


      TAR(1)                      (UNIX 5.0)                     TAR(1)



      NAME
           tar - tape file archiver

      SYNTAX
           tar [ key ] [ files ]

      DESCRIPTION
           Tar saves and restores files on magnetic tape.  Its actions
           are controlled by the key argument.  The key is a string of
           characters containing at most one function letter and
           possibly one or more function modifiers.  Other arguments to
           the command are files (or directory names) specifying which
           files are to be dumped or restored.  In all cases,
           appearance of a directory name refers to the files and
           (recursively) subdirectories of that directory.

           The function portion of the key is specified by one of the
           following letters:

           r       The named files are written on the end of the tape.
                   The c function implies this function.
           x       The named files are extracted from the tape.  If a
                   named file matches a directory whose contents had
                   been written onto the tape, this directory is
                   (recursively) extracted.  The owner, modification
                   time, and mode are restored (if possible).  If no
                   files argument is given, the entire content of the
                   tape is extracted.  Note that if several files with
                   the same name are on the tape, the last one
                   overwrites all earlier ones.
           t       The names of the specified files are listed on
                   stderr each time they occur on the tape.  If no
                   files argument is given, all the names on the tape
                   are listed.
           u       The named files are added to the tape if they are
                   not already there, or have been modified since last
                   written on that tape.
           c       Create a new tape; writing begins at the beginning
                   of the tape, instead of after the last file.  This
                   command implies the r function.

           The following characters may be used in addition to the
           letter that selects the desired function:

           0,...,7 This modifier selects the drive on which the tape is
                   mounted.  The default is 1.
           v       Normally, tar does its work silently.  The v
                   (verbose) option causes it to type on stderr the
                   name of each file it treats, preceded by the
                   function letter.  With the t function, v gives more
                   information about the tape entries:  protection
                   bits, user and group id, file size in bytes, last



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      TAR(1)                      (UNIX 5.0)                     TAR(1)



                   modification date, and file name.
           w       causes tar to print the action to be taken, followed
                   by the name of the file, and then wait for the
                   user's confirmation.  If a word beginning with y is
                   given, the action is performed.  Any other input
                   means ``no''.
           f       causes tar to use the next argument as the name of
                   the archive instead of /dev/rmt0.  If the name of
                   the file is -, tar writes to the standard output or
                   reads from the standard input, whichever is
                   appropriate. Thus tar can be used as the head or
                   tail of a pipeline.  Tar can also be used to move
                   hierarchies with the command:

                     cd fromdir; tar cf - . | (cd todir; tar xf -)

           b       causes tar to use the next argument as the blocking
                   factor for tape records.  The default is 1, the
                   maximum is 20.  This option should only be used with
                   raw magnetic tape archives (see f above).  The block
                   size is determined automatically when reading tapes
                   (key letters x and t).
           l       tells tar to complain if it cannot resolve all of
                   the links to the files being dumped.  If l is not
                   specified, no error messages are printed.
           m       tells tar to not restore the modification times.
                   The modification time of the file will be the time
                   of extraction.



























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      TAR(1)                      (UNIX 5.0)                     TAR(1)



      FILES
           /dev/rmt*
           /dev/[n]rtape
           /dev/[n]ct*
           /tmp/tar*

      DIAGNOSTICS
           Complaints about bad key characters and tape read/write
           errors.
           Complaints if enough memory is not available to hold the
           link tables.

      BUGS
           There is no way to ask for the n-th occurrence of a file.
           Tape errors are handled ungracefully.
           The u option can be slow.
           The b option should not be used with magnetic tape archives
           that are going to be updated.  The current magnetic tape
           driver cannot backspace raw magnetic tape.  If the archive
           is on a disk file, the b option should not be used at all,
           because updating an archive stored on disk can destroy it.

           If archiving to a cartridge tape, the r or u options cannot
           be used due to streaming cartridge tape drive limitations in
           appending to files.
           The current limit on file-name length is 100 characters.





























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