TAR(1) SysV TAR(1)
NAME
tar - process tape archives
SYNOPSIS
tar -c[APhbfmlvw] device block filename...
tar -r[APhbfmlvw] device block [filename...]
tar -t[Ahfv] device
tar -u[APhbfmlvw] device block
tar -x[Afmovwp] device [filename...]
DESCRIPTION
tar reads and writes archive files which conform to the
Archive/Interchange File Format specified in IEEE Std. 1003.1-1988.
| POSIX standard compliance states that filenames cannot exceed
| 256 characters total; 100 characters for the file name, 155
| characters for the patch, and 1 character for the / between
| the path and the filename.
Options
The following options are available:
-c Creates a new archive; writing begins at the beginning of the
archive, instead of after the last file.
-r Writes named files to the end of the archive.
-t Lists the names of all of the files in the archive.
-u Causes named files to be added to the archive if they are not
already there, or have been modified since last written into
the archive. This implies the -r option.
-x Extracts named files from the archive. If a named file matches
a directory whose contents had been written onto the archive,
that directory is recursively extracted. If a named file in
the archive does not exist on the system, the file is create
with the same mode as the one in the archive, except that the
set-user-id and get-group-id modes are not set unless the user
has appropriate privileges.
If the files exist, their modes are not changed except as described
above. The owner, group and modification time are restored if possible.
If no filename argument is given, the entire contents of the archive is
extracted. Note that if several files with the same name are in the
archive, the last one will overwrite all earlier ones.
-A Causes tar to archive Apollo-specific information. Also allows
tar to handle Domain/OS typed files.
-P Omit the trailing "/" on directory names in the archive.
-b Causes tar to use the next argument on the command line as the
blocking factor for tape records. The default is 20. This
option should only be used with raw magnetic tape archives.
Normally, the block size is determined automatically when
reading tapes.
-f Causes tar to use the next argument on the command line as the
name of the archive instead of the default, which is usually a
tape drive. If - is specified as a filename tar writes to the
standard output or reads from the standard input, whichever is
appropriate for the options given. Thus, tar can be used as
the head or tail of a pipeline.
-h Forces tar to follow symbolic links as if they were normal
files or directories. Normally tar does not follow symbolic
links.
-l Tells tar to report if it cannot resolve all of the links to
the files being archived. If -l is not specified, no error
messages are written to the standard output. This modifier is
only valid with the -c, -r and -u options.
-m Tells tar not to restore the modification times. The
modification time of the file will be the time of extraction.
This modifier is invalid with the -t option.
-o Causes extracted files to take on the user and group identifier
of the user running the program rather than those on the
archive. This modifier is only valid with the -x option.
-p Restore files to their original modes, ignoring the present
umask(2). Restores setuid to the super-user.
-v Causes tar to operate verbosely. Usually, tar does its work
silently, but the v modifier causes it to print the name of
each file it processes, preceded by the option letter. With
the -t option, v gives more information about the archive
entries than just the name.
This option does not display directory entries.
-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". This modifier is invalid with the
-t option.
FILES
/dev/tty used to prompt the user for information when the -w option is
specified.
NOTES
The tar device must first be mounted and rewound. For example, when
using tar with /dev/rct8, first issue the command:
mt -f /dev/rct8 rewind
Then proceed with the tar command.
The -r (write named files to the end of the archive) does not work with
cartridge tape devices. Cartridge tape devices only support writing at
the beginning and at the end of the tape.
BUGS
tar supports multiple volumes. However, you must mount each additional
volume before proceeding. Since the window from which you have issued the
tar command will be in a paused state (waiting for you to enter "go" or
"abort"), you must mount the tape device from another window, using the
mt command. For example, when using tar with /dev/rct8, issue the
command:
mt -f /dev/rct8 rewind
Then proceed to the paused window, and issue "go".
SEE ALSO
cpio(1), dd(1), find(1), pax(1), cpio(4)
COPYRIGHT
Copyright (c) 1989 Mark H. Colburn.
All rights reserved.
Redistribution and use in source and binary forms are permitted provided
that the above copyright notice is duplicated in all such forms and that
any documentation, advertising materials, and other materials related to
such distribution and use acknowledge that the software was developed by
Mark H. Colburn and sponsored by The USENIX Association.
AUTHOR
Mark H. Colburn
NAPS International
117 Mackubin Street, Suite 1
St. Paul, MN 55102
mark@jhereg.MN.ORG
Sponsored by The USENIX Association for public distribution.
Updated 1/94