4.3BSD - /usr/man/cat1/tar.0

TAR(1)                                                                  TAR(1)


NAME
       tar - tape archiver

SYNOPSIS
       tar [ key ] [ name ... ]

DESCRIPTION
       Tar  saves and restores multiple files on a single file (usually a mag‐
       netic tape, but it can be any file).  Tar’s 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 tar are file or directory names specifying which files to
       dump or restore.  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.

       x       The named files are extracted from the tape.  If the 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
               file  argument  is  given,  the  entire  content of the tape is
               extracted.  Note that if multiple entries specifying  the  same
               file are on the tape, the last one overwrites all earlier.

       t       The  names  of  the  specified  files are listed each time they
               occur on the tape.  If no file argument is given,  all  of  the
               names on the tape are listed.

       u       The  named  files  are added to the tape if either they are not
               already there or have been modified since last put on the tape.

       c       Create  a new tape; writing begins on the beginning of the tape
               instead of after the last file.  This command implies r.

       The following characters may be used in addition to  the  letter  which
       selects the function desired.

       o         On  output,  tar normally places information specifying owner
                 and modes of directories in the archive.  Former versions  of
                 tar,  when encountering this information will give error mes‐
                 sage of the form
                      "<name>/: cannot create".
                 This modifier will suppress the directory information.

       p         This modifier says to restore files to their original  modes,
                 ignoring the present umask(2).  Setuid and sticky information
                 will also be restored to the super-user.

       0, ..., 9 This modifier selects an alternate drive on which the tape is
                 mounted.   The  default is drive 0 at 1600 bpi, which is nor‐
                 mally /dev/rmt8.

       v         Normally tar does its work silently.  The v (verbose)  option
                 makes  tar  print the name of each file it treats preceded by
                 the function letter.  With the t function, the verbose option
                 gives more information about the tape entries than just their
                 names.

       w         Tar prints the action to be taken followed by file name, then
                 wait  for  user confirmation. If a word beginning with ‘y’ is
                 given, the action is done. Any other input means don’t do it.

       f         Tar uses the next argument as the name of the archive instead
                 of /dev/rmt?. If the name of the file is ‘-’, tar  writes  to
                 standard  output  or  reads from standard input, whichever is
                 appropriate. Thus, tar can be used as the head or tail  of  a
                 filter  chain.  Tar can also be used to move hierarchies with
                 the command
                         cd fromdir; tar cf - . | (cd todir; tar xf -)

       b         Tar uses the next argument as the blocking  factor  for  tape
                 records.  The default is 20 (the maximum). 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 dumped.  If this is not specified, no error mes‐
                 sages are printed.

       m         tells tar not to restore the modification times.  The modifi‐
                 cation time will be the time of extraction.

       h         Force  tar  to  follow  symbolic links as if they were normal
                 files or directories.  Normally, tar does not follow symbolic
                 links.

       B         Forces  input  and  output  blocking to 20 blocks per record.
                 This option was added so that tar can work across a  communi‐
                 cations channel where the blocking may not be maintained.

       C         If  a  file  name  is preceded by -C, then tar will perform a
                 chdir(2) to that file name.  This allows multiple directories
                 not  related  by  a  close common parent to be archived using
                 short relative path names.  For  example,  to  archive  files
                 from /usr/include and from /etc, one might use
                      tar c -C /usr include -C / etc

       Previous  restrictions  dealing with tar’s inability to properly handle
       blocked archives have been lifted.


FILES
       /dev/rmt?
       /tmp/tar*

SEE ALSO
       tar(5)

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 current limit on file name length is 100 characters.
       There is no way selectively to follow symbolic links.
       When extracting tapes created with the r or u options, directory  modi‐
       fication times may not be set correctly.


7th Edition                      May 12, 1986                           TAR(1)