TAR(1)                     OpenBSD Reference Manual                     TAR(1)

NAME
     tar - tape archiver

SYNOPSIS
     tar {crtux}[014578befHhjLmOoPpqsvwXZz]
         [blocking-factor | archive | replstr] [-C directory] [-I file]
         [file ...]
     tar {-crtux} [-014578eHhjLmOoPpqvwXZz] [-b blocking-factor]
         [-C directory] [-f archive] [-I file] [-s replstr] [file ...]

DESCRIPTION
     The tar command creates, adds files to, or extracts files from an archive
     file in ``tar'' format.  A tar archive is often stored on a magnetic
     tape, but can be stored equally well on a floppy, CD-ROM, or in a regular
     disk file.

     In the first (legacy) form, all option flags except for -C and -I must be
     contained within the first argument to tar and must not be prefixed by a
     hyphen (`-').  Option arguments, if any, are processed as subsequent ar-
     guments to tar and are processed in the order in which their correspond-
     ing option flags have been presented on the command line.

     In the second and preferred form, option flags may be given in any order
     and are immediately followed by their corresponding option argument val-
     ues.

     One of the following flags must be present:

     -c      Create new archive, or overwrite an existing archive, adding the
             specified files to it.

     -r      Append the named new files to existing archive.  Note that this
             will only work on media on which an end-of-file mark can be over-
             written.

     -t      List contents of archive.  If any files are named on the command
             line, only those files will be listed.  The file arguments may be
             specified as glob patterns (see glob(3) for more information), in
             which case tar will list all archive members that match each pat-
             tern.

     -u      Alias for -r.

     -x      Extract files from archive.  If any files are named on the com-
             mand line, only those files will be extracted from the archive.
             The file arguments may be specified as glob patterns (see glob(3)
             for more information), in which case tar will extract all archive
             members that match each pattern.

             If more than one copy of a file exists in the archive, later
             copies will overwrite earlier copies during extraction.  The file
             mode and modification time are preserved if possible.  The file
             mode is subject to modification by the umask(2).

     In addition to the flags mentioned above, any of the following flags may
     be used:

     -b blocking-factor
             Set blocking factor to use for the archive.  tar uses 512-byte
             blocks.  The default is 20, the maximum is 126.  Archives with a
             blocking factor larger than 63 violate the POSIX standard and
             will not be portable to all systems.

     -C directory
             This is a positional argument which sets the working directory
             for the following files.  When extracting, files will be extract-
             ed into the specified directory; when creating, the specified
             files will be matched from the directory.

     -e      Stop after the first error.

     -f archive
             Filename where the archive is stored.  Defaults to /dev/rst0.

     -H      Follow symlinks given on the command line only.

     -h      Follow symbolic links as if they were normal files or directo-
             ries.  In extract mode this means that a directory entry in the
             archive will not overwrite an existing symbolic link, but rather
             what the link ultimately points to.

     -I file
             This is a positional argument which reads the names of files to
             archive or extract from the given file, one per line.

     -j      Compress archive using bzip2.  The bzip2 utility must be in-
             stalled separately.

     -L      Synonym for the -h option.

     -m      Do not preserve modification time.

     -O      Write old-style (non-POSIX) archives.

     -o      Don't write directory information that the older (V7) style tar
             is unable to decode.  This implies the -O flag.

     -P      Do not strip leading slashes (`/') from pathnames.  The default
             is to strip leading slashes.

     -p      Preserve user and group ID as well as file mode regardless of the
             current umask(2).  The setuid and setgid bits are only preserved
             if the user is the superuser.  Only meaningful in conjunction
             with the -x flag.

     -q      Select the first archive member that matches each file operand.
             No more than one archive member is matched for each file.  When
             members of type directory are matched, the file hierarchy rooted
             at that directory is also matched.

     -s replstr
             Modify the archive member names according to the substitution ex-
             pression replstr, using the syntax of the ed(1) utility regular
             expressions.  file arguments may be given to restrict the list of
             archive members to those specified.

             The format of these regular expressions is

                   /old/new/[gp]

             As in ed(1), old is a basic regular expression (see re_format(7))
             and new can contain an ampersand (`&'), `\n' (where n is a digit)
             back-references, or subexpression matching.  The old string may
             also contain newline characters.  Any non-null character can be
             used as a delimiter (`/' is shown here).  Multiple -s expressions
             can be specified.  The expressions are applied in the order they
             are specified on the command line, terminating with the first
             successful substitution.

             The optional trailing g continues to apply the substitution ex-
             pression to the pathname substring, which starts with the first
             character following the end of the last successful substitution.
             The first unsuccessful substitution stops the operation of the g
             option.  The optional trailing p will cause the final result of a
             successful substitution to be written to standard error in the
             following format:

                   original-pathname >> new-pathname

             File or archive member names that substitute to the empty string
             are not selected and will be skipped.

     -v      Verbose operation mode.

     -w      Interactively rename files.  This option causes tar to prompt the
             user for the filename to use when storing or extracting files in
             an archive.

     -X      Do not cross mount points in the file system.

     -Z      Compress archive using compress(1).

     -z      Compress archive using gzip(1).

     The options [-014578] can be used to select one of the compiled-in backup
     devices, /dev/rstN.

ENVIRONMENT
     TMPDIR      Path in which to store temporary files.

     TAPE        Default tape device to use instead of /dev/rst0.

FILES
     /dev/rst0  default archive name

EXAMPLES
     Create an archive on the default tape drive, containing the files named
     bonvole and sekve:

           $ tar c bonvole sekve

     Output a gzip(1) compressed archive containing the files bonvole and
     sekve to a file called foriru.tar.gz:

           $ tar zcf foriru.tar.gz bonvole sekve

     Verbosely create an archive, called backup.tar.gz, of all files matching
     the shell glob(3) function *.c:

           $ tar zcvf backup.tar.gz *.c

     Verbosely list, but do not extract, all files ending in .jpeg from a com-
     pressed archive named backup.tar.gz.  Note that the glob pattern has been
     quoted to avoid expansion by the shell:

           $ tar tvzf backup.tar.gz '*.jpeg'

     For more detailed examples, see pax(1).

DIAGNOSTICS
     tar will exit with one of the following values:

           0   All files were processed successfully.

           1   An error occurred.

     Whenever tar cannot create a file or a link when extracting an archive or
     cannot find a file while writing an archive, or cannot preserve the user
     ID, group ID, file mode, or access and modification times when the -p op-
     tion is specified, a diagnostic message is written to standard error and
     a non-zero exit value will be returned, but processing will continue.  In
     the case where tar cannot create a link to a file, tar will not create a
     second copy of the file.

     If the extraction of a file from an archive is prematurely terminated by
     a signal or error, tar may have only partially extracted the file the us-
     er wanted.  Additionally, the file modes of extracted files and directo-
     ries may have incorrect file bits, and the modification and access times
     may be wrong.

     If the creation of an archive is prematurely terminated by a signal or
     error, tar may have only partially created the archive, which may violate
     the specific archive format specification.

SEE ALSO
     cpio(1), pax(1)

HISTORY
     A tar command first appeared in Version 7 AT&T UNIX.

AUTHORS
     Keith Muller at the University of California, San Diego.

CAVEATS
     The -j and -L flags are not portable to other versions of tar where they
     may have a different meaning.

OpenBSD 4.7                    December 27, 2008                             4
