              HASH_LIST_ALL option is not set or when some directories in the
              path are not readable, this may falsely report spelling errors
              the first time some commands are used.

              The shell variable CORRECT_IGNORE may be set to a pattern to
              match words that will never be offered as corrections.

       CORRECT_ALL (-O)
              Try to correct the spelling of all arguments in a line.

              The shell variable CORRECT_IGNORE_FILE may be set to a pattern
              to match file names that will never be offered as corrections.

       DVORAK Use the Dvorak keyboard instead of the standard qwerty keyboard
              as a basis for examining spelling mistakes for the CORRECT and
              CORRECT_ALL options and the spell-word editor command.

       FLOW_CONTROL <D>
              If this option is unset, output flow control via start/stop
              characters (usually assigned to ^S/^Q) is disabled in the
              shell's editor.

       IGNORE_EOF (-7)
              Do not exit on end-of-file.  Require the use of exit or logout
              instead.  However, ten consecutive EOFs will cause the shell to
              exit anyway, to avoid the shell hanging if its tty goes away.

              Also, if this option is set and the Zsh Line Editor is used,
              widgets implemented by shell functions can be bound to EOF
              (normally Control-D) without printing the normal warning
              message.  This works only for normal widgets, not for completion
              widgets.

       INTERACTIVE_COMMENTS (-k) <K> <S>
              Allow comments even in interactive shells.

       HASH_CMDS <D>
              Note the location of each command the first time it is executed.
              Subsequent invocations of the same command will use the saved
              location, avoiding a path search.  If this option is unset, no
              path hashing is done at all.  However, when CORRECT is set,
              commands whose names do not appear in the functions or aliases
              hash tables are hashed in order to avoid reporting them as
              spelling errors.

       HASH_DIRS <D>
              Whenever a command name is hashed, hash the directory containing
              it, as well as all directories that occur earlier in the path.
              Has no effect if neither HASH_CMDS nor CORRECT is set.

       HASH_EXECUTABLES_ONLY
              When hashing commands because of HASH_CMDS, check that the file
              to be hashed is actually an executable.  This option is unset by
              default as if the path contains a large number of commands, or
              consists of many remote files, the additional tests can take a
              long time.  Trial and error is needed to show if this option is
              beneficial.

       MAIL_WARNING (-U)
              Print a warning message if a mail file has been accessed since
              the shell last checked.

       PATH_DIRS (-Q)
              Perform a path search even on command names with slashes in
              them.  Thus if `/usr/local/bin' is in the user's path, and he or
              she types `X11/xinit', the command `/usr/local/bin/X11/xinit'
              will be executed (assuming it exists).  Commands explicitly
              beginning with `/', `./' or `../' are not subject to the path
              search.  This also applies to the `.' and source builtins.

              Note that subdirectories of the current directory are always
              searched for executables specified in this form.  This takes
              place before any search indicated by this option, and regardless
              of whether `.' or the current directory appear in the command
              search path.

       PATH_SCRIPT <K> <S>
              If this option is not set, a script passed as the first
              non-option argument to the shell must contain the name of the
              file to open.  If this option is set, and the script does not
              specify a directory path, the script is looked for first in the
              current directory, then in the command path.  See the section
              INVOCATION in zsh(1).

       PRINT_EIGHT_BIT
              Print eight bit characters literally in completion lists, etc.
              This option is not necessary if your system correctly returns
              the printability of eight bit characters (see ctype(3)).

       PRINT_EXIT_VALUE (-1)
              Print the exit value of programs with non-zero exit status.
              This is only available at the command line in interactive
              shells.

       RC_QUOTES
              Allow the character sequence `''' to signify a single quote
              within singly quoted strings.  Note this does not apply in
              quoted strings using the format $'...', where a backslashed
              single quote can be used.

       RM_STAR_SILENT (-H) <K> <S>
              Do not query the user before executing `rm *' or `rm path/*'.

       RM_STAR_WAIT
              If querying the user before executing `rm *' or `rm path/*',
              first wait ten seconds and ignore anything typed in that time.
              This avoids the problem of reflexively answering `yes' to the
              query when one didn't really mean it.  The wait and query can
              always be avoided by expanding the `*' in ZLE (with tab).

       SHORT_LOOPS <C> <Z>
              Allow the short forms of for, repeat, select, if, and function
              constructs.

       SUN_KEYBOARD_HACK (-L)
              If a line ends with a backquote, and there are an odd number of
              backquotes on the line, ignore the trailing backquote.  This is
              useful on some keyboards where the return key is too small, and
              the backquote key lies annoyingly close to it.  As an
              alternative the variable KEYBOARD_HACK lets you choose the
              character to be removed.

   Job Control
       AUTO_CONTINUE
              With this option set, stopped jobs that are removed from the job
              table with the disown builtin command are automatically sent a
              CONT signal to make them running.

       AUTO_RESUME (-W)
              Treat single word simple commands without redirection as
              candidates for resumption of an existing job.

       BG_NICE (-6) <C> <Z>
              Run all background jobs at a lower priority.  This option is set
              by default.

       CHECK_JOBS <Z>
              Report the status of background and suspended jobs before
              exiting a shell with job control; a second attempt to exit the
              shell will succeed.  NO_CHECK_JOBS is best used only in
              combination with NO_HUP, else such jobs will be killed
              automatically.

              The check is omitted if the commands run from the previous
              command line included a `jobs' command, since it is assumed the
              user is aware that there are background or suspended jobs.  A
              `jobs' command run from one of the hook functions defined in the
              section SPECIAL FUNCTIONS in zshmisc(1) is not counted for this
              purpose.

       CHECK_RUNNING_JOBS <Z>
              Check for both running and suspended jobs when CHECK_JOBS is
              enabled.  When this option is disabled, zsh checks only for
              suspended jobs, which matches the default behavior of bash.

              This option has no effect unless CHECK_JOBS is set.

       HUP <Z>
              Send the HUP signal to running jobs when the shell exits.

       LONG_LIST_JOBS (-R)
              Print job notifications in the long format by default.

       MONITOR (-m, ksh: -m)
              Allow job control.  Set by default in interactive shells.

       NOTIFY (-5, ksh: -b) <Z>
              Report the status of background jobs immediately, rather than
              waiting until just before printing a prompt.

       POSIX_JOBS <K> <S>
              This option makes job control more compliant with the POSIX
              standard.

              When the option is not set, the MONITOR option is unset on entry
              to subshells, so that job control is no longer active.  When the
              option is set, the MONITOR option and job control remain active
              in the subshell, but note that the subshell has no access to
              jobs in the parent shell.

              When the option is not set, jobs put in the background or
              foreground with bg or fg are displayed with the same information
              that would be reported by jobs.  When the option is set, only
              the text is printed.  The output from jobs itself is not
              affected by the option.

              When the option is not set, job information from the parent
              shell is saved for output within a subshell (for example, within
              a pipeline).  When the option is set, the output of jobs is
              empty until a job is started within the subshell.

              In previous versions of the shell, it was necessary to enable
              POSIX_JOBS in order for the builtin command wait to return the
              status of background jobs that had already exited.  This is no
              longer the case.

   Prompting
       PROMPT_BANG <K>
              If set, `!' is treated specially in prompt expansion.  See
              EXPANSION OF PROMPT SEQUENCES in zshmisc(1).

       PROMPT_CR (+V) <D>
              Print a carriage return just before printing a prompt in the
              line editor.  This is on by default as multi-line editing is
              only possible if the editor knows where the start of the line
              appears.

       PROMPT_SP <D>
              Attempt to preserve a partial line (i.e. a line that did not end
              with a newline) that would otherwise be covered up by the
              command prompt due to the PROMPT_CR option.  This works by
              outputting some cursor-control characters, including a series of
              spaces, that should make the terminal wrap to the next line when
              a partial line is present (note that this is only successful if
              your terminal has automatic margins, which is typical).

              When a partial line is preserved, by default you will see an
              inverse+bold character at the end of the partial line:  a `%'
              for a normal user or a `#' for root.  If set, the shell
              parameter PROMPT_EOL_MARK can be used to customize how the end
              of partial lines are shown.

              NOTE: if the PROMPT_CR option is not set, enabling this option
              will have no effect.  This option is on by default.

       PROMPT_PERCENT <C> <Z>
              If set, `%' is treated specially in prompt expansion.  See
              EXPANSION OF PROMPT SEQUENCES in zshmisc(1).

       PROMPT_SUBST <K> <S>
              If set, parameter expansion, command substitution and arithmetic
              expansion are performed in prompts.  Substitutions within
              prompts do not affect the command status.

       TRANSIENT_RPROMPT
              Remove any right prompt from display when accepting a command
              line.  This may be useful with terminals with other cut/paste
              methods.

   Scripts and Functions
       ALIAS_FUNC_DEF <S>
              By default, zsh does not allow the definition of functions using
              the `name ()' syntax if name was expanded as an alias: this
              causes an error.  This is usually the desired behaviour, as
              otherwise the combination of an alias and a function based on
              the same definition can easily cause problems.

              When this option is set, aliases can be used for defining
              functions.

              For example, consider the following definitions as they might
              occur in a startup file.

                     alias foo=bar
                     foo() {
                       print This probably does not do what you expect.
                     }

              Here, foo is expanded as an alias to bar before the () is
              encountered, so the function defined would be named bar.  By
              default this is instead an error in native mode.  Note that
              quoting any part of the function name, or using the keyword
              function, avoids the problem, so is recommended when the
              function name can also be an alias.

       C_BASES
              Output hexadecimal numbers in the standard C format, for example
              `0xFF' instead of the usual `16#FF'.  If the option OCTAL_ZEROES
              is also set (it is not by default), octal numbers will be
              treated similarly and hence appear as `077' instead of `8#77'.
              This option has no effect on the choice of the output base, nor
              on the output of bases other than hexadecimal and octal.  Note
              that these formats will be understood on input irrespective of
              the setting of C_BASES.

       C_PRECEDENCES
              This alters the precedence of arithmetic operators to be more
              like C and other programming languages; the section ARITHMETIC
              EVALUATION in zshmisc(1) has an explicit list.

       DEBUG_BEFORE_CMD <D>
              Run the DEBUG trap before each command; otherwise it is run
              after each command.  Setting this option mimics the behaviour of
              ksh 93; with the option unset the behaviour is that of ksh 88.

       ERR_EXIT (-e, ksh: -e)
              If a command has a non-zero exit status, execute the ZERR trap,
              if set, and exit.  This is disabled while running initialization
              scripts.

              The behaviour is also disabled inside DEBUG traps.  In this case
              the option is handled specially: it is unset on entry to the
              trap.  If the option DEBUG_BEFORE_CMD is set, as it is by
              default, and the option ERR_EXIT is found to have been set on
              exit, then the command for which the DEBUG trap is being
              executed is skipped.  The option is restored after the trap
              exits.

              Non-zero status in a command list containing && or || is ignored
              for commands not at the end of the list.  Hence

                     false && true

              does not trigger exit.

              Exiting due to ERR_EXIT has certain interactions with
              asynchronous jobs noted in the section JOBS in zshmisc(1).

       ERR_RETURN
              If a command has a non-zero exit status, return immediately from
              the enclosing function.  The logic is similar to that for
              ERR_EXIT, except that an implicit return statement is executed
              instead of an exit.  This will trigger an exit at the outermost
              level of a non-interactive script.

              Normally this option inherits the behaviour of ERR_EXIT that
              code followed by `&&' `||' does not trigger a return.  Hence in
              the following:

                     summit || true

              no return is forced as the combined effect always has a zero
              return status.

              Note. however, that if summit in the above example is itself a
              function, code inside it is considered separately: it may force
              a return from summit (assuming the option remains set within
              summit), but not from the enclosing context.  This behaviour is
              different from ERR_EXIT which is unaffected by function scope.

       EVAL_LINENO <Z>
              If set, line numbers of expressions evaluated using the builtin
              eval are tracked separately of the enclosing environment.  This
              applies both to the parameter LINENO and the line number output
              by the prompt escape %i.  If the option is set, the prompt
              escape %N will output the string `(eval)' instead of the script
              or function name as an indication.   (The two prompt escapes are
              typically used in the parameter PS4 to be output when the option
              XTRACE is set.)  If EVAL_LINENO is unset, the line number of the
              surrounding script or function is retained during the
              evaluation.

       EXEC (+n, ksh: +n) <D>
              Do execute commands.  Without this option, commands are read and
              checked for syntax errors, but not executed.  This option cannot
              be turned off in an interactive shell, except when `-n' is
              supplied to the shell at startup.

       FUNCTION_ARGZERO <C> <Z>
              When executing a shell function or sourcing a script, set $0
              temporarily to the name of the function/script.  Note that
              toggling FUNCTION_ARGZERO from on to off (or off to on) does not
              change the current value of $0.  Only the state upon entry to
              the function or script has an effect.  Compare POSIX_ARGZERO.

       LOCAL_LOOPS
              When this option is not set, the effect of break and continue
              commands may propagate outside function scope, affecting loops
              in calling functions.  When the option is set in a calling
              function, a break or a continue that is not caught within a
              called function (regardless of the setting of the option within
              that function) produces a warning and the effect is cancelled.

       LOCAL_OPTIONS <K>
              If this option is set at the point of return from a shell
              function, most options (including this one) which were in force
              upon entry to the function are restored; options that are not
              restored are PRIVILEGED and RESTRICTED.  Otherwise, only this
              option, and the LOCAL_LOOPS, XTRACE and PRINT_EXIT_VALUE options
              are restored.  Hence if this is explicitly unset by a shell
              function the other options in force at the point of return will
              remain so.  A shell function can also guarantee itself a known
              shell configuration with a formulation like `emulate -L zsh';
              the -L activates LOCAL_OPTIONS.

       LOCAL_PATTERNS
              If this option is set at the point of return from a shell
              function, the state of pattern disables, as set with the builtin
              command `disable -p', is restored to what it was when the
              function was entered.  The behaviour of this option is similar
              to the effect of LOCAL_OPTIONS on options; hence `emulate -L sh'
              (or indeed any other emulation with the -L option) activates
              LOCAL_PATTERNS.

       LOCAL_TRAPS <K>
              If this option is set when a signal trap is set inside a
              function, then the previous status of the trap for that signal
              will be restored when the function exits.  Note that this option
              must be set prior to altering the trap behaviour in a function;
              unlike LOCAL_OPTIONS, the value on exit from the function is
              irrelevant.  However, it does not need to be set before any
              global trap for that to be correctly restored by a function.
              For example,

                     unsetopt localtraps
                     trap - INT
                     fn() { setopt localtraps; trap '' INT; sleep 3; }

              will restore normal handling of SIGINT after the function exits.

       MULTI_FUNC_DEF <Z>
              Allow definitions of multiple functions at once in the form `fn1
              fn2...()'; if the option is not set, this causes a parse error.
              Definition of multiple functions with the function keyword is
              always allowed.  Multiple function definitions are not often
              used and can cause obscure errors.

       MULTIOS <Z>
              Perform implicit tees or cats when multiple redirections are
              attempted (see the section `Redirection').

       OCTAL_ZEROES <S>
              Interpret any integer constant beginning with a 0 as octal, per
              IEEE Std 1003.2-1992 (ISO 9945-2:1993).  This is not enabled by
              default as it causes problems with parsing of, for example, date
              and time strings with leading zeroes.

              Sequences of digits indicating a numeric base such as the `08'
              component in `08#77' are always interpreted as decimal,
              regardless of leading zeroes.

       PIPE_FAIL
              By default, when a pipeline exits the exit status recorded by
              the shell and returned by the shell variable $? reflects that of
              the rightmost element of a pipeline.  If this option is set, the
              exit status instead reflects the status of the rightmost element
              of the pipeline that was non-zero, or zero if all elements
              exited with zero status.

       SOURCE_TRACE
              If set, zsh will print an informational message announcing the
              name of each file it loads.  The format of the output is similar
              to that for the XTRACE option, with the message <sourcetrace>.
              A file may be loaded by the shell itself when it starts up and
              shuts down (Startup/Shutdown Files) or by the use of the
              `source' and `dot' builtin commands.

       TYPESET_SILENT
              If this is unset, executing any of the `typeset' family of
              commands with no options and a list of parameters that have no
              values to be assigned but already exist will display the value
              of the parameter.  If the option is set, they will only be shown
              when parameters are selected with the `-m' option.  The option
              `-p' is available whether or not the option is set.

       VERBOSE (-v, ksh: -v)
              Print shell input lines as they are read.

       XTRACE (-x, ksh: -x)
              Print commands and their arguments as they are executed.  The
              output is preceded by the value of $PS4, formatted as described
              in the section EXPANSION OF PROMPT SEQUENCES in zshmisc(1).

   Shell Emulation
       APPEND_CREATE <K> <S>
              This option only applies when NO_CLOBBER (-C) is in effect.

              If this option is not set, the shell will report an error when a
              append redirection (>>) is used on a file that does not already
              exists (the traditional zsh behaviour of NO_CLOBBER).  If the
              option is set, no error is reported (POSIX behaviour).

       BASH_REMATCH
              When set, matches performed with the =~ operator will set the
              BASH_REMATCH array variable, instead of the default MATCH and
              match variables.  The first element of the BASH_REMATCH array
              will contain the entire matched text and subsequent elements
              will contain extracted substrings.  This option makes more sense
              when KSH_ARRAYS is also set, so that the entire matched portion
              is stored at index 0 and the first substring is at index 1.
              Without this option, the MATCH variable contains the entire
              matched text and the match array variable contains substrings.

       BSD_ECHO <S>
              Make the echo builtin compatible with the BSD echo(1) command.
              This disables backslashed escape sequences in echo strings
              unless the -e option is specified.

       CONTINUE_ON_ERROR
              If a fatal error is encountered (see the section ERRORS in
              zshmisc(1)), and the code is running in a script, the shell will
              resume execution at the next statement in the script at the top
              level, in other words outside all functions or shell constructs
              such as loops and conditions.  This mimics the behaviour of
              interactive shells, where the shell returns to the line editor
              to read a new command; it was the normal behaviour in versions
              of zsh before 5.0.1.

       CSH_JUNKIE_HISTORY <C>
              A history reference without an event specifier will always refer
              to the previous command.  Without this option, such a history
              reference refers to the same event as the previous history
              reference on the current command line, defaulting to the
              previous command.

       CSH_JUNKIE_LOOPS <C>
              Allow loop bodies to take the form `list; end' instead of `do
              list; done'.

       CSH_JUNKIE_QUOTES <C>
              Changes the rules for single- and double-quoted text to match
              that of csh.  These require that embedded newlines be preceded
              by a backslash; unescaped newlines will cause an error message.
              In double-quoted strings, it is made impossible to escape `$',
              ``' or `"' (and `\' itself no longer needs escaping).  Command
              substitutions are only expanded once, and cannot be nested.

       CSH_NULLCMD <C>
              Do not use the values of NULLCMD and READNULLCMD when running
              redirections with no command.  This make such redirections fail
              (see the section `Redirection').

       KSH_ARRAYS <K> <S>
              Emulate ksh array handling as closely as possible.  If this
              option is set, array elements are numbered from zero, an array
              parameter without subscript refers to the first element instead
              of the whole array, and braces are required to delimit a
              subscript (`${path[2]}' rather than just `$path[2]') or to apply
              modifiers to any parameter (`${PWD:h}' rather than `$PWD:h').

       KSH_AUTOLOAD <K> <S>
              Emulate ksh function autoloading.  This means that when a
              function is autoloaded, the corresponding file is merely
              executed, and must define the function itself.  (By default, the
              function is defined to the contents of the file.  However, the
              most common ksh-style case - of the file containing only a
              simple definition of the function - is always handled in the
              ksh-compatible manner.)

       KSH_OPTION_PRINT <K>
              Alters the way options settings are printed: instead of separate
              lists of set and unset options, all options are shown, marked
              `on' if they are in the non-default state, `off' otherwise.

       KSH_TYPESET
              This option is now obsolete: a better appropximation to the
              behaviour of other shells is obtained with the reserved word
              interface to declare, export, float, integer, local, readonly
              and typeset.  Note that the option is only applied when the
              reserved word interface is not in use.

              Alters the way arguments to the typeset family of commands,
              including declare, export, float, integer, local and readonly,
              are processed.  Without this option, zsh will perform normal
              word splitting after command and parameter expansion in
              arguments of an assignment; with it, word splitting does not
              take place in those cases.

       KSH_ZERO_SUBSCRIPT
              Treat use of a subscript of value zero in array or string
              expressions as a reference to the first element, i.e. the
              element that usually has the subscript 1.  Ignored if KSH_ARRAYS
              is also set.

              If neither this option nor KSH_ARRAYS is set, accesses to an
              element of an array or string with subscript zero return an
              empty element or string, while attempts to set element zero of
              an array or string are treated as an error.  However, attempts
              to set an otherwise valid subscript range that includes zero
              will succeed.  For example, if KSH_ZERO_SUBSCRIPT is not set,

                     array[0]=(element)

              is an error, while

                     array[0,1]=(element)

              is not and will replace the first element of the array.

              This option is for compatibility with older versions of the
              shell and is not recommended in new code.

       POSIX_ALIASES <K> <S>
              When this option is set, reserved words are not candidates for
              alias expansion:  it is still possible to declare any of them as
              an alias, but the alias will never be expanded.  Reserved words
              are described in the section RESERVED WORDS in zshmisc(1).

              Alias expansion takes place while text is being read; hence when
              this option is set it does not take effect until the end of any
              function or other piece of shell code parsed as one unit.  Note
              this may cause differences from other shells even when the
              option is in effect.  For example, when running a command with
              `zsh -c', or even `zsh -o posixaliases -c', the entire command
              argument is parsed as one unit, so aliases defined within the
              argument are not available even in later lines.  If in doubt,
              avoid use of aliases in non-interactive code.

       POSIX_ARGZERO
              This option may be used to temporarily disable FUNCTION_ARGZERO
              and thereby restore the value of $0 to the name used to invoke
              the shell (or as set by the -c command line option).  For
              compatibility with previous versions of the shell, emulations
              use NO_FUNCTION_ARGZERO instead of POSIX_ARGZERO, which may
              result in unexpected scoping of $0 if the emulation mode is
              changed inside a function or script.  To avoid this, explicitly
              enable POSIX_ARGZERO in the emulate command:

                     emulate sh -o POSIX_ARGZERO

              Note that NO_POSIX_ARGZERO has no effect unless FUNCTION_ARGZERO
              was already enabled upon entry to the function or script.

       POSIX_BUILTINS <K> <S>
              When this option is set the command builtin can be used to
              execute shell builtin commands.  Parameter assignments specified
              before shell functions and special builtins are kept after the
              command completes unless the special builtin is prefixed with
              the command builtin.  Special builtins are ., :, break,
              continue, declare, eval, exit, export, integer, local, readonly,
              return, set, shift, source, times, trap and unset.

              In addition, various error conditions associated with the above
              builtins or exec cause a non-interactive shell to exit and an
              interactive shell to return to its top-level processing.

              Furthermore, functions and shell builtins are not executed after
              an exec prefix; the command to be executed must be an external
              command found in the path.

              Furthermore, the getopts builtin behaves in a POSIX-compatible
              fashion in that the associated variable OPTIND is not made local
              to functions.

              Moreover, the warning and special exit code from [[ -o
              non_existent_option ]] are suppressed.

       POSIX_IDENTIFIERS <K> <S>
              When this option is set, only the ASCII characters a to z, A to
              Z, 0 to 9 and _ may be used in identifiers (names of shell
              parameters and modules).

              In addition, setting this option limits the effect of parameter
              substitution with no braces, so that the expression $# is
              treated as the parameter $# even if followed by a valid
              parameter name.  When it is unset, zsh allows expressions of the
              form $#name to refer to the length of $name, even for special
              variables, for example in expressions such as $#- and $#*.

              Another difference is that with the option set assignment to an
              unset variable in arithmetic context causes the variable to be
              created as a scalar rather than a numeric type.  So after `unset
              t; (( t = 3 ))'. without POSIX_IDENTIFIERS set t has integer
              type, while with it set it has scalar type.

              When the option is unset and multibyte character support is
              enabled (i.e. it is compiled in and the option MULTIBYTE is
              set), then additionally any alphanumeric characters in the local
              character set may be used in identifiers.  Note that scripts and
              functions written with this feature are not portable, and also
              that both options must be set before the script or function is
              parsed; setting them during execution is not sufficient as the
              syntax variable=value has already been parsed as a command
              rather than an assignment.

              If multibyte character support is not compiled into the shell
              this option is ignored; all octets with the top bit set may be
              used in identifiers.  This is non-standard but is the
              traditional zsh behaviour.

       POSIX_STRINGS <K> <S>
              This option affects processing of quoted strings.  Currently it
              only affects the behaviour of null characters, i.e. character 0
              in the portable character set corresponding to US ASCII.

              When this option is not set, null characters embedded within
              strings of the form $'...' are treated as ordinary characters.
              The entire string is maintained within the shell and output to
              files where necessary, although owing to restrictions of the
              library interface the string is truncated at the null character
              in file names, environment variables, or in arguments to
              external programs.

              When this option is set, the $'...' expression is truncated at
              the null character.  Note that remaining parts of the same
              string beyond the termination of the quotes are not truncated.

              For example, the command line argument a$'b\0c'd is treated with
              the option off as the characters a, b, null, c, d, and with the
              option on as the characters a, b, d.

       POSIX_TRAPS <K> <S>
              When this option is set, the usual zsh behaviour of executing
              traps for EXIT on exit from shell functions is suppressed.  In
              that case, manipulating EXIT traps always alters the global trap
              for exiting the shell; the LOCAL_TRAPS option is ignored for the
              EXIT trap.  Furthermore, a return statement executed in a trap
              with no argument passes back from the function the value from
              the surrounding context, not from code executed within the trap.

       SH_FILE_EXPANSION <K> <S>
              Perform filename expansion (e.g., ~ expansion) before parameter
              expansion, command substitution, arithmetic expansion and brace
              expansion.  If this option is unset, it is performed after brace
              expansion, so things like `~$USERNAME' and `~{pfalstad,rc}' will
              work.

       SH_NULLCMD <K> <S>
              Do not use the values of NULLCMD and READNULLCMD when doing
              redirections, use `:' instead (see the section `Redirection').

       SH_OPTION_LETTERS <K> <S>
              If this option is set the shell tries to interpret single letter
              options (which are used with set and setopt) like ksh does.
              This also affects the value of the - special parameter.

       SH_WORD_SPLIT (-y) <K> <S>
              Causes field splitting to be performed on unquoted parameter
              expansions.  Note that this option has nothing to do with word
              splitting.  (See zshexpn(1).)

       TRAPS_ASYNC
              While waiting for a program to exit, handle signals and run
              traps immediately.  Otherwise the trap is run after a child
              process has exited.  Note this does not affect the point at
              which traps are run for any case other than when the shell is
              waiting for a child process.

   Shell State
       INTERACTIVE (-i, ksh: -i)
              This is an interactive shell.  This option is set upon
              initialisation if the standard input is a tty and commands are
              being read from standard input.  (See the discussion of
              SHIN_STDIN.)  This heuristic may be overridden by specifying a
              state for this option on the command line.  The value of this
              option can only be changed via flags supplied at invocation of
              the shell.  It cannot be changed once zsh is running.

       LOGIN (-l, ksh: -l)
              This is a login shell.  If this option is not explicitly set,
              the shell becomes a login shell if the first character of the
              argv[0] passed to the shell is a `-'.

       PRIVILEGED (-p, ksh: -p)
              Turn on privileged mode. Typically this is used when script is
              to be run with elevated privileges. This should be done as
              follows directly with the -p option to zsh so that it takes
              effect during startup.

                     #!/bin/zsh -p

              The option is enabled automatically on startup if the effective
              user (group) ID is not equal to the real user (group) ID. In
              this case, turning the option off causes the effective user and
              group IDs to be set to the real user and group IDs. Be aware
              that if that fails the shell may be running with different IDs
              than was intended so a script should check for failure and act
              accordingly, for example:

                     unsetopt privileged || exit

              The PRIVILEGED option disables sourcing user startup files.  If
              zsh is invoked as `sh' or `ksh' with this option set,
              /etc/suid_profile is sourced (after /etc/profile on interactive
              shells). Sourcing ~/.profile is disabled and the contents of the
              ENV variable is ignored. This option cannot be changed using the
              -m option of setopt and unsetopt, and changing it inside a
              function always changes it globally regardless of the
              LOCAL_OPTIONS option.

       RESTRICTED (-r)
              Enables restricted mode.  This option cannot be changed using
              unsetopt, and setting it inside a function always changes it
              globally regardless of the LOCAL_OPTIONS option.  See the
              section `Restricted Shell'.

       SHIN_STDIN (-s, ksh: -s)
              Commands are being read from the standard input.  Commands are
              read from standard input if no command is specified with -c and
              no file of commands is specified.  If SHIN_STDIN is set
              explicitly on the command line, any argument that would
              otherwise have been taken as a file to run will instead be
              treated as a normal positional parameter.  Note that setting or
              unsetting this option on the command line does not necessarily
              affect the state the option will have while the shell is running
              - that is purely an indicator of whether or not commands are
              actually being read from standard input.  The value of this
              option can only be changed via flags supplied at invocation of
              the shell.  It cannot be changed once zsh is running.

       SINGLE_COMMAND (-t, ksh: -t)
              If the shell is reading from standard input, it exits after a
              single command has been executed.  This also makes the shell
              non-interactive, unless the INTERACTIVE option is explicitly set
              on the command line.  The value of this option can only be
              changed via flags supplied at invocation of the shell.  It
              cannot be changed once zsh is running.

   Zle
       BEEP (+B) <D>
              Beep on error in ZLE.

       COMBINING_CHARS
              Assume that the terminal displays combining characters
              correctly.  Specifically, if a base alphanumeric character is
              followed by one or more zero-width punctuation characters,
              assume that the zero-width characters will be displayed as
              modifications to the base character within the same width.  Not
              all terminals handle this.  If this option is not set,
              zero-width characters are displayed separately with special
              mark-up.

              If this option is set, the pattern test [[:WORD:]] matches a
              zero-width punctuation character on the assumption that it will
              be used as part of a word in combination with a word character.
              Otherwise the base shell does not handle combining characters
              specially.

       EMACS  If ZLE is loaded, turning on this option has the equivalent
              effect of `bindkey -e'.  In addition, the VI option is unset.
              Turning it off has no effect.  The option setting is not
              guaranteed to reflect the current keymap.  This option is
              provided for compatibility; bindkey is the recommended
              interface.

       OVERSTRIKE
              Start up the line editor in overstrike mode.

       SINGLE_LINE_ZLE (-M) <K>
              Use single-line command line editing instead of multi-line.

              Note that although this is on by default in ksh emulation it
              only provides superficial compatibility with the ksh line editor
              and reduces the effectiveness of the zsh line editor.  As it has
              no effect on shell syntax, many users may wish to disable this
              option when using ksh emulation interactively.

       VI     If ZLE is loaded, turning on this option has the equivalent
              effect of `bindkey -v'.  In addition, the EMACS option is unset.
              Turning it off has no effect.  The option setting is not
              guaranteed to reflect the current keymap.  This option is
              provided for compatibility; bindkey is the recommended
              interface.

       ZLE (-Z)
              Use the zsh line editor.  Set by default in interactive shells
              connected to a terminal.

OPTION ALIASES
       Some options have alternative names.  These aliases are never used for
       output, but can be used just like normal option names when specifying
       options to the shell.

       BRACE_EXPAND
              NO_IGNORE_BRACES (ksh and bash compatibility)

       DOT_GLOB
              GLOB_DOTS (bash compatibility)

       HASH_ALL
              HASH_CMDS (bash compatibility)

       HIST_APPEND
              APPEND_HISTORY (bash compatibility)

       HIST_EXPAND
              BANG_HIST (bash compatibility)

       LOG    NO_HIST_NO_FUNCTIONS (ksh compatibility)

       MAIL_WARN
              MAIL_WARNING (bash compatibility)

       ONE_CMD
              SINGLE_COMMAND (bash compatibility)

       PHYSICAL
              CHASE_LINKS (ksh and bash compatibility)

       PROMPT_VARS
              PROMPT_SUBST (bash compatibility)

       STDIN  SHIN_STDIN (ksh compatibility)

       TRACK_ALL
              HASH_CMDS (ksh compatibility)

SINGLE LETTER OPTIONS
   Default set
       -0     CORRECT
       -1     PRINT_EXIT_VALUE
       -2     NO_BAD_PATTERN
       -3     NO_NOMATCH
       -4     GLOB_DOTS
       -5     NOTIFY
       -6     BG_NICE
       -7     IGNORE_EOF
       -8     MARK_DIRS
       -9     AUTO_LIST
       -B     NO_BEEP
       -C     NO_CLOBBER
       -D     PUSHD_TO_HOME
       -E     PUSHD_SILENT
       -F     NO_GLOB
       -G     NULL_GLOB
       -H     RM_STAR_SILENT
       -I     IGNORE_BRACES
       -J     AUTO_CD
       -K     NO_BANG_HIST
       -L     SUN_KEYBOARD_HACK
       -M     SINGLE_LINE_ZLE
       -N     AUTO_PUSHD
       -O     CORRECT_ALL
       -P     RC_EXPAND_PARAM
       -Q     PATH_DIRS
       -R     LONG_LIST_JOBS
       -S     REC_EXACT
       -T     CDABLE_VARS
       -U     MAIL_WARNING
       -V     NO_PROMPT_CR
       -W     AUTO_RESUME
       -X     LIST_TYPES
       -Y     MENU_COMPLETE
       -Z     ZLE
       -a     ALL_EXPORT
       -e     ERR_EXIT
       -f     NO_RCS
       -g     HIST_IGNORE_SPACE
       -h     HIST_IGNORE_DUPS
       -i     INTERACTIVE
       -k     INTERACTIVE_COMMENTS
       -l     LOGIN
       -m     MONITOR
       -n     NO_EXEC
       -p     PRIVILEGED
       -r     RESTRICTED
       -s     SHIN_STDIN
       -t     SINGLE_COMMAND
       -u     NO_UNSET
       -v     VERBOSE
       -w     CHASE_LINKS
       -x     XTRACE
       -y     SH_WORD_SPLIT

   sh/ksh emulation set
       -C     NO_CLOBBER
       -T     TRAPS_ASYNC
       -X     MARK_DIRS
       -a     ALL_EXPORT
       -b     NOTIFY
       -e     ERR_EXIT
       -f     NO_GLOB
       -i     INTERACTIVE
       -l     LOGIN
       -m     MONITOR
       -n     NO_EXEC
       -p     PRIVILEGED
       -r     RESTRICTED
       -s     SHIN_STDIN
       -t     SINGLE_COMMAND
       -u     NO_UNSET
       -v     VERBOSE
       -x     XTRACE

   Also note
       -A     Used by set for setting arrays
       -b     Used on the command line to specify end of option processing
       -c     Used on the command line to specify a single command
       -m     Used by setopt for pattern-matching option setting
       -o     Used in all places to allow use of long option names
       -s     Used by set to sort positional parameters




ZSHBUILTINS(1)              General Commands Manual             ZSHBUILTINS(1)



NAME
       zshbuiltins - zsh built-in commands

SHELL BUILTIN COMMANDS
       Some shell builtin commands take options as described in individual
       entries; these are often referred to in the list below as `flags' to
       avoid confusion with shell options, which may also have an effect on
       the behaviour of builtin commands.  In this introductory section,
       `option' always has the meaning of an option to a command that should
       be familiar to most command line users.

       Typically, options are single letters preceded by a hyphen (-).
       Options that take an argument accept it either immediately following
       the option letter or after white space, for example `print -C3 {1..9}'
       or `print -C 3 {1..9}' are equivalent.  Arguments to options are not
       the same as arguments to the command; the documentation indicates which
       is which.  Options that do not take an argument may be combined in a
       single word, for example `print -rca -- *' and `print -r -c -a -- *'
       are equivalent.

       Some shell builtin commands also take options that begin with `+'
       instead of `-'.  The list below makes clear which commands these are.

       Options (together with their individual arguments, if any) must appear
       in a group before any non-option arguments; once the first non-option
       argument has been found, option processing is terminated.

       All builtin commands other than `echo' and precommand modifiers, even
       those that have no options, can be given the argument `--' to terminate
       option processing.  This indicates that the following words are
       non-option arguments, but is otherwise ignored.  This is useful in
       cases where arguments to the command may begin with `-'.  For
       historical reasons, most builtin commands (including `echo') also
       recognize a single `-' in a separate word for this purpose; note that
       this is less standard and use of `--' is recommended.

       - simple command
              See the section `Precommand Modifiers' in zshmisc(1).

       . file [ arg ... ]
              Read commands from file and execute them in the current shell
              environment.

              If file does not contain a slash, or if PATH_DIRS is set, the
              shell looks in the components of $path to find the directory
              containing file.  Files in the current directory are not read
              unless `.' appears somewhere in $path.  If a file named
              `file.zwc' is found, is newer than file, and is the compiled
              form (created with the zcompile builtin) of file, then commands
              are read from that file instead of file.

              If any arguments arg are given, they become the positional
              parameters; the old positional parameters are restored when the
              file is done executing.  However, if no arguments are given, the
              positional parameters remain those of the calling context, and
              no restoring is done.

              If file was not found the return status is 127; if file was
              found but contained a syntax error the return status is 126;
              else the return status is the exit status of the last command
              executed.

       : [ arg ... ]
              This command does nothing, although normal argument expansions
              is performed which may have effects on shell parameters.  A zero
              exit status is returned.

       alias [ {+|-}gmrsL ] [ name[=value] ... ]
              For each name with a corresponding value, define an alias with
              that value.  A trailing space in value causes the next word to
              be checked for alias expansion.  If the -g flag is present,
              define a global alias; global aliases are expanded even if they
              do not occur in command position.

              If the -s flag is present, define a suffix alias: if the command
              word on a command line is in the form `text.name', where text is
              any non-empty string, it is replaced by the text `value
              text.name'.  Note that name is treated as a literal string, not
              a pattern.  A trailing space in value is not special in this
              case.  For example,

                     alias -s ps='gv --'

              will cause the command `*.ps' to be expanded to `gv -- *.ps'.
              As alias expansion is carried out earlier than globbing, the
              `*.ps' will then be expanded.  Suffix aliases constitute a
              different name space from other aliases (so in the above example
              it is still possible to create an alias for the command ps) and
              the two sets are never listed together.

              For each name with no value, print the value of name, if any.
              With no arguments, print all currently defined aliases other
              than suffix aliases.  If the -m flag is given the arguments are
              taken as patterns (they should be quoted to preserve them from
              being interpreted as glob patterns), and the aliases matching
              these patterns are printed.  When printing aliases and one of
              the -g, -r or -s flags is present, restrict the printing to
              global, regular or suffix aliases, respectively; a regular alias
              is one which is neither a global nor a suffix alias.   Using `+'
              instead of `-', or ending the option list with a single `+',
              prevents the values of the aliases from being printed.

              If the -L flag is present, then print each alias in a manner
              suitable for putting in a startup script.  The exit status is
              nonzero if a name (with no value) is given for which no alias
              has been defined.

              For more on aliases, include common problems, see the section
              ALIASING in zshmisc(1).

       autoload [ {+|-}RTUXdkmrtWz ] [ -w ] [ name ... ]
              See the section `Autoloading Functions' in zshmisc(1) for full
              details.  The fpath parameter will be searched to find the
              function definition when the function is first referenced.

              If name consists of an absolute path, the function is defined to
              load from the file given (searching as usual for dump files in
              the given location).  The name of the function is the basename
              (non-directory part) of the file.  It is normally an error if
              the function is not found in the given location; however, if the
              option -d is given, searching for the function defaults to
              $fpath.  If a function is loaded by absolute path, any functions
              loaded from it that are marked for autoload without an absolute
              path have the load path of the parent function temporarily
              prepended to $fpath.

              If the option -r or -R is given, the function is searched for
              immediately and the location is recorded internally for use when
              the function is executed; a relative path is expanded using the
              value of $PWD.  This protects against a change to $fpath after
              the call to autoload.  With -r, if the function is not found, it
              is silently left unresolved until execution; with -R, an error
              message is printed and command processing aborted immediately
              the search fails, i.e. at the autoload command rather than at
              function execution..

              The flag -X may be used only inside a shell function.  It causes
              the calling function to be marked for autoloading and then
              immediately loaded and executed, with the current array of
              positional parameters as arguments.  This replaces the previous
              definition of the function.  If no function definition is found,
              an error is printed and the function remains undefined and
              marked for autoloading.  If an argument is given, it is used as
              a directory (i.e. it does not include the name of the function)
              in which the function is to be found; this may be combined with
              the -d option to allow the function search to default to $fpath
              if it is not in the given location.

              The flag +X attempts to load each name as an autoloaded
              function, but does not execute it.  The exit status is zero
              (success) if the function was not previously defined and a
              definition for it was found.  This does not replace any existing
              definition of the function.  The exit status is nonzero
              (failure) if the function was already defined or when no
              definition was found.  In the latter case the function remains
              undefined and marked for autoloading.  If ksh-style autoloading
              is enabled, the function created will contain the contents of
              the file plus a call to the function itself appended to it, thus
              giving normal ksh autoloading behaviour on the first call to the
              function.  If the -m flag is also given each name is treated as
              a pattern and all functions already marked for autoload that
              match the pattern are loaded.

              With the -t flag, turn on execution tracing; with -T, turn on
              execution tracing only for the current function, turning it off
              on entry to any called functions that do not also have tracing
              enabled.

              With the -U flag, alias expansion is suppressed when the
              function is loaded.

              With the -w flag, the names are taken as names of files compiled
              with the zcompile builtin, and all functions defined in them are
              marked for autoloading.

              The flags -z and -k mark the function to be autoloaded using the
              zsh or ksh style, as if the option KSH_AUTOLOAD were unset or
              were set, respectively.  The flags override the setting of the
              option at the time the function is loaded.

              Note that the autoload command makes no attempt to ensure the
              shell options set during the loading or execution of the file
              have any particular value.  For this, the emulate command can be
              used:

                     emulate zsh -c 'autoload -Uz func'

              arranges that when func is loaded the shell is in native zsh
              emulation, and this emulation is also applied when func is run.

              Some of the functions of autoload are also provided by functions
              -u or functions -U, but autoload is a more comprehensive
              interface.

       bg [ job ... ]
       job ... &
              Put each specified job in the background, or the current job if
              none is specified.

       bindkey
              See the section `Zle Builtins' in zshzle(1).

       break [ n ]
              Exit from an enclosing for, while, until, select or repeat loop.
              If an arithmetic expression n is specified, then break n levels
              instead of just one.

       builtin name [ args ... ]
              Executes the builtin name, with the given args.

       bye    Same as exit.

       cap    See the section `The zsh/cap Module' in zshmodules(1).

       cd [ -qsLP ] [ arg ]
       cd [ -qsLP ] old new
       cd [ -qsLP ] {+|-}n
              Change the current directory.  In the first form, change the
              current directory to arg, or to the value of $HOME if arg is not
              specified.  If arg is `-', change to the previous directory.

              Otherwise, if arg begins with a slash, attempt to change to the
              directory given by arg.

              If arg does not begin with a slash, the behaviour depends on
              whether the current directory `.' occurs in the list of
              directories contained in the shell parameter cdpath.  If it does
              not, first attempt to change to the directory arg under the
              current directory, and if that fails but cdpath is set and
              contains at least one element attempt to change to the directory
              arg under each component of cdpath in turn until successful.  If
              `.' occurs in cdpath, then cdpath is searched strictly in order
              so that `.' is only tried at the appropriate point.

              The order of testing cdpath is modified if the option POSIX_CD
              is set, as described in the documentation for the option.

              If no directory is found, the option CDABLE_VARS is set, and a
              parameter named arg exists whose value begins with a slash,
              treat its value as the directory.  In that case, the parameter
              is added to the named directory hash table.

              The second form of cd substitutes the string new for the string
              old in the name of the current directory, and tries to change to
              this new directory.

              The third form of cd extracts an entry from the directory stack,
              and changes to that directory.  An argument of the form `+n'
              identifies a stack entry by counting from the left of the list
              shown by the dirs command, starting with zero.  An argument of
              the form `-n' counts from the right.  If the PUSHD_MINUS option
              is set, the meanings of `+' and `-' in this context are swapped.
              If the POSIX_CD option is set, this form of cd is not recognised
              and will be interpreted as the first form.

              If the -q (quiet) option is specified, the hook function chpwd
              and the functions in the array chpwd_functions are not called.
              This is useful for calls to cd that do not change the
              environment seen by an interactive user.

              If the -s option is specified, cd refuses to change the current
              directory if the given pathname contains symlinks.  If the -P
              option is given or the CHASE_LINKS option is set, symbolic links
              are resolved to their true values.  If the -L option is given
              symbolic links are retained in the directory (and not resolved)
              regardless of the state of the CHASE_LINKS option.

       chdir  Same as cd.

       clone  See the section `The zsh/clone Module' in zshmodules(1).

       command [ -pvV ] simple command
              The simple command argument is taken as an external command
              instead of a function or builtin and is executed. If the
              POSIX_BUILTINS option is set, builtins will also be executed but
              certain special properties of them are suppressed. The -p flag
              causes a default path to be searched instead of that in $path.
              With the -v flag, command is similar to whence and with -V, it
              is equivalent to whence -v.

              See also the section `Precommand Modifiers' in zshmisc(1).

       comparguments
              See the section `The zsh/computil Module' in zshmodules(1).

       compcall
              See the section `The zsh/compctl Module' in zshmodules(1).

       compctl
              See the section `The zsh/compctl Module' in zshmodules(1).

       compdescribe
              See the section `The zsh/computil Module' in zshmodules(1).

       compfiles
              See the section `The zsh/computil Module' in zshmodules(1).

       compgroups
              See the section `The zsh/computil Module' in zshmodules(1).

       compquote
              See the section `The zsh/computil Module' in zshmodules(1).

       comptags
              See the section `The zsh/computil Module' in zshmodules(1).

       comptry
              See the section `The zsh/computil Module' in zshmodules(1).

       compvalues
              See the section `The zsh/computil Module' in zshmodules(1).

       continue [ n ]
              Resume the next iteration of the enclosing for, while, until,
              select or repeat loop. If an arithmetic expression n is
              specified, break out of n-1 loops and resume at the nth
              enclosing loop.

       declare
              Same as typeset.

       dirs [ -c ] [ arg ... ]
       dirs [ -lpv ]
              With no arguments, print the contents of the directory stack.
              Directories are added to this stack with the pushd command, and
              removed with the cd or popd commands.  If arguments are
              specified, load them onto the directory stack, replacing
              anything that was there, and push the current directory onto the
              stack.

              -c     clear the directory stack.

              -l     print directory names in full instead of using of using ~
                     expressions (see Dynamic and Static named directories in
                     zshexpn(1)).

              -p     print directory entries one per line.

              -v     number the directories in the stack when printing.

       disable [ -afmprs ] name ...
              Temporarily disable the named hash table elements or patterns.
              The default is to disable builtin commands.  This allows you to
              use an external command with the same name as a builtin command.
              The -a option causes disable to act on regular or global
              aliases.  The -s option causes disable to act on suffix aliases.
              The -f option causes disable to act on shell functions.  The -r
              options causes disable to act on reserved words.  Without
              arguments all disabled hash table elements from the
              corresponding hash table are printed.  With the -m flag the
              arguments are taken as patterns (which should be quoted to
              prevent them from undergoing filename expansion), and all hash
              table elements from the corresponding hash table matching these
              patterns are disabled.  Disabled objects can be enabled with the
              enable command.

              With the option -p, name ... refer to elements of the shell's
              pattern syntax as described in the section `Filename
              Generation'.  Certain elements can be disabled separately, as
              given below.

              Note that patterns not allowed by the current settings for the
              options EXTENDED_GLOB, KSH_GLOB and SH_GLOB are never enabled,
              regardless of the setting here.  For example, if EXTENDED_GLOB
              is not active, the pattern ^ is ineffective even if `disable -p
              "^"' has not been issued.  The list below indicates any option
              settings that restrict the use of the pattern.  It should be
              noted that setting SH_GLOB has a wider effect than merely
              disabling patterns as certain expressions, in particular those
              involving parentheses, are parsed differently.

              The following patterns may be disabled; all the strings need
              quoting on the command line to prevent them from being
              interpreted immediately as patterns and the patterns are shown
              below in single quotes as a reminder.

              '?'    The pattern character ? wherever it occurs, including
                     when preceding a parenthesis with KSH_GLOB.

              '*'    The pattern character * wherever it occurs, including
                     recursive globbing and when preceding a parenthesis with
                     KSH_GLOB.

              '['    Character classes.

              '<' (NO_SH_GLOB)
                     Numeric ranges.

              '|' (NO_SH_GLOB)
                     Alternation in grouped patterns, case statements, or
                     KSH_GLOB parenthesised expressions.

              '(' (NO_SH_GLOB)
                     Grouping using single parentheses.  Disabling this does
                     not disable the use of parentheses for KSH_GLOB where
                     they are introduced by a special character, nor for glob
                     qualifiers (use `setopt NO_BARE_GLOB_QUAL' to disable
                     glob qualifiers that use parentheses only).

              '~' (EXTENDED_GLOB)
                     Exclusion in the form A~B.

              '^' (EXTENDED_GLOB)
                     Exclusion in the form A^B.

              '#' (EXTENDED_GLOB)
                     The pattern character # wherever it occurs, both for
                     repetition of a previous pattern and for indicating
                     globbing flags.

              '?(' (KSH_GLOB)
                     The grouping form ?(...).  Note this is also disabled if
                     '?' is disabled.

              '*(' (KSH_GLOB)
                     The grouping form *(...).  Note this is also disabled if
                     '*' is disabled.

              '+(' (KSH_GLOB)
                     The grouping form +(...).

              '!(' (KSH_GLOB)
                     The grouping form !(...).

              '@(' (KSH_GLOB)
                     The grouping form @(...).

       disown [ job ... ]
       job ... &|
       job ... &!
              Remove the specified jobs from the job table; the shell will no
              longer report their status, and will not complain if you try to
              exit an interactive shell with them running or stopped.  If no
              job is specified, disown the current job.

              If the jobs are currently stopped and the AUTO_CONTINUE option
              is not set, a warning is printed containing information about
              how to make them running after they have been disowned.  If one
              of the latter two forms is used, the jobs will automatically be
              made running, independent of the setting of the AUTO_CONTINUE
              option.

       echo [ -neE ] [ arg ... ]
              Write each arg on the standard output, with a space separating
              each one.  If the -n flag is not present, print a newline at the
              end.  echo recognizes the following escape sequences:

              \a     bell character
              \b     backspace
              \c     suppress subsequent characters and final newline
              \e     escape
              \f     form feed
              \n     linefeed (newline)
              \r     carriage return
              \t     horizontal tab
              \v     vertical tab
              \\     backslash
              \0NNN  character code in octal
              \xNN   character code in hexadecimal
              \uNNNN unicode character code in hexadecimal
              \UNNNNNNNN
                     unicode character code in hexadecimal

              The -E flag, or the BSD_ECHO option, can be used to disable
              these escape sequences.  In the latter case, -e flag can be used
              to enable them.

              Note that for standards compliance a double dash does not
              terminate option processing; instead, it is printed directly.
              However, a single dash does terminate option processing, so the
              first dash, possibly following options, is not printed, but
              everything following it is printed as an argument.  The single
              dash behaviour is different from other shells.  For a more
              portable way of printing text, see printf, and for a more
              controllable way of printing text within zsh, see print.

       echotc See the section `The zsh/termcap Module' in zshmodules(1).

       echoti See the section `The zsh/terminfo Module' in zshmodules(1).

       emulate [ -lLR ] [ {zsh|sh|ksh|csh} [ flags ... ] ]
              Without any argument print current emulation mode.

              With single argument set up zsh options to emulate the specified
              shell as much as possible.  csh will never be fully emulated.
              If the argument is not one of the shells listed above, zsh will
              be used as a default; more precisely, the tests performed on the
              argument are the same as those used to determine the emulation
              at startup based on the shell name, see the section
              COMPATIBILITY in zsh(1) .  In addition to setting shell options,
              the command also restores the pristine state of pattern enables,
              as if all patterns had been enabled using enable -p.

              If the emulate command occurs inside a function that has been
              marked for execution tracing with functions -t then the xtrace
              option will be turned on regardless of emulation mode or other
              options.  Note that code executed inside the function by the .,
              source, or eval commands is not considered to be running
              directly from the function, hence does not provoke this
              behaviour.

              If the -R switch is given, all settable options are reset to
              their default value corresponding to the specified emulation
              mode, except for certain options describing the interactive
              environment; otherwise, only those options likely to cause
              portability problems in scripts and functions are altered.  If
              the -L switch is given, the options LOCAL_OPTIONS,
              LOCAL_PATTERNS and LOCAL_TRAPS will be set as well, causing the
              effects of the emulate command and any setopt, disable -p or
              enable -p, and trap commands to be local to the immediately
              surrounding shell function, if any; normally these options are
              turned off in all emulation modes except ksh. The -L switch is
              mutually exclusive with the use of -c in flags.

              If there is a single argument and the -l switch is given, the
              options that would be set or unset (the latter indicated with
              the prefix `no') are listed.  -l can be combined with -L or -R
              and the list will be modified in the appropriate way.  Note the
              list does not depend on the current setting of options, i.e. it
              includes all options that may in principle change, not just
              those that would actually change.

              The flags may be any of the invocation-time flags described in
              the section INVOCATION in zsh(1), except that `-o EMACS' and `-o
              VI' may not be used.  Flags such as `+r'/`+o RESTRICTED' may be
              prohibited in some circumstances.

              If -c arg appears in flags, arg is evaluated while the requested
              emulation is temporarily in effect.  In this case the emulation
              mode and all options are restored to their previous values
              before emulate returns.  The -R switch may precede the name of
              the shell to emulate; note this has a meaning distinct from
              including -R in flags.

              Use of -c enables `sticky' emulation mode for functions defined
              within the evaluated expression:  the emulation mode is
              associated thereafter with the function so that whenever the
              function is executed the emulation (respecting the -R switch, if
              present) and all options are set (and pattern disables cleared)
              before entry to the function, and the state is restored after
              exit.  If the function is called when the sticky emulation is
              already in effect, either within an `emulate shell -c'
              expression or within another function with the same sticky
              emulation, entry and exit from the function do not cause options
              to be altered (except due to standard processing such as the
              LOCAL_OPTIONS option).  This also applies to functions marked
              for autoload within the sticky emulation; the appropriate set of
              options will be applied at the point the function is loaded as
              well as when it is run.

              For example:

                     emulate sh -c 'fni() { setopt cshnullglob; }
                     fno() { fni; }'
                     fno

              The two functions fni and fno are defined with sticky sh
              emulation.  fno is then executed, causing options associated
              with emulations to be set to their values in sh.  fno then calls
              fni; because fni is also marked for sticky sh emulation, no
              option changes take place on entry to or exit from it.  Hence
              the option cshnullglob, turned off by sh emulation, will be
              turned on within fni and remain on return to fno.  On exit from
              fno, the emulation mode and all options will be restored to the
              state they were in before entry to the temporary emulation.

              The documentation above is typically sufficient for the intended
              purpose of executing code designed for other shells in a
              suitable environment.  More detailed rules follow.
              1.     The sticky emulation environment provided by `emulate
                     shell -c' is identical to that provided by entry to a
                     function marked for sticky emulation as a consequence of
                     being defined in such an environment.  Hence, for
                     example, the sticky emulation is inherited by
                     subfunctions defined within functions with sticky
                     emulation.
              2.     No change of options takes place on entry to or exit from
                     functions that are not marked for sticky emulation, other
                     than those that would normally take place, even if those
                     functions are called within sticky emulation.
              3.     No special handling is provided for functions marked for
                     autoload nor for functions present in wordcode created by
                     the zcompile command.
              4.     The presence or absence of the -R switch to emulate
                     corresponds to different sticky emulation modes, so for
                     example `emulate sh -c', `emulate -R sh -c' and `emulate
                     csh -c' are treated as three distinct sticky emulations.
              5.     Difference in shell options supplied in addition to the
                     basic emulation also mean the sticky emulations are
                     different, so for example `emulate zsh -c' and `emulate
                     zsh -o cbases -c' are treated as distinct sticky
                     emulations.

       enable [ -afmprs ] name ...
              Enable the named hash table elements, presumably disabled
              earlier with disable.  The default is to enable builtin
              commands.  The -a option causes enable to act on regular or
              global aliases.  The -s option causes enable to act on suffix
              aliases.  The -f option causes enable to act on shell functions.
              The -r option causes enable to act on reserved words.  Without
              arguments all enabled hash table elements from the corresponding
              hash table are printed.  With the -m flag the arguments are
              taken as patterns (should be quoted) and all hash table elements
              from the corresponding hash table matching these patterns are
              enabled.  Enabled objects can be disabled with the disable
              builtin command.

              enable -p reenables patterns disabled with disable -p.  Note
              that it does not override globbing options; for example, `enable
              -p "~"' does not cause the pattern character ~ to be active
              unless the EXTENDED_GLOB option is also set.  To enable all
              possible patterns (so that they may be individually disabled
              with disable -p), use `setopt EXTENDED_GLOB KSH_GLOB
              NO_SH_GLOB'.

       eval [ arg ... ]
              Read the arguments as input to the shell and execute the
              resulting command(s) in the current shell process.  The return
              status is the same as if the commands had been executed directly
              by the shell; if there are no args or they contain no commands
              (i.e. are an empty string or whitespace) the return status is
              zero.

       exec [ -cl ] [ -a argv0 ] [ command [ arg ... ] ]
              Replace the current shell with command rather than forking.  If
              command is a shell builtin command or a shell function, the
              shell executes it, and exits when the command is complete.

              With -c clear the environment; with -l prepend - to the argv[0]
              string of the command executed (to simulate a login shell); with
              -a argv0 set the argv[0] string of the command executed.  See
              the section `Precommand Modifiers' in zshmisc(1).

              If the option POSIX_BUILTINS is set, command is never
              interpreted as a shell builtin command or shell function.  This
              means further precommand modifiers such as builtin and noglob
              are also not interpreted within the shell.  Hence command is
              always found by searching the command path.

              If command is omitted but any redirections are specified, then
              the redirections will take effect in the current shell.

       exit [ n ]
              Exit the shell with the exit status specified by an arithmetic
              expression n; if none is specified, use the exit status from the
              last command executed.  An EOF condition will also cause the
              shell to exit, unless the IGNORE_EOF option is set.

              See notes at the end of the section JOBS in zshmisc(1) for some
              possibly unexpected interactions of the exit command with jobs.

       export [ name[=value] ... ]
              The specified names are marked for automatic export to the
              environment of subsequently executed commands.  Equivalent to
              typeset -gx.  If a parameter specified does not already exist,
              it is created in the global scope.

       false [ arg ... ]
              Do nothing and return an exit status of 1.


       fc [ -e ename ] [ -LI ] [ -m match ] [ old=new ... ] [ first [ last ] ]
       fc -l [ -LI ] [ -nrdfEiD ] [ -t timefmt ] [ -m match ]
             [ old=new ... ] [ first [ last ] ]
       fc -p [ -a ] [ filename [ histsize [ savehistsize ] ] ]
       fc -P
       fc -ARWI [ filename ]
              The fc command controls the interactive history mechanism.  Note
              that reading and writing of history options is only performed if
              the shell is interactive.  Usually this is detected
              automatically, but it can be forced by setting the interactive
              option when starting the shell.

              The first two forms of this command select a range of events
              from first to last from the history list.  The arguments first
              and last may be specified as a number or as a string.  A
              negative number is used as an offset to the current history
              event number.  A string specifies the most recent event
              beginning with the given string.  All substitutions old=new, if
              any, are then performed on the text of the events.

              In addition to the number range,
              -I     restricts to only internal events (not from $HISTFILE)
              -L     restricts to only local events (not from other shells,
                     see SHARE_HISTORY in zshoptions(1) -- note that $HISTFILE
                     is considered local when read at startup)
              -m     takes the first argument as a pattern (should be quoted)
                     and only the history events matching this pattern are
                     considered

              If first is not specified, it will be set to -1 (the most recent
              event), or to -16 if the -l flag is given.  If last is not
              specified, it will be set to first, or to -1 if the -l flag is
              given.  However, if the current event has added entries to the
              history with `print -s' or `fc -R', then the default last for -l
              includes all new history entries since the current event began.

              When the -l flag is given, the resulting events are listed on
              standard output.  Otherwise the editor program specified by -e
              ename is invoked on a file containing these history events.  If
              -e is not given, the value of the parameter FCEDIT is used; if
              that is not set the value of the parameter EDITOR is used; if
              that is not set a builtin default, usually `vi' is used.  If
              ename is `-', no editor is invoked.  When editing is complete,
              the edited command is executed.

              The flag -r reverses the order of the events and the flag -n
              suppresses event numbers when listing.

              Also when listing,
              -d     prints timestamps for each event
              -f     prints full time-date stamps in the US `MM/DD/YY hh:mm'
                     format
              -E     prints full time-date stamps in the European `dd.mm.yyyy
                     hh:mm' format
              -i     prints full time-date stamps in ISO8601 `yyyy-mm-dd
                     hh:mm' format
              -t fmt prints time and date stamps in the given format; fmt is
                     formatted with the strftime function with the zsh
                     extensions described for the %D{string} prompt format in
                     the section EXPANSION OF PROMPT SEQUENCES in zshmisc(1).
                     The resulting formatted string must be no more than 256
                     characters or will not be printed
              -D     prints elapsed times; may be combined with one of the
                     options above

              `fc -p' pushes the current history list onto a stack and
              switches to a new history list.  If the -a option is also
              specified, this history list will be automatically popped when
              the current function scope is exited, which is a much better
              solution than creating a trap function to call `fc -P' manually.
              If no arguments are specified, the history list is left empty,
              $HISTFILE is unset, and $HISTSIZE & $SAVEHIST are set to their
              default values.  If one argument is given, $HISTFILE is set to
              that filename, $HISTSIZE & $SAVEHIST are left unchanged, and the
              history file is read in (if it exists) to initialize the new
              list.  If a second argument is specified, $HISTSIZE & $SAVEHIST
              are instead set to the single specified numeric value.  Finally,
              if a third argument is specified, $SAVEHIST is set to a separate
              value from $HISTSIZE.  You are free to change these environment
              values for the new history list however you desire in order to
              manipulate the new history list.

              `fc -P' pops the history list back to an older list saved by `fc
              -p'.  The current list is saved to its $HISTFILE before it is
              destroyed (assuming that $HISTFILE and $SAVEHIST are set
              appropriately, of course).  The values of $HISTFILE, $HISTSIZE,
              and $SAVEHIST are restored to the values they had when `fc -p'
              was called.  Note that this restoration can conflict with making
              these variables "local", so your best bet is to avoid local
              declarations for these variables in functions that use `fc -p'.
              The one other guaranteed-safe combination is declaring these
              variables to be local at the top of your function and using the
              automatic option (-a) with `fc -p'.  Finally, note that it is
              legal to manually pop a push marked for automatic popping if you
              need to do so before the function exits.

              `fc -R' reads the history from the given file, `fc -W' writes
              the history out to the given file, and `fc -A' appends the
              history out to the given file.  If no filename is specified, the
              $HISTFILE is assumed.  If the -I option is added to -R, only
              those events that are not already contained within the internal
              history list are added.  If the -I option is added to -A or -W,
              only those events that are new since last incremental
              append/write to the history file are appended/written.  In any
              case, the created file will have no more than $SAVEHIST entries.

       fg [ job ... ]
       job ...
              Bring each specified job in turn to the foreground.  If no job
              is specified, resume the current job.

       float [ {+|-}Hghlprtux ] [ {+|-}EFLRZ [ n ] ] [ name[=value] ... ]
              Equivalent to typeset -E, except that options irrelevant to
              floating point numbers are not permitted.

       functions [ {+|-}UkmtTuWz ] [ -x num ] [ name ... ]
       functions -c oldfn newfn
       functions -M [-s] mathfn [ min [ max [ shellfn ] ] ]
       functions -M [ -m pattern ... ]
       functions +M [ -m ] mathfn ...
              Equivalent to typeset -f, with the exception of the -c, -x, -M
              and -W options.  For functions -u and functions -U, see
              autoload, which provides additional options.

              The -x option indicates that any functions output will have each
              leading tab for indentation, added by the shell to show
              syntactic structure, expanded to the given number num of spaces.
              num can also be 0 to suppress all indentation.

              The -W option turns on the option WARN_NESTED_VAR for the named
              function or functions only.  The option is turned off at the
              start of nested functions (apart from anonoymous functions)
              unless the called function also has the -W attribute.

              The -c option causes oldfn to be copied to newfn.  The copy is
              efficiently handled internally by reference counting.  If oldfn
              was marked for autoload it is first loaded and if this fails the
              copy fails.  Either function may subsequently be redefined
              without affecting the other.  A typical idiom is that oldfn is
              the name of a library shell function which is then redefined to
              call newfn, thereby installing a modified version of the
              function.

              Use of the -M option may not be combined with any of the options
              handled by typeset -f.

              functions -M mathfn defines mathfn as the name of a mathematical
              function recognised in all forms of arithmetical expressions;
              see the section `Arithmetic Evaluation' in zshmisc(1).  By
              default mathfn may take any number of comma-separated arguments.
              If min is given, it must have exactly min args; if min and max
              are both given, it must have at least min and at most max args.
              max may be -1 to indicate that there is no upper limit.

              By default the function is implemented by a shell function of
              the same name; if shellfn is specified it gives the name of the
              corresponding shell function while mathfn remains the name used
              in arithmetical expressions.  The name of the function in $0 is
              mathfn (not shellfn as would usually be the case), provided the
              option FUNCTION_ARGZERO is in effect.  The positional parameters
              in the shell function correspond to the arguments of the
              mathematical function call.  The result of the last arithmetical
              expression evaluated inside the shell function (even if it is a
              form that normally only returns a status) gives the result of
              the mathematical function.

              If the additional option -s is given to functions -M, the
              argument to the function is a single string: anything between
              the opening and matching closing parenthesis is passed to the
              function as a single argument, even if it includes commas or
              white space.  The minimum and maximum argument specifiers must
              therefore be 1 if given.  An empty argument list is passed as a
              zero-length string.

              functions -M with no arguments lists all such user-defined
              functions in the same form as a definition.  With the additional
              option -m and a list of arguments, all functions whose mathfn
              matches one of the pattern arguments are listed.

              function +M removes the list of mathematical functions; with the
              additional option -m the arguments are treated as patterns and
              all functions whose mathfn matches the pattern are removed.
              Note that the shell function implementing the behaviour is not
              removed (regardless of whether its name coincides with mathfn).

              For example, the following prints the cube of 3:

                     zmath_cube() { (( $1 * $1 * $1 )) }
                     functions -M cube 1 1 zmath_cube
                     print $(( cube(3) ))

              The following string function takes a single argument, including
              the commas, so prints 11:

                     stringfn() { (( $#1 )) }
                     functions -Ms stringfn
                     print $(( stringfn(foo,bar,rod) ))

       getcap See the section `The zsh/cap Module' in zshmodules(1).

       getln [ -AclneE ] name ...
              Read the top value from the buffer stack and put it in the shell
              parameter name.  Equivalent to read -zr.

       getopts optstring name [ arg ... ]
              Checks the args for legal options.  If the args are omitted, use
              the positional parameters.  A valid option argument begins with
              a `+' or a `-'.  An argument not beginning with a `+' or a `-',
              or the argument `--', ends the options.  Note that a single `-'
              is not considered a valid option argument.  optstring contains
              the letters that getopts recognizes.  If a letter is followed by
              a `:', that option requires an argument.  The options can be
              separated from the argument by blanks.

              Each time it is invoked, getopts places the option letter it
              finds in the shell parameter name, prepended with a `+' when arg
              begins with a `+'.  The index of the next arg is stored in
              OPTIND.  The option argument, if any, is stored in OPTARG.

              The first option to be examined may be changed by explicitly
              assigning to OPTIND.  OPTIND has an initial value of 1, and is
              normally set to 1 upon entry to a shell function and restored
              upon exit (this is disabled by the POSIX_BUILTINS option).
              OPTARG is not reset and retains its value from the most recent
              call to getopts.  If either of OPTIND or OPTARG is explicitly
              unset, it remains unset, and the index or option argument is not
              stored.  The option itself is still stored in name in this case.

              A leading `:' in optstring causes getopts to store the letter of
              any invalid option in OPTARG, and to set name to `?' for an
              unknown option and to `:' when a required argument is missing.
              Otherwise, getopts sets name to `?' and prints an error message
              when an option is invalid.  The exit status is nonzero when
              there are no more options.

       hash [ -Ldfmrv ] [ name[=value] ] ...
              hash can be used to directly modify the contents of the command
              hash table, and the named directory hash table.  Normally one
              would modify these tables by modifying one's PATH (for the
              command hash table) or by creating appropriate shell parameters
              (for the named directory hash table).  The choice of hash table
              to work on is determined by the -d option; without the option
              the command hash table is used, and with the option the named
              directory hash table is used.

              A command name starting with a / is never hashed, whether by
              explicit use of the hash command or otherwise.  Such a command
              is always found by direct look up in the file system.

              Given no arguments, and neither the -r or -f options, the
              selected hash table will be listed in full.

              The -r option causes the selected hash table to be emptied.  It
              will be subsequently rebuilt in the normal fashion.  The -f
              option causes the selected hash table to be fully rebuilt
              immediately.  For the command hash table this hashes all the
              absolute directories in the PATH, and for the named directory
              hash table this adds all users' home directories.  These two
              options cannot be used with any arguments.

              The -m option causes the arguments to be taken as patterns
              (which should be quoted) and the elements of the hash table
              matching those patterns are printed.  This is the only way to
              display a limited selection of hash table elements.

              For each name with a corresponding value, put `name' in the
              selected hash table, associating it with the pathname `value'.
              In the command hash table, this means that whenever `name' is
              used as a command argument, the shell will try to execute the
              file given by `value'.  In the named directory hash table, this
              means that `value' may be referred to as `~name'.

              For each name with no corresponding value, attempt to add name
              to the hash table, checking what the appropriate value is in the
              normal manner for that hash table.  If an appropriate value
              can't be found, then the hash table will be unchanged.

              The -v option causes hash table entries to be listed as they are
              added by explicit specification.  If has no effect if used with
              -f.

              If the -L flag is present, then each hash table entry is printed
              in the form of a call to hash.

       history
              Same as fc -l.

       integer [ {+|-}Hghlprtux ] [ {+|-}LRZi [ n ] ] [ name[=value] ... ]
              Equivalent to typeset -i, except that options irrelevant to
              integers are not permitted.

       jobs [ -dlprs ] [ job ... ]
       jobs -Z string
              Lists information about each given job, or all jobs if job is
              omitted.  The -l flag lists process IDs, and the -p flag lists
              process groups.  If the -r flag is specified only running jobs
              will be listed and if the -s flag is given only stopped jobs are
              shown.  If the -d flag is given, the directory from which the
              job was started (which may not be the current directory of the
              job) will also be shown.

              The -Z option replaces the shell's argument and environment
              space with the given string, truncated if necessary to fit.
              This will normally be visible in ps (ps(1)) listings.  This
              feature is typically used by daemons, to indicate their state.

       kill [ -s signal_name | -n signal_number | -sig ] job ...
       kill -l [ sig ... ]
              Sends either SIGTERM or the specified signal to the given jobs
              or processes.  Signals are given by number or by names, with or
              without the `SIG' prefix.  If the signal being sent is not
              `KILL' or `CONT', then the job will be sent a `CONT' signal if
              it is stopped.  The argument job can be the process ID of a job
              not in the job list.  In the second form, kill -l, if sig is not
              specified the signal names are listed.  Otherwise, for each sig
              that is a name, the corresponding signal number is listed.  For
              each sig that is a signal number or a number representing the
              exit status of a process which was terminated or stopped by a
              signal the name of the signal is printed.

              On some systems, alternative signal names are allowed for a few
              signals.  Typical examples are SIGCHLD and SIGCLD or SIGPOLL and
              SIGIO, assuming they correspond to the same signal number.  kill
              -l will only list the preferred form, however kill -l alt will
              show if the alternative form corresponds to a signal number.
              For example, under Linux kill -l IO and kill -l POLL both output
              29, hence kill -IO and kill -POLL have the same effect.

              Many systems will allow process IDs to be negative to kill a
              process group or zero to kill the current process group.

       let arg ...
              Evaluate each arg as an arithmetic expression.  See the section
              `Arithmetic Evaluation' in zshmisc(1) for a description of
              arithmetic expressions.  The exit status is 0 if the value of
              the last expression is nonzero, 1 if it is zero, and 2 if an
              error occurred.

       limit [ -hs ] [ resource [ limit ] ] ...
              Set or display resource limits.  Unless the -s flag is given,
              the limit applies only the children of the shell.  If -s is
              given without other arguments, the resource limits of the
              current shell is set to the previously set resource limits of
              the children.

              If limit is not specified, print the current limit placed on
              resource, otherwise set the limit to the specified value.  If
              the -h flag is given, use hard limits instead of soft limits.
              If no resource is given, print all limits.

              When looping over multiple resources, the shell will abort
              immediately if it detects a badly formed argument.  However, if
              it fails to set a limit for some other reason it will continue
              trying to set the remaining limits.

              resource can be one of:

              addressspace
                     Maximum amount of address space used.
              aiomemorylocked
                     Maximum amount of memory locked in RAM for AIO
                     operations.
              aiooperations
                     Maximum number of AIO operations.
              cachedthreads
                     Maximum number of cached threads.
              coredumpsize
                     Maximum size of a core dump.
              cputime
                     Maximum CPU seconds per process.
              datasize
                     Maximum data size (including stack) for each process.
              descriptors
                     Maximum value for a file descriptor.
              filesize
                     Largest single file allowed.
              kqueues
                     Maximum number of kqueues allocated.
              maxproc
                     Maximum number of processes.
              maxpthreads
                     Maximum number of threads per process.
              memorylocked
                     Maximum amount of memory locked in RAM.
              memoryuse
                     Maximum resident set size.
              msgqueue
                     Maximum number of bytes in POSIX message queues.
              posixlocks
                     Maximum number of POSIX locks per user.
              pseudoterminals
                     Maximum number of pseudo-terminals.
              resident
                     Maximum resident set size.
              sigpending
                     Maximum number of pending signals.
              sockbufsize
                     Maximum size of all socket buffers.
              stacksize
                     Maximum stack size for each process.
              swapsize
                     Maximum amount of swap used.
              vmemorysize
                     Maximum amount of virtual memory.

              Which of these resource limits are available depends on the
              system.  resource can be abbreviated to any unambiguous prefix.
              It can also be an integer, which corresponds to the integer
              defined for the resource by the operating system.

              If argument corresponds to a number which is out of the range of
              the resources configured into the shell, the shell will try to
              read or write the limit anyway, and will report an error if this
              fails.  As the shell does not store such resources internally,
              an attempt to set the limit will fail unless the -s option is
              present.

              limit is a number, with an optional scaling factor, as follows:

              nh     hours
              nk     kilobytes (default)
              nm     megabytes or minutes
              ng     gigabytes
              [mm:]ss
                     minutes and seconds

              The limit command is not made available by default when the
              shell starts in a mode emulating another shell.  It can be made
              available with the command `zmodload -F zsh/rlimits b:limit'.

       local [ {+|-}AHUahlprtux ] [ {+|-}EFLRZi [ n ] ] [ name[=value] ... ]
              Same as typeset, except that the options -g, and -f are not
              permitted.  In this case the -x option does not force the use of
              -g, i.e. exported variables will be local to functions.

       log    List all users currently logged in who are affected by the
              current setting of the watch parameter.

       logout [ n ]
              Same as exit, except that it only works in a login shell.

       noglob simple command
              See the section `Precommand Modifiers' in zshmisc(1).

       popd [ -q ] [ {+|-}n ]
              Remove an entry from the directory stack, and perform a cd to
              the new top directory.  With no argument, the current top entry
              is removed.  An argument of the form `+n' identifies a stack
              entry by counting from the left of the list shown by the dirs
              command, starting with zero.  An argument of the form -n counts
              from the right.  If the PUSHD_MINUS option is set, the meanings
              of `+' and `-' in this context are swapped.

              If the -q (quiet) option is specified, the hook function chpwd
              and the functions in the array $chpwd_functions are not called,
              and the new directory stack is not printed.  This is useful for
              calls to popd that do not change the environment seen by an
              interactive user.

       print [ -abcDilmnNoOpPrsSz ] [ -u n ] [ -f format ] [ -C cols ]
             [ -v name ] [ -xX tabstop ] [ -R [ -en ]] [ arg ... ]
              With the `-f' option the arguments are printed as described by
              printf.  With no flags or with the flag `-', the arguments are
              printed on the standard output as described by echo, with the
              following differences: the escape sequence `\M-x' (or `\Mx')
              metafies the character x (sets the highest bit), `\C-x' (or
              `\Cx') produces a control character (`\C-@' and `\C-?' give the
              characters NULL and delete), a character code in octal is
              represented by `\NNN' (instead of `\0NNN'), and `\E' is a
              synonym for `\e'.  Finally, if not in an escape sequence, `\'
              escapes the following character and is not printed.

              -a     Print arguments with the column incrementing first.  Only
                     useful with the -c and -C options.

              -b     Recognize all the escape sequences defined for the
                     bindkey command, see the section `Zle Builtins' in
                     zshzle(1).

              -c     Print the arguments in columns.  Unless -a is also given,
                     arguments are printed with the row incrementing first.

              -C cols
                     Print the arguments in cols columns.  Unless -a is also
                     given, arguments are printed with the row incrementing
                     first.

              -D     Treat the arguments as paths, replacing directory
                     prefixes with ~ expressions corresponding to directory
                     names, as appropriate.

              -i     If given together with -o or -O, sorting is performed
                     case-independently.

              -l     Print the arguments separated by newlines instead of
                     spaces.  Note: if the list of arguments is empty, print
                     -l will still output one empty line. To print a
                     possibly-empty list of arguments one per line, use print
                     -C1, as in `print -rC1 -- "$list[@]"'.

              -m     Take the first argument as a pattern (should be quoted),
                     and remove it from the argument list together with
                     subsequent arguments that do not match this pattern.

              -n     Do not add a newline to the output.

              -N     Print the arguments separated and terminated by nulls.
                     Again, print -rNC1 -- "$list[@]" is a canonical way to
                     print an arbitrary list as null-delimited records.

              -o     Print the arguments sorted in ascending order.

              -O     Print the arguments sorted in descending order.

              -p     Print the arguments to the input of the coprocess.

              -P     Perform prompt expansion (see EXPANSION OF PROMPT
                     SEQUENCES in zshmisc(1)).  In combination with `-f',
                     prompt escape sequences are parsed only within
                     interpolated arguments, not within the format string.

              -r     Ignore the escape conventions of echo.

              -R     Emulate the BSD echo command, which does not process
                     escape sequences unless the -e flag is given.  The -n
                     flag suppresses the trailing newline.  Only the -e and -n
                     flags are recognized after -R; all other arguments and
                     options are printed.

              -s     Place the results in the history list instead of on the
                     standard output.  Each argument to the print command is
                     treated as a single word in the history, regardless of
                     its content.

              -S     Place the results in the history list instead of on the
                     standard output.  In this case only a single argument is
                     allowed; it will be split into words as if it were a full
                     shell command line.  The effect is similar to reading the
                     line from a history file with the HIST_LEX_WORDS option
                     active.

              -u n   Print the arguments to file descriptor n.

              -v name
                     Store the printed arguments as the value of the parameter
                     name.

              -x tab-stop
                     Expand leading tabs on each line of output in the printed
                     string assuming a tab stop every tab-stop characters.
                     This is appropriate for formatting code that may be
                     indented with tabs.  Note that leading tabs of any
                     argument to print, not just the first, are expanded, even
                     if print is using spaces to separate arguments (the
                     column count is maintained across arguments but may be
                     incorrect on output owing to previous unexpanded tabs).

                     The start of the output of each print command is assumed
                     to be aligned with a tab stop.  Widths of multibyte
                     characters are handled if the option MULTIBYTE is in
                     effect.  This option is ignored if other formatting
                     options are in effect, namely column alignment or printf
                     style, or if output is to a special location such as
                     shell history or the command line editor.

              -X tab-stop
                     This is similar to -x, except that all tabs in the
                     printed string are expanded.  This is appropriate if tabs
                     in the arguments are being used to produce a table
                     format.

              -z     Push the arguments onto the editing buffer stack,
                     separated by spaces.

              If any of `-m', `-o' or `-O' are used in combination with `-f'
              and there are no arguments (after the removal process in the
              case of `-m') then nothing is printed.

       printf [ -v name ] format [ arg ... ]
              Print the arguments according to the format specification.
              Formatting rules are the same as used in C. The same escape
              sequences as for echo are recognised in the format. All C
              conversion specifications ending in one of csdiouxXeEfgGn are
              handled. In addition to this, `%b' can be used instead of `%s'
              to cause escape sequences in the argument to be recognised and
              `%q' can be used to quote the argument in such a way that allows
              it to be reused as shell input. With the numeric format
              specifiers, if the corresponding argument starts with a quote
              character, the numeric value of the following character is used
              as the number to print; otherwise the argument is evaluated as
              an arithmetic expression. See the section `Arithmetic
              Evaluation' in zshmisc(1) for a description of arithmetic
              expressions. With `%n', the corresponding argument is taken as
              an identifier which is created as an integer parameter.

              Normally, conversion specifications are applied to each argument
              in order but they can explicitly specify the nth argument is to
              be used by replacing `%' by `%n$' and `*' by `*n$'.  It is
              recommended that you do not mix references of this explicit
              style with the normal style and the handling of such mixed
              styles may be subject to future change.

              If arguments remain unused after formatting, the format string
              is reused until all arguments have been consumed. With the print
              builtin, this can be suppressed by using the -r option. If more
              arguments are required by the format than have been specified,
              the behaviour is as if zero or an empty string had been
              specified as the argument.

              The -v option causes the output to be stored as the value of the
              parameter name, instead of printed. If name is an array and the
              format string is reused when consuming arguments then one array
              element will be used for each use of the format string.

       pushd [ -qsLP ] [ arg ]
       pushd [ -qsLP ] old new
       pushd [ -qsLP ] {+|-}n
              Change the current directory, and push the old current directory
              onto the directory stack.  In the first form, change the current
              directory to arg.  If arg is not specified, change to the second
              directory on the stack (that is, exchange the top two entries),
              or change to $HOME if the PUSHD_TO_HOME option is set or if
              there is only one entry on the stack.  Otherwise, arg is
              interpreted as it would be by cd.  The meaning of old and new in
              the second form is also the same as for cd.

              The third form of pushd changes directory by rotating the
              directory list.  An argument of the form `+n' identifies a stack
              entry by counting from the left of the list shown by the dirs
              command, starting with zero.  An argument of the form `-n'
              counts from the right.  If the PUSHD_MINUS option is set, the
              meanings of `+' and `-' in this context are swapped.

              If the -q (quiet) option is specified, the hook function chpwd
              and the functions in the array $chpwd_functions are not called,
              and the new directory stack is not printed.  This is useful for
              calls to pushd that do not change the environment seen by an
              interactive user.

              If the option -q is not specified and the shell option
              PUSHD_SILENT is not set, the directory stack will be printed
              after a pushd is performed.

              The options -s, -L and -P have the same meanings as for the cd
              builtin.

       pushln [ arg ... ]
              Equivalent to print -nz.

       pwd [ -rLP ]
              Print the absolute pathname of the current working directory.
              If the -r or the -P flag is specified, or the CHASE_LINKS option
              is set and the -L flag is not given, the printed path will not
              contain symbolic links.

       r      Same as fc -e -.


       read [ -rszpqAclneE ] [ -t [ num ] ] [ -k [ num ] ] [ -d delim ]
            [ -u n ] [ name[?prompt] ] [ name ...  ]
              Read one line and break it into fields using the characters in
              $IFS as separators, except as noted below.  The first field is
              assigned to the first name, the second field to the second name,
              etc., with leftover fields assigned to the last name.  If name
              is omitted then REPLY is used for scalars and reply for arrays.

              -r     Raw mode: a `\' at the end of a line does not signify
                     line continuation and backslashes in the line don't quote
                     the following character and are not removed.

              -s     Don't echo back characters if reading from the terminal.

              -q     Read only one character from the terminal and set name to
                     `y' if this character was `y' or `Y' and to `n'
                     otherwise.  With this flag set the return status is zero
                     only if the character was `y' or `Y'.  This option may be
                     used with a timeout (see -t); if the read times out, or
                     encounters end of file, status 2 is returned.  Input is
                     read from the terminal unless one of -u or -p is present.
                     This option may also be used within zle widgets.

              -k [ num ]
                     Read only one (or num) characters.  All are assigned to
                     the first name, without word splitting.  This flag is
                     ignored when -q is present.  Input is read from the
                     terminal unless one of -u or -p is present.  This option
                     may also be used within zle widgets.

                     Note that despite the mnemonic `key' this option does
                     read full characters, which may consist of multiple bytes
                     if the option MULTIBYTE is set.

              -z     Read one entry from the editor buffer stack and assign it
                     to the first name, without word splitting.  Text is
                     pushed onto the stack with `print -z' or with push-line
                     from the line editor (see zshzle(1)).  This flag is
                     ignored when the -k or -q flags are present.

              -e
              -E     The input read is printed (echoed) to the standard
                     output.  If the -e flag is used, no input is assigned to
                     the parameters.

              -A     The first name is taken as the name of an array and all
                     words are assigned to it.

              -c
              -l     These flags are allowed only if called inside a function
                     used for completion (specified with the -K flag to
                     compctl).  If the -c flag is given, the words of the
                     current command are read. If the -l flag is given, the
                     whole line is assigned as a scalar.  If both flags are
                     present, -l is used and -c is ignored.

              -n     Together with -c, the number of the word the cursor is on
                     is read.  With -l, the index of the character the cursor
                     is on is read.  Note that the command name is word number
                     1, not word 0, and that when the cursor is at the end of
                     the line, its character index is the length of the line
                     plus one.

              -u n   Input is read from file descriptor n.

              -p     Input is read from the coprocess.

              -d delim
                     Input is terminated by the first character of delim
                     instead of by newline.

              -t [ num ]
                     Test if input is available before attempting to read.  If
                     num is present, it must begin with a digit and will be
                     evaluated to give a number of seconds, which may be a
                     floating point number; in this case the read times out if
                     input is not available within this time.  If num is not
                     present, it is taken to be zero, so that read returns
                     immediately if no input is available.  If no input is
                     available, return status 1 and do not set any variables.

                     This option is not available when reading from the editor
                     buffer with -z, when called from within completion with
                     -c or -l, with -q which clears the input queue before
                     reading, or within zle where other mechanisms should be
                     used to test for input.

                     Note that read does not attempt to alter the input
                     processing mode.  The default mode is canonical input, in
                     which an entire line is read at a time, so usually `read
                     -t' will not read anything until an entire line has been
                     typed.  However, when reading from the terminal with -k
                     input is processed one key at a time; in this case, only
                     availability of the first character is tested, so that
                     e.g. `read -t -k 2' can still block on the second
                     character.  Use two instances of `read -t -k' if this is
                     not what is wanted.

              If the first argument contains a `?', the remainder of this word
              is used as a prompt on standard error when the shell is
              interactive.

              The value (exit status) of read is 1 when an end-of-file is
              encountered, or when -c or -l is present and the command is not
              called from a compctl function, or as described for -q.
              Otherwise the value is 0.

              The behavior of some combinations of the -k, -p, -q, -u and -z
              flags is undefined.  Presently -q cancels all the others, -p
              cancels -u, -k cancels -z, and otherwise -z cancels both -p and
              -u.

              The -c or -l flags cancel any and all of -kpquz.

       readonly
              Same as typeset -r.  With the POSIX_BUILTINS option set, same as
              typeset -gr.

       rehash Same as hash -r.

       return [ n ]
              Causes a shell function or `.' script to return to the invoking
              script with the return status specified by an arithmetic
              expression n. If n is omitted, the return status is that of the
              last command executed.

              If return was executed from a trap in a TRAPNAL function, the
              effect is different for zero and non-zero return status.  With
              zero status (or after an implicit return at the end of the
              trap), the shell will return to whatever it was previously
              processing; with a non-zero status, the shell will behave as
              interrupted except that the return status of the trap is
              retained.  Note that the numeric value of the signal which
              caused the trap is passed as the first argument, so the
              statement `return $((128+$1))' will return the same status as if
              the signal had not been trapped.

       sched  See the section `The zsh/sched Module' in zshmodules(1).


       set [ {+|-}options | {+|-}o [ option_name ] ] ... [ {+|-}A [ name ] ]
           [ arg ... ]
              Set the options for the shell and/or set the positional
              parameters, or declare and set an array.  If the -s option is
              given, it causes the specified arguments to be sorted before
              assigning them to the positional parameters (or to the array
              name if -A is used).  With +s sort arguments in descending
              order.  For the meaning of the other flags, see zshoptions(1).
              Flags may be specified by name using the -o option. If no option
              name is supplied with -o, the current option states are printed:
              see the description of setopt below for more information on the
              format.  With +o they are printed in a form that can be used as
              input to the shell.

              If the -A flag is specified, name is set to an array containing
              the given args; if no name is specified, all arrays are printed
              together with their values.

              If +A is used and name is an array, the given arguments will
              replace the initial elements of that array; if no name is
              specified, all arrays are printed without their values.

              The behaviour of arguments after -A name or +A name depends on
              whether the option KSH_ARRAYS is set.  If it is not set, all
              arguments following name are treated as values for the array,
              regardless of their form.  If the option is set, normal option
              processing continues at that point; only regular arguments are
              treated as values for the array.  This means that

                     set -A array -x -- foo

              sets array to `-x -- foo' if KSH_ARRAYS is not set, but sets the
              array to foo and turns on the option `-x' if it is set.

              If the -A flag is not present, but there are arguments beyond
              the options, the positional parameters are set.  If the option
              list (if any) is terminated by `--', and there are no further
              arguments, the positional parameters will be unset.

              If no arguments and no `--' are given, then the names and values
              of all parameters are printed on the standard output.  If the
              only argument is `+', the names of all parameters are printed.

              For historical reasons, `set -' is treated as `set +xv' and `set
              - args' as `set +xv -- args' when in any other emulation mode
              than zsh's native mode.

       setcap See the section `The zsh/cap Module' in zshmodules(1).

       setopt [ {+|-}options | {+|-}o option_name ] [ -m ] [ name ... ]
              Set the options for the shell.  All options specified either
              with flags or by name are set.

              If no arguments are supplied, the names of all options currently
              set are printed.  The form is chosen so as to minimize the
              differences from the default options for the current emulation
              (the default emulation being native zsh, shown as <Z> in
              zshoptions(1)).  Options that are on by default for the
              emulation are shown with the prefix no only if they are off,
              while other options are shown without the prefix no and only if
              they are on.  In addition to options changed from the default
              state by the user, any options activated automatically by the
              shell (for example, SHIN_STDIN or INTERACTIVE) will be shown in
              the list.  The format is further modified by the option
              KSH_OPTION_PRINT, however the rationale for choosing options
              with or without the no prefix remains the same in this case.

              If the -m flag is given the arguments are taken as patterns
              (which should be quoted to protect them from filename
              expansion), and all options with names matching these patterns
              are set.

              Note that a bad option name does not cause execution of
              subsequent shell code to be aborted; this is behaviour is
              different from that of `set -o'.  This is because set is
              regarded as a special builtin by the POSIX standard, but setopt
              is not.

       shift [ -p ] [ n ] [ name ... ]
              The positional parameters ${n+1} ... are renamed to $1 ...,
              where n is an arithmetic expression that defaults to 1.  If any
              names are given then the arrays with these names are shifted
              instead of the positional parameters.

              If the option -p is given arguments are instead removed (popped)
              from the end rather than the start of the array.

       source file [ arg ... ]
              Same as `.', except that the current directory is always
              searched and is always searched first, before directories in
              $path.

       stat   See the section `The zsh/stat Module' in zshmodules(1).

       suspend [ -f ]
              Suspend the execution of the shell (send it a SIGTSTP) until it
              receives a SIGCONT.  Unless the -f option is given, this will
              refuse to suspend a login shell.

       test [ arg ... ]
       [ [ arg ... ] ]
              Like the system version of test.  Added for compatibility; use
              conditional expressions instead (see the section `Conditional
              Expressions').  The main differences between the conditional
              expression syntax and the test and [ builtins are:  these
              commands are not handled syntactically, so for example an empty
              variable expansion may cause an argument to be omitted; syntax
              errors cause status 2 to be returned instead of a shell error;
              and arithmetic operators expect integer arguments rather than
              arithmetic expressions.

              The command attempts to implement POSIX and its extensions where
              these are specified.  Unfortunately there are intrinsic
              ambiguities in the syntax; in particular there is no distinction
              between test operators and strings that resemble them.  The
              standard attempts to resolve these for small numbers of
              arguments (up to four); for five or more arguments compatibility
              cannot be relied on.  Users are urged wherever possible to use
              the `[[' test syntax which does not have these ambiguities.

       times  Print the accumulated user and system times for the shell and
              for processes run from the shell.

       trap [ arg ] [ sig ... ]
              arg is a series of commands (usually quoted to protect it from
              immediate evaluation by the shell) to be read and executed when
              the shell receives any of the signals specified by one or more
              sig args.  Each sig can be given as a number, or as the name of
              a signal either with or without the string SIG in front (e.g. 1,
              HUP, and SIGHUP are all the same signal).

              If arg is `-', then the specified signals are reset to their
              defaults, or, if no sig args are present, all traps are reset.

              If arg is an empty string, then the specified signals are
              ignored by the shell (and by the commands it invokes).

              If arg is omitted but one or more sig args are provided (i.e.
              the first argument is a valid signal number or name), the effect
              is the same as if arg had been specified as `-'.

              The trap command with no arguments prints a list of commands
              associated with each signal.

              If sig is ZERR then arg will be executed after each command with
              a nonzero exit status.  ERR is an alias for ZERR on systems that
              have no SIGERR signal (this is the usual case).

              If sig is DEBUG then arg will be executed before each command if
              the option DEBUG_BEFORE_CMD is set (as it is by default), else
              after each command.  Here, a `command' is what is described as a
              `sublist' in the shell grammar, see the section SIMPLE COMMANDS
              & PIPELINES in zshmisc(1).  If DEBUG_BEFORE_CMD is set various
              additional features are available.  First, it is possible to
              skip the next command by setting the option ERR_EXIT; see the
              description of the ERR_EXIT option in zshoptions(1).  Also, the
              shell parameter ZSH_DEBUG_CMD is set to the string corresponding
              to the command to be executed following the trap.  Note that
              this string is reconstructed from the internal format and may
              not be formatted the same way as the original text.  The
              parameter is unset after the trap is executed.

              If sig is 0 or EXIT and the trap statement is executed inside
              the body of a function, then the command arg is executed after
              the function completes.  The value of $? at the start of
              execution is the exit status of the shell or the return status
              of the function exiting.  If sig is 0 or EXIT and the trap
              statement is not executed inside the body of a function, then
              the command arg is executed when the shell terminates; the trap
              runs before any zshexit hook functions.

              ZERR, DEBUG, and EXIT traps are not executed inside other traps.
              ZERR and DEBUG traps are kept within subshells, while other
              traps are reset.

              Note that traps defined with the trap builtin are slightly
              different from those defined as `TRAPNAL () { ... }', as the
              latter have their own function environment (line numbers, local
              variables, etc.) while the former use the environment of the
              command in which they were called.  For example,

                     trap 'print $LINENO' DEBUG

              will print the line number of a command executed after it has
              run, while

                     TRAPDEBUG() { print $LINENO; }

              will always print the number zero.

              Alternative signal names are allowed as described under kill
              above.  Defining a trap under either name causes any trap under
              an alternative name to be removed.  However, it is recommended
              that for consistency users stick exclusively to one name or
              another.

       true [ arg ... ]
              Do nothing and return an exit status of 0.

       ttyctl [ -fu ]
              The -f option freezes the tty (i.e. terminal or terminal
              emulator), and -u unfreezes it.  When the tty is frozen, no
              changes made to the tty settings by external programs will be
              honored by the shell, except for changes in the size of the
              screen; the shell will simply reset the settings to their
              previous values as soon as each command exits or is suspended.
              Thus, stty and similar programs have no effect when the tty is
              frozen.  Freezing the tty does not cause the current state to be
              remembered: instead, it causes future changes to the state to be
              blocked.

              Without options it reports whether the terminal is frozen or
              not.

              Note that, regardless of whether the tty is frozen or not, the
              shell needs to change the settings when the line editor starts,
              so unfreezing the tty does not guarantee settings made on the
              command line are preserved.  Strings of commands run between
              editing the command line will see a consistent tty state.  See
              also the shell variable STTY for a means of initialising the tty
              before running external commands.

       type [ -wfpamsS ] name ...
              Equivalent to whence -v.


       typeset [ {+|-}AHUaghlmrtux ] [ {+|-}EFLRZip [ n ] ]
               [ + ] [ name[=value] ... ]
       typeset -T [ {+|-}Uglrux ] [ {+|-}LRZp [ n ] ]
               [ + | SCALAR[=value] array[=(value ...)] [ sep ] ]
       typeset -f [ {+|-}TUkmtuz ] [ + ] [ name ... ]
              Set or display attributes and values for shell parameters.

              Except as noted below for control flags that change the
              behavior, a parameter is created for each name that does not
              already refer to one.  When inside a function, a new parameter
              is created for every name (even those that already exist), and
              is unset again when the function completes.  See `Local
              Parameters' in zshparam(1).  The same rules apply to special
              shell parameters, which retain their special attributes when
              made local.

              For each name=value assignment, the parameter name is set to
              value.

              If the shell option TYPESET_SILENT is not set, for each
              remaining name that refers to a parameter that is already set,
              the name and value of the parameter are printed in the form of
              an assignment.  Nothing is printed for newly-created parameters,
              or when any attribute flags listed below are given along with
              the name.  Using `+' instead of minus to introduce an attribute
              turns it off.

              If no name is present, the names and values of all parameters
              are printed.  In this case the attribute flags restrict the
              display to only those parameters that have the specified
              attributes, and using `+' rather than `-' to introduce the flag
              suppresses printing of the values of parameters when there is no
              parameter name.

              All forms of the command handle scalar assignment.  Array
              assignment is possible if any of the reserved words declare,
              export, float, integer, local, readonly or typeset is matched
              when the line is parsed (N.B. not when it is executed).  In this
              case the arguments are parsed as assignments, except that the
              `+=' syntax and the GLOB_ASSIGN option are not supported, and
              scalar values after = are not split further into words, even if
              expanded (regardless of the setting of the KSH_TYPESET option;
              this option is obsolete).

              Examples of the differences between command and reserved word
              parsing:

                     # Reserved word parsing
                     typeset svar=$(echo one word) avar=(several words)

              The above creates a scalar parameter svar and an array parameter
              avar as if the assignments had been

                     svar="one word"
                     avar=(several words)

              On the other hand:

                     # Normal builtin interface
                     builtin typeset svar=$(echo two words)

              The builtin keyword causes the above to use the standard builtin
              interface to typeset in which argument parsing is performed in
              the same way as for other commands.  This example creates a
              scalar svar containing the value two and another scalar
              parameter words with no value.  An array value in this case
              would either cause an error or be treated as an obscure set of
              glob qualifiers.

              Arbitrary arguments are allowed if they take the form of
              assignments after command line expansion; however, these only
              perform scalar assignment:

                     var='svar=val'
                     typeset $var

              The above sets the scalar parameter svar to the value val.
              Parentheses around the value within var would not cause array
              assignment as they will be treated as ordinary characters when
              $var is substituted.  Any non-trivial expansion in the name part
              of the assignment causes the argument to be treated in this
              fashion:

                     typeset {var1,var2,var3}=name

              The above syntax is valid, and has the expected effect of
              setting the three parameters to the same value, but the command
              line is parsed as a set of three normal command line arguments
              to typeset after expansion.  Hence it is not possible to assign
              to multiple arrays by this means.

              Note that each interface to any of the commands my be disabled
              separately.  For example, `disable -r typeset' disables the
              reserved word interface to typeset, exposing the builtin
              interface, while `disable typeset' disables the builtin.  Note
              that disabling the reserved word interface for typeset may cause
              problems with the output of `typeset -p', which assumes the
              reserved word interface is available in order to restore array
              and associative array values.

              Unlike parameter assignment statements, typeset's exit status on
              an assignment that involves a command substitution does not
              reflect the exit status of the command substitution.  Therefore,
              to test for an error in a command substitution, separate the
              declaration of the parameter from its initialization:

                     # WRONG
                     typeset var1=$(exit 1) || echo "Trouble with var1"

                     # RIGHT
                     typeset var1 && var1=$(exit 1) || echo "Trouble with var1"

              To initialize a parameter param to a command output and mark it
              readonly, use typeset -r param or readonly param after the
              parameter assignment statement.

              If no attribute flags are given, and either no name arguments
              are present or the flag +m is used, then each parameter name
              printed is preceded by a list of the attributes of that
              parameter (array, association, exported, float, integer,
              readonly, or undefined for autoloaded parameters not yet
              loaded).  If +m is used with attribute flags, and all those
              flags are introduced with +, the matching parameter names are
              printed but their values are not.

              The following control flags change the behavior of typeset:

              +      If `+' appears by itself in a separate word as the last
                     option, then the names of all parameters (functions with
                     -f) are printed, but the values (function bodies) are
                     not.  No name arguments may appear, and it is an error
                     for any other options to follow `+'.  The effect of `+'
                     is as if all attribute flags which precede it were given
                     with a `+' prefix.  For example, `typeset -U +' is
                     equivalent to `typeset +U' and displays the names of all
                     arrays having the uniqueness attribute, whereas `typeset
                     -f -U +' displays the names of all autoloadable
                     functions.  If + is the only option, then type
                     information (array, readonly, etc.) is also printed for
                     each parameter, in the same manner as `typeset +m "*"'.

              -g     The -g (global) means that any resulting parameter will
                     not be restricted to local scope.  Note that this does
                     not necessarily mean that the parameter will be global,
                     as the flag will apply to any existing parameter (even if
                     unset) from an enclosing function.  This flag does not
                     affect the parameter after creation, hence it has no
                     effect when listing existing parameters, nor does the
                     flag +g have any effect except in combination with -m
                     (see below).

              -m     If the -m flag is given the name arguments are taken as
                     patterns (use quoting to prevent these from being
                     interpreted as file patterns).  With no attribute flags,
                     all parameters (or functions with the -f flag) with
                     matching names are printed (the shell option
                     TYPESET_SILENT is not used in this case).

                     If the +g flag is combined with -m, a new local parameter
                     is created for every matching parameter that is not
                     already local.  Otherwise -m applies all other flags or
                     assignments to the existing parameters.

                     Except when assignments are made with name=value, using
                     +m forces the matching parameters and their attributes to
                     be printed, even inside a function.  Note that -m is
                     ignored if no patterns are given, so `typeset -m'
                     displays attributes but `typeset -a +m' does not.

              -p [ n ]
                     If the -p option is given, parameters and values are
                     printed in the form of a typeset command with an
                     assignment, regardless of other flags and options.  Note
                     that the -H flag on parameters is respected; no value
                     will be shown for these parameters.

                     -p may be followed by an optional integer argument.
                     Currently only the value 1 is supported.  In this case
                     arrays and associative arrays are printed with newlines
                     between indented elements for readability.

              -T [ scalar[=value] array[=(value ...)] [ sep ] ]
                     This flag has a different meaning when used with -f; see
                     below.  Otherwise the -T option requires zero, two, or
                     three arguments to be present.  With no arguments, the
                     list of parameters created in this fashion is shown.
                     With two or three arguments, the first two are the name
                     of a scalar and of an array parameter (in that order)
                     that will be tied together in the manner of $PATH and
                     $path.  The optional third argument is a single-character
                     separator which will be used to join the elements of the
                     array to form the scalar; if absent, a colon is used, as
                     with $PATH.  Only the first character of the separator is
                     significant; any remaining characters are ignored.
                     Multibyte characters are not yet supported.

                     Only one of the scalar and array parameters may be
                     assigned an initial value (the restrictions on assignment
                     forms described above also apply).

                     Both the scalar and the array may be manipulated as
                     normal.  If one is unset, the other will automatically be
                     unset too.  There is no way of untying the variables
                     without unsetting them, nor of converting the type of one
                     of them with another typeset command; +T does not work,
                     assigning an array to scalar is an error, and assigning a
                     scalar to array sets it to be a single-element array.

                     Note that both `typeset -xT ...'  and `export -T ...'
                     work, but only the scalar will be marked for export.
                     Setting the value using the scalar version causes a split
                     on all separators (which cannot be quoted).  It is
                     possible to apply -T to two previously tied variables but
                     with a different separator character, in which case the
                     variables remain joined as before but the separator is
                     changed.

                     When an existing scalar is tied to a new array, the value
                     of the scalar is preserved but no attribute other than
                     export will be preserved.

              Attribute flags that transform the final value (-L, -R, -Z, -l,
              -u) are only applied to the expanded value at the point of a
              parameter expansion expression using `$'.  They are not applied
              when a parameter is retrieved internally by the shell for any
              purpose.

              The following attribute flags may be specified:

              -A     The names refer to associative array parameters; see
                     `Array Parameters' in zshparam(1).

              -L [ n ]
                     Left justify and remove leading blanks from the value
                     when the parameter is expanded.  If n is nonzero, it
                     defines the width of the field.  If n is zero, the width
                     is determined by the width of the value of the first
                     assignment.  In the case of numeric parameters, the
                     length of the complete value assigned to the parameter is
                     used to determine the width, not the value that would be
                     output.

                     The width is the count of characters, which may be
                     multibyte characters if the MULTIBYTE option is in
                     effect.  Note that the screen width of the character is
                     not taken into account; if this is required, use padding
                     with parameter expansion flags ${(ml...)...} as described
                     in `Parameter Expansion Flags' in zshexpn(1).

                     When the parameter is expanded, it is filled on the right
                     with blanks or truncated if necessary to fit the field.
                     Note truncation can lead to unexpected results with
                     numeric parameters.  Leading zeros are removed if the -Z
                     flag is also set.

              -R [ n ]
                     Similar to -L, except that right justification is used;
                     when the parameter is expanded, the field is left filled
                     with blanks or truncated from the end.  May not be
                     combined with the -Z flag.

              -U     For arrays (but not for associative arrays), keep only
                     the first occurrence of each duplicated value.  This may
                     also be set for tied parameters (see -T) or
                     colon-separated special parameters like PATH or FIGNORE,
                     etc.  Note the flag takes effect on assignment, and the
                     type of the variable being assigned to is determinative;
                     for variables with shared values it is therefore
                     recommended to set the flag for all interfaces, e.g.
                     `typeset -U PATH path'.

                     This flag has a different meaning when used with -f; see
                     below.

              -Z [ n ]
                     Specially handled if set along with the -L flag.
                     Otherwise, similar to -R, except that leading zeros are
                     used for padding instead of blanks if the first non-blank
                     character is a digit.  Numeric parameters are specially
                     handled: they are always eligible for padding with
                     zeroes, and the zeroes are inserted at an appropriate
                     place in the output.

              -a     The names refer to array parameters.  An array parameter
                     may be created this way, but it may be assigned to in the
                     typeset statement only if the reserved word form of
                     typeset is enabled (as it is by default).  When
                     displaying, both normal and associative arrays are shown.

              -f     The names refer to functions rather than parameters.  No
                     assignments can be made, and the only other valid flags
                     are -t, -T, -k, -u, -U and -z.  The flag -t turns on
                     execution tracing for this function; the flag -T does the
                     same, but turns off tracing for any named (not anonymous)
                     function called from the present one, unless that
                     function also has the -t or -T flag.  The -u and -U flags
                     cause the function to be marked for autoloading; -U also
                     causes alias expansion to be suppressed when the function
                     is loaded.  See the description of the `autoload' builtin
                     for details.

                     Note that the builtin functions provides the same basic
                     capabilities as typeset -f but gives access to a few
                     extra options; autoload gives further additional options
                     for the case typeset -fu and typeset -fU.

              -h     Hide: only useful for special parameters (those marked
                     `<S>' in the table in zshparam(1)), and for local
                     parameters with the same name as a special parameter,
                     though harmless for others.  A special parameter with
                     this attribute will not retain its special effect when
                     made local.  Thus after `typeset -h PATH', a function
                     containing `typeset PATH' will create an ordinary local
                     parameter without the usual behaviour of PATH.
                     Alternatively, the local parameter may itself be given
                     this attribute; hence inside a function `typeset -h PATH'
                     creates an ordinary local parameter and the special PATH
                     parameter is not altered in any way.  It is also possible
                     to create a local parameter using `typeset +h special',
                     where the local copy of special will retain its special
                     properties regardless of having the -h attribute.  Global
                     special parameters loaded from shell modules (currently
                     those in zsh/mapfile and zsh/parameter) are automatically
                     given the -h attribute to avoid name clashes.

              -H     Hide value: specifies that typeset will not display the
                     value of the parameter when listing parameters; the
                     display for such parameters is always as if the `+' flag
                     had been given.  Use of the parameter is in other
                     respects normal, and the option does not apply if the
                     parameter is specified by name, or by pattern with the -m
                     option.  This is on by default for the parameters in the
                     zsh/parameter and zsh/mapfile modules.  Note, however,
                     that unlike the -h flag this is also useful for
                     non-special parameters.

              -i [ n ]
                     Use an internal integer representation.  If n is nonzero
                     it defines the output arithmetic base, otherwise it is
                     determined by the first assignment.  Bases from 2 to 36
                     inclusive are allowed.

              -E [ n ]
                     Use an internal double-precision floating point
                     representation.  On output the variable will be converted
                     to scientific notation.  If n is nonzero it defines the
                     number of significant figures to display; the default is
                     ten.

              -F [ n ]
                     Use an internal double-precision floating point
                     representation.  On output the variable will be converted
                     to fixed-point decimal notation.  If n is nonzero it
                     defines the number of digits to display after the decimal
                     point; the default is ten.

              -l     Convert the result to lower case whenever the parameter
                     is expanded.  The value is not converted when assigned.

              -r     The given names are marked readonly.  Note that if name
                     is a special parameter, the readonly attribute can be
                     turned on, but cannot then be turned off.

                     If the POSIX_BUILTINS option is set, the readonly
                     attribute is more restrictive: unset variables can be
                     marked readonly and cannot then be set; furthermore, the
                     readonly attribute cannot be removed from any variable.

                     It is still possible to change other attributes of the
                     variable though, some of which like -U or -Z would affect
                     the value. More generally, the readonly attribute should
                     not be relied on as a security mechanism.

                     Note that in zsh (like in pdksh but unlike most other
                     shells) it is still possible to create a local variable
                     of the same name as this is considered a different
                     variable (though this variable, too, can be marked
                     readonly). Special variables that have been made readonly
                     retain their value and readonly attribute when made
                     local.

              -t     Tags the named parameters.  Tags have no special meaning
                     to the shell.  This flag has a different meaning when
                     used with -f; see above.

              -u     Convert the result to upper case whenever the parameter
                     is expanded.  The value is not converted when assigned.
                     This flag has a different meaning when used with -f; see
                     above.

              -x     Mark for automatic export to the environment of
                     subsequently executed commands.  If the option
                     GLOBAL_EXPORT is set, this implies the option -g, unless
                     +g is also explicitly given; in other words the parameter
                     is not made local to the enclosing function.  This is for
                     compatibility with previous versions of zsh.

       ulimit [ -HSa ] [ { -bcdfiklmnpqrsTtvwx | -N resource } [ limit ] ... ]
              Set or display resource limits of the shell and the processes
              started by the shell.  The value of limit can be a number in the
              unit specified below or one of the values `unlimited', which
              removes the limit on the resource, or `hard', which uses the
              current value of the hard limit on the resource.

              By default, only soft limits are manipulated. If the -H flag is
              given use hard limits instead of soft limits.  If the -S flag is
              given together with the -H flag set both hard and soft limits.

              If no options are used, the file size limit (-f) is assumed.

              If limit is omitted the current value of the specified resources
              are printed.  When more than one resource value is printed, the
              limit name and unit is printed before each value.

              When looping over multiple resources, the shell will abort
              immediately if it detects a badly formed argument.  However, if
              it fails to set a limit for some other reason it will continue
              trying to set the remaining limits.

              Not all the following resources are supported on all systems.
              Running ulimit -a will show which are supported.

              -a     Lists all of the current resource limits.
              -b     Socket buffer size in bytes (N.B. not kilobytes)
              -c     512-byte blocks on the size of core dumps.
              -d     Kilobytes on the size of the data segment.
              -f     512-byte blocks on the size of files written.
              -i     The number of pending signals.
              -k     The number of kqueues allocated.
              -l     Kilobytes on the size of locked-in memory.
              -m     Kilobytes on the size of physical memory.
              -n     open file descriptors.
              -p     The number of pseudo-terminals.
              -q     Bytes in POSIX message queues.
              -r     Maximum real time priority.  On some systems where this
                     is not available, such as NetBSD, this has the same
                     effect as -T for compatibility with sh.
              -s     Kilobytes on the size of the stack.
              -T     The number of simultaneous threads available to the user.
              -t     CPU seconds to be used.
              -u     The number of processes available to the user.
              -v     Kilobytes on the size of virtual memory.  On some systems
                     this refers to the limit called `address space'.
              -w     Kilobytes on the size of swapped out memory.
              -x     The number of locks on files.

              A resource may also be specified by integer in the form `-N
              resource', where resource corresponds to the integer defined for
              the resource by the operating system.  This may be used to set
              the limits for resources known to the shell which do not
              correspond to option letters.  Such limits will be shown by
              number in the output of `ulimit -a'.

              The number may alternatively be out of the range of limits
              compiled into the shell.  The shell will try to read or write
              the limit anyway, and will report an error if this fails.

       umask [ -S ] [ mask ]
              The umask is set to mask.  mask can be either an octal number or
              a symbolic value as described in chmod(1).  If mask is omitted,
              the current value is printed.  The -S option causes the mask to
              be printed as a symbolic value.  Otherwise, the mask is printed
              as an octal number.  Note that in the symbolic form the
              permissions you specify are those which are to be allowed (not
              denied) to the users specified.

       unalias [ -ams ] name ...
              Removes aliases.  This command works the same as unhash -a,
              except that the -a option removes all regular or global aliases,
              or with -s all suffix aliases: in this case no name arguments
              may appear.  The options -m (remove by pattern) and -s without
              -a (remove listed suffix aliases) behave as for unhash -a.  Note
              that the meaning of -a is different between unalias and unhash.

       unfunction
              Same as unhash -f.

       unhash [ -adfms ] name ...
              Remove the element named name from an internal hash table.  The
              default is remove elements from the command hash table.  The -a
              option causes unhash to remove regular or global aliases; note
              when removing a global aliases that the argument must be quoted
              to prevent it from being expanded before being passed to the
              command.  The -s option causes unhash to remove suffix aliases.
              The -f option causes unhash to remove shell functions.  The -d
              options causes unhash to remove named directories.  If the -m
              flag is given the arguments are taken as patterns (should be
              quoted) and all elements of the corresponding hash table with
              matching names will be removed.

       unlimit [ -hs ] resource ...
              The resource limit for each resource is set to the hard limit.
              If the -h flag is given and the shell has appropriate
              privileges, the hard resource limit for each resource is
              removed.  The resources of the shell process are only changed if
              the -s flag is given.

              The unlimit command is not made available by default when the
              shell starts in a mode emulating another shell.  It can be made
              available with the command `zmodload -F zsh/rlimits b:unlimit'.

       unset [ -fmv ] name ...
              Each named parameter is unset.  Local parameters remain local
              even if unset; they appear unset within scope, but the previous
              value will still reappear when the scope ends.

              Individual elements of associative array parameters may be unset
              by using subscript syntax on name, which should be quoted (or
              the entire command prefixed with noglob) to protect the
              subscript from filename generation.

              If the -m flag is specified the arguments are taken as patterns
              (should be quoted) and all parameters with matching names are
              unset.  Note that this cannot be used when unsetting associative
              array elements, as the subscript will be treated as part of the
              pattern.

              The -v flag specifies that name refers to parameters. This is
              the default behaviour.

              unset -f is equivalent to unfunction.

       unsetopt [ {+|-}options | {+|-}o option_name ] [ name ... ]
              Unset the options for the shell.  All options specified either
              with flags or by name are unset.  If no arguments are supplied,
              the names of all options currently unset are printed.  If the -m
              flag is given the arguments are taken as patterns (which should
              be quoted to preserve them from being interpreted as glob
              patterns), and all options with names matching these patterns
              are unset.

       vared  See the section `Zle Builtins' in zshzle(1).

       wait [ job ... ]
              Wait for the specified jobs or processes.  If job is not given
              then all currently active child processes are waited for.  Each
              job can be either a job specification or the process ID of a job
              in the job table.  The exit status from this command is that of
              the job waited for.  If job represents an unknown job or process
              ID, a warning is printed (unless the POSIX_BUILTINS option is
              set) and the exit status is 127.

              It is possible to wait for recent processes (specified by
              process ID, not by job) that were running in the background even
              if the process has exited.  Typically the process ID will be
              recorded by capturing the value of the variable $! immediately
              after the process has been started.  There is a limit on the
              number of process IDs remembered by the shell; this is given by
              the value of the system configuration parameter CHILD_MAX.  When
              this limit is reached, older process IDs are discarded, least
              recently started processes first.

              Note there is no protection against the process ID wrapping,
              i.e. if the wait is not executed soon enough there is a chance
              the process waited for is the wrong one.  A conflict implies
              both process IDs have been generated by the shell, as other
              processes are not recorded, and that the user is potentially
              interested in both, so this problem is intrinsic to process IDs.

       whence [ -vcwfpamsS ] [ -x num ] name ...
              For each name, indicate how it would be interpreted if used as a
              command name.

              If name is not an alias, built-in command, external command,
              shell function, hashed command, or a reserved word, the exit
              status shall be non-zero, and -- if -v, -c, or -w was passed --
              a message will be written to standard output.  (This is
              different from other shells that write that message to standard
              error.)

              whence is most useful when name is only the last path component
              of a command, i.e. does not include a `/'; in particular,
              pattern matching only succeeds if just the non-directory
              component of the command is passed.

              -v     Produce a more verbose report.

              -c     Print the results in a csh-like format.  This takes
                     precedence over -v.

              -w     For each name, print `name: word' where word is one of
                     alias, builtin, command, function, hashed, reserved or
                     none, according as name corresponds to an alias, a
                     built-in command, an external command, a shell function,
                     a command defined with the hash builtin, a reserved word,
                     or is not recognised.  This takes precedence over -v and
                     -c.

              -f     Causes the contents of a shell function to be displayed,
                     which would otherwise not happen unless the -c flag were
                     used.

              -p     Do a path search for name even if it is an alias,
                     reserved word, shell function or builtin.

              -a     Do a search for all occurrences of name throughout the
                     command path.  Normally only the first occurrence is
                     printed.

              -m     The arguments are taken as patterns (pattern characters
                     should be quoted), and the information is displayed for
                     each command matching one of these patterns.

              -s     If a pathname contains symlinks, print the symlink-free
                     pathname as well.

              -S     As -s, but if the pathname had to be resolved by
                     following multiple symlinks, the intermediate steps are
                     printed, too.  The symlink resolved at each step might be
                     anywhere in the path.

              -x num Expand tabs when outputting shell functions using the -c
                     option.  This has the same effect as the -x option to the
                     functions builtin.

       where [ -wpmsS ] [ -x num ] name ...
              Equivalent to whence -ca.

       which [ -wpamsS ] [ -x num ] name ...
              Equivalent to whence -c.

       zcompile [ -U ] [ -z | -k ] [ -R | -M ] file [ name ... ]
       zcompile -ca [ -m ] [ -R | -M ] file [ name ... ]
       zcompile -t file [ name ... ]
              This builtin command can be used to compile functions or
              scripts, storing the compiled form in a file, and to examine
              files containing the compiled form.  This allows faster
              autoloading of functions and sourcing of scripts by avoiding
              parsing of the text when the files are read.

              The first form (without the -c, -a or -t options) creates a
              compiled file.  If only the file argument is given, the output
              file has the name `file.zwc' and will be placed in the same
              directory as the file.  The shell will load the compiled file
              instead of the normal function file when the function is
              autoloaded; see the section `Autoloading Functions' in
              zshmisc(1) for a description of how autoloaded functions are
              searched.  The extension .zwc stands for `zsh word code'.

              If there is at least one name argument, all the named files are
              compiled into the output file given as the first argument.  If
              file does not end in .zwc, this extension is automatically
              appended.  Files containing multiple compiled functions are
              called `digest' files, and are intended to be used as elements
              of the FPATH/fpath special array.

              The second form, with the -c or -a options, writes the compiled
              definitions for all the named functions into file.  For -c, the
              names must be functions currently defined in the shell, not
              those marked for autoloading.  Undefined functions that are
              marked for autoloading may be written by using the -a option, in
              which case the fpath is searched and the contents of the
              definition files for those functions, if found, are compiled
              into file.  If both -c and -a are given, names of both defined
              functions and functions marked for autoloading may be given.  In
              either case, the functions in files written with the -c or -a
              option will be autoloaded as if the KSH_AUTOLOAD option were
              unset.

              The reason for handling loaded and not-yet-loaded functions with
              different options is that some definition files for autoloading
              define multiple functions, including the function with the same
              name as the file, and, at the end, call that function.  In such
              cases the output of `zcompile -c' does not include the
              additional functions defined in the file, and any other
              initialization code in the file is lost.  Using `zcompile -a'
              captures all this extra information.

              If the -m option is combined with -c or -a, the names are used
              as patterns and all functions whose names match one of these
              patterns will be written. If no name is given, the definitions
              of all functions currently defined or marked as autoloaded will
              be written.

              Note the second form cannot be used for compiling functions that
              include redirections as part of the definition rather than
              within the body of the function; for example

                     fn1() { { ... } >~/logfile }

              can be compiled but

                     fn1() { ... } >~/logfile

              cannot.  It is possible to use the first form of zcompile to
              compile autoloadable functions that include the full function
              definition instead of just the body of the function.

              The third form, with the -t option, examines an existing
              compiled file.  Without further arguments, the names of the
              original files compiled into it are listed.  The first line of
              output shows the version of the shell which compiled the file
              and how the file will be used (i.e. by reading it directly or by
              mapping it into memory).  With arguments, nothing is output and
              the return status is set to zero if definitions for all names
              were found in the compiled file, and non-zero if the definition
              for at least one name was not found.

              Other options:

              -U     Aliases are not expanded when compiling the named files.

              -R     When the compiled file is read, its contents are copied
                     into the shell's memory, rather than memory-mapped (see
                     -M).  This happens automatically on systems that do not
                     support memory mapping.

                     When compiling scripts instead of autoloadable functions,
                     it is often desirable to use this option; otherwise the
                     whole file, including the code to define functions which
                     have already been defined, will remain mapped,
                     consequently wasting memory.

              -M     The compiled file is mapped into the shell's memory when
                     read. This is done in such a way that multiple instances
                     of the shell running on the same host will share this
                     mapped file.  If neither -R nor -M is given, the zcompile
                     builtin decides what to do based on the size of the
                     compiled file.

              -k
              -z     These options are used when the compiled file contains
                     functions which are to be autoloaded. If -z is given, the
                     function will be autoloaded as if the KSH_AUTOLOAD option
                     is not set, even if it is set at the time the compiled
                     file is read, while if the -k is given, the function will
                     be loaded as if KSH_AUTOLOAD is set.  These options also
                     take precedence over any -k or -z options specified to
                     the autoload builtin. If neither of these options is
                     given, the function will be loaded as determined by the
                     setting of the KSH_AUTOLOAD option at the time the
                     compiled file is read.

                     These options may also appear as many times as necessary
                     between the listed names to specify the loading style of
                     all following functions, up to the next -k or -z.

                     The created file always contains two versions of the
                     compiled format, one for big-endian machines and one for
                     small-endian machines.  The upshot of this is that the
                     compiled file is machine independent and if it is read or
                     mapped, only one half of the file is actually used (and
                     mapped).

       zformat
              See the section `The zsh/zutil Module' in zshmodules(1).

       zftp   See the section `The zsh/zftp Module' in zshmodules(1).

       zle    See the section `Zle Builtins' in zshzle(1).

       zmodload [ -dL ] [ -s ] [ ... ]
       zmodload -F [ -alLme -P param ] module [ [+-]feature ... ]
       zmodload -e [ -A ] [ ... ]
       zmodload [ -a [ -bcpf [ -I ] ] ] [ -iL ] ...
       zmodload -u [ -abcdpf [ -I ] ] [ -iL ] ...
       zmodload -A [ -L ] [ modalias[=module] ... ]
       zmodload -R modalias ...
              Performs operations relating to zsh's loadable modules.  Loading
              of modules while the shell is running (`dynamical loading') is
              not available on all operating systems, or on all installations
              on a particular operating system, although the zmodload command
              itself is always available and can be used to manipulate modules
              built into versions of the shell executable without dynamical
              loading.

              Without arguments the names of all currently loaded binary
              modules are printed.  The -L option causes this list to be in
              the form of a series of zmodload commands.  Forms with arguments
              are:

              zmodload [ -is ] name ...
              zmodload -u [ -i ] name ...
                     In the simplest case, zmodload loads a binary module.
                     The module must be in a file with a name consisting of
                     the specified name followed by a standard suffix, usually
                     `.so' (`.sl' on HPUX).  If the module to be loaded is
                     already loaded the duplicate module is ignored.  If
                     zmodload detects an inconsistency, such as an invalid
                     module name or circular dependency list, the current code
                     block is aborted.  If it is available, the module is
                     loaded if necessary, while if it is not available,
                     non-zero status is silently returned.  The option -i is
                     accepted for compatibility but has no effect.

                     The named module is searched for in the same way a
                     command is, using $module_path instead of $path.
                     However, the path search is performed even when the
                     module name contains a `/', which it usually does.  There
                     is no way to prevent the path search.

                     If the module supports features (see below), zmodload
                     tries to enable all features when loading a module.  If
                     the module was successfully loaded but not all features
                     could be enabled, zmodload returns status 2.

                     If the option -s is given, no error is printed if the
                     module was not available (though other errors indicating
                     a problem with the module are printed).  The return
                     status indicates if the module was loaded.  This is
                     appropriate if the caller considers the module optional.

                     With -u, zmodload unloads modules.  The same name must be
                     given that was given when the module was loaded, but it
                     is not necessary for the module to exist in the file
                     system.  The -i option suppresses the error if the module
                     is already unloaded (or was never loaded).

                     Each module has a boot and a cleanup function.  The
                     module will not be loaded if its boot function fails.
                     Similarly a module can only be unloaded if its cleanup
                     function runs successfully.

              zmodload -F [ -almLe -P param ] module [ [+-]feature ... ]
                     zmodload -F allows more selective control over the
                     features provided by modules.  With no options apart from
                     -F, the module named module is loaded, if it was not
                     already loaded, and the list of features is set to the
                     required state.  If no features are specified, the module
                     is loaded, if it was not already loaded, but the state of
                     features is unchanged.  Each feature may be preceded by a
                     + to turn the feature on, or - to turn it off; the + is
                     assumed if neither character is present.  Any feature not
                     explicitly mentioned is left in its current state; if the
                     module was not previously loaded this means any such
                     features will remain disabled.  The return status is zero
                     if all features were set, 1 if the module failed to load,
                     and 2 if some features could not be set (for example, a
                     parameter couldn't be added because there was a different
                     parameter of the same name) but the module was loaded.

                     The standard features are builtins, conditions,
                     parameters and math functions; these are indicated by the
                     prefix `b:', `c:' (`C:' for an infix condition), `p:' and
                     `f:', respectively, followed by the name that the
                     corresponding feature would have in the shell.  For
                     example, `b:strftime' indicates a builtin named strftime
                     and p:EPOCHSECONDS indicates a parameter named
                     EPOCHSECONDS.  The module may provide other (`abstract')
                     features of its own as indicated by its documentation;
                     these have no prefix.

                     With -l or -L, features provided by the module are
                     listed.  With -l alone, a list of features together with
                     their states is shown, one feature per line.  With -L
                     alone, a zmodload -F command that would cause enabled
                     features of the module to be turned on is shown.  With
                     -lL, a zmodload -F command that would cause all the
                     features to be set to their current state is shown.  If
                     one of these combinations is given with the option -P
                     param then the parameter param is set to an array of
                     features, either features together with their state or
                     (if -L alone is given) enabled features.

                     With the option -L the module name may be omitted; then a
                     list of all enabled features for all modules providing
                     features is printed in the form of zmodload -F commands.
                     If -l is also given, the state of both enabled and
                     disabled features is output in that form.

                     A set of features may be provided together with -l or -L
                     and a module name; in that case only the state of those
                     features is considered.  Each feature may be preceded by
                     + or - but the character has no effect.  If no set of
                     features is provided, all features are considered.

                     With -e, the command first tests that the module is
                     loaded; if it is not, status 1 is returned.  If the
                     module is loaded, the list of features given as an
                     argument is examined.  Any feature given with no prefix
                     is simply tested to see if the module provides it; any
                     feature given with a prefix + or - is tested to see if is
                     provided and in the given state.  If the tests on all
                     features in the list succeed, status 0 is returned, else
                     status 1.

                     With -m, each entry in the given list of features is
                     taken as a pattern to be matched against the list of
                     features provided by the module.  An initial + or - must
                     be given explicitly.  This may not be combined with the
                     -a option as autoloads must be specified explicitly.

                     With -a, the given list of features is marked for
                     autoload from the specified module, which may not yet be
                     loaded.  An optional + may appear before the feature
                     name.  If the feature is prefixed with -, any existing
                     autoload is removed.  The options -l and -L may be used
                     to list autoloads.  Autoloading is specific to individual
                     features; when the module is loaded only the requested
                     feature is enabled.  Autoload requests are preserved if
                     the module is subsequently unloaded until an explicit
                     `zmodload -Fa module -feature' is issued.  It is not an
                     error to request an autoload for a feature of a module
                     that is already loaded.

                     When the module is loaded each autoload is checked
                     against the features actually provided by the module; if
                     the feature is not provided the autoload request is
                     deleted.  A warning message is output; if the module is
                     being loaded to provide a different feature, and that
                     autoload is successful, there is no effect on the status
                     of the current command.  If the module is already loaded
                     at the time when zmodload -Fa is run, an error message is
                     printed and status 1 returned.

                     zmodload -Fa can be used with the -l, -L, -e and -P
                     options for listing and testing the existence of
                     autoloadable features.  In this case -l is ignored if -L
                     is specified.  zmodload -FaL with no module name lists
                     autoloads for all modules.

                     Note that only standard features as described above can
                     be autoloaded; other features require the module to be
                     loaded before enabling.

              zmodload -d [ -L ] [ name ]
              zmodload -d name dep ...
              zmodload -ud name [ dep ... ]
                     The -d option can be used to specify module dependencies.
                     The modules named in the second and subsequent arguments
                     will be loaded before the module named in the first
                     argument.

                     With -d and one argument, all dependencies for that
                     module are listed.  With -d and no arguments, all module
                     dependencies are listed.  This listing is by default in a
                     Makefile-like format.  The -L option changes this format
                     to a list of zmodload -d commands.

                     If -d and -u are both used, dependencies are removed.  If
                     only one argument is given, all dependencies for that
                     module are removed.

              zmodload -ab [ -L ]
              zmodload -ab [ -i ] name [ builtin ... ]
              zmodload -ub [ -i ] builtin ...
                     The -ab option defines autoloaded builtins.  It defines
                     the specified builtins.  When any of those builtins is
                     called, the module specified in the first argument is
                     loaded and all its features are enabled (for selective
                     control of features use `zmodload -F -a' as described
                     above).  If only the name is given, one builtin is
                     defined, with the same name as the module.  -i suppresses
                     the error if the builtin is already defined or
                     autoloaded, but not if another builtin of the same name
                     is already defined.

                     With -ab and no arguments, all autoloaded builtins are
                     listed, with the module name (if different) shown in
                     parentheses after the builtin name.  The -L option
                     changes this format to a list of zmodload -a commands.

                     If -b is used together with the -u option, it removes
                     builtins previously defined with -ab.  This is only
                     possible if the builtin is not yet loaded.  -i suppresses
                     the error if the builtin is already removed (or never
                     existed).

                     Autoload requests are retained if the module is
                     subsequently unloaded until an explicit `zmodload -ub
                     builtin' is issued.

              zmodload -ac [ -IL ]
              zmodload -ac [ -iI ] name [ cond ... ]
              zmodload -uc [ -iI ] cond ...
                     The -ac option is used to define autoloaded condition
                     codes. The cond strings give the names of the conditions
                     defined by the module. The optional -I option is used to
                     define infix condition names. Without this option prefix
                     condition names are defined.

                     If given no condition names, all defined names are listed
                     (as a series of zmodload commands if the -L option is
                     given).

                     The -uc option removes definitions for autoloaded
                     conditions.

              zmodload -ap [ -L ]
              zmodload -ap [ -i ] name [ parameter ... ]
              zmodload -up [ -i ] parameter ...
                     The -p option is like the -b and -c options, but makes
                     zmodload work on autoloaded parameters instead.

              zmodload -af [ -L ]
              zmodload -af [ -i ] name [ function ... ]
              zmodload -uf [ -i ] function ...
                     The -f option is like the -b, -p, and -c options, but
                     makes zmodload work on autoloaded math functions instead.

              zmodload -a [ -L ]
              zmodload -a [ -i ] name [ builtin ... ]
              zmodload -ua [ -i ] builtin ...
                     Equivalent to -ab and -ub.

              zmodload -e [ -A ] [ string ... ]
                     The -e option without arguments lists all loaded modules;
                     if the -A option is also given, module aliases
                     corresponding to loaded modules are also shown.  If
                     arguments are provided, nothing is printed; the return
                     status is set to zero if all strings given as arguments
                     are names of loaded modules and to one if at least on
                     string is not the name of a loaded module.  This can be
                     used to test for the availability of things implemented
                     by modules.  In this case, any aliases are automatically
                     resolved and the -A flag is not used.

              zmodload -A [ -L ] [ modalias[=module] ... ]
                     For each argument, if both modalias and module are given,
                     define modalias to be an alias for the module module.  If
                     the module modalias is ever subsequently requested,
                     either via a call to zmodload or implicitly, the shell
                     will attempt to load module instead.  If module is not
                     given, show the definition of modalias.  If no arguments
                     are given, list all defined module aliases.  When
                     listing, if the -L flag was also given, list the
                     definition as a zmodload command to recreate the alias.

                     The existence of aliases for modules is completely
                     independent of whether the name resolved is actually
                     loaded as a module: while the alias exists, loading and
                     unloading the module under any alias has exactly the same
                     effect as using the resolved name, and does not affect
                     the connection between the alias and the resolved name
                     which can be removed either by zmodload -R or by
                     redefining the alias.  Chains of aliases (i.e. where the
                     first resolved name is itself an alias) are valid so long
                     as these are not circular.  As the aliases take the same
                     format as module names, they may include path separators:
                     in this case, there is no requirement for any part of the
                     path named to exist as the alias will be resolved first.
                     For example, `any/old/alias' is always a valid alias.

                     Dependencies added to aliased modules are actually added
                     to the resolved module; these remain if the alias is
                     removed.  It is valid to create an alias whose name is
                     one of the standard shell modules and which resolves to a
                     different module.  However, if a module has dependencies,
                     it will not be possible to use the module name as an
                     alias as the module will already be marked as a loadable
                     module in its own right.

                     Apart from the above, aliases can be used in the zmodload
                     command anywhere module names are required.  However,
                     aliases will not be shown in lists of loaded modules with
                     a bare `zmodload'.

              zmodload -R modalias ...
                     For each modalias argument that was previously defined as
                     a module alias via zmodload -A, delete the alias.  If any
                     was not defined, an error is caused and the remainder of
                     the line is ignored.

              Note that zsh makes no distinction between modules that were
              linked into the shell and modules that are loaded dynamically.
              In both cases this builtin command has to be used to make
              available the builtins and other things defined by modules
              (unless the module is autoloaded on these definitions). This is
              true even for systems that don't support dynamic loading of
              modules.

       zparseopts
              See the section `The zsh/zutil Module' in zshmodules(1).

       zprof  See the section `The zsh/zprof Module' in zshmodules(1).

       zpty   See the section `The zsh/zpty Module' in zshmodules(1).

       zregexparse
              See the section `The zsh/zutil Module' in zshmodules(1).

       zsocket
              See the section `The zsh/net/socket Module' in zshmodules(1).

       zstyle See the section `The zsh/zutil Module' in zshmodules(1).

       ztcp   See the section `The zsh/net/tcp Module' in zshmodules(1).




ZSHZLE(1)                   General Commands Manual                  ZSHZLE(1)



NAME
       zshzle - zsh command line editor

DESCRIPTION
       If the ZLE option is set (which it is by default in interactive shells)
       and the shell input is attached to the terminal, the user is able to
       edit command lines.

       There are two display modes.  The first, multiline mode, is the
       default.  It only works if the TERM parameter is set to a valid
       terminal type that can move the cursor up.  The second, single line
       mode, is used if TERM is invalid or incapable of moving the cursor up,
       or if the SINGLE_LINE_ZLE option is set.  This mode is similar to ksh,
       and uses no termcap sequences.  If TERM is "emacs", the ZLE option will
       be unset by default.

       The parameters BAUD, COLUMNS, and LINES are also used by the line
       editor. See Parameters Used By The Shell in zshparam(1).

       The parameter zle_highlight is also used by the line editor; see
       Character Highlighting below.  Highlighting of special characters and
       the region between the cursor and the mark (as set with
       set-mark-command in Emacs mode, or by visual-mode in Vi mode) is
       enabled by default; consult this reference for more information.
       Irascible conservatives will wish to know that all highlighting may be
       disabled by the following setting:

              zle_highlight=(none)

       In many places, references are made to the numeric argument.  This can
       by default be entered in emacs mode by holding the alt key and typing a
       number, or pressing escape before each digit, and in vi command mode by
       typing the number before entering a command.  Generally the numeric
       argument causes the next command entered to be repeated the specified
       number of times, unless otherwise noted below; this is implemented by
       the digit-argument widget. See also the Arguments subsection of the
       Widgets section for some other ways the numeric argument can be
       modified.

KEYMAPS
       A keymap in ZLE contains a set of bindings between key sequences and
       ZLE commands.  The empty key sequence cannot be bound.

       There can be any number of keymaps at any time, and each keymap has one
       or more names.  If all of a keymap's names are deleted, it disappears.
       bindkey can be used to manipulate keymap names.

       Initially, there are eight keymaps:

       emacs  EMACS emulation
       viins  vi emulation - insert mode
       vicmd  vi emulation - command mode
       viopp  vi emulation - operator pending
       visual vi emulation - selection active
       isearch
              incremental search mode
       command
              read a command name
       .safe  fallback keymap

       The `.safe' keymap is special.  It can never be altered, and the name
       can never be removed.  However, it can be linked to other names, which
       can be removed.  In the future other special keymaps may be added;
       users should avoid using names beginning with `.' for their own
       keymaps.

       In addition to these names, either `emacs' or `viins' is also linked to
       the name `main'.  If one of the VISUAL or EDITOR environment variables
       contain the string `vi' when the shell starts up then it will be
       `viins', otherwise it will be `emacs'.  bindkey's -e and -v options
       provide a convenient way to override this default choice.

       When the editor starts up, it will select the `main' keymap.  If that
       keymap doesn't exist, it will use `.safe' instead.

       In the `.safe' keymap, each single key is bound to self-insert, except
       for ^J (line feed) and ^M (return) which are bound to accept-line.
       This is deliberately not pleasant to use; if you are using it, it means
       you deleted the main keymap, and you should put it back.

   Reading Commands
       When ZLE is reading a command from the terminal, it may read a sequence
       that is bound to some command and is also a prefix of a longer bound
       string.  In this case ZLE will wait a certain time to see if more
       characters are typed, and if not (or they don't match any longer
       string) it will execute the binding.  This timeout is defined by the
       KEYTIMEOUT parameter; its default is 0.4 sec.  There is no timeout if
       the prefix string is not itself bound to a command.

       The key timeout is also applied when ZLE is reading the bytes from a
       multibyte character string when it is in the appropriate mode.  (This
       requires that the shell was compiled with multibyte mode enabled;
       typically also the locale has characters with the UTF-8 encoding,
       although any multibyte encoding known to the operating system is
       supported.)  If the second or a subsequent byte is not read within the
       timeout period, the shell acts as if ? were typed and resets the input
       state.

       As well as ZLE commands, key sequences can be bound to other strings,
       by using `bindkey -s'.  When such a sequence is read, the replacement
       string is pushed back as input, and the command reading process starts
       again using these fake keystrokes.  This input can itself invoke
       further replacement strings, but in order to detect loops the process
       will be stopped if there are twenty such replacements without a real
       command being read.

       A key sequence typed by the user can be turned into a command name for
       use in user-defined widgets with the read-command widget, described in
       the subsection `Miscellaneous' of the section `Standard Widgets' below.

   Local Keymaps
       While for normal editing a single keymap is used exclusively, in many
       modes a local keymap allows for some keys to be customised. For
       example, in an incremental search mode, a binding in the isearch keymap
       will override a binding in the main keymap but all keys that are not
       overridden can still be used.

       If a key sequence is defined in a local keymap, it will hide a key
       sequence in the global keymap that is a prefix of that sequence. An
       example of this occurs with the binding of iw in viopp as this hides
       the binding of i in vicmd. However, a longer sequence in the global
       keymap that shares the same prefix can still apply so for example the
       binding of ^Xa in the global keymap will be unaffected by the binding
       of ^Xb in the local keymap.

ZLE BUILTINS
       The ZLE module contains three related builtin commands. The bindkey
       command manipulates keymaps and key bindings; the vared command invokes
       ZLE on the value of a shell parameter; and the zle command manipulates
       editing widgets and allows command line access to ZLE commands from
       within shell functions.

       bindkey [ options ] -l [ -L ] [ keymap ... ]
       bindkey [ options ] -d
       bindkey [ options ] -D keymap ...
       bindkey [ options ] -A old-keymap new-keymap
       bindkey [ options ] -N new-keymap [ old-keymap ]
       bindkey [ options ] -m
       bindkey [ options ] -r in-string ...
       bindkey [ options ] -s in-string out-string ...
       bindkey [ options ] in-string command ...
       bindkey [ options ] [ in-string ]
              bindkey's options can be divided into three categories: keymap
              selection for the current command, operation selection, and
              others.  The keymap selection options are:

              -e     Selects keymap `emacs' for any operations by the current
                     command, and also links `emacs' to `main' so that it is
                     selected by default the next time the editor starts.

              -v     Selects keymap `viins' for any operations by the current
                     command, and also links `viins' to `main' so that it is
                     selected by default the next time the editor starts.

              -a     Selects keymap `vicmd' for any operations by the current
                     command.

              -M keymap
                     The keymap specifies a keymap name that is selected for
                     any operations by the current command.

              If a keymap selection is required and none of the options above
              are used, the `main' keymap is used.  Some operations do not
              permit a keymap to be selected, namely:

              -l     List all existing keymap names; if any arguments are
                     given, list just those keymaps.

                     If the -L option is also used, list in the form of
                     bindkey commands to create or link the keymaps.  `bindkey
                     -lL main' shows which keymap is linked to `main', if any,
                     and hence if the standard emacs or vi emulation is in
                     effect.  This option does not show the .safe keymap
                     because it cannot be created in that fashion; however,
                     neither is `bindkey -lL .safe' reported as an error, it
                     simply outputs nothing.

              -d     Delete all existing keymaps and reset to the default
                     state.

              -D keymap ...
                     Delete the named keymaps.

              -A old-keymap new-keymap
                     Make the new-keymap name an alias for old-keymap, so that
                     both names refer to the same keymap.  The names have
                     equal standing; if either is deleted, the other remains.
                     If there is already a keymap with the new-keymap name, it
                     is deleted.

              -N new-keymap [ old-keymap ]
                     Create a new keymap, named new-keymap.  If a keymap
                     already has that name, it is deleted.  If an old-keymap
                     name is given, the new keymap is initialized to be a
                     duplicate of it, otherwise the new keymap will be empty.

              To use a newly created keymap, it should be linked to main.
              Hence the sequence of commands to create and use a new keymap
              `mymap' initialized from the emacs keymap (which remains
              unchanged) is:

                     bindkey -N mymap emacs
                     bindkey -A mymap main

              Note that while `bindkey -A newmap main' will work when newmap
              is emacs or viins, it will not work for vicmd, as switching from
              vi insert to command mode becomes impossible.

              The following operations act on the `main' keymap if no keymap
              selection option was given:

              -m     Add the built-in set of meta-key bindings to the selected
                     keymap.  Only keys that are unbound or bound to
                     self-insert are affected.

              -r in-string ...
                     Unbind the specified in-strings in the selected keymap.
                     This is exactly equivalent to binding the strings to
                     undefined-key.

                     When -R is also used, interpret the in-strings as ranges.

                     When -p is also used, the in-strings specify prefixes.
                     Any binding that has the given in-string as a prefix, not
                     including the binding for the in-string itself, if any,
                     will be removed.  For example,

                            bindkey -rpM viins '^['

                     will remove all bindings in the vi-insert keymap
                     beginning with an escape character (probably cursor
                     keys), but leave the binding for the escape character
                     itself (probably vi-cmd-mode).  This is incompatible with
                     the option -R.

              -s in-string out-string ...
                     Bind each in-string to each out-string.  When in-string
                     is typed, out-string will be pushed back and treated as
                     input to the line editor.  When -R is also used,
                     interpret the in-strings as ranges.

                     Note that both in-string and out-string are subject to
                     the same form of interpretation, as described below.

              in-string command ...
                     Bind each in-string to each command.  When -R is used,
                     interpret the in-strings as ranges.

              [ in-string ]
                     List key bindings.  If an in-string is specified, the
                     binding of that string in the selected keymap is
                     displayed.  Otherwise, all key bindings in the selected
                     keymap are displayed.  (As a special case, if the -e or
                     -v option is used alone, the keymap is not displayed -
                     the implicit linking of keymaps is the only thing that
                     happens.)

                     When the option -p is used, the in-string must be
                     present.  The listing shows all bindings which have the
                     given key sequence as a prefix, not including any
                     bindings for the key sequence itself.

                     When the -L option is used, the list is in the form of
                     bindkey commands to create the key bindings.

              When the -R option is used as noted above, a valid range
              consists of two characters, with an optional `-' between them.
              All characters between the two specified, inclusive, are bound
              as specified.

              For either in-string or out-string, the following escape
              sequences are recognised:

              \a     bell character
              \b     backspace
              \e, \E escape
              \f     form feed
              \n     linefeed (newline)
              \r     carriage return
              \t     horizontal tab
              \v     vertical tab
              \NNN   character code in octal
              \xNN   character code in hexadecimal
              \uNNNN unicode character code in hexadecimal
              \UNNNNNNNN
                     unicode character code in hexadecimal
              \M[-]X character with meta bit set
              \C[-]X control character
              ^X     control character

              In all other cases, `\' escapes the following character.  Delete
              is written as `^?'.  Note that `\M^?' and `^\M?' are not the
              same, and that (unlike emacs), the bindings `\M-X' and `\eX' are
              entirely distinct, although they are initialized to the same
              bindings by `bindkey -m'.


       vared [ -Aacghe ] [ -p prompt ] [ -r rprompt ]
             [ -M main-keymap ] [ -m vicmd-keymap ]
             [ -i init-widget ] [ -f finish-widget ]
             [ -t tty ] name
              The value of the parameter name is loaded into the edit buffer,
              and the line editor is invoked.  When the editor exits, name is
              set to the string value returned by the editor.  When the -c
              flag is given, the parameter is created if it doesn't already
              exist.  The -a flag may be given with -c to create an array
              parameter, or the -A flag to create an associative array.  If
              the type of an existing parameter does not match the type to be
              created, the parameter is unset and recreated.  The -g flag may
              be given to suppress warnings from the WARN_CREATE_GLOBAL and
              WARN_NESTED_VAR options.

              If an array or array slice is being edited, separator characters
              as defined in $IFS will be shown quoted with a backslash, as
              will backslashes themselves.  Conversely, when the edited text
              is split into an array, a backslash quotes an immediately
              following separator character or backslash; no other special
              handling of backslashes, or any handling of quotes, is
              performed.

              Individual elements of existing array or associative array
              parameters may be edited by using subscript syntax on name.  New
              elements are created automatically, even without -c.

              If the -p flag is given, the following string will be taken as
              the prompt to display at the left.  If the -r flag is given, the
              following string gives the prompt to display at the right.  If
              the -h flag is specified, the history can be accessed from ZLE.
              If the -e flag is given, typing ^D (Control-D) on an empty line
              causes vared to exit immediately with a non-zero return value.

              The -M option gives a keymap to link to the main keymap during
              editing, and the -m option gives a keymap to link to the vicmd
              keymap during editing.  For vi-style editing, this allows a pair
              of keymaps to override viins and vicmd.  For emacs-style
              editing, only -M is normally needed but the -m option may still
              be used.  On exit, the previous keymaps will be restored.

              Vared calls the usual `zle-line-init' and `zle-line-finish'
              hooks before and after it takes control. Using the -i and -f
              options, it is possible to replace these with other custom
              widgets.

              If `-t tty' is given, tty is the name of a terminal device to be
              used instead of the default /dev/tty.  If tty does not refer to
              a terminal an error is reported.

       zle
       zle -l [ -L | -a ] [ string ... ]
       zle -D widget ...
       zle -A old-widget new-widget
       zle -N widget [ function ]
       zle -f flag [ flag... ]
       zle -C widget completion-widget function
       zle -R [ -c ] [ display-string ] [ string ... ]
       zle -M string
       zle -U string
       zle -K keymap
       zle -F [ -L | -w ] [ fd [ handler ] ]
       zle -I
       zle -T [ tc function | -r tc | -L ]
       zle widget [ -n num ] [ -Nw ] [ -K keymap ] args ...
              The zle builtin performs a number of different actions
              concerning ZLE.

              With no options and no arguments, only the return status will be
              set.  It is zero if ZLE is currently active and widgets could be
              invoked using this builtin command and non-zero otherwise.  Note
              that even if non-zero status is returned, zle may still be
              active as part of the completion system; this does not allow
              direct calls to ZLE widgets.

              Otherwise, which operation it performs depends on its options:

              -l [ -L | -a ] [ string ]
                     List all existing user-defined widgets.  If the -L option
                     is used, list in the form of zle commands to create the
                     widgets.

                     When combined with the -a option, all widget names are
                     listed, including the builtin ones. In this case the -L
                     option is ignored.

                     If at least one string is given, and -a is present or -L
                     is not used, nothing will be printed.  The return status
                     will be zero if all strings are names of existing widgets
                     and non-zero if at least one string is not a name of a
                     defined widget.  If -a is also present, all widget names
                     are used for the comparison including builtin widgets,
                     else only user-defined widgets are used.

                     If at least one string is present and the -L option is
                     used, user-defined widgets matching any string are listed
                     in the form of zle commands to create the widgets.

              -D widget ...
                     Delete the named widgets.

              -A old-widget new-widget
                     Make the new-widget name an alias for old-widget, so that
                     both names refer to the same widget.  The names have
                     equal standing; if either is deleted, the other remains.
                     If there is already a widget with the new-widget name, it
                     is deleted.

              -N widget [ function ]
                     Create a user-defined widget.  If there is already a
                     widget with the specified name, it is overwritten.  When
                     the new widget is invoked from within the editor, the
                     specified shell function is called.  If no function name
                     is specified, it defaults to the same name as the widget.
                     For further information, see the section `Widgets' below.

              -f flag [ flag... ]
                     Set various flags on the running widget.  Possible values
                     for flag are:

                     yank for indicating that the widget has yanked text into
                     the buffer.  If the widget is wrapping an existing
                     internal widget, no further action is necessary, but if
                     it has inserted the text manually, then it should also
                     take care to set YANK_START and YANK_END correctly.
                     yankbefore does the same but is used when the yanked text
                     appears after the cursor.

                     kill for indicating that text has been killed into the
                     cutbuffer.  When repeatedly invoking a kill widget, text
                     is appended to the cutbuffer instead of replacing it, but
                     when wrapping such widgets, it is necessary to call `zle
                     -f kill' to retain this effect.

                     vichange for indicating that the widget represents a vi
                     change that can be repeated as a whole with
                     `vi-repeat-change'. The flag should be set early in the
                     function before inspecting the value of NUMERIC or
                     invoking other widgets. This has no effect for a widget
                     invoked from insert mode. If insert mode is active when
                     the widget finishes, the change extends until next
                     returning to command mode.

              -C widget completion-widget function
                     Create a user-defined completion widget named widget. The
                     completion widget will behave like the built-in
                     completion-widget whose name is given as
                     completion-widget. To generate the completions, the shell
                     function function will be called.  For further
                     information, see zshcompwid(1).

              -R [ -c ] [ display-string ] [ string ... ]
                     Redisplay the command line; this is to be called from
                     within a user-defined widget to allow changes to become
                     visible.  If a display-string is given and not empty,
                     this is shown in the status line (immediately below the
                     line being edited).

                     If the optional strings are given they are listed below
                     the prompt in the same way as completion lists are
                     printed. If no strings are given but the -c option is
                     used such a list is cleared.

                     Note that this option is only useful for widgets that do
                     not exit immediately after using it because the strings
                     displayed will be erased immediately after return from
                     the widget.

                     This command can safely be called outside user defined
                     widgets; if zle is active, the display will be refreshed,
                     while if zle is not active, the command has no effect.
                     In this case there will usually be no other arguments.

                     The status is zero if zle was active, else one.

              -M string
                     As with the -R option, the string will be displayed below
                     the command line; unlike the -R option, the string will
                     not be put into the status line but will instead be
                     printed normally below the prompt.  This means that the
                     string will still be displayed after the widget returns
                     (until it is overwritten by subsequent commands).

              -U string
                     This pushes the characters in the string onto the input
                     stack of ZLE.  After the widget currently executed
                     finishes ZLE will behave as if the characters in the
                     string were typed by the user.

                     As ZLE uses a stack, if this option is used repeatedly
                     the last string pushed onto the stack will be processed
                     first.  However, the characters in each string will be
                     processed in the order in which they appear in the
                     string.

              -K keymap
                     Selects the keymap named keymap.  An error message will
                     be displayed if there is no such keymap.

                     This keymap selection affects the interpretation of
                     following keystrokes within this invocation of ZLE.  Any
                     following invocation (e.g., the next command line) will
                     start as usual with the `main' keymap selected.

              -F [ -L | -w ] [ fd [ handler ] ]
                     Only available if your system supports one of the `poll'
                     or `select' system calls; most modern systems do.

                     Installs handler (the name of a shell function) to handle
                     input from file descriptor fd.  Installing a handler for
                     an fd which is already handled causes the existing
                     handler to be replaced.  Any number of handlers for any
                     number of readable file descriptors may be installed.
                     Note that zle makes no attempt to check whether this fd
                     is actually readable when installing the handler.  The
                     user must make their own arrangements for handling the
                     file descriptor when zle is not active.

                     When zle is attempting to read data, it will examine both
                     the terminal and the list of handled fd's.  If data
                     becomes available on a handled fd, zle calls handler with
                     the fd which is ready for reading as the first argument.
                     Under normal circumstances this is the only argument, but
                     if an error was detected, a second argument provides
                     details: `hup' for a disconnect, `nval' for a closed or
                     otherwise invalid descriptor, or `err' for any other
                     condition.  Systems that support only the `select' system
                     call always use `err'.

                     If the option -w is also given, the handler is instead a
                     line editor widget, typically a shell function made into
                     a widget using `zle -N'.  In that case handler can use
                     all the facilities of zle to update the current editing
                     line.  Note, however, that as handling fd takes place at
                     a low level changes to the display will not automatically
                     appear; the widget should call `zle -R' to force
                     redisplay.  As of this writing, widget handlers only
                     support a single argument and thus are never passed a
                     string for error state, so widgets must be prepared to
                     test the descriptor themselves.

                     If either type of handler produces output to the
                     terminal, it should call `zle -I' before doing so (see
                     below).  Handlers should not attempt to read from the
                     terminal.

                     If no handler is given, but an fd is present, any handler
                     for that fd is removed.  If there is none, an error
                     message is printed and status 1 is returned.

                     If no arguments are given, or the -L option is supplied,
                     a list of handlers is printed in a form which can be
                     stored for later execution.

                     An fd (but not a handler) may optionally be given with
                     the -L option; in this case, the function will list the
                     handler if any, else silently return status 1.

                     Note that this feature should be used with care.
                     Activity on one of the fd's which is not properly handled
                     can cause the terminal to become unusable.  Removing an
                     fd handler from within a signal trap may cause
                     unpredictable behavior.

                     Here is a simple example of using this feature.  A
                     connection to a remote TCP port is created using the ztcp
                     command; see the description of the zsh/net/tcp module in
                     zshmodules(1).  Then a handler is installed which simply
                     prints out any data which arrives on this connection.
                     Note that `select' will indicate that the file descriptor
                     needs handling if the remote side has closed the
                     connection; we handle that by testing for a failed read.

                            if ztcp pwspc 2811; then
                              tcpfd=$REPLY
                              handler() {
                                zle -I
                                local line
                                if ! read -r line <&$1; then
                                  # select marks this fd if we reach EOF,
                                  # so handle this specially.
                                  print "[Read on fd $1 failed, removing.]" >&2
                                  zle -F $1
                                  return 1
                                fi
                                print -r - $line
                              }
                              zle -F $tcpfd handler
                            fi

              -I     Unusually, this option is most useful outside ordinary
                     widget functions, though it may be used within if normal
                     output to the terminal is required.  It invalidates the
                     current zle display in preparation for output; typically
                     this will be from a trap function.  It has no effect if
                     zle is not active.  When a trap exits, the shell checks
                     to see if the display needs restoring, hence the
                     following will print output in such a way as not to
                     disturb the line being edited:

                            TRAPUSR1() {
                              # Invalidate zle display
                              [[ -o zle ]] && zle -I
                              # Show output
                              print Hello
                            }

                     In general, the trap function may need to test whether
                     zle is active before using this method (as shown in the
                     example), since the zsh/zle module may not even be
                     loaded; if it is not, the command can be skipped.

                     It is possible to call `zle -I' several times before
                     control is returned to the editor; the display will only
                     be invalidated the first time to minimise disruption.

                     Note that there are normally better ways of manipulating
                     the display from within zle widgets; see, for example,
                     `zle -R' above.

                     The returned status is zero if zle was invalidated, even
                     though this may have been by a previous call to `zle -I'
                     or by a system notification.  To test if a zle widget may
                     be called at this point, execute zle with no arguments
                     and examine the return status.

              -T     This is used to add, list or remove internal
                     transformations on the processing performed by the line
                     editor.  It is typically used only for debugging or
                     testing and is therefore of little interest to the
                     general user.

                     `zle -T transformation func' specifies that the given
                     transformation (see below) is effected by shell function
                     func.

                     `zle -Tr transformation' removes the given transformation
                     if it was present (it is not an error if none was).

                     `zle -TL' can be used to list all transformations
                     currently in operation.

                     Currently the only transformation is tc.  This is used
                     instead of outputting termcap codes to the terminal.
                     When the transformation is in operation the shell
                     function is passed the termcap code that would be output
                     as its first argument; if the operation required a
                     numeric argument, that is passed as a second argument.
                     The function should set the shell variable REPLY to the
                     transformed termcap code.  Typically this is used to
                     produce some simply formatted version of the code and
                     optional argument for debugging or testing.  Note that
                     this transformation is not applied to other non-printing
                     characters such as carriage returns and newlines.

              widget [ -n num ] [ -Nw ] [ -K keymap ] args ...
                     Invoke the specified widget.  This can only be done when
                     ZLE is active; normally this will be within a
                     user-defined widget.

                     With the options -n and -N, the current numeric argument
                     will be saved and then restored after the call to widget;
                     `-n num' sets the numeric argument temporarily to num,
                     while `-N' sets it to the default, i.e. as if there were
                     none.

                     With the option -K, keymap will be used as the current
                     keymap during the execution of the widget.  The previous
                     keymap will be restored when the widget exits.

                     Normally, calling a widget in this way does not set the
                     special parameter WIDGET and related parameters, so that
                     the environment appears as if the top-level widget called
                     by the user were still active.  With the option -w,
                     WIDGET and related parameters are set to reflect the
                     widget being executed by the zle call.

                     Any further arguments will be passed to the widget; note
                     that as standard argument handling is performed, any
                     general argument list should be preceded by --.  If it is
                     a shell function, these are passed down as positional
                     parameters; for builtin widgets it is up to the widget in
                     question what it does with them.  Currently arguments are
                     only handled by the incremental-search commands, the
                     history-search-forward and -backward and the
                     corresponding functions prefixed by vi-, and by
                     universal-argument.  No error is flagged if the command
                     does not use the arguments, or only uses some of them.

                     The return status reflects the success or failure of the
                     operation carried out by the widget, or if it is a
                     user-defined widget the return status of the shell
                     function.

                     A non-zero return status causes the shell to beep when
                     the widget exits, unless the BEEP options was unset or
                     the widget was called via the zle command.  Thus if a
                     user defined widget requires an immediate beep, it should
                     call the beep widget directly.

WIDGETS
       All actions in the editor are performed by `widgets'.  A widget's job
       is simply to perform some small action.  The ZLE commands that key
       sequences in keymaps are bound to are in fact widgets.  Widgets can be
       user-defined or built in.

       The standard widgets built into ZLE are listed in Standard Widgets
       below.  Other built-in widgets can be defined by other modules (see
       zshmodules(1)).  Each built-in widget has two names: its normal
       canonical name, and the same name preceded by a `.'.  The `.' name is
       special: it can't be rebound to a different widget.  This makes the
       widget available even when its usual name has been redefined.

       User-defined widgets are defined using `zle -N', and implemented as
       shell functions.  When the widget is executed, the corresponding shell
       function is executed, and can perform editing (or other) actions.  It
       is recommended that user-defined widgets should not have names starting
       with `.'.

USER-DEFINED WIDGETS
       User-defined widgets, being implemented as shell functions, can execute
       any normal shell command.  They can also run other widgets (whether
       built-in or user-defined) using the zle builtin command. The standard
       input of the function is redirected from /dev/null to prevent external
       commands from unintentionally blocking ZLE by reading from the
       terminal, but read -k or read -q can be used to read characters.
       Finally, they can examine and edit the ZLE buffer being edited by
       reading and setting the special parameters described below.

       These special parameters are always available in widget functions, but
       are not in any way special outside ZLE.  If they have some normal value
       outside ZLE, that value is temporarily inaccessible, but will return
       when the widget function exits.  These special parameters in fact have
       local scope, like parameters created in a function using local.

       Inside completion widgets and traps called while ZLE is active, these
       parameters are available read-only.

       Note that the parameters appear as local to any ZLE widget in which
       they appear.  Hence if it is desired to override them this needs to be
       done within a nested function:

              widget-function() {
                # $WIDGET here refers to the special variable
                # that is local inside widget-function
                () {
                   # This anonymous nested function allows WIDGET
                   # to be used as a local variable.  The -h
                   # removes the special status of the variable.
                   local -h WIDGET
                }
              }

       BUFFER (scalar)
              The entire contents of the edit buffer.  If it is written to,
              the cursor remains at the same offset, unless that would put it
              outside the buffer.

       BUFFERLINES (integer)
              The number of screen lines needed for the edit buffer currently
              displayed on screen (i.e. without any changes to the preceding
              parameters done after the last redisplay); read-only.

       CONTEXT (scalar)
              The context in which zle was called to read a line; read-only.
              One of the values:

              start  The start of a command line (at prompt PS1).

              cont   A continuation to a command line (at prompt PS2).

              select In a select loop (at prompt PS3).

              vared  Editing a variable in vared.

       CURSOR (integer)
              The offset of the cursor, within the edit buffer.  This is in
              the range 0 to $#BUFFER, and is by definition equal to
              $#LBUFFER.  Attempts to move the cursor outside the buffer will
              result in the cursor being moved to the appropriate end of the
              buffer.

       CUTBUFFER (scalar)
              The last item cut using one of the `kill-' commands; the string
              which the next yank would insert in the line.  Later entries in
              the kill ring are in the array killring.  Note that the command
              `zle copy-region-as-kill string' can be used to set the text of
              the cut buffer from a shell function and cycle the kill ring in
              the same way as interactively killing text.

       HISTNO (integer)
              The current history number.  Setting this has the same effect as
              moving up or down in the history to the corresponding history
              line.  An attempt to set it is ignored if the line is not stored
              in the history.  Note this is not the same as the parameter
              HISTCMD, which always gives the number of the history line being
              added to the main shell's history.  HISTNO refers to the line
              being retrieved within zle.

       ISEARCHMATCH_ACTIVE (integer)
       ISEARCHMATCH_START (integer)
       ISEARCHMATCH_END (integer)
              ISEARCHMATCH_ACTIVE indicates whether a part of the BUFFER is
              currently matched by an incremental search pattern.
              ISEARCHMATCH_START and ISEARCHMATCH_END give the location of the
              matched part and are in the same units as CURSOR. They are only
              valid for reading when ISEARCHMATCH_ACTIVE is non-zero.

              All parameters are read-only.

       KEYMAP (scalar)
              The name of the currently selected keymap; read-only.

       KEYS (scalar)
              The keys typed to invoke this widget, as a literal string;
              read-only.

       KEYS_QUEUED_COUNT (integer)
              The number of bytes pushed back to the input queue and therefore
              available for reading immediately before any I/O is done;
              read-only.  See also PENDING; the two values are distinct.

       killring (array)
              The array of previously killed items, with the most recently
              killed first.  This gives the items that would be retrieved by a
              yank-pop in the same order.  Note, however, that the most
              recently killed item is in $CUTBUFFER; $killring shows the array
              of previous entries.

              The default size for the kill ring is eight, however the length
              may be changed by normal array operations.  Any empty string in
              the kill ring is ignored by the yank-pop command, hence the size
              of the array effectively sets the maximum length of the kill
              ring, while the number of non-zero strings gives the current
              length, both as seen by the user at the command line.

       LASTABORTEDSEARCH (scalar)
              The last search string used by an interactive search that was
              aborted by the user (status 3 returned by the search widget).

       LASTSEARCH (scalar)
              The last search string used by an interactive search; read-only.
              This is set even if the search failed (status 0, 1 or 2 returned
              by the search widget), but not if it was aborted by the user.

       LASTWIDGET (scalar)
              The name of the last widget that was executed; read-only.

       LBUFFER (scalar)
              The part of the buffer that lies to the left of the cursor
              position.  If it is assigned to, only that part of the buffer is
              replaced, and the cursor remains between the new $LBUFFER and
              the old $RBUFFER.

       MARK (integer)
              Like CURSOR, but for the mark. With vi-mode operators that wait
              for a movement command to select a region of text, setting MARK
              allows the selection to extend in both directions from the
              initial cursor position.

       NUMERIC (integer)
              The numeric argument. If no numeric argument was given, this
              parameter is unset. When this is set inside a widget function,
              builtin widgets called with the zle builtin command will use the
              value assigned. If it is unset inside a widget function, builtin
              widgets called behave as if no numeric argument was given.

       PENDING (integer)
              The number of bytes pending for input, i.e. the number of bytes
              which have already been typed and can immediately be read. On
              systems where the shell is not able to get this information,
              this parameter will always have a value of zero.  Read-only.
              See also KEYS_QUEUED_COUNT; the two values are distinct.

       PREBUFFER (scalar)
              In a multi-line input at the secondary prompt, this read-only
              parameter contains the contents of the lines before the one the
              cursor is currently in.

       PREDISPLAY (scalar)
              Text to be displayed before the start of the editable text
              buffer.  This does not have to be a complete line; to display a
              complete line, a newline must be appended explicitly.  The text
              is reset on each new invocation (but not recursive invocation)
              of zle.

       POSTDISPLAY (scalar)
              Text to be displayed after the end of the editable text buffer.
              This does not have to be a complete line; to display a complete
              line, a newline must be prepended explicitly.  The text is reset
              on each new invocation (but not recursive invocation) of zle.

       RBUFFER (scalar)
              The part of the buffer that lies to the right of the cursor
              position.  If it is assigned to, only that part of the buffer is
              replaced, and the cursor remains between the old $LBUFFER and
              the new $RBUFFER.

       REGION_ACTIVE (integer)
              Indicates if the region is currently active.  It can be assigned
              0 or 1 to deactivate and activate the region respectively. A
              value of 2 activates the region in line-wise mode with the
              highlighted text extending for whole lines only; see Character
              Highlighting below.

       region_highlight (array)
              Each element of this array may be set to a string that describes
              highlighting for an arbitrary region of the command line that
              will take effect the next time the command line is redisplayed.
              Highlighting of the non-editable parts of the command line in
              PREDISPLAY and POSTDISPLAY are possible, but note that the P
              flag is needed for character indexing to include PREDISPLAY.

              Each string consists of the following parts:

              ·      Optionally, a `P' to signify that the start and end
                     offset that follow include any string set by the
                     PREDISPLAY special parameter; this is needed if the
                     predisplay string itself is to be highlighted.
                     Whitespace may follow the `P'.

              ·      A start offset in the same units as CURSOR, terminated by
                     whitespace.

              ·      An end offset in the same units as CURSOR, terminated by
                     whitespace.

              ·      A highlight specification in the same format as used for
                     contexts in the parameter zle_highlight, see the section
                     `Character Highlighting' below; for example, standout or
                     fg=red,bold

              For example,

                     region_highlight=("P0 20 bold")

              specifies that the first twenty characters of the text including
              any predisplay string should be highlighted in bold.

              Note that the effect of region_highlight is not saved and
              disappears as soon as the line is accepted.

              The final highlighting on the command line depends on both
              region_highlight and zle_highlight; see the section CHARACTER
              HIGHLIGHTING below for details.

       registers (associative array)
              The contents of each of the vi register buffers. These are
              typically set using vi-set-buffer followed by a delete, change
              or yank command.

       SUFFIX_ACTIVE (integer)
       SUFFIX_START (integer)
       SUFFIX_END (integer)
              SUFFIX_ACTIVE indicates whether an auto-removable completion
              suffix is currently active. SUFFIX_START and SUFFIX_END give the
              location of the suffix and are in the same units as CURSOR. They
              are only valid for reading when SUFFIX_ACTIVE is non-zero.

              All parameters are read-only.

       UNDO_CHANGE_NO (integer)
              A number representing the state of the undo history.  The only
              use of this is passing as an argument to the undo widget in
              order to undo back to the recorded point.  Read-only.

       UNDO_LIMIT_NO (integer)
              A number corresponding to an existing change in the undo
              history; compare UNDO_CHANGE_NO.  If this is set to a value
              greater than zero, the undo command will not allow the line to
              be undone beyond the given change number.  It is still possible
              to use `zle undo change' in a widget to undo beyond that point;
              in that case, it will not be possible to undo at all until
              UNDO_LIMIT_NO is reduced.  Set to 0 to disable the limit.

              A typical use of this variable in a widget function is as
              follows (note the additional function scope is required):

                     () {
                       local UNDO_LIMIT_NO=$UNDO_CHANGE_NO
                       # Perform some form of recursive edit.
                     }

       WIDGET (scalar)
              The name of the widget currently being executed; read-only.

       WIDGETFUNC (scalar)
              The name of the shell function that implements a widget defined
              with either zle -N or zle -C.  In the former case, this is the
              second argument to the zle -N command that defined the widget,
              or the first argument if there was no second argument.  In the
              latter case this is the third argument to the zle -C command
              that defined the widget.  Read-only.

       WIDGETSTYLE (scalar)
              Describes the implementation behind the completion widget
              currently being executed; the second argument that followed zle
              -C when the widget was defined.  This is the name of a builtin
              completion widget.  For widgets defined with zle -N this is set
              to the empty string.  Read-only.

       YANK_ACTIVE (integer)
       YANK_START (integer)
       YANK_END (integer)
              YANK_ACTIVE indicates whether text has just been yanked (pasted)
              into the buffer.  YANK_START and YANK_END give the location of
              the pasted text and are in the same units as CURSOR.  They are
              only valid for reading when YANK_ACTIVE is non-zero.  They can
              also be assigned by widgets that insert text in a yank-like
              fashion, for example wrappers of bracketed-paste.  See also zle
              -f.

              YANK_ACTIVE is read-only.

       ZLE_RECURSIVE (integer)
              Usually zero, but incremented inside any instance of
              recursive-edit.  Hence indicates the current recursion level.

              ZLE_RECURSIVE is read-only.

       ZLE_STATE (scalar)
              Contains a set of space-separated words that describe the
              current zle state.

              Currently, the states shown are the insert mode as set by the
              overwrite-mode or vi-replace widgets and whether history
              commands will visit imported entries as controlled by the
              set-local-history widget.  The string contains `insert' if
              characters to be inserted on the command line move existing
              characters to the right or `overwrite' if characters to be
              inserted overwrite existing characters. It contains
              `localhistory' if only local history commands will be visited or
              `globalhistory' if imported history commands will also be
              visited.

              The substrings are sorted in alphabetical order so that if you
              want to test for two specific substrings in a future-proof way,
              you can do match by doing:

                     if [[ $ZLE_STATE == *globalhistory*insert* ]]; then ...; fi

   Special Widgets
       There are a few user-defined widgets which are special to the shell.
       If they do not exist, no special action is taken.  The environment
       provided is identical to that for any other editing widget.

       zle-isearch-exit
              Executed at the end of incremental search at the point where the
              isearch prompt is removed from the display.  See
              zle-isearch-update for an example.

       zle-isearch-update
              Executed within incremental search when the display is about to
              be redrawn.  Additional output below the incremental search
              prompt can be generated by using `zle -M' within the widget.
              For example,

                     zle-isearch-update() { zle -M "Line $HISTNO"; }
                     zle -N zle-isearch-update

              Note the line output by `zle -M' is not deleted on exit from
              incremental search.  This can be done from a zle-isearch-exit
              widget:

                     zle-isearch-exit() { zle -M ""; }
                     zle -N zle-isearch-exit

       zle-line-pre-redraw
              Executed whenever the input line is about to be redrawn,
              providing an opportunity to update the region_highlight array.

       zle-line-init
              Executed every time the line editor is started to read a new
              line of input.  The following example puts the line editor into
              vi command mode when it starts up.

                     zle-line-init() { zle -K vicmd; }
                     zle -N zle-line-init

              (The command inside the function sets the keymap directly; it is
              equivalent to zle vi-cmd-mode.)

       zle-line-finish
              This is similar to zle-line-init but is executed every time the
              line editor has finished reading a line of input.

       zle-history-line-set
              Executed when the history line changes.

       zle-keymap-select
              Executed every time the keymap changes, i.e. the special
              parameter KEYMAP is set to a different value, while the line
              editor is active.  Initialising the keymap when the line editor
              starts does not cause the widget to be called.

              The value $KEYMAP within the function reflects the new keymap.
              The old keymap is passed as the sole argument.

              This can be used for detecting switches between the vi command
              (vicmd) and insert (usually main) keymaps.

STANDARD WIDGETS
       The following is a list of all the standard widgets, and their default
       bindings in emacs mode, vi command mode and vi insert mode (the
       `emacs', `vicmd' and `viins' keymaps, respectively).

       Note that cursor keys are bound to movement keys in all three keymaps;
       the shell assumes that the cursor keys send the key sequences reported
       by the terminal-handling library (termcap or terminfo).  The key
       sequences shown in the list are those based on the VT100, common on
       many modern terminals, but in fact these are not necessarily bound.  In
       the case of the viins keymap, the initial escape character of the
       sequences serves also to return to the vicmd keymap: whether this
       happens is determined by the KEYTIMEOUT parameter, see zshparam(1).

   Movement
       vi-backward-blank-word (unbound) (B) (unbound)
              Move backward one word, where a word is defined as a series of
              non-blank characters.

       vi-backward-blank-word-end (unbound) (gE) (unbound)
              Move to the end of the previous word, where a word is defined as
              a series of non-blank characters.

       backward-char (^B ESC-[D) (unbound) (unbound)
              Move backward one character.

       vi-backward-char (unbound) (^H h ^?) (ESC-[D)
              Move backward one character, without changing lines.

       backward-word (ESC-B ESC-b) (unbound) (unbound)
              Move to the beginning of the previous word.

       emacs-backward-word
              Move to the beginning of the previous word.

       vi-backward-word (unbound) (b) (unbound)
              Move to the beginning of the previous word, vi-style.

       vi-backward-word-end (unbound) (ge) (unbound)
              Move to the end of the previous word, vi-style.

       beginning-of-line (^A) (unbound) (unbound)
              Move to the beginning of the line.  If already at the beginning
              of the line, move to the beginning of the previous line, if any.

       vi-beginning-of-line
              Move to the beginning of the line, without changing lines.

       down-line (unbound) (unbound) (unbound)
              Move down a line in the buffer.

       end-of-line (^E) (unbound) (unbound)
              Move to the end of the line.  If already at the end of the line,
              move to the end of the next line, if any.

       vi-end-of-line (unbound) ($) (unbound)
              Move to the end of the line.  If an argument is given to this
              command, the cursor will be moved to the end of the line
              (argument - 1) lines down.

       vi-forward-blank-word (unbound) (W) (unbound)
              Move forward one word, where a word is defined as a series of
              non-blank characters.

       vi-forward-blank-word-end (unbound) (E) (unbound)
              Move to the end of the current word, or, if at the end of the
              current word, to the end of the next word, where a word is
              defined as a series of non-blank characters.

       forward-char (^F ESC-[C) (unbound) (unbound)
              Move forward one character.

       vi-forward-char (unbound) (space l) (ESC-[C)
              Move forward one character.

       vi-find-next-char (^X^F) (f) (unbound)
              Read a character from the keyboard, and move to the next
              occurrence of it in the line.

       vi-find-next-char-skip (unbound) (t) (unbound)
              Read a character from the keyboard, and move to the position
              just before the next occurrence of it in the line.

       vi-find-prev-char (unbound) (F) (unbound)
              Read a character from the keyboard, and move to the previous
              occurrence of it in the line.

       vi-find-prev-char-skip (unbound) (T) (unbound)
              Read a character from the keyboard, and move to the position
              just after the previous occurrence of it in the line.

       vi-first-non-blank (unbound) (^) (unbound)
              Move to the first non-blank character in the line.

       vi-forward-word (unbound) (w) (unbound)
              Move forward one word, vi-style.

       forward-word (ESC-F ESC-f) (unbound) (unbound)
              Move to the beginning of the next word.  The editor's idea of a
              word is specified with the WORDCHARS parameter.

       emacs-forward-word
              Move to the end of the next word.

       vi-forward-word-end (unbound) (e) (unbound)
              Move to the end of the next word.

       vi-goto-column (ESC-|) (|) (unbound)
              Move to the column specified by the numeric argument.

       vi-goto-mark (unbound) (`) (unbound)
              Move to the specified mark.

       vi-goto-mark-line (unbound) (') (unbound)
              Move to beginning of the line containing the specified mark.

       vi-repeat-find (unbound) (;) (unbound)
              Repeat the last vi-find command.

       vi-rev-repeat-find (unbound) (,) (unbound)
              Repeat the last vi-find command in the opposite direction.

       up-line (unbound) (unbound) (unbound)
              Move up a line in the buffer.

   History Control
       beginning-of-buffer-or-history (ESC-<) (gg) (unbound)
              Move to the beginning of the buffer, or if already there, move
              to the first event in the history list.

       beginning-of-line-hist
              Move to the beginning of the line.  If already at the beginning
              of the buffer, move to the previous history line.

       beginning-of-history
              Move to the first event in the history list.

       down-line-or-history (^N ESC-[B) (j) (ESC-[B)
              Move down a line in the buffer, or if already at the bottom
              line, move to the next event in the history list.

       vi-down-line-or-history (unbound) (+) (unbound)
              Move down a line in the buffer, or if already at the bottom
              line, move to the next event in the history list.  Then move to
              the first non-blank character on the line.

       down-line-or-search
              Move down a line in the buffer, or if already at the bottom
              line, search forward in the history for a line beginning with
              the first word in the buffer.

              If called from a function by the zle command with arguments, the
              first argument is taken as the string for which to search,
              rather than the first word in the buffer.

       down-history (unbound) (^N) (unbound)
              Move to the next event in the history list.

       history-beginning-search-backward
              Search backward in the history for a line beginning with the
              current line up to the cursor.  This leaves the cursor in its
              original position.

       end-of-buffer-or-history (ESC->) (unbound) (unbound)
              Move to the end of the buffer, or if already there, move to the
              last event in the history list.

       end-of-line-hist
              Move to the end of the line.  If already at the end of the
              buffer, move to the next history line.

       end-of-history
              Move to the last event in the history list.

       vi-fetch-history (unbound) (G) (unbound)
              Fetch the history line specified by the numeric argument.  This
              defaults to the current history line (i.e. the one that isn't
              history yet).

       history-incremental-search-backward (^R ^Xr) (unbound) (unbound)
              Search backward incrementally for a specified string.  The
              search is case-insensitive if the search string does not have
              uppercase letters and no numeric argument was given.  The string
              may begin with `^' to anchor the search to the beginning of the
              line.  When called from a user-defined function returns the
              following statuses: 0, if the search succeeded; 1, if the search
              failed; 2, if the search term was a bad pattern; 3, if the
              search was aborted by the send-break command.

              A restricted set of editing functions is available in the
              mini-buffer.  Keys are looked up in the special isearch keymap,
              and if not found there in the main keymap (note that by default
              the isearch keymap is empty).  An interrupt signal, as defined
              by the stty setting, will stop the search and go back to the
              original line.  An undefined key will have the same effect.
              Note that the following always perform the same task within
              incremental searches and cannot be replaced by user defined
              widgets, nor can the set of functions be extended.  The
              supported functions are:

              accept-and-hold
              accept-and-infer-next-history
              accept-line
              accept-line-and-down-history
                     Perform the usual function after exiting incremental
                     search.  The command line displayed is executed.

              backward-delete-char
              vi-backward-delete-char
                     Back up one place in the search history.  If the search
                     has been repeated this does not immediately erase a
                     character in the minibuffer.

              accept-search
                     Exit incremental search, retaining the command line but
                     performing no further action.  Note that this function is
                     not bound by default and has no effect outside
                     incremental search.

              backward-delete-word
              backward-kill-word
              vi-backward-kill-word
                     Back up one character in the minibuffer; if multiple
                     searches have been performed since the character was
                     inserted the search history is rewound to the point just
                     before the character was entered.  Hence this has the
                     effect of repeating backward-delete-char.

              clear-screen
                     Clear the screen, remaining in incremental search mode.

              history-incremental-search-backward
                     Find the next occurrence of the contents of the
                     mini-buffer. If the mini-buffer is empty, the most recent
                     previously used search string is reinstated.

              history-incremental-search-forward
                     Invert the sense of the search.

              magic-space
                     Inserts a non-magical space.

              quoted-insert
              vi-quoted-insert
                     Quote the character to insert into the minibuffer.

              redisplay
                     Redisplay the command line, remaining in incremental
                     search mode.

              vi-cmd-mode
                     Select the `vicmd' keymap; the `main' keymap (insert
                     mode) will be selected initially.

                     In addition, the modifications that were made while in vi
                     insert mode are merged to form a single undo event.

              vi-repeat-search
              vi-rev-repeat-search
                     Repeat the search.  The direction of the search is
                     indicated in the mini-buffer.

              Any character that is not bound to one of the above functions,
              or self-insert or self-insert-unmeta, will cause the mode to be
              exited.  The character is then looked up and executed in the
              keymap in effect at that point.

              When called from a widget function by the zle command, the
              incremental search commands can take a string argument.  This
              will be treated as a string of keys, as for arguments to the
              bindkey command, and used as initial input for the command.  Any
              characters in the string which are unused by the incremental
              search will be silently ignored.  For example,

                     zle history-incremental-search-backward forceps

              will search backwards for forceps, leaving the minibuffer
              containing the string `forceps'.

       history-incremental-search-forward (^S ^Xs) (unbound) (unbound)
              Search forward incrementally for a specified string.  The search
              is case-insensitive if the search string does not have uppercase
              letters and no numeric argument was given.  The string may begin
              with `^' to anchor the search to the beginning of the line.  The
              functions available in the mini-buffer are the same as for
              history-incremental-search-backward.

       history-incremental-pattern-search-backward
       history-incremental-pattern-search-forward
              These widgets behave similarly to the corresponding widgets with
              no -pattern, but the search string typed by the user is treated
              as a pattern, respecting the current settings of the various
              options affecting pattern matching.  See FILENAME GENERATION in
              zshexpn(1) for a description of patterns.  If no numeric
              argument was given lowercase letters in the search string may
              match uppercase letters in the history.  The string may begin
              with `^' to anchor the search to the beginning of the line.

              The prompt changes to indicate an invalid pattern; this may
              simply indicate the pattern is not yet complete.

              Note that only non-overlapping matches are reported, so an
              expression with wildcards may return fewer matches on a line
              than are visible by inspection.

       history-search-backward (ESC-P ESC-p) (unbound) (unbound)
              Search backward in the history for a line beginning with the
              first word in the buffer.

              If called from a function by the zle command with arguments, the
              first argument is taken as the string for which to search,
              rather than the first word in the buffer.

       vi-history-search-backward (unbound) (/) (unbound)
              Search backward in the history for a specified string.  The
              string may begin with `^' to anchor the search to the beginning
              of the line.

              A restricted set of editing functions is available in the
              mini-buffer.  An interrupt signal, as defined by the stty
              setting,  will stop the search.  The functions available in the
              mini-buffer are: accept-line, backward-delete-char,
              vi-backward-delete-char, backward-kill-word,
              vi-backward-kill-word, clear-screen, redisplay, quoted-insert
              and vi-quoted-insert.

              vi-cmd-mode is treated the same as accept-line, and magic-space
              is treated as a space.  Any other character that is not bound to
              self-insert or self-insert-unmeta will beep and be ignored. If
              the function is called from vi command mode, the bindings of the
              current insert mode will be used.

              If called from a function by the zle command with arguments, the
              first argument is taken as the string for which to search,
              rather than the first word in the buffer.

       history-search-forward (ESC-N ESC-n) (unbound) (unbound)
              Search forward in the history for a line beginning with the
              first word in the buffer.

              If called from a function by the zle command with arguments, the
              first argument is taken as the string for which to search,
              rather than the first word in the buffer.

       vi-history-search-forward (unbound) (?) (unbound)
              Search forward in the history for a specified string.  The
              string may begin with `^' to anchor the search to the beginning
              of the line. The functions available in the mini-buffer are the
              same as for vi-history-search-backward.  Argument handling is
              also the same as for that command.

       infer-next-history (^X^N) (unbound) (unbound)
              Search in the history list for a line matching the current one
              and fetch the event following it.

       insert-last-word (ESC-_ ESC-.) (unbound) (unbound)
              Insert the last word from the previous history event at the
              cursor position.  If a positive numeric argument is given,
              insert that word from the end of the previous history event.  If
              the argument is zero or negative insert that word from the left
              (zero inserts the previous command word).  Repeating this
              command replaces the word just inserted with the last word from
              the history event prior to the one just used; numeric arguments
              can be used in the same way to pick a word from that event.

              When called from a shell function invoked from a user-defined
              widget, the command can take one to three arguments.  The first
              argument specifies a history offset which applies to successive
              calls to this widget: if it is -1, the default behaviour is
              used, while if it is 1, successive calls will move forwards
              through the history.  The value 0 can be used to indicate that
              the history line examined by the previous execution of the
              command will be reexamined.  Note that negative numbers should
              be preceded by a `--' argument to avoid confusing them with
              options.

              If two arguments are given, the second specifies the word on the
              command line in normal array index notation (as a more natural
              alternative to the numeric argument).  Hence 1 is the first
              word, and -1 (the default) is the last word.

              If a third argument is given, its value is ignored, but it is
              used to signify that the history offset is relative to the
              current history line, rather than the one remembered after the
              previous invocations of insert-last-word.

              For example, the default behaviour of the command corresponds to

                     zle insert-last-word -- -1 -1

              while the command

                     zle insert-last-word -- -1 1 -

              always copies the first word of the line in the history
              immediately before the line being edited.  This has the side
              effect that later invocations of the widget will be relative to
              that line.

       vi-repeat-search (unbound) (n) (unbound)
              Repeat the last vi history search.

       vi-rev-repeat-search (unbound) (N) (unbound)
              Repeat the last vi history search, but in reverse.

       up-line-or-history (^P ESC-[A) (k) (ESC-[A)
              Move up a line in the buffer, or if already at the top line,
              move to the previous event in the history list.

       vi-up-line-or-history (unbound) (-) (unbound)
              Move up a line in the buffer, or if already at the top line,
              move to the previous event in the history list.  Then move to
              the first non-blank character on the line.

       up-line-or-search
              Move up a line in the buffer, or if already at the top line,
              search backward in the history for a line beginning with the
              first word in the buffer.

              If called from a function by the zle command with arguments, the
              first argument is taken as the string for which to search,
              rather than the first word in the buffer.

       up-history (unbound) (^P) (unbound)
              Move to the previous event in the history list.

       history-beginning-search-forward
              Search forward in the history for a line beginning with the
              current line up to the cursor.  This leaves the cursor in its
              original position.

       set-local-history
              By default, history movement commands visit the imported lines
              as well as the local lines. This widget lets you toggle this on
              and off, or set it with the numeric argument. Zero for both
              local and imported lines and nonzero for only local lines.

   Modifying Text
       vi-add-eol (unbound) (A) (unbound)
              Move to the end of the line and enter insert mode.

       vi-add-next (unbound) (a) (unbound)
              Enter insert mode after the current cursor position, without
              changing lines.

       backward-delete-char (^H ^?) (unbound) (unbound)
              Delete the character behind the cursor.

       vi-backward-delete-char (unbound) (X) (^H)
              Delete the character behind the cursor, without changing lines.
              If in insert mode, this won't delete past the point where insert
              mode was last entered.

       backward-delete-word
              Delete the word behind the cursor.

       backward-kill-line
              Kill from the beginning of the line to the cursor position.

       backward-kill-word (^W ESC-^H ESC-^?) (unbound) (unbound)
              Kill the word behind the cursor.

       vi-backward-kill-word (unbound) (unbound) (^W)
              Kill the word behind the cursor, without going past the point
              where insert mode was last entered.

       capitalize-word (ESC-C ESC-c) (unbound) (unbound)
              Capitalize the current word and move past it.

       vi-change (unbound) (c) (unbound)
              Read a movement command from the keyboard, and kill from the
              cursor position to the endpoint of the movement.  Then enter
              insert mode.  If the command is vi-change, change the current
              line.

              For compatibility with vi, if the command is vi-forward-word or
              vi-forward-blank-word, the whitespace after the word is not
              included. If you prefer the more consistent behaviour with the
              whitespace included use the following key binding:

                     bindkey -a -s cw dwi

       vi-change-eol (unbound) (C) (unbound)
              Kill to the end of the line and enter insert mode.

       vi-change-whole-line (unbound) (S) (unbound)
              Kill the current line and enter insert mode.

       copy-region-as-kill (ESC-W ESC-w) (unbound) (unbound)
              Copy the area from the cursor to the mark to the kill buffer.

              If called from a ZLE widget function in the form `zle
              copy-region-as-kill string' then string will be taken as the
              text to copy to the kill buffer.  The cursor, the mark and the
              text on the command line are not used in this case.

       copy-prev-word (ESC-^_) (unbound) (unbound)
              Duplicate the word to the left of the cursor.

       copy-prev-shell-word
              Like copy-prev-word, but the word is found by using shell
              parsing, whereas copy-prev-word looks for blanks. This makes a
              difference when the word is quoted and contains spaces.

       vi-delete (unbound) (d) (unbound)
              Read a movement command from the keyboard, and kill from the
              cursor position to the endpoint of the movement.  If the command
              is vi-delete, kill the current line.

       delete-char
              Delete the character under the cursor.

       vi-delete-char (unbound) (x) (unbound)
              Delete the character under the cursor, without going past the
              end of the line.

       delete-word
              Delete the current word.

       down-case-word (ESC-L ESC-l) (unbound) (unbound)
              Convert the current word to all lowercase and move past it.

       vi-down-case (unbound) (gu) (unbound)
              Read a movement command from the keyboard, and convert all
              characters from the cursor position to the endpoint of the
              movement to lowercase.  If the movement command is vi-down-case,
              swap the case of all characters on the current line.

       kill-word (ESC-D ESC-d) (unbound) (unbound)
              Kill the current word.

       gosmacs-transpose-chars
              Exchange the two characters behind the cursor.

       vi-indent (unbound) (>) (unbound)
              Indent a number of lines.

       vi-insert (unbound) (i) (unbound)
              Enter insert mode.

       vi-insert-bol (unbound) (I) (unbound)
              Move to the first non-blank character on the line and enter
              insert mode.

       vi-join (^X^J) (J) (unbound)
              Join the current line with the next one.

       kill-line (^K) (unbound) (unbound)
              Kill from the cursor to the end of the line.  If already on the
              end of the line, kill the newline character.

       vi-kill-line (unbound) (unbound) (^U)
              Kill from the cursor back to wherever insert mode was last
              entered.

       vi-kill-eol (unbound) (D) (unbound)
              Kill from the cursor to the end of the line.

       kill-region
              Kill from the cursor to the mark.

       kill-buffer (^X^K) (unbound) (unbound)
              Kill the entire buffer.

       kill-whole-line (^U) (unbound) (unbound)
              Kill the current line.

       vi-match-bracket (^X^B) (%) (unbound)
              Move to the bracket character (one of {}, () or []) that matches
              the one under the cursor.  If the cursor is not on a bracket
              character, move forward without going past the end of the line
              to find one, and then go to the matching bracket.

       vi-open-line-above (unbound) (O) (unbound)
              Open a line above the cursor and enter insert mode.

       vi-open-line-below (unbound) (o) (unbound)
              Open a line below the cursor and enter insert mode.

       vi-oper-swap-case (unbound) (g~) (unbound)
              Read a movement command from the keyboard, and swap the case of
              all characters from the cursor position to the endpoint of the
              movement.  If the movement command is vi-oper-swap-case, swap
              the case of all characters on the current line.

       overwrite-mode (^X^O) (unbound) (unbound)
              Toggle between overwrite mode and insert mode.

       vi-put-before (unbound) (P) (unbound)
              Insert the contents of the kill buffer before the cursor.  If
              the kill buffer contains a sequence of lines (as opposed to
              characters), paste it above the current line.

       vi-put-after (unbound) (p) (unbound)
              Insert the contents of the kill buffer after the cursor.  If the
              kill buffer contains a sequence of lines (as opposed to
              characters), paste it below the current line.

       put-replace-selection (unbound) (unbound) (unbound)
              Replace the contents of the current region or selection with the
              contents of the kill buffer. If the kill buffer contains a
              sequence of lines (as opposed to characters), the current line
              will be split by the pasted lines.

       quoted-insert (^V) (unbound) (unbound)
              Insert the next character typed into the buffer literally.  An
              interrupt character will not be inserted.

       vi-quoted-insert (unbound) (unbound) (^Q ^V)
              Display a `^' at the cursor position, and insert the next
              character typed into the buffer literally.  An interrupt
              character will not be inserted.

       quote-line (ESC-') (unbound) (unbound)
              Quote the current line; that is, put a `'' character at the
              beginning and the end, and convert all `'' characters to `'\'''.

       quote-region (ESC-") (unbound) (unbound)
              Quote the region from the cursor to the mark.

       vi-replace (unbound) (R) (unbound)
              Enter overwrite mode.

       vi-repeat-change (unbound) (.) (unbound)
              Repeat the last vi mode text modification.  If a count was used
              with the modification, it is remembered.  If a count is given to
              this command, it overrides the remembered count, and is
              remembered for future uses of this command.  The cut buffer
              specification is similarly remembered.

       vi-replace-chars (unbound) (r) (unbound)
              Replace the character under the cursor with a character read
              from the keyboard.

       self-insert (printable characters) (unbound) (printable characters and
       some control characters)
              Insert a character into the buffer at the cursor position.

       self-insert-unmeta (ESC-^I ESC-^J ESC-^M) (unbound) (unbound)
              Insert a character into the buffer after stripping the meta bit
              and converting ^M to ^J.

       vi-substitute (unbound) (s) (unbound)
              Substitute the next character(s).

       vi-swap-case (unbound) (~) (unbound)
              Swap the case of the character under the cursor and move past
              it.

       transpose-chars (^T) (unbound) (unbound)
              Exchange the two characters to the left of the cursor if at end
              of line, else exchange the character under the cursor with the
              character to the left.

       transpose-words (ESC-T ESC-t) (unbound) (unbound)
              Exchange the current word with the one before it.

              With a positive numeric argument N, the word around the cursor,
              or following it if the cursor is between words, is transposed
              with the preceding N words.  The cursor is put at the end of the
              resulting group of words.

              With a negative numeric argument -N, the effect is the same as
              using a positive argument N except that the original cursor
              position is retained, regardless of how the words are
              rearranged.

       vi-unindent (unbound) (<) (unbound)
              Unindent a number of lines.

       vi-up-case (unbound) (gU) (unbound)
              Read a movement command from the keyboard, and convert all
              characters from the cursor position to the endpoint of the
              movement to lowercase.  If the movement command is vi-up-case,
              swap the case of all characters on the current line.

       up-case-word (ESC-U ESC-u) (unbound) (unbound)
              Convert the current word to all caps and move past it.

       yank (^Y) (unbound) (unbound)
              Insert the contents of the kill buffer at the cursor position.

       yank-pop (ESC-y) (unbound) (unbound)
              Remove the text just yanked, rotate the kill-ring (the history
              of previously killed text) and yank the new top.  Only works
              following yank, vi-put-before, vi-put-after or yank-pop.

       vi-yank (unbound) (y) (unbound)
              Read a movement command from the keyboard, and copy the region
              from the cursor position to the endpoint of the movement into
              the kill buffer.  If the command is vi-yank, copy the current
              line.

       vi-yank-whole-line (unbound) (Y) (unbound)
              Copy the current line into the kill buffer.

       vi-yank-eol
              Copy the region from the cursor position to the end of the line
              into the kill buffer.  Arguably, this is what Y should do in vi,
              but it isn't what it actually does.

   Arguments
       digit-argument (ESC-0..ESC-9) (1-9) (unbound)
              Start a new numeric argument, or add to the current one.  See
              also vi-digit-or-beginning-of-line.  This only works if bound to
              a key sequence ending in a decimal digit.

              Inside a widget function, a call to this function treats the
              last key of the key sequence which called the widget as the
              digit.

       neg-argument (ESC--) (unbound) (unbound)
              Changes the sign of the following argument.

       universal-argument
              Multiply the argument of the next command by 4.  Alternatively,
              if this command is followed by an integer (positive or
              negative), use that as the argument for the next command.  Thus
              digits cannot be repeated using this command.  For example, if
              this command occurs twice, followed immediately by forward-char,
              move forward sixteen spaces; if instead it is followed by -2,
              then forward-char, move backward two spaces.

              Inside a widget function, if passed an argument, i.e. `zle
              universal-argument num', the numeric argument will be set to
              num; this is equivalent to `NUMERIC=num'.

       argument-base
              Use the existing numeric argument as a numeric base, which must
              be in the range 2 to 36 inclusive.  Subsequent use of
              digit-argument and universal-argument will input a new numeric
              argument in the given base.  The usual hexadecimal convention is
              used: the letter a or A corresponds to 10, and so on.  Arguments
              in bases requiring digits from 10 upwards are more conveniently
              input with universal-argument, since ESC-a etc. are not usually
              bound to digit-argument.

              The function can be used with a command argument inside a
              user-defined widget.  The following code sets the base to 16 and
              lets the user input a hexadecimal argument until a key out of
              the digit range is typed:

                     zle argument-base 16
                     zle universal-argument

   Completion
       accept-and-menu-complete
              In a menu completion, insert the current completion into the
              buffer, and advance to the next possible completion.

       complete-word
              Attempt completion on the current word.

       delete-char-or-list (^D) (unbound) (unbound)
              Delete the character under the cursor.  If the cursor is at the
              end of the line, list possible completions for the current word.

       expand-cmd-path
              Expand the current command to its full pathname.

       expand-or-complete (TAB) (unbound) (TAB)
              Attempt shell expansion on the current word.  If that fails,
              attempt completion.

       expand-or-complete-prefix
              Attempt shell expansion on the current word up to cursor.

       expand-history (ESC-space ESC-!) (unbound) (unbound)
              Perform history expansion on the edit buffer.

       expand-word (^X*) (unbound) (unbound)
              Attempt shell expansion on the current word.

       list-choices (ESC-^D) (^D =) (^D)
              List possible completions for the current word.

       list-expand (^Xg ^XG) (^G) (^G)
              List the expansion of the current word.

       magic-space
              Perform history expansion and insert a space into the buffer.
              This is intended to be bound to space.

       menu-complete
              Like complete-word, except that menu completion is used.  See
              the MENU_COMPLETE option.

       menu-expand-or-complete
              Like expand-or-complete, except that menu completion is used.

       reverse-menu-complete
              Perform menu completion, like menu-complete, except that if a
              menu completion is already in progress, move to the previous
              completion rather than the next.

       end-of-list
              When a previous completion displayed a list below the prompt,
              this widget can be used to move the prompt below the list.

   Miscellaneous
       accept-and-hold (ESC-A ESC-a) (unbound) (unbound)
              Push the contents of the buffer on the buffer stack and execute
              it.

       accept-and-infer-next-history
              Execute the contents of the buffer.  Then search the history
              list for a line matching the current one and push the event
              following onto the buffer stack.

       accept-line (^J ^M) (^J ^M) (^J ^M)
              Finish editing the buffer.  Normally this causes the buffer to
              be executed as a shell command.

       accept-line-and-down-history (^O) (unbound) (unbound)
              Execute the current line, and push the next history event on the
              buffer stack.

       auto-suffix-remove
              If the previous action added a suffix (space, slash, etc.) to
              the word on the command line, remove it.  Otherwise do nothing.
              Removing the suffix ends any active menu completion or menu
              selection.

              This widget is intended to be called from user-defined widgets
              to enforce a desired suffix-removal behavior.

       auto-suffix-retain
              If the previous action added a suffix (space, slash, etc.) to
              the word on the command line, force it to be preserved.
              Otherwise do nothing.  Retaining the suffix ends any active menu
              completion or menu selection.

              This widget is intended to be called from user-defined widgets
              to enforce a desired suffix-preservation behavior.

       beep   Beep, unless the BEEP option is unset.

       bracketed-paste
              This widget is invoked when text is pasted to the terminal
              emulator. It is not intended to be bound to actual keys but
              instead to the special sequence generated by the terminal
              emulator when text is pasted.

              When invoked interactively, the pasted text is inserted to the
              buffer and placed in the cutbuffer.  If a numeric argument is
              given, shell quoting will be applied to the pasted text before
              it is inserted.

              When a named buffer is specified with vi-set-buffer ("x), the
              pasted text is stored in that named buffer but not inserted.

              When called from a widget function as `bracketed-paste name`,
              the pasted text is assigned to the variable name and no other
              processing is done.

              See also the zle_bracketed_paste parameter.

       vi-cmd-mode (^X^V) (unbound) (^[)
              Enter command mode; that is, select the `vicmd' keymap.  Yes,
              this is bound by default in emacs mode.

       vi-caps-lock-panic
              Hang until any lowercase key is pressed.  This is for vi users
              without the mental capacity to keep track of their caps lock key
              (like the author).

       clear-screen (^L ESC-^L) (^L) (^L)
              Clear the screen and redraw the prompt.

       deactivate-region
              Make the current region inactive. This disables vim-style visual
              selection mode if it is active.

       describe-key-briefly
              Reads a key sequence, then prints the function bound to that
              sequence.

       exchange-point-and-mark (^X^X) (unbound) (unbound)
              Exchange the cursor position (point) with the position of the
              mark.  Unless a negative numeric argument is given, the region
              between point and mark is activated so that it can be
              highlighted.  If a zero numeric argument is given, the region is
              activated but point and mark are not swapped.

       execute-named-cmd (ESC-x) (:) (unbound)
              Read the name of an editor command and execute it.  Aliasing
              this widget with `zle -A' or replacing it with `zle -N' has no
              effect when interpreting key bindings, but `zle
              execute-named-cmd' will invoke such an alias or replacement.

              A restricted set of editing functions is available in the
              mini-buffer.  Keys are looked up in the special command keymap,
              and if not found there in the main keymap.  An interrupt signal,
              as defined by the stty setting, will abort the function.  Note
              that the following always perform the same task within the
              executed-named-cmd environment and cannot be replaced by user
              defined widgets, nor can the set of functions be extended.  The
              allowed functions are: backward-delete-char,
              vi-backward-delete-char, clear-screen, redisplay, quoted-insert,
              vi-quoted-insert, backward-kill-word, vi-backward-kill-word,
              kill-whole-line, vi-kill-line, backward-kill-line, list-choices,
              delete-char-or-list, complete-word, accept-line,
              expand-or-complete and expand-or-complete-prefix.

              kill-region kills the last word, and vi-cmd-mode is treated the
              same as accept-line.  The space and tab characters, if not bound
              to one of these functions, will complete the name and then list
              the possibilities if the AUTO_LIST option is set.  Any other
              character that is not bound to self-insert or self-insert-unmeta
              will beep and be ignored.  The bindings of the current insert
              mode will be used.

              Currently this command may not be redefined or called by name.

       execute-last-named-cmd (ESC-z) (unbound) (unbound)
              Redo the last function executed with execute-named-cmd.

              Like execute-named-cmd, this command may not be redefined, but
              it may be called by name.

       get-line (ESC-G ESC-g) (unbound) (unbound)
              Pop the top line off the buffer stack and insert it at the
              cursor position.

       pound-insert (unbound) (#) (unbound)
              If there is no # character at the beginning of the buffer, add
              one to the beginning of each line.  If there is one, remove a #
              from each line that has one.  In either case, accept the current
              line.  The INTERACTIVE_COMMENTS option must be set for this to
              have any usefulness.

       vi-pound-insert
              If there is no # character at the beginning of the current line,
              add one.  If there is one, remove it.  The INTERACTIVE_COMMENTS
              option must be set for this to have any usefulness.

       push-input
              Push the entire current multiline construct onto the buffer
              stack and return to the top-level (PS1) prompt.  If the current
              parser construct is only a single line, this is exactly like
              push-line.  Next time the editor starts up or is popped with
              get-line, the construct will be popped off the top of the buffer
              stack and loaded into the editing buffer.

       push-line (^Q ESC-Q ESC-q) (unbound) (unbound)
              Push the current buffer onto the buffer stack and clear the
              buffer.  Next time the editor starts up, the buffer will be
              popped off the top of the buffer stack and loaded into the
              editing buffer.

       push-line-or-edit
              At the top-level (PS1) prompt, equivalent to push-line.  At a
              secondary (PS2) prompt, move the entire current multiline
              construct into the editor buffer.  The latter is equivalent to
              push-input followed by get-line.

       read-command
              Only useful from a user-defined widget.  A keystroke is read
              just as in normal operation, but instead of the command being
              executed the name of the command that would be executed is
              stored in the shell parameter REPLY.  This can be used as the
              argument of a future zle command.  If the key sequence is not
              bound, status 1 is returned; typically, however, REPLY is set to
              undefined-key to indicate a useless key sequence.

       recursive-edit
              Only useful from a user-defined widget.  At this point in the
              function, the editor regains control until one of the standard
              widgets which would normally cause zle to exit (typically an
              accept-line caused by hitting the return key) is executed.
              Instead, control returns to the user-defined widget.  The status
              returned is non-zero if the return was caused by an error, but
              the function still continues executing and hence may tidy up.
              This makes it safe for the user-defined widget to alter the
              command line or key bindings temporarily.

              The following widget, caps-lock, serves as an example.

                     self-insert-ucase() {
                       LBUFFER+=${(U)KEYS[-1]}
                     }

                     integer stat

                     zle -N self-insert self-insert-ucase
                     zle -A caps-lock save-caps-lock
                     zle -A accept-line caps-lock

                     zle recursive-edit
                     stat=$?

                     zle -A .self-insert self-insert
                     zle -A save-caps-lock caps-lock
                     zle -D save-caps-lock

                     (( stat )) && zle send-break

                     return $stat

              This causes typed letters to be inserted capitalised until
              either accept-line (i.e. typically the return key) is typed or
              the caps-lock widget is invoked again; the later is handled by
              saving the old definition of caps-lock as save-caps-lock and
              then rebinding it to invoke accept-line.  Note that an error
              from the recursive edit is detected as a non-zero return status
              and propagated by using the send-break widget.

       redisplay (unbound) (^R) (^R)
              Redisplays the edit buffer.

       reset-prompt (unbound) (unbound) (unbound)
              Force the prompts on both the left and right of the screen to be
              re-expanded, then redisplay the edit buffer.  This reflects
              changes both to the prompt variables themselves and changes in
              the expansion of the values (for example, changes in time or
              directory, or changes to the value of variables referred to by
              the prompt).

              Otherwise, the prompt is only expanded each time zle starts, and
              when the display has been interrupted by output from another
              part of the shell (such as a job notification) which causes the
              command line to be reprinted.

              reset-prompt doesn't alter the special parameter LASTWIDGET.

       send-break (^G ESC-^G) (unbound) (unbound)
              Abort the current editor function, e.g. execute-named-command,
              or the editor itself, e.g. if you are in vared. Otherwise abort
              the parsing of the current line; in this case the aborted line
              is available in the shell variable ZLE_LINE_ABORTED.  If the
              editor is aborted from within vared, the variable
              ZLE_VARED_ABORTED is set.

       run-help (ESC-H ESC-h) (unbound) (unbound)
              Push the buffer onto the buffer stack, and execute the command
              `run-help cmd', where cmd is the current command.  run-help is
              normally aliased to man.

       vi-set-buffer (unbound) (") (unbound)
              Specify a buffer to be used in the following command.  There are
              37 buffers that can be specified: the 26 `named' buffers "a to
              "z, the `yank' buffer "0, the nine `queued' buffers "1 to "9 and
              the `black hole' buffer "_.  The named buffers can also be
              specified as "A to "Z.

              When a buffer is specified for a cut, change or yank command,
              the text concerned replaces the previous contents of the
              specified buffer. If a named buffer is specified using a
              capital, the newly cut text is appended to the buffer instead of
              overwriting it. When using the "_ buffer, nothing happens. This
              can be useful for deleting text without affecting any buffers.

              If no buffer is specified for a cut or change command, "1 is
              used, and the contents of "1 to "8 are each shifted along one
              buffer; the contents of "9 is lost. If no buffer is specified
              for a yank command, "0 is used. Finally, a paste command without
              a specified buffer will paste the text from the most recent
              command regardless of any buffer that might have been used with
              that command.

              When called from a widget function by the zle command, the
              buffer can optionally be specified with an argument. For
              example,

                     zle vi-set-buffer A

       vi-set-mark (unbound) (m) (unbound)
              Set the specified mark at the cursor position.

       set-mark-command (^@) (unbound) (unbound)
              Set the mark at the cursor position.  If called with a negative
              numeric argument, do not set the mark but deactivate the region
              so that it is no longer highlighted (it is still usable for
              other purposes).  Otherwise the region is marked as active.

       spell-word (ESC-$ ESC-S ESC-s) (unbound) (unbound)
              Attempt spelling correction on the current word.

       split-undo
              Breaks the undo sequence at the current change.  This is useful
              in vi mode as changes made in insert mode are coalesced on
              entering command mode.  Similarly, undo will normally revert as
              one all the changes made by a user-defined widget.

       undefined-key
              This command is executed when a key sequence that is not bound
              to any command is typed.  By default it beeps.

       undo (^_ ^Xu ^X^U) (u) (unbound)
              Incrementally undo the last text modification.  When called from
              a user-defined widget, takes an optional argument indicating a
              previous state of the undo history as returned by the
              UNDO_CHANGE_NO variable; modifications are undone until that
              state is reached, subject to any limit imposed by the
              UNDO_LIMIT_NO variable.

              Note that when invoked from vi command mode, the full prior
              change made in insert mode is reverted, the changes having been
              merged when command mode was selected.

       redo (unbound) (^R) (unbound)
              Incrementally redo undone text modifications.

       vi-undo-change (unbound) (unbound) (unbound)
              Undo the last text modification.  If repeated, redo the
              modification.

       visual-mode (unbound) (v) (unbound)
              Toggle vim-style visual selection mode. If line-wise visual mode
              is currently enabled then it is changed to being character-wise.
              If used following an operator, it forces the subsequent movement
              command to be treated as a character-wise movement.

       visual-line-mode (unbound) (V) (unbound)
              Toggle vim-style line-wise visual selection mode. If
              character-wise visual mode is currently enabled then it is
              changed to being line-wise. If used following an operator, it
              forces the subsequent movement command to be treated as a
              line-wise movement.

       what-cursor-position (^X=) (ga) (unbound)
              Print the character under the cursor, its code as an octal,
              decimal and hexadecimal number, the current cursor position
              within the buffer and the column of the cursor in the current
              line.

       where-is
              Read the name of an editor command and print the listing of key
              sequences that invoke the specified command.  A restricted set
              of editing functions is available in the mini-buffer.  Keys are
              looked up in the special command keymap, and if not found there
              in the main keymap.

       which-command (ESC-?) (unbound) (unbound)
              Push the buffer onto the buffer stack, and execute the command
              `which-command cmd'. where cmd is the current command.
              which-command is normally aliased to whence.

       vi-digit-or-beginning-of-line (unbound) (0) (unbound)
              If the last command executed was a digit as part of an argument,
              continue the argument.  Otherwise, execute vi-beginning-of-line.

   Text Objects
       Text objects are commands that can be used to select a block of text
       according to some criteria. They are a feature of the vim text editor
       and so are primarily intended for use with vi operators or from visual
       selection mode. However, they can also be used from vi-insert or emacs
       mode. Key bindings listed below apply to the viopp and visual keymaps.

       select-a-blank-word (aW)
              Select a word including adjacent blanks, where a word is defined
              as a series of non-blank characters. With a numeric argument,
              multiple words will be selected.

       select-a-shell-word (aa)
              Select the current command argument applying the normal rules
              for quoting.

       select-a-word (aw)
              Select a word including adjacent blanks, using the normal
              vi-style word definition. With a numeric argument, multiple
              words will be selected.

       select-in-blank-word (iW)
              Select a word, where a word is defined as a series of non-blank
              characters. With a numeric argument, multiple words will be
              selected.

       select-in-shell-word (ia)
              Select the current command argument applying the normal rules
              for quoting. If the argument begins and ends with matching quote
              characters, these are not included in the selection.

       select-in-word (iw)
              Select a word, using the normal vi-style word definition. With a
              numeric argument, multiple words will be selected.

CHARACTER HIGHLIGHTING
       The line editor has the ability to highlight characters or regions of
       the line that have a particular significance.  This is controlled by
       the array parameter zle_highlight, if it has been set by the user.

       If the parameter contains the single entry none all highlighting is
       turned off.  Note the parameter is still expected to be an array.

       Otherwise each entry of the array should consist of a word indicating a
       context for highlighting, then a colon, then a comma-separated list of
       the types of highlighting to apply in that context.

       The contexts available for highlighting are the following:

       default
              Any text within the command line not affected by any other
              highlighting.  Text outside the editable area of the command
              line is not affected.

       isearch
              When one of the incremental history search widgets is active,
              the area of the command line matched by the search string or
              pattern.

       region The currently selected text. In emacs terminology, this is
              referred to as the region and is bounded by the cursor (point)
              and the mark. The region is only highlighted if it is active,
              which is the case after the mark is modified with
              set-mark-command or exchange-point-and-mark.  Note that whether
              or not the region is active has no effect on its use within
              emacs style widgets, it simply determines whether it is
              highlighted. In vi mode, the region corresponds to selected text
              in visual mode.

       special
              Individual characters that have no direct printable
              representation but are shown in a special manner by the line
              editor.  These characters are described below.

       suffix This context is used in completion for characters that are
              marked as suffixes that will be removed if the completion ends
              at that point, the most obvious example being a slash (/) after
              a directory name.  Note that suffix removal is configurable; the
              circumstances under which the suffix will be removed may differ
              for different completions.

       paste  Following a command to paste text, the characters that were
              inserted.

       When region_highlight is set, the contexts that describe a region --
       isearch, region, suffix, and paste -- are applied first, then
       region_highlight is applied, then the remaining zle_highlight contexts
       are applied.  If a particular character is affected by multiple
       specifications, the last specification wins.

       zle_highlight may contain additional fields for controlling how
       terminal sequences to change colours are output.  Each of the following
       is followed by a colon and a string in the same form as for key
       bindings.  This will not be necessary for the vast majority of
       terminals as the defaults shown in parentheses are widely used.

       fg_start_code (\e[3)
              The start of the escape sequence for the foreground colour.
              This is followed by one to three ASCII digits representing the
              colour.  Only used for palette colors, i.e. not 24-bit colors
              specified via a color triplet.

       fg_default_code (9)
              The number to use instead of the colour to reset the default
              foreground colour.

       fg_end_code (m)
              The end of the escape sequence for the foreground colour.

       bg_start_code (\e[4)
              The start of the escape sequence for the background colour.  See
              fg_start_code above.

       bg_default_code (9)
              The number to use instead of the colour to reset the default
              background colour.

       bg_end_code (m)
              The end of the escape sequence for the background colour.

       The available types of highlighting are the following.  Note that not
       all types of highlighting are available on all terminals:

       none   No highlighting is applied to the given context.  It is not
              useful for this to appear with other types of highlighting; it
              is used to override a default.

       fg=colour
              The foreground colour should be set to colour, a decimal
              integer, the name of one of the eight most widely-supported
              colours or as a `#' followed by an RGB triplet in hexadecimal
              format.

              Not all terminals support this and, of those that do, not all
              provide facilities to test the support, hence the user should
              decide based on the terminal type.  Most terminals support the
              colours black, red, green, yellow, blue, magenta, cyan and
              white, which can be set by name.  In addition. default may be
              used to set the terminal's default foreground colour.
              Abbreviations are allowed; b or bl selects black.  Some
              terminals may generate additional colours if the bold attribute
              is also present.

              On recent terminals and on systems with an up-to-date terminal
              database the number of colours supported may be tested by the
              command `echotc Co'; if this succeeds, it indicates a limit on
              the number of colours which will be enforced by the line editor.
              The number of colours is in any case limited to 256 (i.e. the
              range 0 to 255).

              Some modern terminal emulators have support for 24-bit true
              colour (16 million colours). In this case, the hex triplet
              format can be used. This consists of a `#' followed by either a
              three or six digit hexadecimal number describing the red, green
              and blue components of the colour. Hex triplets can also be used
              with 88 and 256 colour terminals via the zsh/nearcolor module
              (see zshmodules(1)).

              Colour is also known as color.

       bg=colour
              The background colour should be set to colour.  This works
              similarly to the foreground colour, except the background is not
              usually affected by the bold attribute.

       bold   The characters in the given context are shown in a bold font.
              Not all terminals distinguish bold fonts.

       standout
              The characters in the given context are shown in the terminal's
              standout mode.  The actual effect is specific to the terminal;
              on many terminals it is inverse video.  On some such terminals,
              where the cursor does not blink it appears with standout mode
              negated, making it less than clear where the cursor actually is.
              On such terminals one of the other effects may be preferable for
              highlighting the region and matched search string.

       underline
              The characters in the given context are shown underlined.  Some
              terminals show the foreground in a different colour instead; in
              this case whitespace will not be highlighted.

       The characters described above as `special' are as follows.  The
       formatting described here is used irrespective of whether the
       characters are highlighted:

       ASCII control characters
              Control characters in the ASCII range are shown as `^' followed
              by the base character.

       Unprintable multibyte characters
              This item applies to control characters not in the ASCII range,
              plus other characters as follows.  If the MULTIBYTE option is in
              effect, multibyte characters not in the ASCII character set that
              are reported as having zero width are treated as combining
              characters when the option COMBINING_CHARS is on.  If the option
              is off, or if a character appears where a combining character is
              not valid, the character is treated as unprintable.

              Unprintable multibyte characters are shown as a hexadecimal
              number between angle brackets.  The number is the code point of
              the character in the wide character set; this may or may not be
              Unicode, depending on the operating system.

       Invalid multibyte characters
              If the MULTIBYTE option is in effect, any sequence of one or
              more bytes that does not form a valid character in the current
              character set is treated as a series of bytes each shown as a
              special character.  This case can be distinguished from other
              unprintable characters as the bytes are represented as two
              hexadecimal digits between angle brackets, as distinct from the
              four or eight digits that are used for unprintable characters
              that are nonetheless valid in the current character set.

              Not all systems support this: for it to work, the system's
              representation of wide characters must be code values from the
              Universal Character Set, as defined by IS0 10646 (also known as
              Unicode).

       Wrapped double-width characters
              When a double-width character appears in the final column of a
              line, it is instead shown on the next line. The empty space left
              in the original position is highlighted as a special character.

       If zle_highlight is not set or no value applies to a particular
       context, the defaults applied are equivalent to

              zle_highlight=(region:standout special:standout
              suffix:bold isearch:underline paste:standout)

       i.e. both the region and special characters are shown in standout mode.

       Within widgets, arbitrary regions may be highlighted by setting the
       special array parameter region_highlight; see above.

ZSHCOMPWID(1)               General Commands Manual              ZSHCOMPWID(1)



NAME
       zshcompwid - zsh completion widgets

DESCRIPTION
       The shell's programmable completion mechanism can be manipulated in two
       ways; here the low-level features supporting the newer, function-based
       mechanism are defined.  A complete set of shell functions based on
       these features is described in zshcompsys(1), and users with no
       interest in adding to that system (or, potentially, writing their own
       -- see dictionary entry for `hubris') should skip the current section.
       The older system based on the compctl builtin command is described in
       zshcompctl(1).

       Completion widgets are defined by the -C option to the zle builtin
       command provided by the zsh/zle module (see zshzle(1)). For example,

              zle -C complete expand-or-complete completer

       defines a widget named `complete'.  The second argument is the name of
       any of the builtin widgets that handle completions: complete-word,
       expand-or-complete, expand-or-complete-prefix, menu-complete,
       menu-expand-or-complete, reverse-menu-complete, list-choices, or
       delete-char-or-list.  Note that this will still work even if the widget
       in question has been re-bound.

       When this newly defined widget is bound to a key using the bindkey
       builtin command defined in the zsh/zle module (see zshzle(1)), typing
       that key will call the shell function `completer'. This function is
       responsible for generating the possible matches using the builtins
       described below.  As with other ZLE widgets, the function is called
       with its standard input closed.

       Once the function returns, the completion code takes over control again
       and treats the matches in the same manner as the specified builtin
       widget, in this case expand-or-complete.

COMPLETION SPECIAL PARAMETERS
       The parameters ZLE_REMOVE_SUFFIX_CHARS and ZLE_SPACE_SUFFIX_CHARS are
       used by the completion mechanism, but are not special. See Parameters
       Used By The Shell in zshparam(1).

       Inside completion widgets, and any functions called from them, some
       parameters have special meaning; outside these functions they are not
       special to the shell in any way.  These parameters are used to pass
       information between the completion code and the completion widget. Some
       of the builtin commands and the condition codes use or change the
       current values of these parameters.  Any existing values will be hidden
       during execution of completion widgets; except for compstate, the
       parameters are reset on each function exit (including nested function
       calls from within the completion widget) to the values they had when
       the function was entered.

       CURRENT
              This is the number of the current word, i.e. the word the cursor
              is currently on in the words array.  Note that this value is
              only correct if the ksharrays option is not set.

       IPREFIX
              Initially this will be set to the empty string.  This parameter
              functions like PREFIX; it contains a string which precedes the
              one in PREFIX and is not considered part of the list of matches.
              Typically, a string is transferred from the beginning of PREFIX
              to the end of IPREFIX, for example:

                     IPREFIX=${PREFIX%%\=*}=
                     PREFIX=${PREFIX#*=}

              causes the part of the prefix up to and including the first
              equal sign not to be treated as part of a matched string.  This
              can be done automatically by the compset builtin, see below.

       ISUFFIX
              As IPREFIX, but for a suffix that should not be considered part
              of the matches; note that the ISUFFIX string follows the SUFFIX
              string.

       PREFIX Initially this will be set to the part of the current word from
              the beginning of the word up to the position of the cursor; it
              may be altered to give a common prefix for all matches.

       QIPREFIX
              This parameter is read-only and contains the quoted string up to
              the word being completed. E.g. when completing `"foo', this
              parameter contains the double quote. If the -q option of compset
              is used (see below), and the original string was `"foo bar' with
              the cursor on the `bar', this parameter contains `"foo '.

       QISUFFIX
              Like QIPREFIX, but containing the suffix.

       SUFFIX Initially this will be set to the part of the current word from
              the cursor position to the end; it may be altered to give a
              common suffix for all matches.  It is most useful when the
              option COMPLETE_IN_WORD is set, as otherwise the whole word on
              the command line is treated as a prefix.

       compstate
              This is an associative array with various keys and values that
              the completion code uses to exchange information with the
              completion widget.  The keys are:

              all_quotes
                     The -q option of the compset builtin command (see below)
                     allows a quoted string to be broken into separate words;
                     if the cursor is on one of those words, that word will be
                     completed, possibly invoking `compset -q' recursively.
                     With this key it is possible to test the types of quoted
                     strings which are currently broken into parts in this
                     fashion.  Its value contains one character for each
                     quoting level.  The characters are a single quote or a
                     double quote for strings quoted with these characters, a
                     dollars sign for strings quoted with $'...' and a
                     backslash for strings not starting with a quote
                     character.  The first character in the value always
                     corresponds to the innermost quoting level.

              context
                     This will be set by the completion code to the overall
                     context in which completion is attempted. Possible values
                     are:

                     array_value
                            when completing inside the value of an array
                            parameter assignment; in this case the words array
                            contains the words inside the parentheses.

                     brace_parameter
                            when completing the name of a parameter in a
                            parameter expansion beginning with ${.  This
                            context will also be set when completing parameter
                            flags following ${(; the full command line
                            argument is presented and the handler must test
                            the value to be completed to ascertain that this
                            is the case.

                     assign_parameter
                            when completing the name of a parameter in a
                            parameter assignment.

                     command
                            when completing for a normal command (either in
                            command position or for an argument of the
                            command).

                     condition
                            when completing inside a `[[...]]' conditional
                            expression; in this case the words array contains
                            only the words inside the conditional expression.

                     math   when completing in a mathematical environment such
                            as a `((...))' construct.

                     parameter
                            when completing the name of a parameter in a
                            parameter expansion beginning with $ but not ${.

                     redirect
                            when completing after a redirection operator.

                     subscript
                            when completing inside a parameter subscript.

                     value  when completing the value of a parameter
                            assignment.

              exact  Controls the behaviour when the REC_EXACT option is set.
                     It will be set to accept if an exact match would be
                     accepted, and will be unset otherwise.

                     If it was set when at least one match equal to the string
                     on the line was generated, the match is accepted.

              exact_string
                     The string of an exact match if one was found, otherwise
                     unset.

              ignored
                     The number of words that were ignored because they
                     matched one of the patterns given with the -F option to
                     the compadd builtin command.

              insert This controls the manner in which a match is inserted
                     into the command line.  On entry to the widget function,
                     if it is unset the command line is not to be changed; if
                     set to unambiguous, any prefix common to all matches is
                     to be inserted; if set to automenu-unambiguous, the
                     common prefix is to be inserted and the next invocation
                     of the completion code may start menu completion (due to
                     the AUTO_MENU option being set); if set to menu or
                     automenu menu completion will be started for the matches
                     currently generated (in the latter case this will happen
                     because the AUTO_MENU is set). The value may also contain
                     the string `tab' when the completion code would normally
                     not really do completion, but only insert the TAB
                     character.

                     On exit it may be set to any of the values above (where
                     setting it to the empty string is the same as unsetting
                     it), or to a number, in which case the match whose number
                     is given will be inserted into the command line.
                     Negative numbers count backward from the last match (with
                     `-1' selecting the last match) and out-of-range values
                     are wrapped around, so that a value of zero selects the
                     last match and a value one more than the maximum selects
                     the first. Unless the value of this key ends in a space,
                     the match is inserted as in a menu completion, i.e.
                     without automatically appending a space.

                     Both menu and automenu may also specify the number of the
                     match to insert, given after a colon.  For example,
                     `menu:2' says to start menu completion, beginning with
                     the second match.

                     Note that a value containing the substring `tab' makes
                     the matches generated be ignored and only the TAB be
                     inserted.

                     Finally, it may also be set to all, which makes all
                     matches generated be inserted into the line.

              insert_positions
                     When the completion system inserts an unambiguous string
                     into the line, there may be multiple places where
                     characters are missing or where the character inserted
                     differs from at least one match.  The value of this key
                     contains a colon separated list of all these positions,
                     as indexes into the command line.

              last_prompt
                     If this is set to a non-empty string for every match
                     added, the completion code will move the cursor back to
                     the previous prompt after the list of completions has
                     been displayed.  Initially this is set or unset according
                     to the ALWAYS_LAST_PROMPT option.

              list   This controls whether or how the list of matches will be
                     displayed.  If it is unset or empty they will never be
                     listed; if its value begins with list, they will always
                     be listed; if it begins with autolist or ambiguous, they
                     will be listed when the AUTO_LIST or LIST_AMBIGUOUS
                     options respectively would normally cause them to be.

                     If the substring force appears in the value, this makes
                     the list be shown even if there is only one match.
                     Normally, the list would be shown only if there are at
                     least two matches.

                     The value contains the substring packed if the
                     LIST_PACKED option is set. If this substring is given for
                     all matches added to a group, this group will show the
                     LIST_PACKED behavior. The same is done for the
                     LIST_ROWS_FIRST option with the substring rows.

                     Finally, if the value contains the string explanations,
                     only the explanation strings, if any, will be listed and
                     if it contains messages, only the messages (added with
                     the -x option of compadd) will be listed.  If it contains
                     both explanations and messages both kinds of explanation
                     strings will be listed.  It will be set appropriately on
                     entry to a completion widget and may be changed there.

              list_lines
                     This gives the number of lines that are needed to display
                     the full list of completions.  Note that to calculate the
                     total number of lines to display you need to add the
                     number of lines needed for the command line to this
                     value, this is available as the value of the BUFFERLINES
                     special parameter.

              list_max
                     Initially this is set to the value of the LISTMAX
                     parameter.  It may be set to any other value; when the
                     widget exits this value will be used in the same way as
                     the value of LISTMAX.

              nmatches
                     The number of matches generated and accepted by the
                     completion code so far.

              old_insert
                     On entry to the widget this will be set to the number of
                     the match of an old list of completions that is currently
                     inserted into the command line. If no match has been
                     inserted, this is unset.

                     As with old_list, the value of this key will only be used
                     if it is the string keep. If it was set to this value by
                     the widget and there was an old match inserted into the
                     command line, this match will be kept and if the value of
                     the insert key specifies that another match should be
                     inserted, this will be inserted after the old one.

              old_list
                     This is set to yes if there is still a valid list of
                     completions from a previous completion at the time the
                     widget is invoked.  This will usually be the case if and
                     only if the previous editing operation was a completion
                     widget or one of the builtin completion functions.  If
                     there is a valid list and it is also currently shown on
                     the screen, the value of this key is shown.

                     After the widget has exited the value of this key is only
                     used if it was set to keep.  In this case the completion
                     code will continue to use this old list.  If the widget
                     generated new matches, they will not be used.

              parameter
                     The name of the parameter when completing in a subscript
                     or in the value of a parameter assignment.

              pattern_insert
                     Normally this is set to menu, which specifies that menu
                     completion will be used whenever a set of matches was
                     generated using pattern matching.  If it is set to any
                     other non-empty string by the user and menu completion is
                     not selected by other option settings, the code will
                     instead insert any common prefix for the generated
                     matches as with normal completion.

              pattern_match
                     Locally controls the behaviour given by the GLOB_COMPLETE
                     option.  Initially it is set to `*' if and only if the
                     option is set.  The completion widget may set it to this
                     value, to an empty string (which has the same effect as
                     unsetting it), or to any other non-empty string.  If it
                     is non-empty, unquoted metacharacters on the command line
                     will be treated as patterns; if it is `*', then
                     additionally a wildcard `*' is assumed at the cursor
                     position; if it is empty or unset, metacharacters will be
                     treated literally.

                     Note that the matcher specifications given to the compadd
                     builtin command are not used if this is set to a
                     non-empty string.

              quote  When completing inside quotes, this contains the
                     quotation character (i.e. either a single quote, a double
                     quote, or a backtick).  Otherwise it is unset.

              quoting
                     When completing inside single quotes, this is set to the
                     string single; inside double quotes, the string double;
                     inside backticks, the string backtick.  Otherwise it is
                     unset.

              redirect
                     The redirection operator when completing in a redirection
                     position, i.e. one of <, >, etc.

              restore
                     This is set to auto before a function is entered, which
                     forces the special parameters mentioned above (words,
                     CURRENT, PREFIX, IPREFIX, SUFFIX, and ISUFFIX) to be
                     restored to their previous values when the function
                     exits.   If a function unsets it or sets it to any other
                     string, they will not be restored.

              to_end Specifies the occasions on which the cursor is moved to
                     the end of a string when a match is inserted.  On entry
                     to a widget function, it may be single if this will
                     happen when a single unambiguous match was inserted or
                     match if it will happen any time a match is inserted (for
                     example, by menu completion; this is likely to be the
                     effect of the ALWAYS_TO_END option).

                     On exit, it may be set to single as above.  It may also
                     be set to always, or to the empty string or unset; in
                     those cases the cursor will be moved to the end of the
                     string always or never respectively.  Any other string is
                     treated as match.

              unambiguous
                     This key is read-only and will always be set to the
                     common (unambiguous) prefix the completion code has
                     generated for all matches added so far.

              unambiguous_cursor
                     This gives the position the cursor would be placed at if
                     the common prefix in the unambiguous key were inserted,
                     relative to the value of that key. The cursor would be
                     placed before the character whose index is given by this
                     key.

              unambiguous_positions
                     This contains all positions where characters in the
                     unambiguous string are missing or where the character
                     inserted differs from at least one of the matches.  The
                     positions are given as indexes into the string given by
                     the value of the unambiguous key.

              vared  If completion is called while editing a line using the
                     vared builtin, the value of this key is set to the name
                     of the parameter given as an argument to vared.  This key
                     is only set while a vared command is active.

       words  This array contains the words present on the command line
              currently being edited.

COMPLETION BUILTIN COMMANDS
       compadd [ -akqQfenUl12C ] [ -F array ]
               [-P prefix ] [ -S suffix ]
               [-p hidden-prefix ] [ -s hidden-suffix ]
               [-i ignored-prefix ] [ -I ignored-suffix ]
               [-W file-prefix ] [ -d array ]
               [-J group-name ] [ -X explanation ] [ -x message ]
               [-V group-name ] [ -o [ order ] ]
               [-r remove-chars ] [ -R remove-func ]
               [-D array ] [ -O array ] [ -A array ]
               [-E number ]
               [-M match-spec ] [ -- ] [ words ... ]

              This builtin command can be used to add matches directly and
              control all the information the completion code stores with each
              possible match. The return status is zero if at least one match
              was added and non-zero if no matches were added.

              The completion code breaks the string to complete into seven
              fields in the order:

                     <ipre><apre><hpre><word><hsuf><asuf><isuf>

              The first field is an ignored prefix taken from the command
              line, the contents of the IPREFIX parameter plus the string
              given with the -i option. With the -U option, only the string
              from the -i option is used. The field <apre> is an optional
              prefix string given with the -P option.  The <hpre> field is a
              string that is considered part of the match but that should not
              be shown when listing completions, given with the -p option; for
              example, functions that do filename generation might specify a
              common path prefix this way.  <word> is the part of the match
              that should appear in the list of completions, i.e. one of the
              words given at the end of the compadd command line. The suffixes
              <hsuf>, <asuf> and <isuf> correspond to the prefixes <hpre>,
              <apre> and <ipre> and are given by the options -s, -S and -I,
              respectively.

              The supported flags are:

              -P prefix
                     This gives a string to be inserted before the given
                     words.  The string given is not considered as part of the
                     match and any shell metacharacters in it will not be
                     quoted when the string is inserted.

              -S suffix
                     Like -P, but gives a string to be inserted after the
                     match.

              -p hidden-prefix
                     This gives a string that should be inserted into the
                     command line before the match but that should not appear
                     in the list of matches. Unless the -U option is given,
                     this string must be matched as part of the string on the
                     command line.

              -s hidden-suffix
                     Like `-p', but gives a string to insert after the match.

              -i ignored-prefix
                     This gives a string to insert into the command line just
                     before any string given with the `-P' option.  Without
                     `-P' the string is inserted before the string given with
                     `-p' or directly before the match.

              -I ignored-suffix
                     Like -i, but gives an ignored suffix.

              -a     With this flag the words are taken as names of arrays and
                     the possible matches are their values.  If only some
                     elements of the arrays are needed, the words may also
                     contain subscripts, as in `foo[2,-1]'.

              -k     With this flag the words are taken as names of
                     associative arrays and the possible matches are their
                     keys.  As for -a, the words may also contain subscripts,
                     as in `foo[(R)*bar*]'.

              -d array
                     This adds per-match display strings. The array should
                     contain one element per word given. The completion code
                     will then display the first element instead of the first
                     word, and so on. The array may be given as the name of an
                     array parameter or directly as a space-separated list of
                     words in parentheses.

                     If there are fewer display strings than words, the
                     leftover words will be displayed unchanged and if there
                     are more display strings than words, the leftover display
                     strings will be silently ignored.

              -l     This option only has an effect if used together with the
                     -d option. If it is given, the display strings are listed
                     one per line, not arrayed in columns.

              -o [ order ]
                     This controls the order in which matches are sorted.
                     order is a comma-separated list comprising the following
                     possible values.  These values can be abbreviated to
                     their initial two or three characters.  Note that the
                     order forms part of the group name space so matches with
                     different orderings will not be in the same group.

                     match  If given, the order of the output is determined by
                            the match strings; otherwise it is determined by
                            the display strings (i.e. the strings given by the
                            -d option). This is the default if `-o' is
                            specified but the order argument is omitted.

                     nosort This specifies that the matches are pre-sorted and
                            their order should be preserved.  This value only
                            makes sense alone and cannot be combined with any
                            others.

                     numeric
                            If the matches include numbers, sort them
                            numerically rather than lexicographically.

                     reverse
                            Arrange the matches backwards by reversing the
                            sort ordering.

              -J group-name
                     Gives the name of the group of matches the words should
                     be stored in.

              -V group-name
                     Like -J but naming an unsorted group. This option is
                     identical to the combination of -J and -o nosort.

              -1     If given together with the -V option, makes only
                     consecutive duplicates in the group be removed. If
                     combined with the -J option, this has no visible effect.
                     Note that groups with and without this flag are in
                     different name spaces.

              -2     If given together with the -J or -V option, makes all
                     duplicates be kept. Again, groups with and without this
                     flag are in different name spaces.

              -X explanation
                     The explanation string will be printed with the list of
                     matches, above the group currently selected.

                     Within the explanation, the following sequences may be
                     used to specify output attributes as described in the
                     section EXPANSION OF PROMPT SEQUENCES in zshmisc(1):
                     `%B', `%S', `%U', `%F', `%K' and their lower case
                     counterparts, as well as `%{...%}'.  `%F', `%K' and
                     `%{...%}' take arguments in the same form as prompt
                     expansion.  (Note that the sequence `%G' is not
                     available; an argument to `%{' should be used instead.)
                     The sequence `%%' produces a literal `%'.

                     These sequences are most often employed by users when
                     customising the format style (see zshcompsys(1)), but
                     they must also be taken into account when writing
                     completion functions, as passing descriptions with
                     unescaped `%' characters to utility functions such as
                     _arguments and _message may produce unexpected results.
                     If arbitrary text is to be passed in a description, it
                     can be escaped using e.g. ${my_str//\%/%%}.

              -x message
                     Like -X, but the message will be printed even if there
                     are no matches in the group.

              -q     The suffix given with -S will be automatically removed if
                     the next character typed is a blank or does not insert
                     anything, or if the suffix consists of only one character
                     and the next character typed is the same character.

              -r remove-chars
                     This is a more versatile form of the -q option.  The
                     suffix given with -S or the slash automatically added
                     after completing directories will be automatically
                     removed if the next character typed inserts one of the
                     characters given in the remove-chars.  This string is
                     parsed as a characters class and understands the
                     backslash sequences used by the print command.  For
                     example, `-r "a-z\t"' removes the suffix if the next
                     character typed inserts a lower case character or a TAB,
                     and `-r "^0-9"' removes the suffix if the next character
                     typed inserts anything but a digit. One extra backslash
                     sequence is understood in this string: `\-' stands for
                     all characters that insert nothing. Thus `-S "=" -q' is
                     the same as `-S "=" -r "= \t\n\-"'.

                     This option may also be used without the -S option; then
                     any automatically added space will be removed when one of
                     the characters in the list is typed.

              -R remove-func
                     This is another form of the -r option. When a suffix has
                     been inserted and the completion accepted, the function
                     remove-func will be called after the next character
                     typed.  It is passed the length of the suffix as an
                     argument and can use the special parameters available in
                     ordinary (non-completion) zle widgets (see zshzle(1)) to
                     analyse and modify the command line.

              -f     If this flag is given, all of the matches built from
                     words are marked as being the names of files.  They are
                     not required to be actual filenames, but if they are, and
                     the option LIST_TYPES is set, the characters describing
                     the types of the files in the completion lists will be
                     shown. This also forces a slash to be added when the name
                     of a directory is completed.

              -e     This flag can be used to tell the completion code that
                     the matches added are parameter names for a parameter
                     expansion. This will make the AUTO_PARAM_SLASH and
                     AUTO_PARAM_KEYS options be used for the matches.

              -W file-prefix
                     This string is a pathname that will be prepended to each
                     of the matches formed by the given words together with
                     any prefix specified by the -p option to form a complete
                     filename for testing.  Hence it is only useful if
                     combined with the -f flag, as the tests will not
                     otherwise be performed.

              -F array
                     Specifies an array containing patterns. Words matching
                     one of these patterns are ignored, i.e. not considered to
                     be possible matches.

                     The array may be the name of an array parameter or a list
                     of literal patterns enclosed in parentheses and quoted,
                     as in `-F "(*?.o *?.h)"'. If the name of an array is
                     given, the elements of the array are taken as the
                     patterns.

              -Q     This flag instructs the completion code not to quote any
                     metacharacters in the words when inserting them into the
                     command line.

              -M match-spec
                     This gives local match specifications as described below
                     in the section `Completion Matching Control'. This option
                     may be given more than once.  In this case all
                     match-specs given are concatenated with spaces between
                     them to form the specification string to use.  Note that
                     they will only be used if the -U option is not given.

              -n     Specifies that the words added are to be used as possible
                     matches, but are not to appear in the completion listing.

              -U     If this flag is given, all words given will be accepted
                     and no matching will be done by the completion code.
                     Normally this is used in functions that do the matching
                     themselves.

              -O array
                     If this option is given, the words are not added to the
                     set of possible completions.  Instead, matching is done
                     as usual and all of the words given as arguments that
                     match the string on the command line will be stored in
                     the array parameter whose name is given as array.

              -A array
                     As the -O option, except that instead of those of the
                     words which match being stored in array, the strings
                     generated internally by the completion code are stored.
                     For example, with a matching specification of `-M
                     "L:|no="', the string `nof' on the command line and the
                     string `foo' as one of the words, this option stores the
                     string `nofoo' in the array, whereas the -O option stores
                     the `foo' originally given.

              -D array
                     As with -O, the words are not added to the set of
                     possible completions.  Instead, the completion code tests
                     whether each word in turn matches what is on the line.
                     If the nth word does not match, the nth element of the
                     array is removed.  Elements for which the corresponding
                     word is matched are retained.

              -C     This option adds a special match which expands to all
                     other matches when inserted into the line, even those
                     that are added after this option is used.  Together with
                     the -d option it is possible to specify a string that
                     should be displayed in the list for this special match.
                     If no string is given, it will be shown as a string
                     containing the strings that would be inserted for the
                     other matches, truncated to the width of the screen.

              -E number
                     This option adds number empty matches after the words
                     have been added.  An empty match takes up space in
                     completion listings but will never be inserted in the
                     line and can't be selected with menu completion or menu
                     selection.  This makes empty matches only useful to
                     format completion lists and to make explanatory string be
                     shown in completion lists (since empty matches can be
                     given display strings with the -d option).  And because
                     all but one empty string would otherwise be removed, this
                     option implies the -V and -2 options (even if an explicit
                     -J option is given).  This can be important to note as it
                     affects the name space into which matches are added.

              -
              --     This flag ends the list of flags and options. All
                     arguments after it will be taken as the words to use as
                     matches even if they begin with hyphens.

              Except for the -M flag, if any of these flags is given more than
              once, the first one (and its argument) will be used.

       compset -p number
       compset -P [ number ] pattern
       compset -s number
       compset -S [ number ] pattern
       compset -n begin [ end ]
       compset -N beg-pat [ end-pat ]
       compset -q
              This command simplifies modification of the special parameters,
              while its return status allows tests on them to be carried out.

              The options are:

              -p number
                     If the value of the PREFIX parameter is at least number
                     characters long, the first number characters are removed
                     from it and appended to the contents of the IPREFIX
                     parameter.

              -P [ number ] pattern
                     If the value of the PREFIX parameter begins with anything
                     that matches the pattern, the matched portion is removed
                     from PREFIX and appended to IPREFIX.

                     Without the optional number, the longest match is taken,
                     but if number is given, anything up to the numberth match
                     is moved.  If the number is negative, the numberth
                     longest match is moved. For example, if PREFIX contains
                     the string `a=b=c', then compset -P '*\=' will move the
                     string `a=b=' into the IPREFIX parameter, but compset -P
                     1 '*\=' will move only the string `a='.

              -s number
                     As -p, but transfer the last number characters from the
                     value of SUFFIX to the front of the value of ISUFFIX.

              -S [ number ] pattern
                     As -P, but match the last portion of SUFFIX and transfer
                     the matched portion to the front of the value of ISUFFIX.

              -n begin [ end ]
                     If the current word position as specified by the
                     parameter CURRENT is greater than or equal to begin,
                     anything up to the beginth word is removed from the words
                     array and the value of the parameter CURRENT is
                     decremented by begin.

                     If the optional end is given, the modification is done
                     only if the current word position is also less than or
                     equal to end. In this case, the words from position end
                     onwards are also removed from the words array.

                     Both begin and end may be negative to count backwards
                     from the last element of the words array.

              -N beg-pat [ end-pat ]
                     If one of the elements of the words array before the one
                     at the index given by the value of the parameter CURRENT
                     matches the pattern beg-pat, all elements up to and
                     including the matching one are removed from the words
                     array and the value of CURRENT is changed to point to the
                     same word in the changed array.

                     If the optional pattern end-pat is also given, and there
                     is an element in the words array matching this pattern,
                     the parameters are modified only if the index of this
                     word is higher than the one given by the CURRENT
                     parameter (so that the matching word has to be after the
                     cursor). In this case, the words starting with the one
                     matching end-pat are also removed from the words array.
                     If words contains no word matching end-pat, the testing
                     and modification is performed as if it were not given.

              -q     The word currently being completed is split on spaces
                     into separate words, respecting the usual shell quoting
                     conventions.  The resulting words are stored in the words
                     array, and CURRENT, PREFIX, SUFFIX, QIPREFIX, and
                     QISUFFIX are modified to reflect the word part that is
                     completed.

              In all the above cases the return status is zero if the test
              succeeded and the parameters were modified and non-zero
              otherwise. This allows one to use this builtin in tests such as:

                     if compset -P '*\='; then ...

              This forces anything up to and including the last equal sign to
              be ignored by the completion code.

       compcall [ -TD ]
              This allows the use of completions defined with the compctl
              builtin from within completion widgets.  The list of matches
              will be generated as if one of the non-widget completion
              functions (complete-word, etc.)  had been called, except that
              only compctls given for specific commands are used. To force the
              code to try completions defined with the -T option of compctl
              and/or the default completion (whether defined by compctl -D or
              the builtin default) in the appropriate places, the -T and/or -D
              flags can be passed to compcall.

              The return status can be used to test if a matching compctl
              definition was found. It is non-zero if a compctl was found and
              zero otherwise.

              Note that this builtin is defined by the zsh/compctl module.

COMPLETION CONDITION CODES
       The following additional condition codes for use within the [[ ... ]]
       construct are available in completion widgets.  These work on the
       special parameters.  All of these tests can also be performed by the
       compset builtin, but in the case of the condition codes the contents of
       the special parameters are not modified.

       -prefix [ number ] pattern
              true if the test for the -P option of compset would succeed.

       -suffix [ number ] pattern
              true if the test for the -S option of compset would succeed.

       -after beg-pat
              true if the test of the -N option with only the beg-pat given
              would succeed.

       -between beg-pat end-pat
              true if the test for the -N option with both patterns would
              succeed.

COMPLETION MATCHING CONTROL
       It is possible by use of the -M option of the compadd builtin command
       to specify how the characters in the string to be completed (referred
       to here as the command line) map onto the characters in the list of
       matches produced by the completion code (referred to here as the trial
       completions). Note that this is not used if the command line contains a
       glob pattern and the GLOB_COMPLETE option is set or the pattern_match
       of the compstate special association is set to a non-empty string.

       The match-spec given as the argument to the -M option (see `Completion
       Builtin Commands' above) consists of one or more matching descriptions
       separated by whitespace.  Each description consists of a letter
       followed by a colon and then the patterns describing which character
       sequences on the line match which character sequences in the trial
       completion.  Any sequence of characters not handled in this fashion
       must match exactly, as usual.

       The forms of match-spec understood are as follows. In each case, the
       form with an upper case initial character retains the string already
       typed on the command line as the final result of completion, while with
       a lower case initial character the string on the command line is
       changed into the corresponding part of the trial completion.

       m:lpat=tpat
       M:lpat=tpat
              Here, lpat is a pattern that matches on the command line,
              corresponding to tpat which matches in the trial completion.

       l:lanchor|lpat=tpat
       L:lanchor|lpat=tpat
       l:lanchor||ranchor=tpat
       L:lanchor||ranchor=tpat
       b:lpat=tpat
       B:lpat=tpat
              These letters are for patterns that are anchored by another
              pattern on the left side. Matching for lpat and tpat is as for m
              and M, but the pattern lpat matched on the command line must be
              preceded by the pattern lanchor.  The lanchor can be blank to
              anchor the match to the start of the command line string;
              otherwise the anchor can occur anywhere, but must match in both
              the command line and trial completion strings.

              If no lpat is given but a ranchor is, this matches the gap
              between substrings matched by lanchor and ranchor. Unlike
              lanchor, the ranchor only needs to match the trial completion
              string.

              The b and B forms are similar to l and L with an empty anchor,
              but need to match only the beginning of the word on the command
              line or trial completion, respectively.

       r:lpat|ranchor=tpat
       R:lpat|ranchor=tpat
       r:lanchor||ranchor=tpat
       R:lanchor||ranchor=tpat
       e:lpat=tpat
       E:lpat=tpat
              As l, L, b and B, with the difference that the command line and
              trial completion patterns are anchored on the right side.  Here
              an empty ranchor and the e and E forms force the match to the
              end of the command line or trial completion string.

       x:     This form is used to mark the end of matching specifications:
              subsequent specifications are ignored. In a single standalone
              list of specifications this has no use but where matching
              specifications are accumulated, such as from nested function
              calls, it can allow one function to override another.

       Each lpat, tpat or anchor is either an empty string or consists of a
       sequence of literal characters (which may be quoted with a backslash),
       question marks, character classes, and correspondence classes; ordinary
       shell patterns are not used.  Literal characters match only themselves,
       question marks match any character, and character classes are formed as
       for globbing and match any character in the given set.

       Correspondence classes are defined like character classes, but with two
       differences: they are delimited by a pair of braces, and negated
       classes are not allowed, so the characters ! and ^ have no special
       meaning directly after the opening brace.  They indicate that a range
       of characters on the line match a range of characters in the trial
       completion, but (unlike ordinary character classes) paired according to
       the corresponding position in the sequence.  For example, to make any
       ASCII lower case letter on the line match the corresponding upper case
       letter in the trial completion, you can use `m:{a-z}={A-Z}' (however,
       see below for the recommended form for this).  More than one pair of
       classes can occur, in which case the first class before the =
       corresponds to the first after it, and so on.  If one side has more
       such classes than the other side, the superfluous classes behave like
       normal character classes.  In anchor patterns correspondence classes
       also behave like normal character classes.

       The standard `[:name:]' forms described for standard shell patterns
       (see the section FILENAME GENERATION in zshexpn(1)) may appear in
       correspondence classes as well as normal character classes.  The only
       special behaviour in correspondence classes is if the form on the left
       and the form on the right are each one of [:upper:], [:lower:].  In
       these cases the character in the word and the character on the line
       must be the same up to a difference in case.  Hence to make any lower
       case character on the line match the corresponding upper case character
       in the trial completion you can use `m:{[:lower:]}={[:upper:]}'.
       Although the matching system does not yet handle multibyte characters,
       this is likely to be a future extension, at which point this syntax
       will handle arbitrary alphabets; hence this form, rather than the use
       of explicit ranges, is the recommended form.  In other cases `[:name:]'
       forms are allowed.  If the two forms on the left and right are the
       same, the characters must match exactly.  In remaining cases, the
       corresponding tests are applied to both characters, but they are not
       otherwise constrained; any matching character in one set goes with any
       matching character in the other set:  this is equivalent to the
       behaviour of ordinary character classes.

       The pattern tpat may also be one or two stars, `*' or `**'. This means
       that the pattern on the command line can match any number of characters
       in the trial completion. In this case the pattern must be anchored (on
       either side); in the case of a single star, the anchor then determines
       how much of the trial completion is to be included -- only the
       characters up to the next appearance of the anchor will be matched.
       With two stars, substrings matched by the anchor can be matched, too.

       Examples:

       The keys of the options association defined by the parameter module are
       the option names in all-lower-case form, without underscores, and
       without the optional no at the beginning even though the builtins
       setopt and unsetopt understand option names with upper case letters,
       underscores, and the optional no.  The following alters the matching
       rules so that the prefix no and any underscore are ignored when trying
       to match the trial completions generated and upper case letters on the
       line match the corresponding lower case letters in the words:

              compadd -M 'L:|[nN][oO]= M:_= M:{[:upper:]}={[:lower:]}' - \
                ${(k)options}

       The first part says that the pattern `[nN][oO]' at the beginning (the
       empty anchor before the pipe symbol) of the string on the line matches
       the empty string in the list of words generated by completion, so it
       will be ignored if present. The second part does the same for an
       underscore anywhere in the command line string, and the third part uses
       correspondence classes so that any upper case letter on the line
       matches the corresponding lower case letter in the word. The use of the
       upper case forms of the specification characters (L and M) guarantees
       that what has already been typed on the command line (in particular the
       prefix no) will not be deleted.

       Note that the use of L in the first part means that it matches only
       when at the beginning of both the command line string and the trial
       completion. I.e., the string `_NO_f' would not be completed to
       `_NO_foo', nor would `NONO_f' be completed to `NONO_foo' because of the
       leading underscore or the second `NO' on the line which makes the
       pattern fail even though they are otherwise ignored. To fix this, one
       would use `B:[nN][oO]=' instead of the first part. As described above,
       this matches at the beginning of the trial completion, independent of
       other characters or substrings at the beginning of the command line
       word which are ignored by the same or other match-specs.

       The second example makes completion case insensitive.  This is just the
       same as in the option example, except here we wish to retain the
       characters in the list of completions:

              compadd -M 'm:{[:lower:]}={[:upper:]}' ...

       This makes lower case letters match their upper case counterparts.  To
       make upper case letters match the lower case forms as well:

              compadd -M 'm:{[:lower:][:upper:]}={[:upper:][:lower:]}' ...

       A nice example for the use of * patterns is partial word completion.
       Sometimes you would like to make strings like `c.s.u' complete to
       strings like `comp.source.unix', i.e. the word on the command line
       consists of multiple parts, separated by a dot in this example, where
       each part should be completed separately -- note, however, that the
       case where each part of the word, i.e. `comp', `source' and `unix' in
       this example, is to be completed from separate sets of matches is a
       different problem to be solved by the implementation of the completion
       widget.  The example can be handled by:

              compadd -M 'r:|.=* r:|=*' \
                - comp.sources.unix comp.sources.misc ...

       The first specification says that lpat is the empty string, while
       anchor is a dot; tpat is *, so this can match anything except for the
       `.' from the anchor in the trial completion word.  So in `c.s.u', the
       matcher sees `c', followed by the empty string, followed by the anchor
       `.', and likewise for the second dot, and replaces the empty strings
       before the anchors, giving `c[omp].s[ources].u[nix]', where the last
       part of the completion is just as normal.

       With the pattern shown above, the string `c.u' could not be completed
       to `comp.sources.unix' because the single star means that no dot
       (matched by the anchor) can be skipped. By using two stars as in
       `r:|.=**', however, `c.u' could be completed to `comp.sources.unix'.
       This also shows that in some cases, especially if the anchor is a real
       pattern, like a character class, the form with two stars may result in
       more matches than one would like.

       The second specification is needed to make this work when the cursor is
       in the middle of the string on the command line and the option
       COMPLETE_IN_WORD is set. In this case the completion code would
       normally try to match trial completions that end with the string as
       typed so far, i.e. it will only insert new characters at the cursor
       position rather than at the end.  However in our example we would like
       the code to recognise matches which contain extra characters after the
       string on the line (the `nix' in the example).  Hence we say that the
       empty string at the end of the string on the line matches any
       characters at the end of the trial completion.

       More generally, the specification

              compadd -M 'r:|[.,_-]=* r:|=*' ...

       allows one to complete words with abbreviations before any of the
       characters in the square brackets.  For example, to complete
       veryverylongfile.c rather than veryverylongheader.h with the above in
       effect, you can just type very.c before attempting completion.

       The specifications with both a left and a right anchor are useful to
       complete partial words whose parts are not separated by some special
       character. For example, in some places strings have to be completed
       that are formed `LikeThis' (i.e. the separate parts are determined by a
       leading upper case letter) or maybe one has to complete strings with
       trailing numbers. Here one could use the simple form with only one
       anchor as in:

              compadd -M 'r:|[[:upper:]0-9]=* r:|=*' LikeTHIS FooHoo 5foo123 5bar234

       But with this, the string `H' would neither complete to `FooHoo' nor to
       `LikeTHIS' because in each case there is an upper case letter before
       the `H' and that is matched by the anchor. Likewise, a `2' would not be
       completed. In both cases this could be changed by using
       `r:|[[:upper:]0-9]=**', but then `H' completes to both `LikeTHIS' and
       `FooHoo' and a `2' matches the other strings because characters can be
       inserted before every upper case letter and digit. To avoid this one
       would use:

              compadd -M 'r:[^[:upper:]0-9]||[[:upper:]0-9]=** r:|=*' \
                  LikeTHIS FooHoo foo123 bar234

       By using these two anchors, a `H' matches only upper case `H's that are
       immediately preceded by something matching the left anchor
       `[^[:upper:]0-9]'. The effect is, of course, that `H' matches only the
       string `FooHoo', a `2' matches only `bar234' and so on.

       When using the completion system (see zshcompsys(1)), users can define
       match specifications that are to be used for specific contexts by using
       the matcher and matcher-list styles. The values for the latter will be
       used everywhere.

COMPLETION WIDGET EXAMPLE
       The first step is to define the widget:

              zle -C complete complete-word complete-files

       Then the widget can be bound to a key using the bindkey builtin
       command:

              bindkey '^X\t' complete

       After that the shell function complete-files will be invoked after
       typing control-X and TAB. The function should then generate the
       matches, e.g.:

              complete-files () { compadd - * }

       This function will complete files in the current directory matching the
       current word.




ZSHCOMPSYS(1)               General Commands Manual              ZSHCOMPSYS(1)



NAME
       zshcompsys - zsh completion system

DESCRIPTION
       This describes the shell code for the `new' completion system, referred
       to as compsys.  It is written in shell functions based on the features
       described in zshcompwid(1).

       The features are contextual, sensitive to the point at which completion
       is started.  Many completions are already provided.  For this reason, a
       user can perform a great many tasks without knowing any details beyond
       how to initialize the system, which is described below in
       INITIALIZATION.

       The context that decides what completion is to be performed may be
       ·      an argument or option position: these describe the position on
              the command line at which completion is requested.  For example
              `first argument to rmdir, the word being completed names a
              directory';


       ·      a special context, denoting an element in the shell's syntax.
              For example `a word in command position' or `an array
              subscript'.


       A full context specification contains other elements, as we shall
       describe.

       Besides commands names and contexts, the system employs two more
       concepts, styles and tags.  These provide ways for the user to
       configure the system's behaviour.

       Tags play a dual role.  They serve as a classification system for the
       matches, typically indicating a class of object that the user may need
       to distinguish.  For example, when completing arguments of the ls
       command the user may prefer to try files before directories, so both of
       these are tags.  They also appear as the rightmost element in a context
       specification.

       Styles modify various operations of the completion system, such as
       output formatting, but also what kinds of completers are used (and in
       what order), or which tags are examined.  Styles may accept arguments
       and are manipulated using the zstyle command described in see
       zshmodules(1).

       In summary, tags describe what the completion objects are, and style
       how they are to be completed.  At various points of execution, the
       completion system checks what styles and/or tags are defined for the
       current context, and uses that to modify its behavior.  The full
       description of context handling, which determines how tags and other
       elements of the context influence the behaviour of styles, is described
       below in COMPLETION SYSTEM CONFIGURATION.

       When a completion is requested, a dispatcher function is called; see
       the description of _main_complete in the list of control functions
       below. This dispatcher decides which function should be called to
       produce the completions, and calls it. The result is passed to one or
       more completers, functions that implement individual completion
       strategies: simple completion, error correction, completion with error
       correction, menu selection, etc.

       More generally, the shell functions contained in the completion system
       are of two types:
       ·      those beginning `comp' are to be called directly; there are only
              a few of these;


       ·      those beginning `_' are called by the completion code.  The
              shell functions of this set, which implement completion
              behaviour and may be bound to keystrokes, are referred to as
              `widgets'.  These proliferate as new completions are required.


INITIALIZATION
       If the system was installed completely, it should be enough to call the
       shell function compinit from your initialization file; see the next
       section.  However, the function compinstall can be run by a user to
       configure various aspects of the completion system.

       Usually, compinstall will insert code into .zshrc, although if that is
       not writable it will save it in another file and tell you that file's
       location.  Note that it is up to you to make sure that the lines added
       to .zshrc are actually run; you may, for example, need to move them to
       an earlier place in the file if .zshrc usually returns early.  So long
       as you keep them all together (including the comment lines at the start
       and finish), you can rerun compinstall and it will correctly locate and
       modify these lines.  Note, however, that any code you add to this
       section by hand is likely to be lost if you rerun compinstall, although
       lines using the command `zstyle' should be gracefully handled.

       The new code will take effect next time you start the shell, or run
       .zshrc by hand; there is also an option to make them take effect
       immediately.  However, if compinstall has removed definitions, you will
       need to restart the shell to see the changes.

       To run compinstall you will need to make sure it is in a directory
       mentioned in your fpath parameter, which should already be the case if
       zsh was properly configured as long as your startup files do not remove
       the appropriate directories from fpath.  Then it must be autoloaded
       (`autoload -U compinstall' is recommended).  You can abort the
       installation any time you are being prompted for information, and your
       .zshrc will not be altered at all; changes only take place right at the
       end, where you are specifically asked for confirmation.

   Use of compinit
       This section describes the use of compinit to initialize completion for
       the current session when called directly; if you have run compinstall
       it will be called automatically from your .zshrc.

       To initialize the system, the function compinit should be in a
       directory mentioned in the fpath parameter, and should be autoloaded
       (`autoload -U compinit' is recommended), and then run simply as
       `compinit'.  This will define a few utility functions, arrange for all
       the necessary shell functions to be autoloaded, and will then re-define
       all widgets that do completion to use the new system.  If you use the
       menu-select widget, which is part of the zsh/complist module, you
       should make sure that that module is loaded before the call to compinit
       so that that widget is also re-defined.  If completion styles (see
       below) are set up to perform expansion as well as completion by
       default, and the TAB key is bound to expand-or-complete, compinit will
       rebind it to complete-word; this is necessary to use the correct form
       of expansion.

       Should you need to use the original completion commands, you can still
       bind keys to the old widgets by putting a `.' in front of the widget
       name, e.g. `.expand-or-complete'.

       To speed up the running of compinit, it can be made to produce a dumped
       configuration that will be read in on future invocations; this is the
       default, but can be turned off by calling compinit with the option -D.
       The dumped file is .zcompdump in the same directory as the startup
       files (i.e. $ZDOTDIR or $HOME); alternatively, an explicit file name
       can be given by `compinit -d dumpfile'.  The next invocation of
       compinit will read the dumped file instead of performing a full
       initialization.

       If the number of completion files changes, compinit will recognise this
       and produce a new dump file.  However, if the name of a function or the
       arguments in the first line of a #compdef function (as described below)
       change, it is easiest to delete the dump file by hand so that compinit
       will re-create it the next time it is run.  The check performed to see
       if there are new functions can be omitted by giving the option -C.  In
       this case the dump file will only be created if there isn't one
       already.

       The dumping is actually done by another function, compdump, but you
       will only need to run this yourself if you change the configuration
       (e.g. using compdef) and then want to dump the new one.  The name of
       the old dumped file will be remembered for this purpose.

       If the parameter _compdir is set, compinit uses it as a directory where
       completion functions can be found; this is only necessary if they are
       not already in the function search path.

       For security reasons compinit also checks if the completion system
       would use files not owned by root or by the current user, or files in
       directories that are world- or group-writable or that are not owned by
       root or by the current user.  If such files or directories are found,
       compinit will ask if the completion system should really be used.  To
       avoid these tests and make all files found be used without asking, use
       the option -u, and to make compinit silently ignore all insecure files
       and directories use the option -i.  This security check is skipped
       entirely when the -C option is given.

       The security check can be retried at any time by running the function
       compaudit.  This is the same check used by compinit, but when it is
       executed directly any changes to fpath are made local to the function
       so they do not persist.  The directories to be checked may be passed as
       arguments; if none are given, compaudit uses fpath and _compdir to find
       completion system directories, adding missing ones to fpath as
       necessary.  To force a check of exactly the directories currently named
       in fpath, set _compdir to an empty string before calling compaudit or
       compinit.

       The function bashcompinit provides compatibility with bash's
       programmable completion system.  When run it will define the functions,
       compgen and complete which correspond to the bash builtins with the
       same names.  It will then be possible to use completion specifications
       and functions written for bash.

   Autoloaded files
       The convention for autoloaded functions used in completion is that they
       start with an underscore; as already mentioned, the fpath/FPATH
       parameter must contain the directory in which they are stored.  If zsh
       was properly installed on your system, then fpath/FPATH automatically
       contains the required directories for the standard functions.

       For incomplete installations, if compinit does not find enough files
       beginning with an underscore (fewer than twenty) in the search path, it
       will try to find more by adding the directory _compdir to the search
       path.  If that directory has a subdirectory named Base, all
       subdirectories will be added to the path.  Furthermore, if the
       subdirectory Base has a subdirectory named Core, compinit will add all
       subdirectories of the subdirectories to the path: this allows the
       functions to be in the same format as in the zsh source distribution.

       When compinit is run, it searches all such files accessible via
       fpath/FPATH and reads the first line of each of them.  This line should
       contain one of the tags described below.  Files whose first line does
       not start with one of these tags are not considered to be part of the
       completion system and will not be treated specially.

       The tags are:

       #compdef name ... [ -{p|P} pattern ... [ -N name ... ] ]
              The file will be made autoloadable and the function defined in
              it will be called when completing names, each of which is either
              the name of a command whose arguments are to be completed or one
              of a number of special contexts in the form -context- described
              below.

              Each name may also be of the form `cmd=service'.  When
              completing the command cmd, the function typically behaves as if
              the command (or special context) service was being completed
              instead.  This provides a way of altering the behaviour of
              functions that can perform many different completions.  It is
              implemented by setting the parameter $service when calling the
              function; the function may choose to interpret this how it
              wishes, and simpler functions will probably ignore it.

              If the #compdef line contains one of the options -p or -P, the
              words following are taken to be patterns.  The function will be
              called when completion is attempted for a command or context
              that matches one of the patterns.  The options -p and -P are
              used to specify patterns to be tried before or after other
              completions respectively.  Hence -P may be used to specify
              default actions.

              The option -N is used after a list following -p or -P; it
              specifies that remaining words no longer define patterns.  It is
              possible to toggle between the three options as many times as
              necessary.

       #compdef -k style key-sequence ...
              This option creates a widget behaving like the builtin widget
              style and binds it to the given key-sequences, if any.  The
              style must be one of the builtin widgets that perform
              completion, namely complete-word, delete-char-or-list,
              expand-or-complete, expand-or-complete-prefix, list-choices,
              menu-complete, menu-expand-or-complete, or
              reverse-menu-complete.  If the zsh/complist module is loaded
              (see zshmodules(1)) the widget menu-select is also available.

              When one of the key-sequences is typed, the function in the file
              will be invoked to generate the matches.  Note that a key will
              not be re-bound if it already was (that is, was bound to
              something other than undefined-key).  The widget created has the
              same name as the file and can be bound to any other keys using
              bindkey as usual.

       #compdef -K widget-name style key-sequence [ name style seq ... ]
              This is similar to -k except that only one key-sequence argument
              may be given for each widget-name style pair.  However, the
              entire set of three arguments may be repeated with a different
              set of arguments.  Note in particular that the widget-name must
              be distinct in each set.  If it does not begin with `_' this
              will be added.  The widget-name should not clash with the name
              of any existing widget: names based on the name of the function
              are most useful.  For example,

                     #compdef -K _foo_complete complete-word "^X^C" \
                       _foo_list list-choices "^X^D"

              (all on one line) defines a widget _foo_complete for completion,
              bound to `^X^C', and a widget _foo_list for listing, bound to
              `^X^D'.

       #autoload [ options ]
              Functions with the #autoload tag are marked for autoloading but
              are not otherwise treated specially.  Typically they are to be
              called from within one of the completion functions.  Any options
              supplied will be passed to the autoload builtin; a typical use
              is +X to force the function to be loaded immediately.  Note that
              the -U and -z flags are always added implicitly.

       The # is part of the tag name and no white space is allowed after it.
       The #compdef tags use the compdef function described below; the main
       difference is that the name of the function is supplied implicitly.

       The special contexts for which completion functions can be defined are:

       -array-value-
              The right hand side of an array-assignment (`name=(...)')

       -brace-parameter-
              The name of a parameter expansion within braces (`${...}')

       -assign-parameter-
              The name of a parameter in an assignment, i.e. on the left hand
              side of an `='

       -command-
              A word in command position

       -condition-
              A word inside a condition (`[[...]]')

       -default-
              Any word for which no other completion is defined

       -equal-
              A word beginning with an equals sign

       -first-
              This is tried before any other completion function.  The
              function called may set the _compskip parameter to one of
              various values: all: no further completion is attempted; a
              string containing the substring patterns: no pattern completion
              functions will be called; a string containing default: the
              function for the `-default-' context will not be called, but
              functions defined for commands will be.

       -math- Inside mathematical contexts, such as `((...))'

       -parameter-
              The name of a parameter expansion (`$...')

       -redirect-
              The word after a redirection operator.

       -subscript-
              The contents of a parameter subscript.

       -tilde-
              After an initial tilde (`~'), but before the first slash in the
              word.

       -value-
              On the right hand side of an assignment.

       Default implementations are supplied for each of these contexts.  In
       most cases the context -context- is implemented by a corresponding
       function _context, for example the context `-tilde-' and the function
       `_tilde').

       The contexts -redirect- and -value- allow extra context-specific
       information.  (Internally, this is handled by the functions for each
       context calling the function _dispatch.)  The extra information is
       added separated by commas.

       For the -redirect- context, the extra information is in the form
       `-redirect-,op,command', where op is the redirection operator and
       command is the name of the command on the line.  If there is no command
       on the line yet, the command field will be empty.

       For the -value- context, the form is `-value-,name,command', where name
       is the name of the parameter on the left hand side of the assignment.
       In the case of elements of an associative array, for example
       `assoc=(key <TAB>', name is expanded to `name-key'.  In certain special
       contexts, such as completing after `make CFLAGS=', the command part
       gives the name of the command, here make; otherwise it is empty.

       It is not necessary to define fully specific completions as the
       functions provided will try to generate completions by progressively
       replacing the elements with `-default-'.  For example, when completing
       after `foo=<TAB>', _value will try the names `-value-,foo,' (note the
       empty command part), `-value-,foo,-default-'
       and`-value-,-default-,-default-', in that order, until it finds a
       function to handle the context.

       As an example:

              compdef '_files -g "*.log"' '-redirect-,2>,-default-'

       completes files matching `*.log' after `2> <TAB>' for any command with
       no more specific handler defined.

       Also:

              compdef _foo -value-,-default-,-default-

       specifies that _foo provides completions for the values of parameters
       for which no special function has been defined.  This is usually
       handled by the function _value itself.

       The same lookup rules are used when looking up styles (as described
       below); for example

              zstyle ':completion:*:*:-redirect-,2>,*:*' file-patterns '*.log'

       is another way to make completion after `2> <TAB>' complete files
       matching `*.log'.

   Functions
       The following function is defined by compinit and may be called
       directly.

       compdef [ -ane ] function name ... [ -{p|P} pattern ... [ -N name ...]]
       compdef -d name ...
       compdef -k [ -an ] function style key-sequence [ key-sequence ... ]
       compdef -K [ -an ] function name style key-seq [ name style seq ... ]
              The first form defines the function to call for completion in
              the given contexts as described for the #compdef tag above.

              Alternatively, all the arguments may have the form
              `cmd=service'.  Here service should already have been defined by
              `cmd1=service' lines in #compdef files, as described above.  The
              argument for cmd will be completed in the same way as service.

              The function argument may alternatively be a string containing
              almost any shell code.  If the string contains an equal sign,
              the above will take precedence.  The option -e may be used to
              specify the first argument is to be evaluated as shell code even
              if it contains an equal sign.  The string will be executed using
              the eval builtin command to generate completions.  This provides
              a way of avoiding having to define a new completion function.
              For example, to complete files ending in `.h' as arguments to
              the command foo:

                     compdef '_files -g "*.h"' foo

              The option -n prevents any completions already defined for the
              command or context from being overwritten.

              The option -d deletes any completion defined for the command or
              contexts listed.

              The names may also contain -p, -P and -N options as described
              for the #compdef tag.  The effect on the argument list is
              identical, switching between definitions of patterns tried
              initially, patterns tried finally, and normal commands and
              contexts.

              The parameter $_compskip may be set by any function defined for
              a pattern context.  If it is set to a value containing the
              substring `patterns' none of the pattern-functions will be
              called; if it is set to a value containing the substring `all',
              no other function will be called.  Setting $_compskip in this
              manner is of particular utility when using the -p option, as
              otherwise the dispatcher will move on to additional functions
              (likely the default one) after calling the pattern-context one,
              which can mangle the display of completion possibilities if not
              handled properly.

              The form with -k defines a widget with the same name as the
              function that will be called for each of the key-sequences; this
              is like the #compdef -k tag.  The function should generate the
              completions needed and will otherwise behave like the builtin
              widget whose name is given as the style argument.  The widgets
              usable for this are: complete-word, delete-char-or-list,
              expand-or-complete, expand-or-complete-prefix, list-choices,
              menu-complete, menu-expand-or-complete, and
              reverse-menu-complete, as well as menu-select if the
              zsh/complist module is loaded.  The option -n prevents the key
              being bound if it is already to bound to something other than
              undefined-key.

              The form with -K is similar and defines multiple widgets based
              on the same function, each of which requires the set of three
              arguments name, style and key-sequence, where the latter two are
              as for -k and the first must be a unique widget name beginning
              with an underscore.

              Wherever applicable, the -a option makes the function
              autoloadable, equivalent to autoload -U function.

       The function compdef can be used to associate existing completion
       functions with new commands.  For example,

              compdef _pids foo

       uses the function _pids to complete process IDs for the command foo.

       Note also the _gnu_generic function described below, which can be used
       to complete options for commands that understand the `--help' option.

COMPLETION SYSTEM CONFIGURATION
       This section gives a short overview of how the completion system works,
       and then more detail on how users can configure how and when matches
       are generated.

   Overview
       When completion is attempted somewhere on the command line the
       completion system begins building the context.  The context represents
       everything that the shell knows about the meaning of the command line
       and the significance of the cursor position.  This takes account of a
       number of things including the command word (such as `grep' or `zsh')
       and options to which the current word may be an argument (such as the
       `-o' option to zsh which takes a shell option as an argument).

       The context starts out very generic ("we are beginning a completion")
       and becomes more specific as more is learned ("the current word is in a
       position that is usually a command name" or "the current word might be
       a variable name" and so on).  Therefore the context will vary during
       the same call to the completion system.

       This context information is condensed into a string consisting of
       multiple fields separated by colons, referred to simply as `the
       context' in the remainder of the documentation.  Note that a user of
       the completion system rarely needs to compose a context string, unless
       for example a new function is being written to perform completion for a
       new command.  What a user may need to do is compose a style pattern,
       which is matched against a context when needed to look up
       context-sensitive options that configure the completion system.

       The next few paragraphs explain how a context is composed within the
       completion function suite.  Following that is discussion of how styles
       are defined.  Styles determine such things as how the matches are
       generated, similarly to shell options but with much more control.  They
       are defined with the zstyle builtin command (see zshmodules(1)).

       The context string always consists of a fixed set of fields, separated
       by colons and with a leading colon before the first.  Fields which are
       not yet known are left empty, but the surrounding colons appear anyway.
       The fields are always in the order
       :completion:function:completer:command:argument:tag.  These have the
       following meaning:

       ·      The literal string completion, saying that this style is used by
              the completion system.  This distinguishes the context from
              those used by, for example, zle widgets and ZFTP functions.


       ·      The function, if completion is called from a named widget rather
              than through the normal completion system.  Typically this is
              blank, but it is set by special widgets such as predict-on and
              the various functions in the Widget directory of the
              distribution to the name of that function, often in an
              abbreviated form.


       ·      The completer currently active, the name of the function without
              the leading underscore and with other underscores converted to
              hyphens.  A `completer' is in overall control of how completion
              is to be performed; `complete' is the simplest, but other
              completers exist to perform related tasks such as correction, or
              to modify the behaviour of a later completer.  See the section
              `Control Functions' below for more information.


       ·      The command or a special -context-, just at it appears following
              the #compdef tag or the compdef function.  Completion functions
              for commands that have sub-commands usually modify this field to
              contain the name of the command followed by a minus sign and the
              sub-command.  For example, the completion function for the cvs
              command sets this field to cvs-add when completing arguments to
              the add subcommand.


       ·      The argument; this indicates which command line or option
              argument we are completing.  For command arguments this
              generally takes the form argument-n, where n is the number of
              the argument, and for arguments to options the form option-opt-n
              where n is the number of the argument to option opt.  However,
              this is only the case if the command line is parsed with
              standard UNIX-style options and arguments, so many completions
              do not set this.


       ·      The tag.  As described previously, tags are used to discriminate
              between the types of matches a completion function can generate
              in a certain context.  Any completion function may use any tag
              name it likes, but a list of the more common ones is given
              below.


       The context is gradually put together as the functions are executed,
       starting with the main entry point, which adds :completion: and the
       function element if necessary.  The completer then adds the completer
       element.  The contextual completion adds the command and argument
       options.  Finally, the tag is added when the types of completion are
       known.  For example, the context name

              :completion::complete:dvips:option-o-1:files

       says that normal completion was attempted as the first argument to the
       option -o of the command dvips:

              dvips -o ...

       and the completion function will generate filenames.

       Usually completion will be tried for all possible tags in an order
       given by the completion function.  However, this can be altered by
       using the tag-order style.  Completion is then restricted to the list
       of given tags in the given order.

       The _complete_help bindable command shows all the contexts and tags
       available for completion at a particular point.  This provides an easy
       way of finding information for tag-order and other styles.  It is
       described in the section `Bindable Commands' below.

       When looking up styles the completion system uses full context names,
       including the tag.  Looking up the value of a style therefore consists
       of two things: the context, which is matched to the most specific (best
       fitting) style pattern, and the name of the style itself, which must be
       matched exactly.  The following examples demonstrate that style
       patterns may be loosely defined for styles that apply broadly, or as
       tightly defined as desired for styles that apply in narrower
       circumstances.

       For example, many completion functions can generate matches in a simple
       and a verbose form and use the verbose style to decide which form
       should be used.  To make all such functions use the verbose form, put

              zstyle ':completion:*' verbose yes

       in a startup file (probably .zshrc).  This gives the verbose style the
       value yes in every context inside the completion system, unless that
       context has a more specific definition.  It is best to avoid giving the
       context as `*' in case the style has some meaning outside the
       completion system.

       Many such general purpose styles can be configured simply by using the
       compinstall function.

       A more specific example of the use of the verbose style is by the
       completion for the kill builtin.  If the style is set, the builtin
       lists full job texts and process command lines; otherwise it shows the
       bare job numbers and PIDs.  To turn the style off for this use only:

              zstyle ':completion:*:*:kill:*:*' verbose no

       For even more control, the style can use one of the tags `jobs' or
       `processes'.  To turn off verbose display only for jobs:

              zstyle ':completion:*:*:kill:*:jobs' verbose no

       The -e option to zstyle even allows completion function code to appear
       as the argument to a style; this requires some understanding of the
       internals of completion functions (see see zshcompwid(1))).  For
       example,

              zstyle -e ':completion:*' hosts 'reply=($myhosts)'

       This forces the value of the hosts style to be read from the variable
       myhosts each time a host name is needed; this is useful if the value of
       myhosts can change dynamically.  For another useful example, see the
       example in the description of the file-list style below.  This form can
       be slow and should be avoided for commonly examined styles such as menu
       and list-rows-first.

       Note that the order in which styles are defined does not matter; the
       style mechanism uses the most specific possible match for a particular
       style to determine the set of values.  More precisely, strings are
       preferred over patterns (for example, `:completion::complete:::foo' is
       more specific than `:completion::complete:::*'), and longer patterns
       are preferred over shorter patterns.

       A good rule of thumb is that any completion style pattern that needs to
       include more than one wildcard (*) and that does not end in a tag name,
       should include all six colons (:), possibly surrounding additional
       wildcards.

       Style names like those of tags are arbitrary and depend on the
       completion function.  However, the following two sections list some of
       the most common tags and styles.

   Standard Tags
       Some of the following are only used when looking up particular styles
       and do not refer to a type of match.

       accounts
              used to look up the users-hosts style

       all-expansions
              used by the _expand completer when adding the single string
              containing all possible expansions

       all-files
              for the names of all files (as distinct from a particular
              subset, see the globbed-files tag).

       arguments
              for arguments to a command

       arrays for names of array parameters

       association-keys
              for keys of associative arrays; used when completing inside a
              subscript to a parameter of this type

       bookmarks
              when completing bookmarks (e.g. for URLs and the zftp function
              suite)

       builtins
              for names of builtin commands

       characters
              for single characters in arguments of commands such as stty.
              Also used when completing character classes after an opening
              bracket

       colormapids
              for X colormap ids

       colors for color names

       commands
              for names of external commands.  Also used by complex commands
              such as cvs when completing names subcommands.

       contexts
              for contexts in arguments to the zstyle builtin command

       corrections
              used by the _approximate and _correct completers for possible
              corrections

       cursors
              for cursor names used by X programs

       default
              used in some contexts to provide a way of supplying a default
              when more specific tags are also valid.  Note that this tag is
              used when only the function field of the context name is set

       descriptions
              used when looking up the value of the format style to generate
              descriptions for types of matches

       devices
              for names of device special files

       directories
              for names of directories -- local-directories is used instead
              when completing arguments of cd and related builtin commands
              when the cdpath array is set

       directory-stack
              for entries in the directory stack

       displays
              for X display names

       domains
              for network domains

       email-plugin
              for email addresses from the `_email-plugin' backend of
              _email_addresses

       expansions
              used by the _expand completer for individual words (as opposed
              to the complete set of expansions) resulting from the expansion
              of a word on the command line

       extensions
              for X server extensions

       file-descriptors
              for numbers of open file descriptors

       files  the generic file-matching tag used by functions completing
              filenames

       fonts  for X font names

       fstypes
              for file system types (e.g. for the mount command)

       functions
              names of functions -- normally shell functions, although certain
              commands may understand other kinds of function

       globbed-files
              for filenames when the name has been generated by pattern
              matching

       groups for names of user groups

       history-words
              for words from the history

       hosts  for hostnames

       indexes
              for array indexes

       jobs   for jobs (as listed by the `jobs' builtin)

       interfaces
              for network interfaces

       keymaps
              for names of zsh keymaps

       keysyms
              for names of X keysyms

       libraries
              for names of system libraries

       limits for system limits

       local-directories
              for names of directories that are subdirectories of the current
              working directory when completing arguments of cd and related
              builtin commands (compare path-directories) -- when the cdpath
              array is unset, directories is used instead

       manuals
              for names of manual pages

       mailboxes
              for e-mail folders

       maps   for map names (e.g. NIS maps)

       messages
              used to look up the format style for messages

       modifiers
              for names of X modifiers

       modules
              for modules (e.g. zsh modules)

       my-accounts
              used to look up the users-hosts style

       named-directories
              for named directories (you wouldn't have guessed that, would
              you?)

       names  for all kinds of names

       newsgroups
              for USENET groups

       nicknames
              for nicknames of NIS maps

       options
              for command options

       original
              used by the _approximate, _correct and _expand completers when
              offering the original string as a match

       other-accounts
              used to look up the users-hosts style

       other-files
              for the names of any non-directory files.  This is used instead
              of all-files when the list-dirs-first style is in effect.

       packages
              for packages (e.g. rpm or installed Debian packages)

       parameters
              for names of parameters

       path-directories
              for names of directories found by searching the cdpath array
              when completing arguments of cd and related builtin commands
              (compare local-directories)

       paths  used to look up the values of the expand, ambiguous and
              special-dirs styles

       pods   for perl pods (documentation files)

       ports  for communication ports

       prefixes
              for prefixes (like those of a URL)

       printers
              for print queue names

       processes
              for process identifiers

       processes-names
              used to look up the command style when generating the names of
              processes for killall

       sequences
              for sequences (e.g. mh sequences)

       sessions
              for sessions in the zftp function suite

       signals
              for signal names

       strings
              for strings (e.g. the replacement strings for the cd builtin
              command)

       styles for styles used by the zstyle builtin command

       suffixes
              for filename extensions

       tags   for tags (e.g. rpm tags)

       targets
              for makefile targets

       time-zones
              for time zones (e.g. when setting the TZ parameter)

       types  for types of whatever (e.g. address types for the xhost command)

       urls   used to look up the urls and local styles when completing URLs

       users  for usernames

       values for one of a set of values in certain lists

       variant
              used by _pick_variant to look up the command to run when
              determining what program is installed for a particular command
              name.

       visuals
              for X visuals

       warnings
              used to look up the format style for warnings

       widgets
              for zsh widget names

       windows
              for IDs of X windows

       zsh-options
              for shell options

   Standard Styles
       Note that the values of several of these styles represent boolean
       values.  Any of the strings `true', `on', `yes', and `1' can be used
       for the value `true' and any of the strings `false', `off', `no', and
       `0' for the value `false'.  The behavior for any other value is
       undefined except where explicitly mentioned.  The default value may be
       either `true' or `false' if the style is not set.

       Some of these styles are tested first for every possible tag
       corresponding to a type of match, and if no style was found, for the
       default tag.  The most notable styles of this type are menu,
       list-colors and styles controlling completion listing such as
       list-packed and last-prompt.  When tested for the default tag, only the
       function field of the context will be set so that a style using the
       default tag will normally be defined along the lines of:

              zstyle ':completion:*:default' menu ...

       accept-exact
              This is tested for the default tag in addition to the tags valid
              for the current context.  If it is set to `true' and any of the
              trial matches is the same as the string on the command line,
              this match will immediately be accepted (even if it would
              otherwise be considered ambiguous).

              When completing pathnames (where the tag used is `paths') this
              style accepts any number of patterns as the value in addition to
              the boolean values.  Pathnames matching one of these patterns
              will be accepted immediately even if the command line contains
              some more partially typed pathname components and these match no
              file under the directory accepted.

              This style is also used by the _expand completer to decide if
              words beginning with a tilde or parameter expansion should be
              expanded.  For example, if there are parameters foo and foobar,
              the string `$foo' will only be expanded if accept-exact is set
              to `true'; otherwise the completion system will be allowed to
              complete $foo to $foobar. If the style is set to `continue',
              _expand will add the expansion as a match and the completion
              system will also be allowed to continue.

       accept-exact-dirs
              This is used by filename completion.  Unlike accept-exact it is
              a boolean.  By default, filename completion examines all
              components of a path to see if there are completions of that
              component, even if the component matches an existing directory.
              For example, when completion after /usr/bin/, the function
              examines possible completions to /usr.

              When this style is `true', any prefix of a path that matches an
              existing directory is accepted without any attempt to complete
              it further.  Hence, in the given example, the path /usr/bin/ is
              accepted immediately and completion tried in that directory.

              This style is also useful when completing after directories that
              magically appear when referenced, such as ZFS .zfs directories
              or NetApp .snapshot directories.  When the style is set the
              shell does not check for the existence of the directory within
              the parent directory.

              If you wish to inhibit this behaviour entirely, set the
              path-completion style (see below) to `false'.

       add-space
              This style is used by the _expand completer.  If it is `true'
              (the default), a space will be inserted after all words
              resulting from the expansion, or a slash in the case of
              directory names.  If the value is `file', the completer will
              only add a space to names of existing files.  Either a boolean
              `true' or the value `file' may be combined with `subst', in
              which case the completer will not add a space to words generated
              from the expansion of a substitution of the form `$(...)' or
              `${...}'.

              The _prefix completer uses this style as a simple boolean value
              to decide if a space should be inserted before the suffix.

       ambiguous
              This applies when completing non-final components of filename
              paths, in other words those with a trailing slash.  If it is
              set, the cursor is left after the first ambiguous component,
              even if menu completion is in use.  The style is always tested
              with the paths tag.

       assign-list
              When completing after an equals sign that is being treated as an
              assignment, the completion system normally completes only one
              filename.  In some cases the value  may be a list of filenames
              separated by colons, as with PATH and similar parameters.  This
              style can be set to a list of patterns matching the names of
              such parameters.

              The default is to complete lists when the word on the line
              already contains a colon.

       auto-description
              If set, this style's value will be used as the description for
              options that are not described by the completion functions, but
              that have exactly one argument.  The sequence `%d' in the value
              will be replaced by the description for this argument.
              Depending on personal preferences, it may be useful to set this
              style to something like `specify: %d'.  Note that this may not
              work for some commands.

       avoid-completer
              This is used by the _all_matches completer to decide if the
              string consisting of all matches should be added to the list
              currently being generated.  Its value is a list of names of
              completers.  If any of these is the name of the completer that
              generated the matches in this completion, the string will not be
              added.

              The default value for this style is `_expand _old_list _correct
              _approximate', i.e. it contains the completers for which a
              string with all matches will almost never be wanted.

       cache-path
              This style defines the path where any cache files containing
              dumped completion data are stored.  It defaults to
              `$ZDOTDIR/.zcompcache', or `$HOME/.zcompcache' if $ZDOTDIR is
              not defined.  The completion cache will not be used unless the
              use-cache style is set.

       cache-policy
              This style defines the function that will be used to determine
              whether a cache needs rebuilding.  See the section on the
              _cache_invalid function below.

       call-command
              This style is used in the function for commands such as make and
              ant where calling the command directly to generate matches
              suffers problems such as being slow or, as in the case of make
              can potentially cause actions in the makefile to be executed. If
              it is set to `true' the command is called to generate matches.
              The default value of this style is `false'.

       command
              In many places, completion functions need to call external
              commands to generate the list of completions.  This style can be
              used to override the command that is called in some such cases.
              The elements of the value are joined with spaces to form a
              command line to execute.  The value can also start with a
              hyphen, in which case the usual command will be added to the
              end; this is most useful for putting `builtin' or `command' in
              front to make sure the appropriate version of a command is
              called, for example to avoid calling a shell function with the
              same name as an external command.

              As an example, the completion function for process IDs uses this
              style with the processes tag to generate the IDs to complete and
              the list of processes to display (if the verbose style is
              `true').  The list produced by the command should look like the
              output of the ps command.  The first line is not displayed, but
              is searched for the string `PID' (or `pid') to find the position
              of the process IDs in the following lines.  If the line does not
              contain `PID', the first numbers in each of the other lines are
              taken as the process IDs to complete.

              Note that the completion function generally has to call the
              specified command for each attempt to generate the completion
              list.  Hence care should be taken to specify only commands that
              take a short time to run, and in particular to avoid any that
              may never terminate.

       command-path
              This is a list of directories to search for commands to
              complete.  The default for this style is the value of the
              special parameter path.

       commands
              This is used by the function completing sub-commands for the
              system initialisation scripts (residing in /etc/init.d or
              somewhere not too far away from that).  Its values give the
              default commands to complete for those commands for which the
              completion function isn't able to find them out automatically.
              The default for this style are the two strings `start' and
              `stop'.

       complete
              This is used by the _expand_alias function when invoked as a
              bindable command.  If set to `true' and the word on the command
              line is not the name of an alias, matching alias names will be
              completed.

       complete-options
              This is used by the completer for cd, chdir and pushd.  For
              these commands a - is used to introduce a directory stack entry
              and completion of these is far more common than completing
              options.  Hence unless the value of this style is `true' options
              will not be completed, even after an initial -.  If it is
              `true', options will be completed after an initial - unless
              there is a preceding -- on the command line.

       completer
              The strings given as the value of this style provide the names
              of the completer functions to use. The available completer
              functions are described in the section `Control Functions'
              below.

              Each string may be either the name of a completer function or a
              string of the form `function:name'.  In the first case the
              completer field of the context will contain the name of the
              completer without the leading underscore and with all other
              underscores replaced by hyphens.  In the second case the
              function is the name of the completer to call, but the context
              will contain the user-defined name in the completer field of the
              context.  If the name starts with a hyphen, the string for the
              context will be build from the name of the completer function as
              in the first case with the name appended to it.  For example:

                     zstyle ':completion:*' completer _complete _complete:-foo

              Here, completion will call the _complete completer twice, once
              using `complete' and once using `complete-foo' in the completer
              field of the context.  Normally, using the same completer more
              than once only makes sense when used with the `functions:name'
              form, because otherwise the context name will be the same in all
              calls to the completer; possible exceptions to this rule are the
              _ignored and _prefix completers.

              The default value for this style is `_complete _ignored': only
              completion will be done, first using the ignored-patterns style
              and the $fignore array and then without ignoring matches.

       condition
              This style is used by the _list completer function to decide if
              insertion of matches should be delayed unconditionally. The
              default is `true'.

       delimiters
              This style is used when adding a delimiter for use with history
              modifiers or glob qualifiers that have delimited arguments.  It
              is an array of preferred delimiters to add.  Non-special
              characters are preferred as the completion system may otherwise
              become confused.  The default list is :, +, /, -, %.  The list
              may be empty to force a delimiter to be typed.

       disabled
              If this is set to `true', the _expand_alias completer and
              bindable command will try to expand disabled aliases, too.  The
              default is `false'.

       domains
              A list of names of network domains for completion.  If this is
              not set, domain names will be taken from the file
              /etc/resolv.conf.

       environ
              The environ style is used when completing for `sudo'.  It is set
              to an array of `VAR=value' assignments to be exported into the
              local environment before the completion for the target command
              is invoked.
              zstyle ':completion:*:sudo::' environ \
                PATH="/sbin:/usr/sbin:$PATH" HOME="/root"

       expand This style is used when completing strings consisting of
              multiple parts, such as path names.

              If one of its values is the string `prefix', the partially typed
              word from the line will be expanded as far as possible even if
              trailing parts cannot be completed.

              If one of its values is the string `suffix', matching names for
              components after the first ambiguous one will also be added.
              This means that the resulting string is the longest unambiguous
              string possible.  However, menu completion can be used to cycle
              through all matches.

       fake   This style may be set for any completion context.  It specifies
              additional strings that will always be completed in that
              context.  The form of each string is `value:description'; the
              colon and description may be omitted, but any literal colons in
              value must be quoted with a backslash.  Any description provided
              is shown alongside the value in completion listings.

              It is important to use a sufficiently restrictive context when
              specifying fake strings.  Note that the styles fake-files and
              fake-parameters provide additional features when completing
              files or parameters.

       fake-always
              This works identically to the fake style except that the
              ignored-patterns style is not applied to it.  This makes it
              possible to override a set of matches completely by setting the
              ignored patterns to `*'.

              The following shows a way of supplementing any tag with
              arbitrary data, but having it behave for display purposes like a
              separate tag.  In this example we use the features of the
              tag-order style to divide the named-directories tag into two
              when performing completion with the standard completer complete
              for arguments of cd.  The tag named-directories-normal behaves
              as normal, but the tag named-directories-mine contains a fixed
              set of directories.  This has the effect of adding the match
              group `extra directories' with the given completions.

                     zstyle ':completion::complete:cd:*' tag-order \
                       'named-directories:-mine:extra\ directories
                       named-directories:-normal:named\ directories *'
                     zstyle ':completion::complete:cd:*:named-directories-mine' \
                       fake-always mydir1 mydir2
                     zstyle ':completion::complete:cd:*:named-directories-mine' \
                       ignored-patterns '*'

       fake-files
              This style is used when completing files and looked up without a
              tag.  Its values are of the form `dir:names...'.  This will add
              the names (strings separated by spaces) as possible matches when
              completing in the directory dir, even if no such files really
              exist.  The dir may be a pattern; pattern characters or colons
              in dir should be quoted with a backslash to be treated
              literally.

              This can be useful on systems that support special file systems
              whose top-level pathnames can not be listed or generated with
              glob patterns (but see accept-exact-dirs for a more general way
              of dealing with this problem).  It can also be used for
              directories for which one does not have read permission.

              The pattern form can be used to add a certain `magic' entry to
              all directories on a particular file system.

       fake-parameters
              This is used by the completion function for parameter names.
              Its values are names of parameters that might not yet be set but
              should be completed nonetheless.  Each name may also be followed
              by a colon and a string specifying the type of the parameter
              (like `scalar', `array' or `integer').  If the type is given,
              the name will only be completed if parameters of that type are
              required in the particular context.  Names for which no type is
              specified will always be completed.

       file-list
              This style controls whether files completed using the standard
              builtin mechanism are to be listed with a long list similar to
              ls -l.  Note that this feature uses the shell module zsh/stat
              for file information; this loads the builtin stat which will
              replace any external stat executable.  To avoid this the
              following code can be included in an initialization file:

                     zmodload -i zsh/stat
                     disable stat

              The style may either be set to a `true' value (or `all'), or one
              of the values `insert' or `list', indicating that files are to
              be listed in long format in all circumstances, or when
              attempting to insert a file name, or when listing file names
              without attempting to insert one.

              More generally, the value may be an array of any of the above
              values, optionally followed by =num.  If num is present it gives
              the maximum number of matches for which long listing style will
              be used.  For example,

                     zstyle ':completion:*' file-list list=20 insert=10

              specifies that long format will be used when listing up to 20
              files or inserting a file with up to 10 matches (assuming a
              listing is to be shown at all, for example on an ambiguous
              completion), else short format will be used.

                     zstyle -e ':completion:*' file-list \
                            '(( ${+NUMERIC} )) && reply=(true)'

              specifies that long format will be used any time a numeric
              argument is supplied, else short format.

       file-patterns
              This is used by the standard function for completing filenames,
              _files.  If the style is unset up to three tags are offered,
              `globbed-files',`directories' and `all-files', depending on the
              types of files  expected by the caller of _files.  The first two
              (`globbed-files' and `directories') are normally offered
              together to make it easier to complete files in sub-directories.

              The file-patterns style provides alternatives to the default
              tags, which are not used.  Its value consists of elements of the
              form `pattern:tag'; each string may contain any number of such
              specifications separated by spaces.

              The pattern is a pattern that is to be used to generate
              filenames.  Any occurrence of the sequence `%p' is replaced by
              any pattern(s) passed by the function calling _files.  Colons in
              the pattern must be preceded by a backslash to make them
              distinguishable from the colon before the tag.  If more than one
              pattern is needed, the patterns can be given inside braces,
              separated by commas.

              The tags of all strings in the value will be offered by _files
              and used when looking up other styles.  Any tags in the same
              word will be offered at the same time and before later words.
              If no `:tag' is given the `files' tag will be used.

              The tag may also be followed by an optional second colon and a
              description, which will be used for the `%d' in the value of the
              format style (if that is set) instead of the default description
              supplied by the completion function.  If the description given
              here contains itself a `%d', that is replaced with the
              description supplied by the completion function.

              For example, to make the rm command first complete only names of
              object files and then the names of all files if there is no
              matching object file:

                     zstyle ':completion:*:*:rm:*:*' file-patterns \
                         '*.o:object-files' '%p:all-files'

              To alter the default behaviour of file completion -- offer files
              matching a pattern and directories on the first attempt, then
              all files -- to offer only matching files on the first attempt,
              then directories, and finally all files:

                     zstyle ':completion:*' file-patterns \
                         '%p:globbed-files' '*(-/):directories' '*:all-files'

              This works even where there is no special pattern: _files
              matches all files using the pattern `*' at the first step and
              stops when it sees this pattern.  Note also it will never try a
              pattern more than once for a single completion attempt.

              During the execution of completion functions, the EXTENDED_GLOB
              option is in effect, so the characters `#', `~' and `^' have
              special meanings in the patterns.

       file-sort
              The standard filename completion function uses this style
              without a tag to determine in which order the names should be
              listed; menu completion will cycle through them in the same
              order.  The possible values are: `size' to sort by the size of
              the file; `links' to sort by the number of links to the file;
              `modification' (or `time' or `date') to sort by the last
              modification time; `access' to sort by the last access time; and
              `inode' (or `change') to sort by the last inode change time.  If
              the style is set to any other value, or is unset, files will be
              sorted alphabetically by name.  If the value contains the string
              `reverse', sorting is done in the opposite order.  If the value
              contains the string `follow', timestamps are associated with the
              targets of symbolic links; the default is to use the timestamps
              of the links themselves.

       file-split-chars
              A set of characters that will cause all file completions for the
              given context to be split at the point where any of the
              characters occurs.  A typical use is to set the style to :; then
              everything up to and including the last : in the string so far
              is ignored when completing files.  As this is quite
              heavy-handed, it is usually preferable to update completion
              functions for contexts where this behaviour is useful.

       filter The ldap plugin of email address completion (see
              _email_addresses) uses this style to specify the attributes to
              match against when filtering entries.  So for example, if the
              style is set to `sn', matching is done against surnames.
              Standard LDAP filtering is used so normal completion matching is
              bypassed.  If this style is not set, the LDAP plugin is skipped.
              You may also need to set the command style to specify how to
              connect to your LDAP server.

       force-list
              This forces a list of completions to be shown at any point where
              listing is done, even in cases where the list would usually be
              suppressed.  For example, normally the list is only shown if
              there are at least two different matches.  By setting this style
              to `always', the list will always be shown, even if there is
              only a single match that will immediately be accepted.  The
              style may also be set to a number.  In this case the list will
              be shown if there are at least that many matches, even if they
              would all insert the same string.

              This style is tested for the default tag as well as for each tag
              valid for the current completion.  Hence the listing can be
              forced only for certain types of match.

       format If this is set for the descriptions tag, its value is used as a
              string to display above matches in completion lists.  The
              sequence `%d' in this string will be replaced with a short
              description of what these matches are.  This string may also
              contain the output attribute sequences understood by compadd -X
              (see zshcompwid(1)).

              The style is tested with each tag valid for the current
              completion before it is tested for the descriptions tag.  Hence
              different format strings can be defined for different types of
              match.

              Note also that some completer functions define additional
              `%'-sequences.  These are described for the completer functions
              that make use of them.

              Some completion functions display messages that may be
              customised by setting this style for the messages tag.  Here,
              the `%d' is replaced with a message given by the completion
              function.

              Finally, the format string is looked up with the warnings tag,
              for use when no matches could be generated at all.  In this case
              the `%d' is replaced with the descriptions for the matches that
              were expected separated by spaces.  The sequence `%D' is
              replaced with the same descriptions separated by newlines.

              It is possible to use printf-style field width specifiers with
              `%d' and similar escape sequences.  This is handled by the
              zformat builtin command from the zsh/zutil module, see
              zshmodules(1).

       glob   This is used by the _expand completer.  If it is set to `true'
              (the default), globbing will be attempted on the words resulting
              from a previous substitution (see the substitute style) or else
              the original string from the line.

       global If this is set to `true' (the default), the _expand_alias
              completer and bindable command will try to expand global
              aliases.

       group-name
              The completion system can group different types of matches,
              which appear in separate lists.  This style can be used to give
              the names of groups for particular tags.  For example, in
              command position the completion system generates names of
              builtin and external commands, names of aliases, shell functions
              and parameters and reserved words as possible completions.  To
              have the external commands and shell functions listed
              separately:

                     zstyle ':completion:*:*:-command-:*:commands' \
                            group-name commands
                     zstyle ':completion:*:*:-command-:*:functions' \
                            group-name functions

              As a consequence, any match with the same tag will be displayed
              in the same group.

              If the name given is the empty string the name of the tag for
              the matches will be used as the name of the group.  So, to have
              all different types of matches displayed separately, one can
              just set:

                     zstyle ':completion:*' group-name ''

              All matches for which no group name is defined will be put in a
              group named -default-.

       group-order
              This style is additional to the group-name style to specify the
              order for display of the groups defined by that style (compare
              tag-order, which determines which completions appear at all).
              The groups named are shown in the given order; any other groups
              are shown in the order defined by the completion function.

              For example, to have names of builtin commands, shell functions
              and external commands appear in that order when completing in
              command position:

                     zstyle ':completion:*:*:-command-:*:*' group-order \
                            builtins functions commands

       groups A list of names of UNIX groups.  If this is not set, group names
              are taken from the YP database or the file `/etc/group'.

       hidden If this is set to `true', matches for the given context will not
              be listed, although any description for the matches set with the
              format style will be shown.  If it is set to `all', not even the
              description will be displayed.

              Note that the matches will still be completed; they are just not
              shown in the list.  To avoid having matches considered as
              possible completions at all, the tag-order style can be modified
              as described below.

       hosts  A list of names of hosts that should be completed.  If this is
              not set, hostnames are taken from the file `/etc/hosts'.

       hosts-ports
              This style is used by commands that need or accept hostnames and
              network ports.  The strings in the value should be of the form
              `host:port'.  Valid ports are determined by the presence of
              hostnames; multiple ports for the same host may appear.

       ignore-line
              This is tested for each tag valid for the current completion.
              If it is set to `true', none of the words that are already on
              the line will be considered as possible completions.  If it is
              set to `current', the word the cursor is on will not be
              considered as a possible completion.  The value `current-shown'
              is similar but only applies if the list of completions is
              currently shown on the screen.  Finally, if the style is set to
              `other', all words on the line except for the current one will
              be excluded from the possible completions.

              The values `current' and `current-shown' are a bit like the
              opposite of the accept-exact style:  only strings with missing
              characters will be completed.

              Note that you almost certainly don't want to set this to `true'
              or `other' for a general context such as `:completion:*'.  This
              is because it would disallow completion of, for example, options
              multiple times even if the command in question accepts the
              option more than once.

       ignore-parents
              The style is tested without a tag by the function completing
              pathnames in order to determine whether to ignore the names of
              directories already mentioned in the current word, or the name
              of the current working directory.  The value must include one or
              both of the following strings:

              parent The name of any directory whose path is already contained
                     in the word on the line is ignored.  For example, when
                     completing after foo/../, the directory foo will not be
                     considered a valid completion.

              pwd    The name of the current working directory will not be
                     completed; hence, for example, completion after ../ will
                     not use the name of the current directory.

              In addition, the value may include one or both of:

              ..     Ignore the specified directories only when the word on
                     the line contains the substring `../'.

              directory
                     Ignore the specified directories only when names of
                     directories are completed, not when completing names of
                     files.

              Excluded values act in a similar fashion to values of the
              ignored-patterns style, so they can be restored to consideration
              by the _ignored completer.

       extra-verbose
              If set, the completion listing is more verbose at the cost of a
              probable decrease in completion speed.  Completion performance
              will suffer if this style is set to `true'.

       ignored-patterns
              A list of patterns; any trial completion matching one of the
              patterns will be excluded from consideration.  The _ignored
              completer can appear in the list of completers to restore the
              ignored matches.  This is a more configurable version of the
              shell parameter $fignore.

              Note that the EXTENDED_GLOB option is set during the execution
              of completion functions, so the characters `#', `~' and `^' have
              special meanings in the patterns.

       insert This style is used by the _all_matches completer to decide
              whether to insert the list of all matches unconditionally
              instead of adding the list as another match.

       insert-ids
              When completing process IDs, for example as arguments to the
              kill and wait builtins the name of a command may be converted to
              the appropriate process ID.  A problem arises when the process
              name typed is not unique.  By default (or if this style is set
              explicitly to `menu') the name will be converted immediately to
              a set of possible IDs, and menu completion will be started to
              cycle through them.

              If the value of the style is `single', the shell will wait until
              the user has typed enough to make the command unique before
              converting the name to an ID; attempts at completion will be
              unsuccessful until that point.  If the value is any other
              string, menu completion will be started when the string typed by
              the user is longer than the common prefix to the corresponding
              IDs.

       insert-tab
              If this is set to `true', the completion system will insert a
              TAB character (assuming that was used to start completion)
              instead of performing completion when there is no non-blank
              character to the left of the cursor.  If it is set to `false',
              completion will be done even there.

              The value may also contain the substrings `pending' or
              `pending=val'.  In this case, the typed character will be
              inserted instead of starting completion when there is
              unprocessed input pending.  If a val is given, completion will
              not be done if there are at least that many characters of
              unprocessed input.  This is often useful when pasting characters
              into a terminal.  Note however, that it relies on the $PENDING
              special parameter from the zsh/zle module being set properly
              which is not guaranteed on all platforms.

              The default value of this style is `true' except for completion
              within vared builtin command where it is `false'.

       insert-unambiguous
              This is used by the _match and _approximate completers.  These
              completers are often used with menu completion since the word
              typed may bear little resemblance to the final completion.
              However, if this style is `true', the completer will start menu
              completion only if it could find no unambiguous initial string
              at least as long as the original string typed by the user.

              In the case of the _approximate completer, the completer field
              in the context will already have been set to one of correct-num
              or approximate-num, where num is the number of errors that were
              accepted.

              In the case of the _match completer, the style may also be set
              to the string `pattern'.  Then the pattern on the line is left
              unchanged if it does not match unambiguously.

       gain-privileges
              If set to true, this style enables the use of commands like sudo
              or doas to gain extra privileges when retrieving information for
              completion. This is only done when a command such as sudo
              appears on the command-line. To force the use of, e.g. sudo or
              to override any prefix that might be added due to
              gain-privileges, the command style can be used with a value that
              begins with a hyphen.

       keep-prefix
              This style is used by the _expand completer.  If it is `true',
              the completer will try to keep a prefix containing a tilde or
              parameter expansion.  Hence, for example, the string `~/f*'
              would be expanded to `~/foo' instead of `/home/user/foo'.  If
              the style is set to `changed' (the default), the prefix will
              only be left unchanged if there were other changes between the
              expanded words and the original word from the command line.  Any
              other value forces the prefix to be expanded unconditionally.

              The behaviour of _expand when this style is `true' is to cause
              _expand to give up when a single expansion with the restored
              prefix is the same as the original; hence any remaining
              completers may be called.

       last-prompt
              This is a more flexible form of the ALWAYS_LAST_PROMPT option.
              If it is `true', the completion system will try to return the
              cursor to the previous command line after displaying a
              completion list.  It is tested for all tags valid for the
              current completion, then the default tag.  The cursor will be
              moved back to the previous line if this style is `true' for all
              types of match.  Note that unlike the ALWAYS_LAST_PROMPT option
              this is independent of the numeric argument.

       known-hosts-files
              This style should contain a list of files to search for host
              names and (if the use-ip style is set) IP addresses in a format
              compatible with ssh known_hosts files.  If it is not set, the
              files /etc/ssh/ssh_known_hosts and ~/.ssh/known_hosts are used.

       list   This style is used by the _history_complete_word bindable
              command.  If it is set to `true' it has no effect.  If it is set
              to `false' matches will not be listed.  This overrides the
              setting of the options controlling listing behaviour, in
              particular AUTO_LIST.  The context always starts with
              `:completion:history-words'.

       list-colors
              If the zsh/complist module is loaded, this style can be used to
              set color specifications.  This mechanism replaces the use of
              the ZLS_COLORS and ZLS_COLOURS parameters described in the
              section `The zsh/complist Module' in zshmodules(1), but the
              syntax is the same.

              If this style is set for the default tag, the strings in the
              value are taken as specifications that are to be used
              everywhere.  If it is set for other tags, the specifications are
              used only for matches of the type described by the tag.  For
              this to work best, the group-name style must be set to an empty
              string.

              In addition to setting styles for specific tags, it is also
              possible to use group names specified explicitly by the
              group-name tag together with the `(group)' syntax allowed by the
              ZLS_COLORS and ZLS_COLOURS parameters and simply using the
              default tag.

              It is possible to use any color specifications already set up
              for the GNU version of the ls command:

                     zstyle ':completion:*:default' list-colors \
                            ${(s.:.)LS_COLORS}

              The default colors are the same as for the GNU ls command and
              can be obtained by setting the style to an empty string (i.e.
              '').

       list-dirs-first
              This is used by file completion.  If set, directories to be
              completed are listed separately from and before completion for
              other files, regardless of tag ordering.  In addition, the tag
              other-files is used in place of all-files for the remaining
              files, to indicate that no directories are presented with that
              tag.

       list-grouped
              If this style is `true' (the default), the completion system
              will try to make certain completion listings more compact by
              grouping matches.  For example, options for commands that have
              the same description (shown when the verbose style is set to
              `true') will appear as a single entry.  However, menu selection
              can be used to cycle through all the matches.

       list-packed
              This is tested for each tag valid in the current context as well
              as the default tag.  If it is set to `true', the corresponding
              matches appear in listings as if the LIST_PACKED option were
              set.  If it is set to `false', they are listed normally.

       list-prompt
              If this style is set for the default tag, completion lists that
              don't fit on the screen can be scrolled (see the description of
              the zsh/complist module in zshmodules(1)).  The value, if not
              the empty string, will be displayed after every screenful and
              the shell will prompt for a key press; if the style is set to
              the empty string, a default prompt will be used.

              The value may contain the escape sequences: `%l' or `%L', which
              will be replaced by the number of the last line displayed and
              the total number of lines; `%m' or `%M', the number of the  last
              match shown and the total number of matches; and `%p' and `%P',
              `Top' when at the beginning of the list, `Bottom' when at the
              end and the position shown as a percentage of the total length
              otherwise.  In each case the form with the uppercase letter will
              be replaced by a string of fixed width, padded to the  right
              with spaces, while the lowercase form will be replaced by a
              variable width string.  As in other prompt strings, the escape
              sequences `%S', `%s', `%B', `%b', `%U', `%u' for entering and
              leaving the display modes standout, bold and underline, and
              `%F', `%f', `%K', `%k' for changing the foreground background
              colour, are also available, as is the form `%{...%}' for
              enclosing escape sequences which display with zero (or, with a
              numeric argument, some other) width.

              After deleting this prompt the variable LISTPROMPT should be
              unset for the removal to take effect.

       list-rows-first
              This style is tested in the same way as the list-packed style
              and determines whether matches are to be listed in a rows-first
              fashion as if the LIST_ROWS_FIRST option were set.

       list-suffixes
              This style is used by the function that completes filenames.  If
              it is `true', and completion is attempted on a string containing
              multiple partially typed pathname components, all ambiguous
              components will be shown.  Otherwise, completion stops at the
              first ambiguous component.

       list-separator
              The value of this style is used in completion listing to
              separate the string to complete from a description when possible
              (e.g. when completing options).  It defaults to `--' (two
              hyphens).

       local  This is for use with functions that complete URLs for which the
              corresponding files are available directly from the file system.
              Its value should consist of three strings: a hostname, the path
              to the default web pages for the server, and the directory name
              used by a user placing web pages within their home area.

              For example:

                     zstyle ':completion:*' local toast \
                         /var/http/public/toast public_html

              Completion after `http://toast/stuff/' will look for files in
              the directory /var/http/public/toast/stuff,  while completion
              after `http://toast/~yousir/' will look for files in the
              directory ~yousir/public_html.

       mail-directory
              If set, zsh will assume that mailbox files can be found in the
              directory specified.  It defaults to `~/Mail'.

       match-original
              This is used by the _match completer.  If it is set to only,
              _match will try to generate matches without inserting a `*' at
              the cursor position.  If set to any other non-empty value, it
              will first try to generate matches without inserting the `*' and
              if that yields no matches, it will try again with the `*'
              inserted.  If it is unset or set to the empty string, matching
              will only be performed with the `*' inserted.

       matcher
              This style is tested separately for each tag valid in the
              current context.  Its value is placed before any match
              specifications given by the matcher-list style so can override
              them via the use of an x: specification.  The value should be in
              the form described in the section `Completion Matching Control'
              in zshcompwid(1).  For examples of this, see the description of
              the tag-order style.

              For notes comparing the use of this and the matcher-list style,
              see under the description of the tag-order style.

       matcher-list
              This style can be set to a list of match specifications that are
              to be applied everywhere. Match specifications are described in
              the section `Completion Matching Control' in zshcompwid(1).  The
              completion system will try them one after another for each
              completer selected.  For example, to try first simple completion
              and, if that generates no matches, case-insensitive completion:

                     zstyle ':completion:*' matcher-list '' 'm:{a-zA-Z}={A-Za-z}'

              By default each specification replaces the previous one;
              however, if a specification is prefixed with +, it is added to
              the existing list.  Hence it is possible to create increasingly
              general specifications without repetition:

                     zstyle ':completion:*' matcher-list \
                            '' '+m:{a-z}={A-Z}' '+m:{A-Z}={a-z}'

              It is possible to create match specifications valid for
              particular completers by using the third field of the context.
              This applies only to completers that override the global
              matcher-list, which as of this writing includes only _prefix and
              _ignored.  For example, to use the completers _complete and
              _prefix but allow case-insensitive completion only with
              _complete:

                     zstyle ':completion:*' completer _complete _prefix
                     zstyle ':completion:*:complete:*:*:*' matcher-list \
                            '' 'm:{a-zA-Z}={A-Za-z}'

              User-defined names, as explained for the completer style, are
              available.  This makes it possible to try the same completer
              more than once with different match specifications each time.
              For example, to try normal completion without a match
              specification, then normal completion with case-insensitive
              matching, then correction, and finally partial-word completion:

                     zstyle ':completion:*' completer \
                         _complete _correct _complete:foo
                     zstyle ':completion:*:complete:*:*:*' matcher-list \
                         '' 'm:{a-zA-Z}={A-Za-z}'
                     zstyle ':completion:*:foo:*:*:*' matcher-list \
                         'm:{a-zA-Z}={A-Za-z} r:|[-_./]=* r:|=*'

              If the style is unset in any context no match specification is
              applied.  Note also that some completers such as _correct and
              _approximate do not use the match specifications at all, though
              these completers will only ever be called once even if the
              matcher-list contains more than one element.

              Where multiple specifications are useful, note that the entire
              completion is done for each element of matcher-list, which can
              quickly reduce the shell's performance.  As a rough rule of
              thumb, one to three strings will give acceptable performance.
              On the other hand, putting multiple space-separated values into
              the same string does not have an appreciable impact on
              performance.

              If there is no current matcher or it is empty, and the option
              NO_CASE_GLOB is in effect, the matching for files is performed
              case-insensitively in any case.  However, any matcher must
              explicitly specify case-insensitive matching if that is
              required.

              For notes comparing the use of this and the matcher style, see
              under the description of the tag-order style.

       max-errors
              This is used by the _approximate and _correct completer
              functions to determine the maximum number of errors to allow.
              The completer will try to generate completions by first allowing
              one error, then two errors, and so on, until either a match or
              matches were found or the maximum number of errors given by this
              style has been reached.

              If the value for this style contains the string `numeric', the
              completer function will take any numeric argument as the maximum
              number of errors allowed. For example, with

                     zstyle ':completion:*:approximate:::' max-errors 2 numeric

              two errors are allowed if no numeric argument is given, but with
              a numeric argument of six (as in `ESC-6 TAB'), up to six errors
              are accepted.  Hence with a value of `0 numeric', no correcting
              completion will be attempted unless a numeric argument is given.

              If the value contains the string `not-numeric', the completer
              will not try to generate corrected completions when given a
              numeric argument, so in this case the number given should be
              greater than zero.  For example, `2 not-numeric' specifies that
              correcting completion with two errors will usually be performed,
              but if a numeric argument is given, correcting completion will
              not be performed.

              The default value for this style is `2 numeric'.

       max-matches-width
              This style is used to determine the trade off between the width
              of the display used for matches and the width used for their
              descriptions when the verbose style is in effect.  The value
              gives the number of display columns to reserve for the matches.
              The default is half the width of the screen.

              This has the most impact when several matches have the same
              description and so will be grouped together.  Increasing the
              style will allow more matches to be grouped together; decreasing
              it will allow more of the description to be visible.

       menu   If this is `true' in the context of any of the tags defined for
              the current completion menu completion will be used.  The value
              for a specific tag will take precedence over that for the
              `default' tag.

              If none of the values found in this way is `true' but at least
              one is set to `auto', the shell behaves as if the AUTO_MENU
              option is set.

              If one of the values is explicitly set to `false', menu
              completion will be explicitly turned off, overriding the
              MENU_COMPLETE option and other settings.

              In the form `yes=num', where `yes' may be any of the `true'
              values (`yes', `true', `on' and `1'), menu completion will be
              turned on if there are at least num matches.  In the form
              `yes=long', menu completion will be turned on if the list does
              not fit on the screen.  This does not activate menu completion
              if the widget normally only lists completions, but menu
              completion can be activated in that case with the value
              `yes=long-list' (Typically, the value `select=long-list'
              described later is more useful as it provides control over
              scrolling.)

              Similarly, with any of the `false' values (as in `no=10'), menu
              completion will not be used if there are num or more matches.

              The value of this widget also controls menu selection, as
              implemented by the zsh/complist module.  The following values
              may appear either alongside or instead of the values above.

              If the value contains the string `select', menu selection will
              be started unconditionally.

              In the form `select=num', menu selection will only be started if
              there are at least num matches.  If the values for more than one
              tag provide a number, the smallest number is taken.

              Menu selection can be turned off explicitly by defining a value
              containing the string`no-select'.

              It is also possible to start menu selection only if the list of
              matches does not fit on the screen by using the value
              `select=long'.  To start menu selection even if the current
              widget only performs listing, use the value `select=long-list'.

              To turn on menu completion or menu selection when there are a
              certain number of matches or the list of matches does not fit on
              the screen, both of `yes=' and `select=' may be given twice,
              once with a number and once with `long' or `long-list'.

              Finally, it is possible to activate two special modes of menu
              selection.  The word `interactive' in the value causes
              interactive mode to be entered immediately when menu selection
              is started; see the description of the zsh/complist module in
              zshmodules(1) for a description of interactive mode.  Including
              the string `search' does the same for incremental search mode.
              To select backward incremental search, include the string
              `search-backward'.

       muttrc If set, gives the location of the mutt configuration file.  It
              defaults to `~/.muttrc'.

       numbers
              This is used with the jobs tag.  If it is `true', the shell will
              complete job numbers instead of the shortest unambiguous prefix
              of the job command text.  If the value is a number, job numbers
              will only be used if that many words from the job descriptions
              are required to resolve ambiguities.  For example, if the value
              is `1', strings will only be used if all jobs differ in the
              first word on their command lines.

       old-list
              This is used by the _oldlist completer.  If it is set to
              `always', then standard widgets which perform listing will
              retain the current list of matches, however they were generated;
              this can be turned off explicitly with the value `never', giving
              the behaviour without the _oldlist completer.  If the style is
              unset, or any other value, then the existing list of completions
              is displayed if it is not already; otherwise, the standard
              completion list is generated; this is the default behaviour of
              _oldlist.  However, if there is an old list and this style
              contains the name of the completer function that generated the
              list, then the old list will be used even if it was generated by
              a widget which does not do listing.

              For example, suppose you type ^Xc to use the _correct_word
              widget, which generates a list of corrections for the word under
              the cursor.  Usually, typing ^D would generate a standard list
              of completions for the word on the command line, and show that.
              With _oldlist, it will instead show the list of corrections
              already generated.

              As another example consider the _match completer: with the
              insert-unambiguous style set to `true' it inserts only a common
              prefix string, if there is any.  However, this may remove parts
              of the original pattern, so that further completion could
              produce more matches than on the first attempt.  By using the
              _oldlist completer and setting this style to _match, the list of
              matches generated on the first attempt will be used again.

       old-matches
              This is used by the _all_matches completer to decide if an old
              list of matches should be used if one exists.  This is selected
              by one of the `true' values or by the string `only'.  If the
              value is `only', _all_matches will only use an old list and
              won't have any effect on the list of matches currently being
              generated.

              If this style is set it is generally unwise to call the
              _all_matches completer unconditionally.  One possible use is for
              either this style or the completer style to be defined with the
              -e option to zstyle to make the style conditional.

       old-menu
              This is used by the _oldlist completer.  It controls how menu
              completion behaves when a completion has already been inserted
              and the user types a standard completion key such as TAB.  The
              default behaviour of _oldlist is that menu completion always
              continues with the existing list of completions.  If this style
              is set to `false', however, a new completion is started if the
              old list was generated by a different completion command; this
              is the behaviour without the _oldlist completer.

              For example, suppose you type ^Xc to generate a list of
              corrections, and menu completion is started in one of the usual
              ways.  Usually, or with this style set to `false', typing TAB at
              this point would start trying to complete the line as it now
              appears.  With _oldlist, it instead continues to cycle through
              the list of corrections.

       original
              This is used by the _approximate and _correct completers to
              decide if the original string should be added as a possible
              completion.  Normally, this is done only if there are at least
              two possible corrections, but if this style is set to `true', it
              is always added.  Note that the style will be examined with the
              completer field in the context name set to correct-num or
              approximate-num, where num is the number of errors that were
              accepted.

       packageset
              This style is used when completing arguments of the Debian
              `dpkg' program.  It contains an override for the default package
              set for a given context.  For example,

                     zstyle ':completion:*:complete:dpkg:option--status-1:*' \
                                    packageset avail

              causes available packages, rather than only installed packages,
              to be completed for `dpkg --status'.

       path   The function that completes color names uses this style with the
              colors tag.  The value should be the pathname of a file
              containing color names in the format of an X11 rgb.txt file.  If
              the style is not set but this file is found in one of various
              standard locations it will be used as the default.

       path-completion
              This is used by filename completion.  By default, filename
              completion examines all components of a path to see if there are
              completions of that component.  For example, /u/b/z can be
              completed to /usr/bin/zsh.  Explicitly setting this style to
              `false' inhibits this behaviour for path components up to the /
              before the cursor; this overrides the setting of
              accept-exact-dirs.

              Even with the style set to `false', it is still possible to
              complete multiple paths by setting the option COMPLETE_IN_WORD
              and moving the cursor back to the first component in the path to
              be completed.  For example, /u/b/z can be completed to
              /usr/bin/zsh if the cursor is after the /u.

       pine-directory
              If set, specifies the directory containing PINE mailbox files.
              There is no default, since recursively searching this directory
              is inconvenient for anyone who doesn't use PINE.

       ports  A list of Internet service names (network ports) to complete.
              If this is not set, service names are taken from the file
              `/etc/services'.

       prefix-hidden
              This is used for certain completions which share a common
              prefix, for example command options beginning with dashes.  If
              it is `true', the prefix will not be shown in the list of
              matches.

              The default value for this style is `false'.

       prefix-needed
              This style is also relevant for matches with a common prefix.
              If it is set to `true' this common prefix must be typed by the
              user to generate the matches.

              The style is applicable to the options, signals, jobs,
              functions, and parameters completion tags.

              For command options, this means that the initial `-', `+', or
              `--' must be typed explicitly before option names will be
              completed.

              For signals, an initial `-' is required before signal names will
              be completed.

              For jobs, an initial `%' is required before job names will be
              completed.

              For function and parameter names, an initial `_' or `.' is
              required before function or parameter names starting with those
              characters will be completed.

              The default value for this style is `false' for function and
              parameter completions, and  `true' otherwise.

       preserve-prefix
              This style is used when completing path names.  Its value should
              be a pattern matching an initial prefix of the word to complete
              that should be left unchanged under all circumstances.  For
              example, on some Unices an initial `//' (double slash) has a
              special meaning; setting this style to the string `//' will
              preserve it.  As another example, setting this style to `?:/'
              under Cygwin would allow completion after `a:/...' and so on.

       range  This is used by the _history completer and the
              _history_complete_word bindable command to decide which words
              should be completed.

              If it is a single number, only the last N words from the history
              will be completed.

              If it is a range of the form `max:slice', the last slice words
              will be completed; then if that yields no matches, the slice
              words before those will be tried and so on.  This process stops
              either when at least one match has been found, or max words have
              been tried.

              The default is to complete all words from the history at once.

       recursive-files
              If this style is set, its value is an array of patterns to be
              tested against `$PWD/': note the trailing slash, which allows
              directories in the pattern to be delimited unambiguously by
              including slashes on both sides.  If an ordinary file completion
              fails and the word on the command line does not yet have a
              directory part to its name, the style is retrieved using the
              same tag as for the completion just attempted, then the elements
              tested against $PWD/ in turn.  If one matches, then the shell
              reattempts completion by prepending the word on the command line
              with each directory in the expansion of **/*(/) in turn.
              Typically the elements of the style will be set to restrict the
              number of directories beneath the current one to a manageable
              number, for example `*/.git/*'.

              For example,

                     zstyle ':completion:*' recursive-files '*/zsh/*'

              If the current directory is /home/pws/zsh/Src, then zle_trTAB
              can be completed to Zle/zle_tricky.c.

       regular
              This style is used by the _expand_alias completer and bindable
              command.  If set to `true' (the default), regular aliases will
              be expanded but only in command position.  If it is set to
              `false', regular aliases will never be expanded.   If it is set
              to `always', regular aliases will be expanded even if not in
              command position.

       rehash If this is set when completing external commands, the internal
              list (hash) of commands will be updated for each search by
              issuing the rehash command.  There is a speed penalty for this
              which is only likely to be noticeable when directories in the
              path have slow file access.

       remote-access
              If set to `false', certain commands will be prevented from
              making Internet connections to retrieve remote information.
              This includes the completion for the CVS command.

              It is not always possible to know if connections are in fact to
              a remote site, so some may be prevented unnecessarily.

       remove-all-dups
              The _history_complete_word bindable command and the _history
              completer use this to decide if all duplicate matches should be
              removed, rather than just consecutive duplicates.

       select-prompt
              If this is set for the default tag, its value will be displayed
              during menu selection (see the menu style above) when the
              completion list does not fit on the screen as a whole.  The same
              escapes as for the list-prompt style are understood, except that
              the numbers refer to the match or line the mark is on.  A
              default prompt is used when the value is the empty string.

       select-scroll
              This style is tested for the default tag and determines how a
              completion list is scrolled during a menu selection (see the
              menu style above) when the completion list does not fit on the
              screen as a whole.  If the value is `0' (zero), the list is
              scrolled by half-screenfuls; if it is a positive integer, the
              list is scrolled by the given number of lines; if it is a
              negative number, the list is scrolled by a screenful minus the
              absolute value of the given number of lines.  The default is to
              scroll by single lines.

       separate-sections
              This style is used with the manuals tag when completing names of
              manual pages.  If it is `true', entries for different sections
              are added separately using tag names of the form `manual.X',
              where X is the section number.  When the group-name style is
              also in effect, pages from different sections will appear
              separately.  This style is also used similarly with the words
              style when completing words for the dict command. It allows
              words from different dictionary databases to be added
              separately.  The default for this style is `false'.

       show-ambiguity
              If the zsh/complist module is loaded, this style can be used to
              highlight the first ambiguous character in completion lists. The
              value is either a color indication such as those supported by
              the list-colors style or, with a value of `true', a default of
              underlining is selected. The highlighting is only applied if the
              completion display strings correspond to the actual matches.

       show-completer
              Tested whenever a new completer is tried.  If it is `true', the
              completion system outputs a progress message in the listing area
              showing what completer is being tried.  The message will be
              overwritten by any output when completions are found and is
              removed after completion is finished.

       single-ignored
              This is used by the _ignored completer when there is only one
              match.  If its value is `show', the single match will be
              displayed but not inserted.  If the value is `menu', then the
              single match and the original string are both added as matches
              and menu completion is started, making it easy to select either
              of them.

       sort   This allows the standard ordering of matches to be overridden.

              If its value is `true' or `false', sorting is enabled or
              disabled.  Additionally the values associated with the `-o'
              option to compadd can also be listed: match, nosort, numeric,
              reverse.  If it is not set for the context, the standard
              behaviour of the calling widget is used.

              The style is tested first against the full context including the
              tag, and if that fails to produce a value against the context
              without the tag.

              In many cases where a calling widget explicitly selects a
              particular ordering in lieu of the default, a value of `true' is
              not honoured.  An example of where this is not the case is for
              command history where the default of sorting matches
              chronologically may be overridden by setting the style to
              `true'.

              In the _expand completer, if it is set to `true', the expansions
              generated will always be sorted.  If it is set to `menu', then
              the expansions are only sorted when they are offered as single
              strings but not in the string containing all possible
              expansions.

       special-dirs
              Normally, the completion code will not produce the directory
              names `.' and `..' as possible completions.  If this style is
              set to `true', it will add both `.' and `..' as possible
              completions; if it is set to `..', only `..' will be added.

              The following example sets special-dirs to `..' when the current
              prefix is empty, is a single `.', or consists only of a path
              beginning with `../'.  Otherwise the value is `false'.

                     zstyle -e ':completion:*' special-dirs \
                        '[[ $PREFIX = (../)#(|.|..) ]] && reply=(..)'

       squeeze-slashes
              If set to `true', sequences of slashes in filename paths (for
              example in `foo//bar') will be treated as a single slash.  This
              is the usual behaviour of UNIX paths.  However, by default the
              file completion function behaves as if there were a `*' between
              the slashes.

       stop   If set to `true', the _history_complete_word bindable command
              will stop once when reaching the beginning or end of the
              history.  Invoking _history_complete_word will then wrap around
              to the opposite end of the history.  If this style is set to
              `false' (the default), _history_complete_word will loop
              immediately as in a menu completion.

       strip-comments
              If set to `true', this style causes non-essential comment text
              to be removed from completion matches.  Currently it is only
              used when completing e-mail addresses where it removes any
              display name from the addresses, cutting them down to plain
              user@host form.

       subst-globs-only
              This is used by the _expand completer.  If it is set to `true',
              the expansion will only be used if it resulted from globbing;
              hence, if expansions resulted from the use of the substitute
              style described below, but these were not further changed by
              globbing, the expansions will be rejected.

              The default for this style is `false'.

       substitute
              This boolean style controls whether the _expand completer will
              first try to expand all substitutions in the string (such as
              `$(...)' and `${...}').

              The default is `true'.

       suffix This is used by the _expand completer if the word starts with a
              tilde or contains a parameter expansion.  If it is set to
              `true', the word will only be expanded if it doesn't have a
              suffix, i.e. if it is something like `~foo' or `$foo' rather
              than `~foo/' or `$foo/bar', unless that suffix itself contains
              characters eligible for expansion.  The default for this style
              is `true'.

       tag-order
              This provides a mechanism for sorting how the tags available in
              a particular context will be used.

              The values for the style are sets of space-separated lists of
              tags.  The tags in each value will be tried at the same time; if
              no match is found, the next value is used.  (See the
              file-patterns style for an exception to this behavior.)

              For example:

                     zstyle ':completion:*:complete:-command-:*:*' tag-order \
                         'commands functions'

              specifies that completion in command position first offers
              external commands and shell functions.  Remaining tags will be
              tried if no completions are found.

              In addition to tag names, each string in the value may take one
              of the following forms:

              -      If any value consists of only a hyphen, then only the
                     tags specified in the other values are generated.
                     Normally all tags not explicitly selected are tried last
                     if the specified tags fail to generate any matches.  This
                     means that a single value consisting only of a single
                     hyphen turns off completion.

              ! tags...
                     A string starting with an exclamation mark specifies
                     names of tags that are not to be used.  The effect is the
                     same as if all other possible tags for the context had
                     been listed.

              tag:label ...
                     Here, tag is one of the standard tags and label is an
                     arbitrary name.  Matches are generated as normal but the
                     name label is used in contexts instead of tag.  This is
                     not useful in words starting with !.

                     If the label starts with a hyphen, the tag is prepended
                     to the label to form the name used for lookup.  This can
                     be used to make the completion system try a certain tag
                     more than once, supplying different style settings for
                     each attempt; see below for an example.

              tag:label:description
                     As before, but description will replace the `%d' in the
                     value of the format style instead of the default
                     description supplied by the completion function.  Spaces
                     in the description must be quoted with a backslash.  A
                     `%d' appearing in description is replaced with the
                     description given by the completion function.

              In any of the forms above the tag may be a pattern or several
              patterns in the form `{pat1,pat2...}'.  In this case all
              matching tags will be used except for any given explicitly in
              the same string.

              One use of these features is to try one tag more than once,
              setting other styles differently on each attempt, but still to
              use all the other tags without having to repeat them all.  For
              example, to make completion of function names in command
              position ignore all the completion functions starting with an
              underscore the first time completion is tried:

                     zstyle ':completion:*:*:-command-:*:*' tag-order \
                         'functions:-non-comp *' functions
                     zstyle ':completion:*:functions-non-comp' \
                         ignored-patterns '_*'

              On the first attempt, all tags will be offered but the functions
              tag will be replaced by functions-non-comp.  The
              ignored-patterns style is set for this tag to exclude functions
              starting with an underscore.  If there are no matches, the
              second value of the tag-order style is used which completes
              functions using the default tag, this time presumably including
              all function names.

              The matches for one tag can be split into different groups.  For
              example:

                     zstyle ':completion:*' tag-order \
                         'options:-long:long\ options
                          options:-short:short\ options
                          options:-single-letter:single\ letter\ options'
                     zstyle ':completion:*:options-long' \
                          ignored-patterns '[-+](|-|[^-]*)'
                     zstyle ':completion:*:options-short' \
                          ignored-patterns '--*' '[-+]?'
                     zstyle ':completion:*:options-single-letter' \
                          ignored-patterns '???*'

              With the group-names style set, options beginning with `--',
              options beginning with a single `-' or `+' but containing
              multiple characters, and single-letter options will be displayed
              in separate groups with different descriptions.

              Another use of patterns is to try multiple match specifications
              one after another.  The matcher-list style offers something
              similar, but it is tested very early in the completion system
              and hence can't be set for single commands nor for more specific
              contexts.  Here is how to try normal completion without any
              match specification and, if that generates no matches, try again
              with case-insensitive matching, restricting the effect to
              arguments of the command foo:

                     zstyle ':completion:*:*:foo:*:*' tag-order '*' '*:-case'
                     zstyle ':completion:*-case' matcher 'm:{a-z}={A-Z}'

              First, all the tags offered when completing after foo are tried
              using the normal tag name.  If that generates no matches, the
              second value of tag-order is used, which tries all tags again
              except that this time each has -case appended to its name for
              lookup of styles.  Hence this time the value for the matcher
              style from the second call to zstyle in the example is used to
              make completion case-insensitive.

              It is possible to use the -e option of the zstyle builtin
              command to specify conditions for the use of particular tags.
              For example:

                     zstyle -e '*:-command-:*' tag-order '
                         if [[ -n $PREFIX$SUFFIX ]]; then
                           reply=( )
                         else
                           reply=( - )
                         fi'

              Completion in command position will be attempted only if the
              string typed so far is not empty.  This is tested using the
              PREFIX special parameter; see zshcompwid for a description of
              parameters which are special inside completion widgets.  Setting
              reply to an empty array provides the default behaviour of trying
              all tags at once; setting it to an array containing only a
              hyphen disables the use of all tags and hence of all
              completions.

              If no tag-order style has been defined for a context, the
              strings `(|*-)argument-* (|*-)option-* values' and `options'
              plus all tags offered by the completion function will be used to
              provide a sensible default behavior that causes arguments
              (whether normal command arguments or arguments of options) to be
              completed before option names for most commands.

       urls   This is used together with the urls tag by functions completing
              URLs.

              If the value consists of more than one string, or if the only
              string does not name a file or directory, the strings are used
              as the URLs to complete.

              If the value contains only one string which is the name of a
              normal file the URLs are taken from that file (where the URLs
              may be separated by white space or newlines).

              Finally, if the only string in the value names a directory, the
              directory hierarchy rooted at this directory gives the
              completions.  The top level directory should be the file access
              method, such as `http', `ftp', `bookmark' and so on.  In many
              cases the next level of directories will be a filename.  The
              directory hierarchy can descend as deep as necessary.

              For example,

                     zstyle ':completion:*' urls ~/.urls
                     mkdir -p ~/.urls/ftp/ftp.zsh.org/pub

              allows completion of all the components of the URL
              ftp://ftp.zsh.org/pub after suitable commands such as `netscape'
              or `lynx'.  Note, however, that access methods and files are
              completed separately, so if the hosts style is set hosts can be
              completed without reference to the urls style.

              See the description in the function _urls itself for more
              information (e.g. `more $^fpath/_urls(N)').

       use-cache
              If this is set, the completion caching layer is activated for
              any completions which use it (via the _store_cache,
              _retrieve_cache, and _cache_invalid functions).  The directory
              containing the cache files can be changed with the cache-path
              style.

       use-compctl
              If this style is set to a string not equal to false, 0, no, and
              off, the completion system may use any completion specifications
              defined with the compctl builtin command.  If the style is
              unset, this is done only if the zsh/compctl module is loaded.
              The string may also contain the substring `first' to use
              completions defined with `compctl -T', and the substring
              `default' to use the completion defined with `compctl -D'.

              Note that this is only intended to smooth the transition from
              compctl to the new completion system and may disappear in the
              future.

              Note also that the definitions from compctl will only be used if
              there is no specific completion function for the command in
              question.  For example, if there is a function _foo to complete
              arguments to the command foo, compctl will never be invoked for
              foo.  However, the compctl version will be tried if foo only
              uses default completion.

       use-ip By default, the function _hosts that completes host names strips
              IP addresses from entries read from host databases such as NIS
              and ssh files.  If this style is `true', the corresponding IP
              addresses can be completed as well.  This style is not use in
              any context where the hosts style is set; note also it must be
              set before the cache of host names is generated (typically the
              first completion attempt).

       users  This may be set to a list of usernames to be completed.  If it
              is not set all usernames will be completed.  Note that if it is
              set only that list of users will be completed; this is because
              on some systems querying all users can take a prohibitive amount
              of time.

       users-hosts
              The values of this style should be of the form `user@host' or
              `user:host'. It is used for commands that need pairs of user-
              and hostnames.  These commands will complete usernames from this
              style (only), and will restrict subsequent hostname completion
              to hosts paired with that user in one of the values of the
              style.

              It is possible to group values for sets of commands which allow
              a remote login, such as rlogin and ssh, by using the my-accounts
              tag.  Similarly, values for sets of commands which usually refer
              to the accounts of other people, such as talk and finger, can be
              grouped by using the other-accounts tag.  More ambivalent
              commands may use the accounts tag.

       users-hosts-ports
              Like users-hosts but used for commands like telnet and
              containing strings of the form `user@host:port'.

       verbose
              If set, as it is by default, the completion listing is more
              verbose.  In particular many commands show descriptions for
              options if this style is `true'.

       word   This is used by the _list completer, which prevents the
              insertion of completions until a second completion attempt when
              the line has not changed.  The normal way of finding out if the
              line has changed is to compare its entire contents between the
              two occasions.  If this style is `true', the comparison is
              instead performed only on the current word.  Hence if completion
              is performed on another word with the same contents, completion
              will not be delayed.

CONTROL FUNCTIONS
       The initialization script compinit redefines all the widgets which
       perform completion to call the supplied widget function _main_complete.
       This function acts as a wrapper calling the so-called `completer'
       functions that generate matches.  If _main_complete is called with
       arguments, these are taken as the names of completer functions to be
       called in the order given.  If no arguments are given, the set of
       functions to try is taken from the completer style.  For example, to
       use normal completion and correction if that doesn't generate any
       matches:

              zstyle ':completion:*' completer _complete _correct

       after calling compinit. The default value for this style is `_complete
       _ignored', i.e. normally only ordinary completion is tried, first with
       the effect of the ignored-patterns style and then without it.  The
       _main_complete function uses the return status of the completer
       functions to decide if other completers should be called.  If the
       return status is zero, no other completers are tried and the
       _main_complete function returns.

       If the first argument to _main_complete is a single hyphen, the
       arguments will not be taken as names of completers.  Instead, the
       second argument gives a name to use in the completer field of the
       context and the other arguments give a command name and arguments to
       call to generate the matches.

       The following completer functions are contained in the distribution,
       although users may write their own.  Note that in contexts the leading
       underscore is stripped, for example basic completion is performed in
       the context `:completion::complete:...'.

       _all_matches
              This completer can be used to add a string consisting of all
              other matches.  As it influences later completers it must appear
              as the first completer in the list.  The list of all matches is
              affected by the avoid-completer and old-matches styles described
              above.

              It may be useful to use the _generic function described below to
              bind _all_matches to its own keystroke, for example:

                     zle -C all-matches complete-word _generic
                     bindkey '^Xa' all-matches
                     zstyle ':completion:all-matches:*' old-matches only
                     zstyle ':completion:all-matches::::' completer _all_matches

              Note that this does not generate completions by itself:  first
              use any of the standard ways of generating a list of
              completions, then use ^Xa to show all matches.  It is possible
              instead to add a standard completer to the list and request that
              the list of all matches should be directly inserted:

                     zstyle ':completion:all-matches::::' completer \
                            _all_matches _complete
                     zstyle ':completion:all-matches:*' insert true

              In this case the old-matches style should not be set.

       _approximate
              This is similar to the basic _complete completer but allows the
              completions to undergo corrections.  The maximum number of
              errors can be specified by the max-errors style; see the
              description of approximate matching in zshexpn(1) for how errors
              are counted.  Normally this completer will only be tried after
              the normal _complete completer:

                     zstyle ':completion:*' completer _complete _approximate

              This will give correcting completion if and only if normal
              completion yields no possible completions.  When corrected
              completions are found, the completer will normally start menu
              completion allowing you to cycle through these strings.

              This completer uses the tags corrections and original when
              generating the possible corrections and the original string.
              The format style for the former may contain the additional
              sequences `%e' and `%o' which will be replaced by the number of
              errors accepted to generate the corrections and the original
              string, respectively.

              The completer progressively increases the number of errors
              allowed up to the limit by the max-errors style, hence if a
              completion is found with one error, no completions with two
              errors will be shown, and so on.  It modifies the completer name
              in the context to indicate the number of errors being tried: on
              the first try the completer field contains `approximate-1', on
              the second try `approximate-2', and so on.

              When _approximate is called from another function, the number of
              errors to accept may be passed with the -a option.  The argument
              is in the same format as the max-errors style, all in one
              string.

              Note that this completer (and the _correct completer mentioned
              below) can be quite expensive to call, especially when a large
              number of errors are allowed.  One way to avoid this is to set
              up the completer style using the -e option to zstyle so that
              some completers are only used when completion is attempted a
              second time on the same string, e.g.:

                     zstyle -e ':completion:*' completer '
                       if [[ $_last_try != "$HISTNO$BUFFER$CURSOR" ]]; then
                         _last_try="$HISTNO$BUFFER$CURSOR"
                         reply=(_complete _match _prefix)
                       else
                         reply=(_ignored _correct _approximate)
                       fi'

              This uses the HISTNO parameter and the BUFFER and CURSOR special
              parameters that are available inside zle and completion widgets
              to find out if the command line hasn't changed since the last
              time completion was tried.  Only then are the _ignored, _correct
              and _approximate completers called.

       _canonical_paths [ -A var ] [ -N ] [ -MJV12nfX ] tag descr [ paths ...
       ]
              This completion function completes all paths given to it, and
              also tries to offer completions which point to the same file as
              one of the paths given (relative path when an absolute path is
              given, and vice versa; when ..'s are present in the word to be
              completed; and some paths got from symlinks).

              -A, if specified, takes the paths from the array variable
              specified. Paths can also be specified on the command line as
              shown above.  -N, if specified, prevents canonicalizing the
              paths given before using them for completion, in case they are
              already so. The options -M, -J, -V, -1, -2, -n, -F, -X are
              passed to compadd.

              See _description for a description of tag and descr.

       _cmdambivalent
              Completes the remaining positional arguments as an external
              command.  The external command and its arguments are completed
              as separate arguments (in a manner appropriate for completing
              /usr/bin/env) if there are two or more remaining positional
              arguments on the command line, and as a quoted command string
              (in the manner of system(...)) otherwise.  See also _cmdstring
              and _precommand.

              This function takes no arguments.

       _cmdstring
              Completes an external command as a single argument, as for
              system(...).

       _complete
              This completer generates all possible completions in a
              context-sensitive manner, i.e. using the settings defined with
              the compdef function explained above and the current settings of
              all special parameters.  This gives the normal completion
              behaviour.

              To complete arguments of commands, _complete uses the utility
              function _normal, which is in turn responsible for finding the
              particular function; it is described below.  Various contexts of
              the form -context- are handled specifically. These are all
              mentioned above as possible arguments to the #compdef tag.

              Before trying to find a function for a specific context,
              _complete checks if the parameter `compcontext' is set. Setting
              `compcontext' allows the usual completion dispatching to be
              overridden which is useful in places such as a function that
              uses vared for input. If it is set to an array, the elements are
              taken to be the possible matches which will be completed using
              the tag `values' and the description `value'. If it is set to an
              associative array, the keys are used as the possible completions
              and the values (if non-empty) are used as descriptions for the
              matches.  If `compcontext' is set to a string containing colons,
              it should be of the form `tag:descr:action'.  In this case the
              tag and descr give the tag and description to use and the action
              indicates what should be completed in one of the forms accepted
              by the _arguments utility function described below.

              Finally, if `compcontext' is set to a string without colons, the
              value is taken as the name of the context to use and the
              function defined for that context will be called.  For this
              purpose, there is a special context named -command-line- that
              completes whole command lines (commands and their arguments).
              This is not used by the completion system itself but is
              nonetheless handled when explicitly called.

       _correct
              Generate corrections, but not completions, for the current word;
              this is similar to _approximate but will not allow any number of
              extra characters at the cursor as that completer does.  The
              effect is similar to spell-checking.  It is based on
              _approximate, but the completer field in the context name is
              correct.

              For example, with:

                     zstyle ':completion:::::' completer \
                            _complete _correct _approximate
                     zstyle ':completion:*:correct:::' max-errors 2 not-numeric
                     zstyle ':completion:*:approximate:::' max-errors 3 numeric

              correction will accept up to two errors.  If a numeric argument
              is given, correction will not be performed, but correcting
              completion will be, and will accept as many errors as given by
              the numeric argument.  Without a numeric argument, first
              correction and then correcting completion will be tried, with
              the first one accepting two errors and the second one accepting
              three errors.

              When _correct is called as a function, the number of errors to
              accept may be given following the -a option.  The argument is in
              the same form a values to the accept style, all in one string.

              This completer function is intended to be used without the
              _approximate completer or, as in the example, just before it.
              Using it after the _approximate completer is useless since
              _approximate will at least generate the corrected strings
              generated by the _correct completer -- and probably more.

       _expand
              This completer function does not really perform completion, but
              instead checks if the word on the command line is eligible for
              expansion and, if it is, gives detailed control over how this
              expansion is done.  For this to happen, the completion system
              needs to be invoked with complete-word, not expand-or-complete
              (the default binding for TAB), as otherwise the string will be
              expanded by the shell's internal mechanism before the completion
              system is started.  Note also this completer should be called
              before the _complete completer function.

              The tags used when generating expansions are all-expansions for
              the string containing all possible expansions, expansions when
              adding the possible expansions as single matches and original
              when adding the original string from the line.  The order in
              which these strings are generated, if at all, can be controlled
              by the group-order and tag-order styles, as usual.

              The format string for all-expansions and for expansions may
              contain the sequence `%o' which will be replaced by the original
              string from the line.

              The kind of expansion to be tried is controlled by the
              substitute, glob and subst-globs-only styles.

              It is also possible to call _expand as a function, in which case
              the different modes may be selected with options: -s for
              substitute, -g for glob and -o for subst-globs-only.

       _expand_alias
              If the word the cursor is on is an alias, it is expanded and no
              other completers are called.  The types of aliases which are to
              be expanded can be controlled with the styles regular, global
              and disabled.

              This function is also a bindable command, see the section
              `Bindable Commands' below.

       _extensions
              If the cursor follows the string `*.', filename extensions are
              completed. The extensions are taken from files in current
              directory or a directory specified at the beginning of the
              current word. For exact matches, completion continues to allow
              other completers such as _expand to expand the pattern. The
              standard add-space and prefix-hidden styles are observed.

       _external_pwds
              Completes current directories of other zsh processes belonging
              to the current user.

              This is intended to be used via _generic, bound to a custom key
              combination. Note that pattern matching is enabled so matching
              is performed similar to how it works with the _match completer.

       _history
              Complete words from the shell's command  history.  This
              completer can be controlled by the remove-all-dups, and sort
              styles as for the _history_complete_word bindable command, see
              the section `Bindable Commands' below and the section
              `Completion System Configuration' above.

       _ignored
              The ignored-patterns style can be set to a list of patterns
              which are compared against possible completions; matching ones
              are removed.  With this completer those matches can be
              reinstated, as if no ignored-patterns style were set.  The
              completer actually generates its own list of matches; which
              completers are invoked is determined in the same way as for the
              _prefix completer.  The single-ignored style is also available
              as described above.

       _list  This completer allows the insertion of matches to be delayed
              until completion is attempted a second time without the word on
              the line being changed.  On the first attempt, only the list of
              matches will be shown.  It is affected by the styles condition
              and word, see the section `Completion System Configuration'
              above.

       _match This completer is intended to be used after the _complete
              completer.  It behaves similarly but the string on the command
              line may be a pattern to match against trial completions.  This
              gives the effect of the GLOB_COMPLETE option.

              Normally completion will be performed by taking the pattern from
              the line, inserting a `*' at the cursor position and comparing
              the resulting pattern with the possible completions generated.
              This can be modified with the match-original style described
              above.

              The generated matches will be offered in a menu completion
              unless the insert-unambiguous style is set to `true'; see the
              description above for other options for this style.

              Note that matcher specifications defined globally or used by the
              completion functions (the styles matcher-list and matcher) will
              not be used.

       _menu  This completer was written as simple example function to show
              how menu completion can be enabled in shell code. However, it
              has the notable effect of disabling menu selection which can be
              useful with _generic based widgets. It should be used as the
              first completer in the list.  Note that this is independent of
              the setting of the MENU_COMPLETE option and does not work with
              the other menu completion widgets such as reverse-menu-complete,
              or accept-and-menu-complete.

       _oldlist
              This completer controls how the standard completion widgets
              behave when there is an existing list of completions which may
              have been generated by a special completion (i.e. a
              separately-bound completion command).  It allows the ordinary
              completion keys to continue to use the list of completions thus
              generated, instead of producing a new list of ordinary
              contextual completions.  It should appear in the list of
              completers before any of the widgets which generate matches.  It
              uses two styles: old-list and old-menu, see the section
              `Completion System Configuration' above.

       _precommand
              Complete an external command in word-separated arguments, as for
              exec and /usr/bin/env.

       _prefix
              This completer can be used to try completion with the suffix
              (everything after the cursor) ignored.  In other words, the
              suffix will not be considered to be part of the word to
              complete.  The effect is similar to the
              expand-or-complete-prefix command.

              The completer style is used to decide which other completers are
              to be called to generate matches.  If this style is unset, the
              list of completers set for the current context is used --
              except, of course, the _prefix completer itself.  Furthermore,
              if this completer appears more than once in the list of
              completers only those completers not already tried by the last
              invocation of _prefix will be called.

              For example, consider this global completer style:

                     zstyle ':completion:*' completer \
                         _complete _prefix _correct _prefix:foo

              Here, the _prefix completer tries normal completion but ignoring
              the suffix.  If that doesn't generate any matches, and neither
              does the call to the _correct completer after it, _prefix will
              be called a second time and, now only trying correction with the
              suffix ignored.  On the second invocation the completer part of
              the context appears as `foo'.

              To use _prefix as the last resort and try only normal completion
              when it is invoked:

                     zstyle ':completion:*' completer _complete ... _prefix
                     zstyle ':completion::prefix:*' completer _complete

              The add-space style is also respected.  If it is set to `true'
              then _prefix will insert a space between the matches generated
              (if any) and the suffix.

              Note that this completer is only useful if the COMPLETE_IN_WORD
              option is set; otherwise, the cursor will be moved to the end of
              the current word before the completion code is called and hence
              there will be no suffix.

       _user_expand
              This completer behaves similarly to the _expand completer but
              instead performs expansions defined by users.  The styles
              add-space and sort styles specific to the _expand completer are
              usable with _user_expand in addition to other styles handled
              more generally by the completion system.  The tag all-expansions
              is also available.

              The expansion depends on the array style user-expand being
              defined for the current context; remember that the context for
              completers is less specific than that for contextual completion
              as the full context has not yet been determined.  Elements of
              the array may have one of the following forms:

              $hash

                     hash is the name of an associative array.  Note this is
                     not a full parameter expression, merely a $, suitably
                     quoted to prevent immediate expansion, followed by the
                     name of an associative array.  If the trial expansion
                     word matches a key in hash, the resulting expansion is
                     the corresponding value.
              _func

                     _func is the name of a shell function whose name must
                     begin with _ but is not otherwise special to the
                     completion system.  The function is called with the trial
                     word as an argument.  If the word is to be expanded, the
                     function should set the array reply to a list of
                     expansions.  Optionally, it can set REPLY to a word that
                     will be used as a description for the set of expansions.
                     The return status of the function is irrelevant.
BINDABLE COMMANDS
       In addition to the context-dependent completions provided, which are
       expected to work in an intuitively obvious way, there are a few widgets
       implementing special behaviour which can be bound separately to keys.
       The following is a list of these and their default bindings.

       _bash_completions
              This function is used by two widgets, _bash_complete-word and
              _bash_list-choices.  It exists to provide compatibility with
              completion bindings in bash.  The last character of the binding
              determines what is completed: `!', command names; `$',
              environment variables; `@', host names; `/', file names; `~'
              user names.  In bash, the binding preceded by `\e' gives
              completion, and preceded by `^X' lists options.  As some of
              these bindings clash with standard zsh bindings, only `\e~' and
              `^X~' are bound by default.  To add the rest, the following
              should be added to .zshrc after compinit has been run:

                     for key in '!' '$' '@' '/' '~'; do
                       bindkey "\e$key" _bash_complete-word
                       bindkey "^X$key" _bash_list-choices
                     done

              This includes the bindings for `~' in case they were already
              bound to something else; the completion code does not override
              user bindings.

       _correct_filename (^XC)
              Correct the filename path at the cursor position.  Allows up to
              six errors in the name.  Can also be called with an argument to
              correct a filename path, independently of zle; the correction is
              printed on standard output.

       _correct_word (^Xc)
              Performs correction of the current argument using the usual
              contextual completions as possible choices. This stores the
              string `correct-word' in the function field of the context name
              and then calls the _correct completer.

       _expand_alias (^Xa)
              This function can be used as a completer and as a bindable
              command.  It expands the word the cursor is on if it is an
              alias.  The types of alias expanded can be controlled with the
              styles regular, global and disabled.

              When used as a bindable command there is one additional feature
              that can be selected by setting the complete style to `true'.
              In this case, if the word is not the name of an alias,
              _expand_alias tries to complete the word to a full alias name
              without expanding it.  It leaves the cursor directly after the
              completed word so that invoking _expand_alias once more will
              expand the now-complete alias name.

       _expand_word (^Xe)
              Performs expansion on the current word:  equivalent to the
              standard expand-word command, but using the _expand completer.
              Before calling it, the function field of the context is set to
              `expand-word'.

       _generic
              This function is not defined as a widget and not bound by
              default.  However, it can be used to define a widget and will
              then store the name of the widget in the function field of the
              context and call the completion system.  This allows custom
              completion widgets with their own set of style settings to be
              defined easily.  For example, to define a widget that performs
              normal completion and starts menu selection:

                     zle -C foo complete-word _generic
                     bindkey '...' foo
                     zstyle ':completion:foo:*' menu yes select=1

              Note in particular that the completer style may be set for the
              context in order to change the set of functions used to generate
              possible matches.  If _generic is called with arguments, those
              are passed through to _main_complete as the list of completers
              in place of those defined by the completer style.

       _history_complete_word (\e/)
              Complete words from the shell's command history. This uses the
              list, remove-all-dups, sort, and stop styles.

       _most_recent_file (^Xm)
              Complete the name of the most recently modified file matching
              the pattern on the command line (which may be blank).  If given
              a numeric argument N, complete the Nth most recently modified
              file.  Note the completion, if any, is always unique.

       _next_tags (^Xn)
              This command alters the set of matches used to that for the next
              tag, or set of tags, either as given by the tag-order style or
              as set by default; these matches would otherwise not be
              available.  Successive invocations of the command cycle through
              all possible sets of tags.

       _read_comp (^X^R)
              Prompt the user for a string, and use that to perform completion
              on the current word.  There are two possibilities for the
              string.  First, it can be a set of words beginning `_', for
              example `_files -/', in which case the function with any
              arguments will be called to generate the completions.
              Unambiguous parts of the function name will be completed
              automatically (normal completion is not available at this point)
              until a space is typed.

              Second, any other string will be passed as a set of arguments to
              compadd and should hence be an expression specifying what should
              be completed.

              A very restricted set of editing commands is available when
              reading the string:  `DEL' and `^H' delete the last character;
              `^U' deletes the line, and `^C' and `^G' abort the function,
              while `RET' accepts the completion.  Note the string is used
              verbatim as a command line, so arguments must be quoted in
              accordance with standard shell rules.

              Once a string has been read, the next call to _read_comp will
              use the existing string instead of reading a new one.  To force
              a new string to be read, call _read_comp with a numeric
              argument.

       _complete_debug (^X?)
              This widget performs ordinary completion, but captures in a
              temporary file a trace of the shell commands executed by the
              completion system.  Each completion attempt gets its own file.
              A command to view each of these files is pushed onto the editor
              buffer stack.

       _complete_help (^Xh)
              This widget displays information about the context names, the
              tags, and the completion functions used when completing at the
              current cursor position. If given a numeric argument other than
              1 (as in `ESC-2 ^Xh'), then the styles used and the contexts for
              which they are used will be shown, too.

              Note that the information about styles may be incomplete; it
              depends on the information available from the completion
              functions called, which in turn is determined by the user's own
              styles and other settings.

       _complete_help_generic
              Unlike other commands listed here, this must be created as a
              normal ZLE widget rather than a completion widget (i.e. with zle
              -N).  It is used for generating help with a widget bound to the
              _generic widget that is described above.

              If this widget is created using the name of the function, as it
              is by default, then when executed it will read a key sequence.
              This is expected to be bound to a call to a completion function
              that uses the _generic widget.  That widget will be executed,
              and information provided in the same format that the
              _complete_help widget displays for contextual completion.

              If the widget's name contains debug, for example if it is
              created as `zle -N _complete_debug_generic
              _complete_help_generic', it will read and execute the keystring
              for a generic widget as before, but then generate debugging
              information as done by _complete_debug for contextual
              completion.

              If the widget's name contains noread, it will not read a
              keystring but instead arrange that the next use of a generic
              widget run in the same shell will have the effect as described
              above.

              The widget works by setting the shell parameter
              ZSH_TRACE_GENERIC_WIDGET which is read by _generic.  Unsetting
              the parameter cancels any pending effect of the noread form.

              For example, after executing the following:

                     zle -N _complete_debug_generic _complete_help_generic
                     bindkey '^x:' _complete_debug_generic

              typing `C-x :' followed by the key sequence for a generic widget
              will cause trace output for that widget to be saved to a file.

       _complete_tag (^Xt)
              This widget completes symbol tags created by the etags or ctags
              programmes (note there is no connection with the completion
              system's tags) stored in a file TAGS, in the format used by
              etags, or tags, in the format created by ctags.  It will look
              back up the path hierarchy for the first occurrence of either
              file; if both exist, the file TAGS is preferred.  You can
              specify the full path to a TAGS or tags file by setting the
              parameter $TAGSFILE or $tagsfile respectively.  The
              corresponding completion tags used are etags and vtags, after
              emacs and vi respectively.

UTILITY FUNCTIONS
       Descriptions follow for utility functions that may be useful when
       writing completion functions.  If functions are installed in
       subdirectories, most of these reside in the Base subdirectory.  Like
       the example functions for commands in the distribution, the utility
       functions generating matches all follow the convention of returning
       status zero if they generated completions and non-zero if no matching
       completions could be added.

       _absolute_command_paths
              This function completes external commands as absolute paths
              (unlike _command_names -e which completes their basenames).  It
              takes no arguments.

       _all_labels [ -x ] [ -12VJ ] tag name descr [ command arg ... ]
              This is a convenient interface to the _next_label function
              below, implementing the loop shown in the _next_label example.
              The command and its arguments are called to generate the
              matches.  The options stored in the parameter name will
              automatically be inserted into the args passed to the command.
              Normally, they are put directly after the command, but if one of
              the args is a single hyphen, they are inserted directly before
              that.  If the hyphen is the last argument, it will be removed
              from the argument list before the command is called.  This
              allows _all_labels to be used in almost all cases where the
              matches can be generated by a single call to the compadd builtin
              command or by a call to one of the utility functions.

              For example:

                     local expl
                     ...
                     if _requested foo; then
                       ...
                       _all_labels foo expl '...' compadd ... - $matches
                     fi

              Will complete the strings from the matches parameter, using
              compadd with additional options which will take precedence over
              those generated by _all_labels.

       _alternative [ -O name ] [ -C name ] spec ...
              This function is useful in simple cases where multiple tags are
              available.  Essentially it implements a loop like the one
              described for the _tags function below.

              The tags to use and the action to perform if a tag is requested
              are described using the specs which are of the form:
              `tag:descr:action'.  The tags are offered using _tags and if the
              tag is requested, the action is executed with the given
              description descr.  The actions are those accepted by the
              _arguments function (described below), excluding the `->state'
              and `=...' forms.

              For example, the action may be a simple function call:

                     _alternative \
                         'users:user:_users' \
                         'hosts:host:_hosts'

              offers usernames and hostnames as possible matches, generated by
              the _users and _hosts functions respectively.

              Like _arguments, this function uses _all_labels to execute the
              actions, which will loop over all sets of tags.  Special
              handling is only required if there is an additional valid tag,
              for example inside a function called from _alternative.

              The option `-O name' is used in the same way as by the
              _arguments function.  In other words, the elements of the name
              array will be passed to compadd when executing an action.