[blocking-factor | archive | replstr]
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
-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 arguments to
tar and are
processed in the order in which their corresponding 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 values.
One of the following flags must be present:
- Create new archive, or overwrite an existing archive, adding the specified files to it.
- 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 overwritten.
- 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(7) for more information), in which case
tarwill list all archive members that match each pattern.
- Alias for
- Extract files from archive. If any files are named on the command line,
only those files will be extracted from the archive. The
file arguments may be specified as glob patterns
(see glob(7) for more information), in which case
tarwill 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:
- Set blocking factor to use for the archive.
taruses 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.
- This is a positional argument which sets the working directory for the following files. When extracting, files will be extracted into the specified directory; when creating, the specified files will be matched from the directory.
- Stop after the first error.
- Filename where the archive is stored. Defaults to
/dev/rst0. If set to hyphen (‘-’)
standard output is used. See also the
- Follow symlinks given on the command line only.
- Follow symbolic links as if they were normal files or directories. 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.
- This is a positional argument which reads the names of files to archive or extract from the given file, one per line.
- Compress archive using bzip2. The bzip2 utility must be installed separately.
- Synonym for the
- Do not preserve modification time.
- Use only the numeric UID and GID values when creating or extracting an archive.
- Write old-style (non-POSIX) archives.
- Don't write directory information that the older (V7) style
taris unable to decode. This implies the
- Do not strip leading slashes (‘/’) from pathnames. The default is to strip leading slashes.
- 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
and group ID could be preserved. Only meaningful in conjunction with the
- 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.
- Modify the archive member names according to the substitution expression
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
The format of these regular expressions is
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
-sexpressions 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
gcontinues to apply the substitution expression 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
goption. The optional trailing
pwill cause the final result of a successful substitution to be written to standard error in the following format:
File or archive member names that substitute to the empty string are not selected and will be skipped.
- Verbose operation mode. If
-vis specified multiple times or if the
-toption is also specified,
tarwill use a long format for listing files, similar to ls(1)
- Interactively rename files. This option causes
tarto prompt the user for the filename to use when storing or extracting files in an archive.
- Do not cross mount points in the file system.
- Compress archive using compress(1).
- Compress archive using gzip(1).
The options [
-014578] can be used to
select one of the compiled-in backup devices,
- Path in which to store temporary files.
- Default tape device to use instead of /dev/rst0. If set to hyphen (‘-’) standard output is used.
- default archive name
tar utility exits with one of the
- All files were processed successfully.
- An error occurred.
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
Verbosely create an archive, called backup.tar.gz, of all files matching the shell glob(7) function *.c:
$ tar zcvf backup.tar.gz
Verbosely list, but do not extract, all files ending in .jpeg from a compressed archive named backup.tar.gz. Note that the glob pattern has been quoted to avoid expansion by the shell:
$ tar tvzf backup.tar.gz
For more detailed examples, see pax(1).
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 option 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 user wanted. Additionally, the file modes
of extracted files and directories 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
tar command first appeared in
Version 7 AT&T UNIX.
Keith Muller at the University of California, San Diego.
flags are not portable to other versions of
where they may have a different meaning.