unzip

UNZIP(1L)                                                              UNZIP(1L)



NAME
       unzip - list, test and extract compressed files in a ZIP archive

SYNOPSIS
       unzip [-Z] [-cflptTuvz[abjnoqsCDKLMUVWX$/:^]] file[.zip] [file(s) ...]
       [-x xfile(s) ...] [-d exdir]

DESCRIPTION
       unzip will list, test, or extract files from a ZIP archive, commonly
       found on MS-DOS systems.  The default behavior (with no options) is to
       extract into the current directory (and subdirectories below it) all
       files from the specified ZIP archive.  A companion program, zip(1L),
       creates ZIP archives; both programs are compatible with archives created
       by PKWARE's PKZIP and PKUNZIP for MS-DOS, but in many cases the program
       options or default behaviors differ.

ARGUMENTS
       file[.zip]
              Path of the ZIP archive(s).  If the file specification is a
              wildcard, each matching file is processed in an order determined
              by the operating system (or file system).  Only the filename can
              be a wildcard; the path itself cannot.  Wildcard expressions are
              similar to those supported in commonly used Unix shells (sh, ksh,
              csh) and may contain:

              *      matches a sequence of 0 or more characters

              ?      matches exactly 1 character

              [...]  matches any single character found inside the brackets;
                     ranges are specified by a beginning character, a hyphen,
                     and an ending character.  If an exclamation point or a
                     caret (`!' or `^') follows the left bracket, then the range
                     of characters within the brackets is complemented (that is,
                     anything except the characters inside the brackets is
                     considered a match).  To specify a verbatim left bracket,
                     the three-character sequence ``[[]'' has to be used.

              (Be sure to quote any character that might otherwise be
              interpreted or modified by the operating system, particularly
              under Unix and VMS.)  If no matches are found, the specification
              is assumed to be a literal filename; and if that also fails, the
              suffix .zip is appended.  Note that self-extracting ZIP files are
              supported, as with any other ZIP archive; just specify the .exe
              suffix (if any) explicitly.

       [file(s)]
              An optional list of archive members to be processed, separated by
              spaces.  (VMS versions compiled with VMSCLI defined must delimit
              files with commas instead.  See -v in OPTIONS below.)  Regular
              expressions (wildcards) may be used to match multiple members; see
              above.  Again, be sure to quote expressions that would otherwise
              be expanded or modified by the operating system.

       [-x xfile(s)]
              An optional list of archive members to be excluded from
              processing.  Since wildcard characters normally match (`/')
              directory separators (for exceptions see the option -W), this
              option may be used to exclude any files that are in
              subdirectories.  For example, ``unzip foo *.[ch] -x */*'' would
              extract all C source files in the main directory, but none in any
              subdirectories.  Without the -x option, all C source files in all
              directories within the zipfile would be extracted.

       [-d exdir]
              An optional directory to which to extract files.  By default, all
              files and subdirectories are recreated in the current directory;
              the -d option allows extraction in an arbitrary directory (always
              assuming one has permission to write to the directory).  This
              option need not appear at the end of the command line; it is also
              accepted before the zipfile specification (with the normal
              options), immediately after the zipfile specification, or between
              the file(s) and the -x option.  The option and directory may be
              concatenated without any white space between them, but note that
              this may cause normal shell behavior to be suppressed.  In
              particular, ``-d ~'' (tilde) is expanded by Unix C shells into the
              name of the user's home directory, but ``-d~'' is treated as a
              literal subdirectory ``~'' of the current directory.

OPTIONS
       Note that, in order to support obsolescent hardware, unzip's usage screen
       is limited to 22 or 23 lines and should therefore be considered only a
       reminder of the basic unzip syntax rather than an exhaustive list of all
       possible flags.  The exhaustive list follows:

       -Z     zipinfo(1L) mode.  If the first option on the command line is -Z,
              the remaining options are taken to be zipinfo(1L) options.  See
              the appropriate manual page for a description of these options.

       -A     [OS/2, Unix DLL] print extended help for the DLL's programming
              interface (API).

       -c     extract files to stdout/screen (``CRT'').  This option is similar
              to the -p option except that the name of each file is printed as
              it is extracted, the -a option is allowed, and ASCII-EBCDIC
              conversion is automatically performed if appropriate.  This option
              is not listed in the unzip usage screen.

       -f     freshen existing files, i.e., extract only those files that
              already exist on disk and that are newer than the disk copies.  By
              default unzip queries before overwriting, but the -o option may be
              used to suppress the queries.  Note that under many operating
              systems, the TZ (timezone) environment variable must be set
              correctly in order for -f and -u to work properly (under Unix the
              variable is usually set automatically).  The reasons for this are
              somewhat subtle but have to do with the differences between DOS-
              format file times (always local time) and Unix-format times
              (always in GMT/UTC) and the necessity to compare the two.  A
              typical TZ value is ``PST8PDT'' (US Pacific time with automatic
              adjustment for Daylight Savings Time or ``summer time'').

       -l     list archive files (short format).  The names, uncompressed file
              sizes and modification dates and times of the specified files are
              printed, along with totals for all files specified.  If UnZip was
              compiled with OS2_EAS defined, the -l option also lists columns
              for the sizes of stored OS/2 extended attributes (EAs) and OS/2
              access control lists (ACLs).  In addition, the zipfile comment and
              individual file comments (if any) are displayed.  If a file was
              archived from a single-case file system (for example, the old MS-
              DOS FAT file system) and the -L option was given, the filename is
              converted to lowercase and is prefixed with a caret (^).

       -p     extract files to pipe (stdout).  Nothing but the file data is sent
              to stdout, and the files are always extracted in binary format,
              just as they are stored (no conversions).

       -t     test archive files.  This option extracts each specified file in
              memory and compares the CRC (cyclic redundancy check, an enhanced
              checksum) of the expanded file with the original file's stored CRC
              value.

       -T     [most OSes] set the timestamp on the archive(s) to that of the
              newest file in each one.  This corresponds to zip's -go option
              except that it can be used on wildcard zipfiles (e.g., ``unzip -T
              \*.zip'') and is much faster.

       -u     update existing files and create new ones if needed.  This option
              performs the same function as the -f option, extracting (with
              query) files that are newer than those with the same name on disk,
              and in addition it extracts those files that do not already exist
              on disk.  See -f above for information on setting the timezone
              properly.

       -v     list archive files (verbose format) or show diagnostic version
              info.  This option has evolved and now behaves as both an option
              and a modifier.  As an option it has two purposes:  when a zipfile
              is specified with no other options, -v lists archive files
              verbosely, adding to the basic -l info the compression method,
              compressed size, compression ratio and 32-bit CRC.  In contrast to
              most of the competing utilities, unzip removes the 12 additional
              header bytes of encrypted entries from the compressed size
              numbers.  Therefore, compressed size and compression ratio figures
              are independent of the entry's encryption status and show the
              correct compression performance.  (The complete size of the
              encrypted compressed data stream for zipfile entries is reported
              by the more verbose zipinfo(1L) reports, see the separate manual.)
              When no zipfile is specified (that is, the complete command is
              simply ``unzip -v''), a diagnostic screen is printed.  In addition
              to the normal header with release date and version, unzip lists
              the home Info-ZIP ftp site and where to find a list of other ftp
              and non-ftp sites; the target operating system for which it was
              compiled, as well as (possibly) the hardware on which it was
              compiled, the compiler and version used, and the compilation date;
              any special compilation options that might affect the program's
              operation (see also DECRYPTION below); and any options stored in
              environment variables that might do the same (see ENVIRONMENT
              OPTIONS below).  As a modifier it works in conjunction with other
              options (e.g., -t) to produce more verbose or debugging output;
              this is not yet fully implemented but will be in future releases.

       -z     display only the archive comment.

MODIFIERS
       -a     convert text files.  Ordinarily all files are extracted exactly as
              they are stored (as ``binary'' files).  The -a option causes files
              identified by zip as text files (those with the `t' label in
              zipinfo listings, rather than `b') to be automatically extracted
              as such, converting line endings, end-of-file characters and the
              character set itself as necessary.  (For example, Unix files use
              line feeds (LFs) for end-of-line (EOL) and have no end-of-file
              (EOF) marker; Macintoshes use carriage returns (CRs) for EOLs; and
              most PC operating systems use CR+LF for EOLs and control-Z for
              EOF.  In addition, IBM mainframes and the Michigan Terminal System
              use EBCDIC rather than the more common ASCII character set, and NT
              supports Unicode.)  Note that zip's identification of text files
              is by no means perfect; some ``text'' files may actually be binary
              and vice versa.  unzip therefore prints ``[text]'' or ``[binary]''
              as a visual check for each file it extracts when using the -a
              option.  The -aa option forces all files to be extracted as text,
              regardless of the supposed file type.  On VMS, see also -S.

       -b     [general] treat all files as binary (no text conversions).  This
              is a shortcut for ---a.

       -b     [Tandem] force the creation files with filecode type 180 ('C')
              when extracting Zip entries marked as "text". (On Tandem, -a is
              enabled by default, see above).

       -b     [VMS] auto-convert binary files (see -a above) to fixed-length,
              512-byte record format.  Doubling the option (-bb) forces all
              files to be extracted in this format. When extracting to standard
              output (-c or -p option in effect), the default conversion of text
              record delimiters is disabled for binary (-b) resp. all (-bb)
              files.

       -B     [when compiled with UNIXBACKUP defined] save a backup copy of each
              overwritten file. The backup file is gets the name of the target
              file with a tilde and optionally a unique sequence number (up to 5
              digits) appended.  The sequence number is applied whenever another
              file with the original name plus tilde already exists.  When used
              together with the "overwrite all" option -o, numbered backup files
              are never created. In this case, all backup files are named as the
              original file with an appended tilde, existing backup files are
              deleted without notice.  This feature works similarly to the
              default behavior of emacs(1) in many locations.

              Example: the old copy of ``foo'' is renamed to ``foo~''.

              Warning: Users should be aware that the -B option does not prevent
              loss of existing data under all circumstances.  For example, when
              unzip is run in overwrite-all mode, an existing ``foo~'' file is
              deleted before unzip attempts to rename ``foo'' to ``foo~''.  When
              this rename attempt fails (because of a file locks, insufficient
              privileges, or ...), the extraction of ``foo~'' gets cancelled,
              but the old backup file is already lost.  A similar scenario takes
              place when the sequence number range for numbered backup files
              gets exhausted (99999, or 65535 for 16-bit systems).  In this
              case, the backup file with the maximum sequence number is deleted
              and replaced by the new backup version without notice.

       -C     use case-insensitive matching for the selection of archive entries
              from the command-line list of extract selection patterns.  unzip's
              philosophy is ``you get what you ask for'' (this is also
              responsible for the -L/-U change; see the relevant options below).
              Because some file systems are fully case-sensitive (notably those
              under the Unix operating system) and because both ZIP archives and
              unzip itself are portable across platforms, unzip's default
              behavior is to match both wildcard and literal filenames case-
              sensitively.  That is, specifying ``makefile'' on the command line
              will only match ``makefile'' in the archive, not ``Makefile'' or
              ``MAKEFILE'' (and similarly for wildcard specifications).  Since
              this does not correspond to the behavior of many other
              operating/file systems (for example, OS/2 HPFS, which preserves
              mixed case but is not sensitive to it), the -C option may be used
              to force all filename matches to be case-insensitive.  In the
              example above, all three files would then match ``makefile'' (or
              ``make*'', or similar).  The -C option affects file specs in both
              the normal file list and the excluded-file list (xlist).

              Please note that the -C option does neither affect the search for
              the zipfile(s) nor the matching of archive entries to existing
              files on the extraction path.  On a case-sensitive file system,
              unzip will never try to overwrite a file ``FOO'' when extracting
              an entry ``foo''!

       -D     skip restoration of timestamps for extracted items.  Normally,
              unzip tries to restore all meta-information for extracted items
              that are supplied in the Zip archive (and do not require
              privileges or impose a security risk).  By specifying -D, unzip is
              told to suppress restoration of timestamps for directories
              explicitly created from Zip archive entries.  This option only
              applies to ports that support setting timestamps for directories
              (currently ATheOS, BeOS, MacOS, OS/2, Unix, VMS, Win32, for other
              unzip ports, -D has no effect).  The duplicated option -DD forces
              suppression of timestamp restoration for all extracted entries
              (files and directories).  This option results in setting the
              timestamps for all extracted entries to the current time.

              On VMS, the default setting for this option is -D for consistency
              with the behaviour of BACKUP: file timestamps are restored,
              timestamps of extracted directories are left at the current time.
              To enable restoration of directory timestamps, the negated option
              --D should be specified.  On VMS, the option -D disables timestamp
              restoration for all extracted Zip archive items.  (Here, a single
              -D on the command line combines with the default -D to do what an
              explicit -DD does on other systems.)

       -E     [MacOS only] display contents of MacOS extra field during restore
              operation.

       -F     [Acorn only] suppress removal of NFS filetype extension from
              stored filenames.

       -F     [non-Acorn systems supporting long filenames with embedded commas,
              and only if compiled with ACORN_FTYPE_NFS defined] translate
              filetype information from ACORN RISC OS extra field blocks into a
              NFS filetype extension and append it to the names of the extracted
              files.  (When the stored filename appears to already have an
              appended NFS filetype extension, it is replaced by the info from
              the extra field.)

       -i     [MacOS only] ignore filenames stored in MacOS extra fields.
              Instead, the most compatible filename stored in the generic part
              of the entry's header is used.

       -j     junk paths.  The archive's directory structure is not recreated;
              all files are deposited in the extraction directory (by default,
              the current one).

       -J     [BeOS only] junk file attributes.  The file's BeOS file attributes
              are not restored, just the file's data.

       -J     [MacOS only] ignore MacOS extra fields.  All Macintosh specific
              info is skipped. Data-fork and resource-fork are restored as
              separate files.

       -K     [AtheOS, BeOS, Unix only] retain SUID/SGID/Tacky file attributes.
              Without this flag, these attribute bits are cleared for security
              reasons.

       -L     convert to lowercase any filename originating on an uppercase-only
              operating system or file system.  (This was unzip's default
              behavior in releases prior to 5.11; the new default behavior is
              identical to the old behavior with the -U option, which is now
              obsolete and will be removed in a future release.)  Depending on
              the archiver, files archived under single-case file systems (VMS,
              old MS-DOS FAT, etc.) may be stored as all-uppercase names; this
              can be ugly or inconvenient when extracting to a case-preserving
              file system such as OS/2 HPFS or a case-sensitive one such as
              under Unix.  By default unzip lists and extracts such filenames
              exactly as they're stored (excepting truncation, conversion of
              unsupported characters, etc.); this option causes the names of all
              files from certain systems to be converted to lowercase.  The -LL
              option forces conversion of every filename to lowercase,
              regardless of the originating file system.

       -M     pipe all output through an internal pager similar to the Unix
              more(1) command.  At the end of a screenful of output, unzip
              pauses with a ``--More--'' prompt; the next screenful may be
              viewed by pressing the Enter (Return) key or the space bar.  unzip
              can be terminated by pressing the ``q'' key and, on some systems,
              the Enter/Return key.  Unlike Unix more(1), there is no forward-
              searching or editing capability.  Also, unzip doesn't notice if
              long lines wrap at the edge of the screen, effectively resulting
              in the printing of two or more lines and the likelihood that some
              text will scroll off the top of the screen before being viewed.
              On some systems the number of available lines on the screen is not
              detected, in which case unzip assumes the height is 24 lines.

       -n     never overwrite existing files.  If a file already exists, skip
              the extraction of that file without prompting.  By default unzip
              queries before extracting any file that already exists; the user
              may choose to overwrite only the current file, overwrite all
              files, skip extraction of the current file, skip extraction of all
              existing files, or rename the current file.

       -N     [Amiga] extract file comments as Amiga filenotes.  File comments
              are created with the -c option of zip(1L), or with the -N option
              of the Amiga port of zip(1L), which stores filenotes as comments.

       -o     overwrite existing files without prompting.  This is a dangerous
              option, so use it with care.  (It is often used with -f, however,
              and is the only way to overwrite directory EAs under OS/2.)

       -P password
              use password to decrypt encrypted zipfile entries (if any).  THIS
              IS INSECURE!  Many multi-user operating systems provide ways for
              any user to see the current command line of any other user; even
              on stand-alone systems there is always the threat of over-the-
              shoulder peeking.  Storing the plaintext password as part of a
              command line in an automated script is even worse.  Whenever
              possible, use the non-echoing, interactive prompt to enter
              passwords.  (And where security is truly important, use strong
              encryption such as Pretty Good Privacy instead of the relatively
              weak encryption provided by standard zipfile utilities.)

       -q     perform operations quietly (-qq = even quieter).  Ordinarily unzip
              prints the names of the files it's extracting or testing, the
              extraction methods, any file or zipfile comments that may be
              stored in the archive, and possibly a summary when finished with
              each archive.  The -q[q] options suppress the printing of some or
              all of these messages.

       -s     [OS/2, NT, MS-DOS] convert spaces in filenames to underscores.
              Since all PC operating systems allow spaces in filenames, unzip by
              default extracts filenames with spaces intact (e.g.,
              ``EA DATA. SF'').  This can be awkward, however, since MS-DOS in
              particular does not gracefully support spaces in filenames.
              Conversion of spaces to underscores can eliminate the awkwardness
              in some cases.

       -S     [VMS] convert text files (-a, -aa) into Stream_LF record format,
              instead of the text-file default, variable-length record format.
              (Stream_LF is the default record format of VMS unzip. It is
              applied unless conversion (-a, -aa and/or -b, -bb) is requested or
              a VMS-specific entry is processed.)

       -U     [UNICODE_SUPPORT only] modify or disable UTF-8 handling.  When
              UNICODE_SUPPORT is available, the option -U forces unzip to escape
              all non-ASCII characters from UTF-8 coded filenames as ``#Uxxxx''
              (for UCS-2 characters, or ``#Lxxxxxx'' for unicode codepoints
              needing 3 octets).  This option is mainly provided for debugging
              purpose when the fairly new UTF-8 support is suspected to mangle
              up extracted filenames.

              The option -UU allows to entirely disable the recognition of UTF-8
              encoded filenames.  The handling of filename codings within unzip
              falls back to the behaviour of previous versions.

              [old, obsolete usage] leave filenames uppercase if created under
              MS-DOS, VMS, etc.  See -L above.

       -V     retain (VMS) file version numbers.  VMS files can be stored with a
              version number, in the format file.ext;##.  By default the ``;##''
              version numbers are stripped, but this option allows them to be
              retained.  (On file systems that limit filenames to particularly
              short lengths, the version numbers may be truncated or stripped
              regardless of this option.)

       -W     [only when WILD_STOP_AT_DIR compile-time option enabled] modifies
              the pattern matching routine so that both `?' (single-char
              wildcard) and `*' (multi-char wildcard) do not match the directory
              separator character `/'.  (The two-character sequence ``**'' acts
              as a multi-char wildcard that includes the directory separator in
              its matched characters.)  Examples:

           "*.c" matches "foo.c" but not "mydir/foo.c"
           "**.c" matches both "foo.c" and "mydir/foo.c"
           "*/*.c" matches "bar/foo.c" but not "baz/bar/foo.c"
           "??*/*" matches "ab/foo" and "abc/foo"
                   but not "a/foo" or "a/b/foo"

              This modified behaviour is equivalent to the pattern matching
              style used by the shells of some of UnZip's supported target OSs
              (one example is Acorn RISC OS).  This option may not be available
              on systems where the Zip archive's internal directory separator
              character `/' is allowed as regular character in native operating
              system filenames.  (Currently, UnZip uses the same pattern
              matching rules for both wildcard zipfile specifications and zip
              entry selection patterns in most ports.  For systems allowing `/'
              as regular filename character, the -W option would not work as
              expected on a wildcard zipfile specification.)

       -X     [VMS, Unix, OS/2, NT, Tandem] restore owner/protection info (UICs
              and ACL entries) under VMS, or user and group info (UID/GID) under
              Unix, or access control lists (ACLs) under certain network-enabled
              versions of OS/2 (Warp Server with IBM LAN Server/Requester 3.0 to
              5.0; Warp Connect with IBM Peer 1.0), or security ACLs under
              Windows NT.  In most cases this will require special system
              privileges, and doubling the option (-XX) under NT instructs unzip
              to use privileges for extraction; but under Unix, for example, a
              user who belongs to several groups can restore files owned by any
              of those groups, as long as the user IDs match his or her own.
              Note that ordinary file attributes are always restored--this
              option applies only to optional, extra ownership info available on
              some operating systems.  [NT's access control lists do not appear
              to be especially compatible with OS/2's, so no attempt is made at
              cross-platform portability of access privileges.  It is not clear
              under what conditions this would ever be useful anyway.]

       -Y     [VMS] treat archived file name endings of ``.nnn'' (where ``nnn''
              is a decimal  number) as if they were VMS version numbers
              (``;nnn'').  (The default is to treat them as file types.)
              Example:
                   "a.b.3" -> "a.b;3".

       -$     [MS-DOS, OS/2, NT] restore the volume label if the extraction
              medium is removable (e.g., a diskette).  Doubling the option (-$$)
              allows fixed media (hard disks) to be labelled as well.  By
              default, volume labels are ignored.

       -/ extensions
              [Acorn only] overrides the extension list supplied by Unzip$Ext
              environment variable. During extraction, filename extensions that
              match one of the items in this extension list are swapped in front
              of the base name of the extracted file.

       -:     [all but Acorn, VM/CMS, MVS, Tandem] allows to extract archive
              members into locations outside of the current `` extraction root
              folder''. For security reasons, unzip normally removes ``parent
              dir'' path components (``../'') from the names of extracted file.
              This safety feature (new for version 5.50) prevents unzip from
              accidentally writing files to ``sensitive'' areas outside the
              active extraction folder tree head.  The -: option lets unzip
              switch back to its previous, more liberal behaviour, to allow
              exact extraction of (older) archives that used ``../'' components
              to create multiple directory trees at the level of the current
              extraction folder.  This option does not enable writing explicitly
              to the root directory (``/'').  To achieve this, it is necessary
              to set the extraction target folder to root (e.g. -d / ).
              However, when the -: option is specified, it is still possible to
              implicitly write to the root directory by specifying enough
              ``../'' path components within the zip archive.  Use this option
              with extreme caution.

       -^     [Unix only] allow control characters in names of extracted ZIP
              archive entries.  On Unix, a file name may contain any (8-bit)
              character code with the two exception '/' (directory delimiter)
              and NUL (0x00, the C string termination indicator), unless the
              specific file system has more restrictive conventions.  Generally,
              this allows to embed ASCII control characters (or even
              sophisticated control sequences) in file names, at least on
              'native' Unix file systems.  However, it may be highly suspicious
              to make use of this Unix "feature".  Embedded control characters
              in file names might have nasty side effects when displayed on
              screen by some listing code without sufficient filtering.  And,
              for ordinary users, it may be difficult to handle such file names
              (e.g. when trying to specify it for open, copy, move, or delete
              operations).  Therefore, unzip applies a filter by default that
              removes potentially dangerous control characters from the
              extracted file names. The -^ option allows to override this filter
              in the rare case that embedded filename control characters are to
              be intentionally restored.

       -2     [VMS] force unconditionally conversion of file names to
              ODS2-compatible names.  The default is to exploit the destination
              file system, preserving case and extended file name characters on
              an ODS5 destination file system; and applying the
              ODS2-compatibility file name filtering on an ODS2 destination file
              system.

ENVIRONMENT OPTIONS
       unzip's default behavior may be modified via options placed in an
       environment variable.  This can be done with any option, but it is
       probably most useful with the -a, -L, -C, -q, -o, or -n modifiers:  make
       unzip auto-convert text files by default, make it convert filenames from
       uppercase systems to lowercase, make it match names case-insensitively,
       make it quieter, or make it always overwrite or never overwrite files as
       it extracts them.  For example, to make unzip act as quietly as possible,
       only reporting errors, one would use one of the following commands:

         Unix Bourne shell:
              UNZIP=-qq; export UNZIP

         Unix C shell:
              setenv UNZIP -qq

         OS/2 or MS-DOS:
              set UNZIP=-qq

         VMS (quotes for lowercase):
              define UNZIP_OPTS "-qq"

       Environment options are, in effect, considered to be just like any other
       command-line options, except that they are effectively the first options
       on the command line.  To override an environment option, one may use the
       ``minus operator'' to remove it.  For instance, to override one of the
       quiet-flags in the example above, use the command

       unzip --q[other options] zipfile

       The first hyphen is the normal switch character, and the second is a
       minus sign, acting on the q option.  Thus the effect here is to cancel
       one quantum of quietness.  To cancel both quiet flags, two (or more)
       minuses may be used:

       unzip -t--q zipfile
       unzip ---qt zipfile

       (the two are equivalent).  This may seem awkward or confusing, but it is
       reasonably intuitive:  just ignore the first hyphen and go from there.
       It is also consistent with the behavior of Unix nice(1).

       As suggested by the examples above, the default variable names are
       UNZIP_OPTS for VMS (where the symbol used to install unzip as a foreign
       command would otherwise be confused with the environment variable), and
       UNZIP for all other operating systems.  For compatibility with zip(1L),
       UNZIPOPT is also accepted (don't ask).  If both UNZIP and UNZIPOPT are
       defined, however, UNZIP takes precedence.  unzip's diagnostic option (-v
       with no zipfile name) can be used to check the values of all four
       possible unzip and zipinfo environment variables.

       The timezone variable (TZ) should be set according to the local timezone
       in order for the -f and -u to operate correctly.  See the description of
       -f above for details.  This variable may also be necessary to get
       timestamps of extracted files to be set correctly.  The WIN32
       (Win9x/ME/NT4/2K/XP/2K3) port of unzip gets the timezone configuration
       from the registry, assuming it is correctly set in the Control Panel.
       The TZ variable is ignored for this port.

DECRYPTION
       Encrypted archives are fully supported by Info-ZIP software, but due to
       United States export restrictions, de-/encryption support might be
       disabled in your compiled binary.  However, since spring 2000, US export
       restrictions have been liberated, and our source archives do now include
       full crypt code.  In case you need binary distributions with crypt
       support enabled, see the file ``WHERE'' in any Info-ZIP source or binary
       distribution for locations both inside and outside the US.

       Some compiled versions of unzip may not support decryption.  To check a
       version for crypt support, either attempt to test or extract an encrypted
       archive, or else check unzip's diagnostic screen (see the -v option
       above) for ``[decryption]'' as one of the special compilation options.

       As noted above, the -P option may be used to supply a password on the
       command line, but at a cost in security.  The preferred decryption method
       is simply to extract normally; if a zipfile member is encrypted, unzip
       will prompt for the password without echoing what is typed.  unzip
       continues to use the same password as long as it appears to be valid, by
       testing a 12-byte header on each file.  The correct password will always
       check out against the header, but there is a 1-in-256 chance that an
       incorrect password will as well.  (This is a security feature of the
       PKWARE zipfile format; it helps prevent brute-force attacks that might
       otherwise gain a large speed advantage by testing only the header.)  In
       the case that an incorrect password is given but it passes the header
       test anyway, either an incorrect CRC will be generated for the extracted
       data or else unzip will fail during the extraction because the
       ``decrypted'' bytes do not constitute a valid compressed data stream.

       If the first password fails the header check on some file, unzip will
       prompt for another password, and so on until all files are extracted.  If
       a password is not known, entering a null password (that is, just a
       carriage return or ``Enter'') is taken as a signal to skip all further
       prompting.  Only unencrypted files in the archive(s) will thereafter be
       extracted.  (In fact, that's not quite true; older versions of zip(1L)
       and zipcloak(1L) allowed null passwords, so unzip checks each encrypted
       file to see if the null password works.  This may result in ``false
       positives'' and extraction errors, as noted above.)

       Archives encrypted with 8-bit passwords (for example, passwords with
       accented European characters) may not be portable across systems and/or
       other archivers.  This problem stems from the use of multiple encoding
       methods for such characters, including Latin-1 (ISO 8859-1) and OEM code
       page 850.  DOS PKZIP 2.04g uses the OEM code page; Windows PKZIP 2.50
       uses Latin-1 (and is therefore incompatible with DOS PKZIP); Info-ZIP
       uses the OEM code page on DOS, OS/2 and Win3.x ports but ISO coding
       (Latin-1 etc.) everywhere else; and Nico Mak's WinZip 6.x does not allow
       8-bit passwords at all.  UnZip 5.3 (or newer) attempts to use the default
       character set first (e.g., Latin-1), followed by the alternate one (e.g.,
       OEM code page) to test passwords.  On EBCDIC systems, if both of these
       fail, EBCDIC encoding will be tested as a last resort.  (EBCDIC is not
       tested on non-EBCDIC systems, because there are no known archivers that
       encrypt using EBCDIC encoding.)  ISO character encodings other than
       Latin-1 are not supported.  The new addition of (partially) Unicode
       (resp.  UTF-8) support in UnZip 6.0 has not yet been adapted to the
       encryption password handling in unzip.  On systems that use UTF-8 as
       native character encoding, unzip simply tries decryption with the native
       UTF-8 encoded password; the built-in attempts to check the password in
       translated encoding have not yet been adapted for UTF-8 support and will
       consequently fail.

EXAMPLES
       To use unzip to extract all members of the archive letters.zip into the
       current directory and subdirectories below it, creating any
       subdirectories as necessary:

       unzip letters

       To extract all members of letters.zip into the current directory only:

       unzip -j letters

       To test letters.zip, printing only a summary message indicating whether
       the archive is OK or not:

       unzip -tq letters

       To test all zipfiles in the current directory, printing only the
       summaries:

       unzip -tq \*.zip

       (The backslash before the asterisk is only required if the shell expands
       wildcards, as in Unix; double quotes could have been used instead, as in
       the source examples below.)  To extract to standard output all members of
       letters.zip whose names end in .tex, auto-converting to the local end-of-
       line convention and piping the output into more(1):

       unzip -ca letters \*.tex | more

       To extract the binary file paper1.dvi to standard output and pipe it to a
       printing program:

       unzip -p articles paper1.dvi | dvips

       To extract all FORTRAN and C source files--*.f, *.c, *.h, and
       Makefile--into the /tmp directory:

       unzip source.zip "*.[fch]" Makefile -d /tmp

       (the double quotes are necessary only in Unix and only if globbing is
       turned on).  To extract all FORTRAN and C source files, regardless of
       case (e.g., both *.c and *.C, and any makefile, Makefile, MAKEFILE or
       similar):

       unzip -C source.zip "*.[fch]" makefile -d /tmp

       To extract any such files but convert any uppercase MS-DOS or VMS names
       to lowercase and convert the line-endings of all of the files to the
       local standard (without respect to any files that might be marked
       ``binary''):

       unzip -aaCL source.zip "*.[fch]" makefile -d /tmp

       To extract only newer versions of the files already in the current
       directory, without querying (NOTE:  be careful of unzipping in one
       timezone a zipfile created in another--ZIP archives other than those
       created by Zip 2.1 or later contain no timezone information, and a
       ``newer'' file from an eastern timezone may, in fact, be older):

       unzip -fo sources

       To extract newer versions of the files already in the current directory
       and to create any files not already there (same caveat as previous
       example):

       unzip -uo sources

       To display a diagnostic screen showing which unzip and zipinfo options
       are stored in environment variables, whether decryption support was
       compiled in, the compiler with which unzip was compiled, etc.:

       unzip -v

       In the last five examples, assume that UNZIP or UNZIP_OPTS is set to -q.
       To do a singly quiet listing:

       unzip -l file.zip

       To do a doubly quiet listing:

       unzip -ql file.zip

       (Note that the ``.zip'' is generally not necessary.)  To do a standard
       listing:

       unzip --ql file.zip
       or
       unzip -l-q file.zip
       or
       unzip -l--q file.zip
       (Extra minuses in options don't hurt.)

TIPS
       The current maintainer, being a lazy sort, finds it very useful to define
       a pair of aliases:  tt for ``unzip -tq'' and ii for ``unzip -Z'' (or
       ``zipinfo'').  One may then simply type ``tt zipfile'' to test an
       archive, something that is worth making a habit of doing.  With luck
       unzip will report ``No errors detected in compressed data of
       zipfile.zip,'' after which one may breathe a sigh of relief.

       The maintainer also finds it useful to set the UNZIP environment variable
       to ``-aL'' and is tempted to add ``-C'' as well.  His ZIPINFO variable is
       set to ``-z''.

DIAGNOSTICS
       The exit status (or error level) approximates the exit codes defined by
       PKWARE and takes on the following values, except under VMS:

              0      normal; no errors or warnings detected.

              1      one or more warning errors were encountered, but processing
                     completed successfully anyway.  This includes zipfiles
                     where one or more files was skipped due to unsupported
                     compression method or encryption with an unknown password.

              2      a generic error in the zipfile format was detected.
                     Processing may have completed successfully anyway; some
                     broken zipfiles created by other archivers have simple
                     work-arounds.

              3      a severe error in the zipfile format was detected.
                     Processing probably failed immediately.

              4      unzip was unable to allocate memory for one or more buffers
                     during program initialization.

              5      unzip was unable to allocate memory or unable to obtain a
                     tty to read the decryption password(s).

              6      unzip was unable to allocate memory during decompression to
                     disk.

              7      unzip was unable to allocate memory during in-memory
                     decompression.

              8      [currently not used]

              9      the specified zipfiles were not found.

              10     invalid options were specified on the command line.

              11     no matching files were found.

              12     invalid zip file with overlapped components (possible zip
                     bomb).

              50     the disk is (or was) full during extraction.

              51     the end of the ZIP archive was encountered prematurely.

              80     the user aborted unzip prematurely with control-C (or
                     similar)

              81     testing or extraction of one or more files failed due to
                     unsupported compression methods or unsupported decryption.

              82     no files were found due to bad decryption password(s).  (If
                     even one file is successfully processed, however, the exit
                     status is 1.)

       VMS interprets standard Unix (or PC) return values as other, scarier-
       looking things, so unzip instead maps them into VMS-style status codes.
       The current mapping is as follows:   1 (success) for normal exit,
       0x7fff0001 for warning errors, and (0x7fff000? +
       16*normal_unzip_exit_status) for all other errors, where the `?' is 2
       (error) for unzip values 2, 9-11 and 80-82, and 4 (fatal error) for the
       remaining ones (3-8, 50, 51).  In addition, there is a compilation option
       to expand upon this behavior:  defining RETURN_CODES results in a human-
       readable explanation of what the error status means.

BUGS
       Multi-part archives are not yet supported, except in conjunction with
       zip.  (All parts must be concatenated together in order, and then ``zip
       -F'' (for zip 2.x) or ``zip -FF'' (for zip 3.x) must be performed on the
       concatenated archive in order to ``fix'' it.  Also, zip 3.0 and later can
       combine multi-part (split) archives into a combined single-file archive
       using ``zip -s- inarchive -O outarchive''.  See the zip 3 manual page for
       more information.)  This will definitely be corrected in the next major
       release.

       Archives read from standard input are not yet supported, except with
       funzip (and then only the first member of the archive can be extracted).

       Archives encrypted with 8-bit passwords (e.g., passwords with accented
       European characters) may not be portable across systems and/or other
       archivers.  See the discussion in DECRYPTION above.

       unzip's -M (``more'') option tries to take into account automatic
       wrapping of long lines. However, the code may fail to detect the correct
       wrapping locations. First, TAB characters (and similar control sequences)
       are not taken into account, they are handled as ordinary printable
       characters.  Second, depending on the actual system / OS port, unzip may
       not detect the true screen geometry but rather rely on "commonly used"
       default dimensions.  The correct handling of tabs would require the
       implementation of a query for the actual tabulator setup on the output
       console.

       Dates, times and permissions of stored directories are not restored
       except under Unix. (On Windows NT and successors, timestamps are now
       restored.)

       [MS-DOS] When extracting or testing files from an archive on a defective
       floppy diskette, if the ``Fail'' option is chosen from DOS's ``Abort,
       Retry, Fail?'' message, older versions of unzip may hang the system,
       requiring a reboot.  This problem appears to be fixed, but control-C (or
       control-Break) can still be used to terminate unzip.

       Under DEC Ultrix, unzip would sometimes fail on long zipfiles (bad CRC,
       not always reproducible).  This was apparently due either to a hardware
       bug (cache memory) or an operating system bug (improper handling of page
       faults?).  Since Ultrix has been abandoned in favor of Digital Unix
       (OSF/1), this may not be an issue anymore.

       [Unix] Unix special files such as FIFO buffers (named pipes), block
       devices and character devices are not restored even if they are somehow
       represented in the zipfile, nor are hard-linked files relinked.
       Basically the only file types restored by unzip are regular files,
       directories and symbolic (soft) links.

       [OS/2] Extended attributes for existing directories are only updated if
       the -o (``overwrite all'') option is given.  This is a limitation of the
       operating system; because directories only have a creation time
       associated with them, unzip has no way to determine whether the stored
       attributes are newer or older than those on disk.  In practice this may
       mean a two-pass approach is required:  first unpack the archive normally
       (with or without freshening/updating existing files), then overwrite just
       the directory entries (e.g., ``unzip -o foo */'').

       [VMS] When extracting to another directory, only the [.foo] syntax is
       accepted for the -d option; the simple Unix foo syntax is silently
       ignored (as is the less common VMS foo.dir syntax).

       [VMS] When the file being extracted already exists, unzip's query only
       allows skipping, overwriting or renaming; there should additionally be a
       choice for creating a new version of the file.  In fact, the
       ``overwrite'' choice does create a new version; the old version is not
       overwritten or deleted.

SEE ALSO
       funzip(1L), zip(1L), zipcloak(1L), zipgrep(1L), zipinfo(1L), zipnote(1L),
       zipsplit(1L)

URL
       The Info-ZIP home page is currently at
       http://www.info-zip.org/pub/infozip/
       or
       ftp://ftp.info-zip.org/pub/infozip/ .

AUTHORS
       The primary Info-ZIP authors (current semi-active members of the Zip-Bugs
       workgroup) are:  Ed Gordon (Zip, general maintenance, shared code, Zip64,
       Win32, Unix, Unicode); Christian Spieler (UnZip maintenance coordination,
       VMS, MS-DOS, Win32, shared code, general Zip and UnZip integration and
       optimization); Onno van der Linden (Zip); Mike White (Win32, Windows GUI,
       Windows DLLs); Kai Uwe Rommel (OS/2, Win32); Steven M. Schweda (VMS,
       Unix, support of new features); Paul Kienitz (Amiga, Win32, Unicode);
       Chris Herborth (BeOS, QNX, Atari); Jonathan Hudson (SMS/QDOS); Sergio
       Monesi (Acorn RISC OS); Harald Denker (Atari, MVS); John Bush (Solaris,
       Amiga); Hunter Goatley (VMS, Info-ZIP Site maintenance); Steve Salisbury
       (Win32); Steve Miller (Windows CE GUI), Johnny Lee (MS-DOS, Win32,
       Zip64); and Dave Smith (Tandem NSK).

       The following people were former members of the Info-ZIP development
       group and provided major contributions to key parts of the current code:
       Greg ``Cave Newt'' Roelofs (UnZip, unshrink decompression); Jean-loup
       Gailly (deflate compression); Mark Adler (inflate decompression, fUnZip).

       The author of the original unzip code upon which Info-ZIP's was based is
       Samuel H. Smith; Carl Mascott did the first Unix port; and David P.
       Kirschbaum organized and led Info-ZIP in its early days with Keith
       Petersen hosting the original mailing list at WSMR-SimTel20.  The full
       list of contributors to UnZip has grown quite large; please refer to the
       CONTRIBS file in the UnZip source distribution for a relatively complete
       version.

VERSIONS
       v1.2   15 Mar 89   Samuel H. Smith
       v2.0    9 Sep 89   Samuel H. Smith
       v2.x   fall 1989   many Usenet contributors
       v3.0    1 May 90   Info-ZIP (DPK, consolidator)
       v3.1   15 Aug 90   Info-ZIP (DPK, consolidator)
       v4.0    1 Dec 90   Info-ZIP (GRR, maintainer)
       v4.1   12 May 91   Info-ZIP
       v4.2   20 Mar 92   Info-ZIP (Zip-Bugs subgroup, GRR)
       v5.0   21 Aug 92   Info-ZIP (Zip-Bugs subgroup, GRR)
       v5.01  15 Jan 93   Info-ZIP (Zip-Bugs subgroup, GRR)
       v5.1    7 Feb 94   Info-ZIP (Zip-Bugs subgroup, GRR)
       v5.11   2 Aug 94   Info-ZIP (Zip-Bugs subgroup, GRR)
       v5.12  28 Aug 94   Info-ZIP (Zip-Bugs subgroup, GRR)
       v5.2   30 Apr 96   Info-ZIP (Zip-Bugs subgroup, GRR)
       v5.3   22 Apr 97   Info-ZIP (Zip-Bugs subgroup, GRR)
       v5.31  31 May 97   Info-ZIP (Zip-Bugs subgroup, GRR)
       v5.32   3 Nov 97   Info-ZIP (Zip-Bugs subgroup, GRR)
       v5.4   28 Nov 98   Info-ZIP (Zip-Bugs subgroup, SPC)
       v5.41  16 Apr 00   Info-ZIP (Zip-Bugs subgroup, SPC)
       v5.42  14 Jan 01   Info-ZIP (Zip-Bugs subgroup, SPC)
       v5.5   17 Feb 02   Info-ZIP (Zip-Bugs subgroup, SPC)
       v5.51  22 May 04   Info-ZIP (Zip-Bugs subgroup, SPC)
       v5.52  28 Feb 05   Info-ZIP (Zip-Bugs subgroup, SPC)
       v6.0   20 Apr 09   Info-ZIP (Zip-Bugs subgroup, SPC)



Info-ZIP                      20 April 2009 (v6.0)                     UNZIP(1L)