PTAR(C) UNIX System V
Name
ptar - process tape archives
Syntax
ptar -c[bfvw] device block filename...
ptar -r[bvw] device block [filename...]
ptar -t[fv] device
ptar -u[bvw] device block
ptar -x[flmovw] device [filename...]
Description
Tar reads and writes archive files which conform to the
Archive/Interchange File Format specified in IEEE Std.
1003.1-1988.
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 names 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.
-b Causes ptar to use the next argument on the
command line 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. Normally, the block size is
determined automatically when reading tapes.
-f Causes ptar 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 ptar writes to the
standard output or reads from the standard input,
whichever is appropriate for the options given.
Thus, ptar can be used as the head or tail of a
pipeline.
-l Tells ptar 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 ptar not to restore the modification times.
The modification time of the file will be the time
of extraction. This modifier is invalid with th
-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.
-v Causes ptar to operate verbosely. Usually, ptar
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.
-w Causes ptar 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
-i or -y options are specified.
See Also
cpio(C), dd(C), find(C), pax(C), pcpio(C)
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.
THE SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS
OR IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE
IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A
PARTICULAR PURPOSE.
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.
Standards Conformance
ptar is conformant with:
IEEE POSIX Std 1003.1-1988 with C Standard Language-
Dependent System Support;
and NIST FIPS 151-1.
(printed 2/15/90) PTAR(C)