TAR(1)

NAME
tar - tape archiver

SYNOPSIS
tar [-]{crtux}[befhmopvwyzHLPRXZ014578] [archive] [blocksize] [-C directory] [-s replstr] file1 [file2...]

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 a floppy or a regular disk file.

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.

-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. 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 63 violate the POSIX standard and will not be portable to all systems.

-e  Stop after first error.

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

-h  Follow symbolic links as if they were normal files or directories.

-m  Do not preserve modification time.

-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  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.

-s replstr
    Modify the file or archive member names specified by the pattern or file operands according to the substitution expression replstr, using the syntax of the ed(1) utility regular expressions. The format of these regular expressions are:
        /old/new/[gp]
    As in ed(1), old is a basic regular expression 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.

-y  Compress archive using bzip2.

-z  Compress archive using gzip.

-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.

-H  Follow symlinks given on command line only.

-L  Follow all symlinks.

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

-R  When verbosely extracting files, prefix the filename with the block offset in the archive. If this is set, file names will be printed to stdout, not stderr.

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

-Z  Compress archive using compress.

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

FILES

/dev/rst0
    The default archive name

SEE ALSO
pax(1), cpio(1)

AUTHOR
Keith Muller at the University of California, San Diego

ERRORS
tar will exit with one of the following values:

0   All files were processed successfully.

1   An error occurred.

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 options 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.