TAR(1) BSD General Commands Manual TAR(1)NAMEtar — tape archiver
SYNOPSIStar [-]{crtux}[-014578befHhjklmOoPpqSvwXZz] [archive] [blocksize]
[-C directory] [-s replstr] [-T file] [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.
One of the following flags must be present:
-c, --create Create new archive, or overwrite an existing archive,
adding the specified files to it.
-r, --append 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 List contents of archive. If any files are named on the
command line, only those files will be listed.
-u, --update Alias for -r.
-x, --extract, --get
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 ar‐
chive, later copies will overwrite earlier copies during
extraction. The file mode and modification time are pre‐
served if possible. The file mode is subject to modifica‐
tion by the umask(2).
In addition to the flags mentioned above, any of the following flags may
be used:
-b blocking factor, --block-size blocking factor
Set blocking factor to use for the archive. tar uses 512
byte blocks. The default is 20, the maximum is 126. Ar‐
chives 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, --file archive
Filename where the archive is stored. Defaults to
/dev/rst0. If the archive is of the form:
[[user@]host:]file then the archive will be processed using
rmt(8).
-h, --dereference
Follow symbolic links as if they were normal files or
directories.
-j, --bzip2, --bunzip2
Use bzip2(1) for compression of the archive. This option
is a GNU extension.
-k, --keep-old-files
Keep existing files; don't overwrite them from archive.
-l, --one-file-system
Do not descend across mount points.
-m, --modification-time
Do not preserve modification time.
-O When creating and appending to an archive, write old-style
(non-POSIX) archives. When extracting from an archive,
extract to standard output.
-o, --portability, --old-archive
Don't write directory information that the older (V7) style
tar is unable to decode. This implies the -O flag.
-p, --preserve-permissions, --preserve
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 meaning‐
ful in conjunction with the -x flag.
-q, --fast-read
Select the first archive member that matches each pattern
operand. No more than one archive member is matched for
each pattern. When members of type directory are matched,
the file hierarchy rooted at that directory is also
matched.
-S, --sparse This flag has no effect as tar always generates sparse
files.
-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 expres‐
sions are:
/old/new/[gps]
As in ed(1), old is a basic regular expression and new can
contain an ampersand (&), \n (where n is a digit) back-ref‐
erences, 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, termi‐
nating 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. The substitu‐
tions are applied by default to the destination hard and
symbolic links. The optional trailing s prevents the sub‐
stitutions from being performed on symbolic link destina‐
tions.
-v Verbose operation mode.
-w, --interactive, --confirmation
Interactively rename files. This option causes tar to
prompt the user for the filename to use when storing or
extracting files in an archive.
--xz Compress/decompress archive using xz(1).
-z, --gzip, --gunzip
Compress/decompress archive using gzip(1).
-B, --read-full-blocks
Reassemble small reads into full blocks (For reading from
4.2BSD pipes).
-C directory, --directory directory
This is a positional argument which sets the working direc‐
tory 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.
This argument and its parameter may also appear in a file
list specified by -T.
-H Only follow symlinks given on command line.
Note SysVr3/i386 picked up ISC/SCO UNIX compatibility which
implemented “-F file” which was defined as obtaining a list
of command line switches and files on which to operate from
the specified file, but SunOS-5 uses “-I file” because they
use ‘-F’ to mean something else. We might someday provide
SunOS-5 compatibility but it makes little sense to confuse
things with ISC/SCO compatibility.
-P, --absolute-paths
Do not strip leading slashes (‘/’) from pathnames. The
default is to strip leading slashes.
-T file, --files-from file
Read the names of files to archive or extract from the
given file, one per line. A line may also specify the
positional argument “-C directory”.
-X file, --exclude-from file
Exclude files matching the shell glob patterns listed in
the given file.
Note that it would be more standard to use this option to
mean ``do not cross filesystem mount points.''
-Z, --compress, --uncompress
Compress archive using compress.
--strict Do not enable GNU tar extensions such as long filenames and
long link names.
--atime-preserve
Preserve file access times.
--chrootchroot() to the current directory before extracting files.
Use with -x and -h to make absolute symlinks relative to
the current directory.
--unlink Ignored, only accepted for compatibility with other tar
implementations. tar always unlinks files before creating
them.
--use-compress-program program
Use the named program as the program to decompress the
input.
--force-local
Do not interpret filenames that contain a ‘:’ as remote
files.
--insecure Normally tar ignores filenames that contain “..” as a path
component. With this option, files that contain “..” can
be processed.
--no-recursion
Cause files of type directory being copied or archived, or
archive members of type directory being extracted, to match
only the directory file or archive member and not the file
hierarchy rooted at the directory.
The options [-014578] can be used to select one of the compiled-in backup
devices, /dev/rstN.
FILES
/dev/rst0 default archive name
DIAGNOSTICStar 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
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 direc‐
tories 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 ALSOcpio(1), pax(1)HISTORY
A tar command first appeared in Version 7 AT&T UNIX.
AUTHORS
Keith Muller at the University of California, San Diego.
BSD June 18, 2011 BSD
