TAR(1)

NAME
tar - tape archiver

SYNOPSIS
tar {crtux}[014578befHhjLmNOoPpqsvwXZz] [blocking-factor | archive | replstr] [-C directory] [-I file] [file ...]
tar {-crtux} [-014578eHhjLmNOoPpqvwXZz] [-b blocking-factor] [-C directory] [-f archive] [-I file] [-s replstr] [file ...]

DESCRIPTION
The 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 -C and -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:

-c  Create new archive, or overwrite an existing archive, adding the specified files to it.

-r  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.

-t  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(3) for more information), in which case tar will list all archive members that match each pattern.

-u  Alias for -r.

-x  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(3) for more information), in which case tar will 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:

-b blocking-factor
    Set blocking factor to use for the archive. tar uses 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.

-C directory
    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.

-e  Stop after the first error.

-f archive
    Filename where the archive is stored. Defaults to /dev/rst0.

-H  Follow symlinks given on the command line only.

-h  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.

-I file
    This is a positional argument which reads the names of files to archive or extract from the given file, one per line.

-j  Compress archive using bzip2. The bzip2 utility must be installed separately.

-L  Synonym for the -h option.

-m  Do not preserve modification time.

-N  Use only the numeric UID and GID values when creating or extracting an archive.

-O  Write old-style (non-POSIX) archives.

-o  Don't write directory information that the older (V7) style tar is unable to decode. This implies the -O flag.

-P  Do not strip leading slashes (‘/’) from pathnames. The default is to strip leading slashes.

-p  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 is the superuser. Only meaningful in conjunction with the -x flag.

-q  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.

-s replstr
    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 specified.

    The format of these regular expressions is

        /old/new/[gp]

    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 -s expressions 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 g continues 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 g option. The optional trailing p will cause the final result of a successful substitution to be written to standard error in the following format:

        original-pathname >> new-pathname

    File or archive member names that substitute to the empty string are not selected and will be skipped.

-v  Verbose operation mode.

-w  Interactively rename files. This option causes tar to prompt the user for the filename to use when storing or extracting files in an archive.

-X  Do not cross mount points in the file system.

-Z  Compress archive using compress(1).

-z  Compress archive using gzip(1).

The options [-014578] can be used to select one of the compiled-in backup devices, /dev/rstN.

ENVIRONMENT

TMPDIR
    Path in which to store temporary files.

TAPE
    Default tape device to use instead of /dev/rst0.

FILES

/dev/rst0
    default archive name

EXIT STATUS
The tar utility exits with one of the following values:

0   All files were processed successfully.
1   An error occurred.

EXAMPLES
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 sekve

Verbosely create an archive, called backup.tar.gz, of all files matching the shell glob(3) function *.c:

    $ tar zcvf backup.tar.gz *.c

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 '*.jpeg'

For more detailed examples, see pax(1).

DIAGNOSTICS
Whenever 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 specification.

SEE ALSO
cpio(1), pax(1)

HISTORY
A tar command first appeared in AT&T UNIX.

AUTHORS
Keith Muller at the University of California, San Diego.

CAVEATS
The -j and -L flags are not portable to other versions of tar where they may have a different meaning.