show

SHOW(1)                             [nmh-1.5]                            SHOW(1)



NAME
       show - show (display) messages

SYNOPSIS
       show [+folder] [msgs] [-draft] [-showproc program] [-showmimeproc
            program] [-header | -noheader] [-checkmime | -nocheckmime]
            [switches for showproc or showmimeproc] [-version] [-help]

DESCRIPTION
       Show lists each of the specified messages to the standard output
       (typically, the terminal).

       By default, text (non-MIME) messages are filtered and displayed by the
       nmh command mhl.  This command will display text messages in a nice,
       uniform format.  It also allows you to configure the format of the
       displayed messages and which headers fields are shown.  See the mhl(1)
       manual page for the details about this command.  This default can be
       changed by defining the showproc profile component.  Any switches not
       recognized by show are passed along to that program.  To override the
       default and the showproc profile component, use the -showproc program
       switch.  For example, -showproc more will cause the more program to list
       the messages with no reformatting.  Normally, this program is specified
       as the showproc in the user's .mh_profile, rather than using a command
       line switch.

       By default, non-text messages (MIME messages with multi-media contents)
       are processed and displayed by the nmh command mhshow.  See the mhshow(1)
       manual page for details about this command.  This default can changed by
       defining the showmimeproc profile component.  Any switches not recognized
       by show are passed along to that program.  To override this default and
       the showmimeproc profile component, use the -showmimeproc program switch.

       Note that in some cases, show may invoke the showmimeproc even for
       textual contents.  This will happen for text messages that specify a
       transfer encoding (such as MIME quoted-printable or base64) or specify a
       character set that show doesn't believe can be displayed natively.  The
       environment variable $MM_CHARSET should be set to the terminal's native
       character set to avoid gratuitous invocations of the showmimeproc.  See
       the mh-profile(5) man page for details about this environment variable.

       The option -checkmime (set by default) instructs show to test if any of
       the messages to be displayed are non-text (MIME) messages.  If any are
       non-text, they are displayed by the program showmimeproc, else they are
       displayed by the program showproc.  The option -nocheckmime disables this
       test and instructs show to use showproc, regardless of whether any of the
       messages are non-text (MIME) messages.

       The -noshowproc switch will disable any formatting or paging of messages.
       It is equivalent to -nocheckmime -showproc cat.  It is still accepted,
       but should be considered (somewhat) obsolete.

       If the environment variable $NOMHNPROC is set, the test for non-text
       (MIME) messages will be disabled.  This method is obsolete.  Use the
       -nocheckmime switch instead.

       The -header switch tells show to display a one-line description of the
       message being shown.  This description includes the folder and the
       message number.

       If no `msgs' are specified, the current message is used.  Although it
       depends on the specific showproc or showmimeproc, in the default setup
       when more than one message is specified, you will be prompted for a
       <RETURN> prior to listing each message.  Each message will be listed a
       page at a time, and when the end of page is reached, the program will
       wait for a <SPACE> or <RETURN>.  If a <RETURN> is entered, it will print
       the next line, whereas <SPACE> will print the next screenful.

       If the standard output is not a terminal, no queries are made, and each
       file is listed with a one-line header and two lines of separation.

       “show -draft” will list the file <mh-dir>/draft if it exists.

       If the profile entry “Unseen-Sequence” is present and non-empty, then
       show will remove each of the messages shown from each sequence named by
       the profile entry.


FILES
       $HOME/.mh_profile          The user profile


PROFILE COMPONENTS
       Path:                To determine the user's nmh directory
       Current-Folder:      To find the default current folder
       Unseen-Sequence:     To name sequences denoting unseen messages
       showproc:            Program to show text (non-MIME) messages
       showmimeproc:        Program to show non-text (MIME) messages


SEE ALSO
       mhl(1), mhshow(1), more(1), next(1), prev(1), scan(1)


DEFAULTS
       `+folder' defaults to the current folder
       `msgs' defaults to cur
       `-checkmime'
       `-header'


CONTEXT
       If a folder is given, it will become the current folder.  The last
       message selected will become the current message.


BUGS
       The -header switch doesn't work when `msgs' expands to more than one
       message.  If the showproc is mhl, then this problem can be circumvented
       by referencing the “messagename” field in the mhl format file.

       Show updates the user's context before showing the message.  Hence show
       will mark messages as seen prior to the user actually seeing them.  This
       is generally not a problem, unless the user relies on the “unseen”
       messages mechanism, and interrupts show while it is showing “unseen”
       messages.

       If your showproc is mhl (the default), then show uses a built-in mhl: it
       does not actually run the mhl program.  Hence, if you define your own
       showproc , don't call it mhl since show won't run it.

       If your showproc is the pager more, then avoid running show in the
       background with only its standard output piped to another process, as in

            show | imprint &

       Due to a bug in more, show will go into a “tty input” state.  To avoid
       this problem, re-direct show's diagnostic output as well.  For users of
       csh:

            show |& imprint &

       For users of sh:

            show 2>&1 | imprint &



MH.6.8                            11 June 2012                           SHOW(1)