\"
\" SPDX-License-Identifier: BSD-2-Clause
\"
\" Copyright (c) 2003-2007 Tim Kientzle
\" Copyright (c) 2017 Martin Matuska
\" All rights reserved.
\"
Dd April 23, 2024
Dt TAR 1
Os
Sh NAME
Nm tar
Nd manipulate tape archives
Sh SYNOPSIS
Nm
Op Ar bundled-flags Ao args Ac
Op Ao Ar file Ac | Ao Ar pattern Ac ...
Nm
Brq Fl c
Op Ar options
Op Ar files | Ar directories
Nm
Brq Fl r | Fl u
Fl f Ar archive-file
Op Ar options
Op Ar files | Ar directories
Nm
Brq Fl t | Fl x
Op Ar options
Op Ar patterns
Sh DESCRIPTION
Nm
creates and manipulates streaming archive files.
This implementation can extract from tar, pax, cpio, zip, jar, ar, xar,
rpm, 7-zip, and ISO 9660 cdrom images and can create tar, pax, cpio, ar, zip,
7-zip, and shar archives.
Pp
The first synopsis form shows a
Dq bundled
option word.
This usage is provided for compatibility with historical implementations.
See COMPATIBILITY below for details.
Pp
The other synopsis forms show the preferred usage.
The first option to
Nm
is a mode indicator from the following list:
Bl -tag -compact -width indent
It Fl c
Create a new archive containing the specified items.
The long option form is
Fl Fl create .
It Fl r
Like
Fl c ,
but new entries are appended to the archive.
Note that this only works on uncompressed archives stored in regular files.
The
Fl f
option is required.
The long option form is
Fl Fl append .
It Fl t
List archive contents to stdout.
The long option form is
Fl Fl list .
It Fl u
Like
Fl r ,
but new entries are added only if they have a modification date
newer than the corresponding entry in the archive.
Note that this only works on uncompressed archives stored in regular files.
The
Fl f
option is required.
The long form is
Fl Fl update .
It Fl x
Extract to disk from the archive.
If a file with the same name appears more than once in the archive,
each copy will be extracted, with later copies overwriting (replacing)
earlier copies.
The long option form is
Fl Fl extract .
El
Pp
In
Fl c ,
Fl r ,
or
Fl u
mode, each specified file or directory is added to the
archive in the order specified on the command line.
By default, the contents of each directory are also archived.
Pp
In extract or list mode, the entire command line
is read and parsed before the archive is opened.
The pathnames or patterns on the command line indicate
which items in the archive should be processed.
Patterns are shell-style globbing patterns as
documented in
Xr tcsh 1 .
Sh OPTIONS
Unless specifically stated otherwise, options are applicable in
all operating modes.
Bl -tag -width indent
It Cm @ Ns Pa archive
(c and r modes only)
The specified archive is opened and the entries
in it will be appended to the current archive.
As a simple example,
Dl Nm Fl c Fl f Pa - Pa newfile Cm @ Ns Pa original.tar
writes a new archive to standard output containing a file
Pa newfile
and all of the entries from
Pa original.tar .
In contrast,
Dl Nm Fl c Fl f Pa - Pa newfile Pa original.tar
creates a new archive with only two entries.
Similarly,
Dl Nm Fl czf Pa - Fl Fl format Cm pax Cm @ Ns Pa -
reads an archive from standard input (whose format will be determined
automatically) and converts it into a gzip-compressed
pax-format archive on stdout.
In this way,
Nm
can be used to convert archives from one format to another.
It Fl a , Fl Fl auto-compress
(c mode only)
Use the archive suffix to decide a set of the format and
the compressions.
As a simple example,
Dl Nm Fl a Fl cf Pa archive.tgz source.c source.h
creates a new archive with restricted pax format and gzip compression,
Dl Nm Fl a Fl cf Pa archive.tar.bz2.uu source.c source.h
creates a new archive with restricted pax format and bzip2 compression
and uuencode compression,
Dl Nm Fl a Fl cf Pa archive.zip source.c source.h
creates a new archive with zip format,
Dl Nm Fl a Fl jcf Pa archive.tgz source.c source.h
ignores the
Dq -j
option, and creates a new archive with restricted pax format
and gzip compression,
Dl Nm Fl a Fl jcf Pa archive.xxx source.c source.h
if it is unknown suffix or no suffix, creates a new archive with
restricted pax format and bzip2 compression.
It Fl Fl acls
(c, r, u, x modes only)
Archive or extract POSIX.1e or NFSv4 ACLs.
This is the reverse of
Fl Fl no-acls
and the default behavior in c, r, and u modes (except on Mac OS X) or if
Nm
is run in x mode as root.
On Mac OS X this option translates extended ACLs to NFSv4 ACLs.
To store extended ACLs the
Fl Fl mac-metadata
option is preferred.
It Fl B , Fl Fl read-full-blocks
Ignored for compatibility with other
Xr tar 1
implementations.
It Fl b Ar blocksize , Fl Fl block-size Ar blocksize
Specify the block size, in 512-byte records, for tape drive I/O.
As a rule, this argument is only needed when reading from or writing
to tape drives, and usually not even then as the default block size of
20 records (10240 bytes) is very common.
It Fl C Ar directory , Fl Fl cd Ar directory , Fl Fl directory Ar directory
In c and r mode, this changes the directory before adding
the following files.
In x mode, change directories after opening the archive
but before extracting entries from the archive.
It Fl Fl chroot
(x mode only)
Fn chroot
to the current directory after processing any
Fl C
options and before extracting any files.
It Fl Fl clear-nochange-fflags
(x mode only)
Before removing file system objects to replace them, clear platform-specific
file attributes or file flags that might prevent removal.
It Fl Fl exclude Ar pattern
Do not process files or directories that match the
specified pattern.
Note that exclusions take precedence over patterns or filenames
specified on the command line.
It Fl Fl exclude-vcs
Do not process files or directories internally used by the
version control systems
Sq Arch ,
Sq Bazaar ,
Sq CVS ,
Sq Darcs ,
Sq Mercurial ,
Sq RCS ,
Sq SCCS ,
Sq SVN
and
Sq git .
It Fl Fl fflags
(c, r, u, x modes only)
Archive or extract platform-specific file attributes or file flags.
This is the reverse of
Fl Fl no-fflags
and the default behavior in c, r, and u modes or if
Nm
is run in x mode as root.
It Fl Fl format Ar format
(c, r, u mode only)
Use the specified format for the created archive.
Supported formats include
Dq cpio ,
Dq pax ,
Dq shar ,
and
Dq ustar .
Other formats may also be supported; see
Xr libarchive-formats 5
for more information about currently-supported formats.
In r and u modes, when extending an existing archive, the format specified
here must be compatible with the format of the existing archive on disk.
It Fl f Ar file , Fl Fl file Ar file
Read the archive from or write the archive to the specified file.
The filename can be
Pa -
for standard input or standard output.
The default varies by system;
on
Fx ,
the default is
Pa /dev/sa0 ;
on Linux, the default is
Pa /dev/st0 .
It Fl Fl gid Ar id
Use the provided group id number.
On extract, this overrides the group id in the archive;
the group name in the archive will be ignored.
On create, this overrides the group id read from disk;
if
Fl Fl gname
is not also specified, the group name will be set to
match the group id.
It Fl Fl gname Ar name
Use the provided group name.
On extract, this overrides the group name in the archive;
if the provided group name does not exist on the system,
the group id
(from the archive or from the
Fl Fl gid
option)
will be used instead.
On create, this sets the group name that will be stored
in the archive;
the name will not be verified against the system group database.
It Fl Fl group Ar name Ns Op : Ns Ar gid
Use the provided group, if
Ar gid
is not provided,
Ar name
can be either a group name or numeric id.
See the
Fl Fl gname
option for details.
It Fl H
(c and r modes only)
Symbolic links named on the command line will be followed; the
target of the link will be archived, not the link itself.
It Fl h
(c and r modes only)
Synonym for
Fl L .
It Fl I
Synonym for
Fl T .
It Fl Fl help
Show usage.
It Fl Fl hfsCompression
(x mode only)
Mac OS X specific (v10.6 or later). Compress extracted regular files with HFS+
compression.
It Fl Fl ignore-zeros
An alias of
Fl Fl options Cm read_concatenated_archives
for compatibility with GNU tar.
It Fl Fl include Ar pattern
Process only files or directories that match the specified pattern.
Note that exclusions specified with
Fl Fl exclude
take precedence over inclusions.
If no inclusions are explicitly specified, all entries are processed by
default.
The
Fl Fl include
option is especially useful when filtering archives.
For example, the command
Dl Nm Fl c Fl f Pa new.tar Fl Fl include='*foo*' Cm @ Ns Pa old.tgz
creates a new archive
Pa new.tar
containing only the entries from
Pa old.tgz
containing the string
Sq foo .
It Fl J , Fl Fl xz
(c mode only)
Compress the resulting archive with
Xr xz 1 .
In extract or list modes, this option is ignored.
Note that this
Nm tar
implementation recognizes XZ compression automatically when reading archives.
It Fl j , Fl Fl bzip , Fl Fl bzip2 , Fl Fl bunzip2
(c mode only)
Compress the resulting archive with
Xr bzip2 1 .
In extract or list modes, this option is ignored.
Note that this
Nm tar
implementation recognizes bzip2 compression automatically when reading
archives.
It Fl k , Fl Fl keep-old-files
(x mode only)
Do not overwrite existing files.
In particular, if a file appears more than once in an archive,
later copies will not overwrite earlier copies.
It Fl Fl keep-newer-files
(x mode only)
Do not overwrite existing files that are newer than the
versions appearing in the archive being extracted.
It Fl L , Fl Fl dereference
(c and r modes only)
All symbolic links will be followed.
Normally, symbolic links are archived as such.
With this option, the target of the link will be archived instead.
It Fl l , Fl Fl check-links
(c and r modes only)
Issue a warning message unless all links to each file are archived.
It Fl Fl lrzip
(c mode only)
Compress the resulting archive with
Xr lrzip 1 .
In extract or list modes, this option is ignored.
Note that this
Nm tar
implementation recognizes lrzip compression automatically when reading
archives.
It Fl Fl lz4
(c mode only)
Compress the archive with lz4-compatible compression before writing it.
In extract or list modes, this option is ignored.
Note that this
Nm tar
implementation recognizes lz4 compression automatically when reading archives.
It Fl Fl zstd
(c mode only)
Compress the archive with zstd-compatible compression before writing it.
In extract or list modes, this option is ignored.
Note that this
Nm tar
implementation recognizes zstd compression automatically when reading archives.
It Fl Fl lzma
(c mode only) Compress the resulting archive with the original LZMA algorithm.
In extract or list modes, this option is ignored.
Use of this option is discouraged and new archives should be created with
Fl Fl xz
instead.
Note that this
Nm tar
implementation recognizes LZMA compression automatically when reading archives.
It Fl Fl lzop
(c mode only)
Compress the resulting archive with
Xr lzop 1 .
In extract or list modes, this option is ignored.
Note that this
Nm tar
implementation recognizes LZO compression automatically when reading archives.
It Fl m , Fl Fl modification-time
(x mode only)
Do not extract modification time.
By default, the modification time is set to the time stored in the archive.
It Fl Fl mac-metadata
(c, r, u and x mode only)
Mac OS X specific.
Archive or extract extended ACLs and extended file
attributes using
Xr copyfile 3
in AppleDouble format.
This is the reverse of
Fl Fl no-mac-metadata .
and the default behavior in c, r, and u modes or if
Nm
is run in x mode as root.
Currently supported only for pax formats
(including "pax restricted", the default tar format for bsdtar.)
It Fl n , Fl Fl norecurse , Fl Fl no-recursion
Do not operate recursively on the content of directories.
It Fl Fl newer Ar date
(c, r, u modes only)
Only include files and directories newer than the specified date.
This compares ctime entries.
It Fl Fl newer-mtime Ar date
(c, r, u modes only)
Like
Fl Fl newer ,
except it compares mtime entries instead of ctime entries.
It Fl Fl newer-than Pa file
(c, r, u modes only)
Only include files and directories newer than the specified file.
This compares ctime entries.
It Fl Fl newer-mtime-than Pa file
(c, r, u modes only)
Like
Fl Fl newer-than ,
except it compares mtime entries instead of ctime entries.
It Fl Fl nodump
(c and r modes only)
Honor the nodump file flag by skipping this file.
It Fl Fl nopreserveHFSCompression
(x mode only)
Mac OS X specific (v10.6 or later). Do not compress extracted regular files
which were compressed with HFS+ compression before archived.
By default, compress the regular files again with HFS+ compression.
It Fl Fl null
(use with
Fl I
or
Fl T )
Filenames or patterns are separated by null characters,
not by newlines.
This is often used to read filenames output by the
Fl print0
option to
Xr find 1 .
It Fl Fl no-acls
(c, r, u, x modes only)
Do not archive or extract POSIX.1e or NFSv4 ACLs.
This is the reverse of
Fl Fl acls
and the default behavior if
Nm
is run as non-root in x mode (on Mac OS X as any user in c, r, u and x modes).
It Fl Fl no-fflags
(c, r, u, x modes only)
Do not archive or extract file attributes or file flags.
This is the reverse of
Fl Fl fflags
and the default behavior if
Nm
is run as non-root in x mode.
It Fl Fl no-mac-metadata
(x mode only)
Mac OS X specific.
Do not archive or extract ACLs and extended file attributes
using
Xr copyfile 3
in AppleDouble format.
This is the reverse of
Fl Fl mac-metadata .
and the default behavior if
Nm
is run as non-root in x mode.
It Fl Fl no-read-sparse
(c, r, u modes only)
Do not read sparse file information from disk.
This is the reverse of
Fl Fl read-sparse .
It Fl Fl no-safe-writes
(x mode only)
Do not create temporary files and use
Xr rename 2
to replace the original ones.
This is the reverse of
Fl Fl safe-writes .
It Fl Fl no-same-owner
(x mode only)
Do not extract owner and group IDs.
This is the reverse of
Fl Fl same-owner
and the default behavior if
Nm
is run as non-root.
It Fl Fl no-same-permissions
(x mode only)
Do not extract full permissions (SGID, SUID, sticky bit,
file attributes or file flags, extended file attributes and ACLs).
This is the reverse of
Fl p
and the default behavior if
Nm
is run as non-root.
It Fl Fl no-xattrs
(c, r, u, x modes only)
Do not archive or extract extended file attributes.
This is the reverse of
Fl Fl xattrs
and the default behavior if
Nm
is run as non-root in x mode.
It Fl Fl numeric-owner
This is equivalent to
Fl Fl uname
Qq
Fl Fl gname
Qq .
On extract, it causes user and group names in the archive
to be ignored in favor of the numeric user and group ids.
On create, it causes user and group names to not be stored
in the archive.
It Fl O , Fl Fl to-stdout
(x, t modes only)
In extract (-x) mode, files will be written to standard out rather than
being extracted to disk.
In list (-t) mode, the file listing will be written to stderr rather than
the usual stdout.
It Fl o
(x mode)
Use the user and group of the user running the program rather
than those specified in the archive.
Note that this has no significance unless
Fl p
is specified, and the program is being run by the root user.
In this case, the file modes and flags from
the archive will be restored, but ACLs or owner information in
the archive will be discarded.
It Fl o
(c, r, u mode)
A synonym for
Fl Fl format Ar ustar
It Fl Fl older Ar date
(c, r, u modes only)
Only include files and directories older than the specified date.
This compares ctime entries.
It Fl Fl older-mtime Ar date
(c, r, u modes only)
Like
Fl Fl older ,
except it compares mtime entries instead of ctime entries.
It Fl Fl older-than Pa file
(c, r, u modes only)
Only include files and directories older than the specified file.
This compares ctime entries.
It Fl Fl older-mtime-than Pa file
(c, r, u modes only)
Like
Fl Fl older-than ,
except it compares mtime entries instead of ctime entries.
It Fl Fl one-file-system
(c, r, and u modes)
Do not cross mount points.
It Fl Fl options Ar options
Select optional behaviors for particular modules.
The argument is a text string containing comma-separated
keywords and values.
These are passed to the modules that handle particular
formats to control how those formats will behave.
Each option has one of the following forms:
Bl -tag -compact -width indent
It Ar key=value
The key will be set to the specified value in every module that supports it.
Modules that do not support this key will ignore it.
It Ar key
The key will be enabled in every module that supports it.
This is equivalent to
Ar key Ns Cm =1 .
It Ar !key
The key will be disabled in every module that supports it.
It Ar module:key=value , Ar module:key , Ar module:!key
As above, but the corresponding key and value will be provided
only to modules whose name matches
Ar module .
El
Pp
The complete list of supported modules and keys
for create and append modes is in
Xr archive_write_set_options 3
and for extract and list modes in
Xr archive_read_set_options 3 .
Pp
Examples of supported options:
Bl -tag -compact -width indent
It Cm iso9660:joliet
Support Joliet extensions.
This is enabled by default, use
Cm !joliet
or
Cm iso9660:!joliet
to disable.
It Cm iso9660:rockridge
Support Rock Ridge extensions.
This is enabled by default, use
Cm !rockridge
or
Cm iso9660:!rockridge
to disable.
It Cm gzip:compression-level
A decimal integer from 1 to 9 specifying the gzip compression level.
It Cm gzip:timestamp
Store timestamp.
This is enabled by default, use
Cm !timestamp
or
Cm gzip:!timestamp
to disable.
It Cm lrzip:compression Ns = Ns Ar type
Use
Ar type
as compression method.
Supported values are bzip2, gzip, lzo (ultra fast),
and zpaq (best, extremely slow).
It Cm lrzip:compression-level
A decimal integer from 1 to 9 specifying the lrzip compression level.
It Cm lz4:compression-level
A decimal integer from 1 to 9 specifying the lzop compression level.
It Cm lz4:stream-checksum
Enable stream checksum.
This is by default, use
Cm lz4:!stream-checksum
to disable.
It Cm lz4:block-checksum
Enable block checksum (Disabled by default).
It Cm lz4:block-size
A decimal integer from 4 to 7 specifying the lz4 compression block size
(7 is set by default).
It Cm lz4:block-dependence
Use the previous block of the block being compressed for
a compression dictionary to improve compression ratio.
It Cm zstd:compression-level Ns = Ns Ar N
A decimal integer specifying the zstd compression level.
Supported values depend
on the library version, common values are from 1 to 22.
It Cm zstd:threads Ns = Ns Ar N
Specify the number of worker threads to use, or 0 to use as many
threads as there are CPU cores in the system.
It Cm zstd:frame-per-file
Start a new compression frame at the beginning of each file in the
archive.
It Cm zstd:min-frame-in Ns = Ns Ar N
In combination with
Cm zstd:frame-per-file ,
do not start a new compression frame unless the uncompressed size of
the current frame is at least
Ar N
bytes.
The number may be followed by
Li k / Li kB ,
Li M / Li MB ,
or
Li G / Li GB
to indicate kilobytes, megabytes or gigabytes respectively.
It Cm zstd:min-frame-out Ns = Ns Ar N , Cm zstd:min-frame-size Ns = Ns Ar N
In combination with
Cm zstd:frame-per-file ,
do not start a new compression frame unless the compressed size of the
current frame is at least
Ar N
bytes.
The number may be followed by
Li k / Li kB ,
Li M / Li MB ,
or
Li G / Li GB
to indicate kilobytes, megabytes or gigabytes respectively.
It Cm zstd:max-frame-in Ns = Ns Ar N , Cm zstd:max-frame-size Ns = Ns Ar N
Start a new compression frame as soon as possible after the
uncompressed size of the current frame exceeds
Ar N
bytes.
The number may be followed by
Li k / Li kB ,
Li M / Li MB ,
or
Li G / Li GB
to indicate kilobytes, megabytes or gigabytes respectively.
Values less than 1,024 will be rejected.
It Cm zstd:max-frame-out Ns = Ns Ar N
Start a new compression frame as soon as possible after the compressed
size of the current frame exceeds
Ar N
bytes.
The number may be followed by
Li k / Li kB ,
Li M / Li MB ,
or
Li G / Li GB
to indicate kilobytes, megabytes or gigabytes respectively.
Values less than 1,024 will be rejected.
It Cm lzop:compression-level
A decimal integer from 1 to 9 specifying the lzop compression level.
It Cm xz:compression-level
A decimal integer from 0 to 9 specifying the xz compression level.
It Cm xz:threads
Specify the number of worker threads to use.
Setting threads to a special value 0 makes
Xr xz 1
use as many threads as there are CPU cores on the system.
It Cm mtree: Ns Ar keyword
The mtree writer module allows you to specify which mtree keywords
will be included in the output.
Supported keywords include:
Cm cksum , Cm device , Cm flags , Cm gid , Cm gname , Cm indent ,
Cm link , Cm md5 , Cm mode , Cm nlink , Cm rmd160 , Cm sha1 , Cm sha256 ,
Cm sha384 , Cm sha512 , Cm size , Cm time , Cm uid , Cm uname .
The default is equivalent to:
Dq device, flags, gid, gname, link, mode, nlink, size, time, type, uid, uname .
It Cm mtree:all
Enables all of the above keywords.
You can also use
Cm mtree:!all
to disable all keywords.
It Cm mtree:use-set
Enable generation of
Cm /set
lines in the output.
It Cm mtree:indent
Produce human-readable output by indenting options and splitting lines
to fit into 80 columns.
It Cm zip:compression Ns = Ns Ar type
Use
Ar type
as compression method.
Supported values are store (uncompressed) and deflate (gzip algorithm).
It Cm zip:encryption
Enable encryption using traditional zip encryption.
It Cm zip:encryption Ns = Ns Ar type
Use
Ar type
as encryption type.
Supported values are zipcrypt (traditional zip encryption),
aes128 (WinZip AES-128 encryption) and aes256 (WinZip AES-256 encryption).
It Cm read_concatenated_archives
Ignore zeroed blocks in the archive, which occurs when multiple tar archives
have been concatenated together.
Without this option, only the contents of
the first concatenated archive would be read.
This option is comparable to the
Fl i , Fl Fl ignore-zeros
option of GNU tar.
El
If a provided option is not supported by any module, that
is a fatal error.
It Fl P , Fl Fl absolute-paths
Preserve pathnames.
By default, absolute pathnames (those that begin with a /
character) have the leading slash removed both when creating archives
and extracting from them.
Also,
Nm
will refuse to extract archive entries whose pathnames contain
Pa ..
or whose target directory would be altered by a symlink.
This option suppresses these behaviors.
It Fl p , Fl Fl insecure , Fl Fl preserve-permissions
(x mode only)
Preserve file permissions.
Attempt to restore the full permissions, including file modes, file attributes
or file flags, extended file attributes and ACLs, if available, for each item
extracted from the archive.
This is the reverse of
Fl Fl no-same-permissions
and the default if
Nm
is being run as root.
It can be partially overridden by also specifying
Fl Fl no-acls ,
Fl Fl no-fflags ,
Fl Fl no-mac-metadata
or
Fl Fl no-xattrs .
It Fl Fl passphrase Ar passphrase
The
Pa passphrase
is used to extract or create an encrypted archive.
Currently, zip is the only supported format that supports encryption.
You shouldn't use this option unless you realize how insecure
use of this option is.
It Fl Fl posix
(c, r, u mode only)
Synonym for
Fl Fl format Ar pax
It Fl q , Fl Fl fast-read
(x and t mode only)
Extract or list only the first archive entry that matches each pattern
or filename operand.
Exit as soon as each specified pattern or filename has been matched.
By default, the archive is always read to the very end, since
there can be multiple entries with the same name and, by convention,
later entries overwrite earlier entries.
This option is provided as a performance optimization.
It Fl Fl read-sparse
(c, r, u modes only)
Read sparse file information from disk.
This is the reverse of
Fl Fl no-read-sparse
and the default behavior.
It Fl S
(x mode only)
Extract files as sparse files.
For every block on disk, check first if it contains only NULL bytes and seek
over it otherwise.
This works similar to the conv=sparse option of dd.
It Fl s Ar pattern
Modify file or archive member names according to
Pa pattern .
The pattern has the format
Ar /old/new/ Ns Op bghHprRsS
where
Ar old
is a basic regular expression,
Ar new
is the replacement string of the matched part,
and the optional trailing letters modify
how the replacement is handled.
If
Ar old
is not matched, the pattern is skipped.
Within
Ar new ,
~ is substituted with the match, \e1 to \e9 with the content of
the corresponding captured group.
The optional trailing g specifies that matching should continue
after the matched part and stop on the first unmatched pattern.
The optional trailing s specifies that the pattern applies to the value
of symbolic links.
The optional trailing p specifies that after a successful substitution
the original path name and the new path name should be printed to
standard error.
The optional trailing b specifies that the substitution should be
matched from the beginning of the string rather than from right after the
position at which the previous matching substitution ended.
Optional trailing H, R, or S characters suppress substitutions
for hardlink targets, regular filenames, or symlink targets,
respectively.
Optional trailing h, r, or s characters enable substitutions
for hardlink targets, regular filenames, or symlink targets,
respectively.
The default is
Ar hrs
which applies substitutions to all names.
In particular, it is never necessary to specify h, r, or s.
It Fl Fl safe-writes
(x mode only)
Extract files atomically.
By default
Nm
unlinks the original file with the same name as the extracted file (if it
exists), and then creates it immediately under the same name and writes to
it.
For a short period of time, applications trying to access the file might
not find it, or see incomplete results.
If
Fl Fl safe-writes
is enabled,
Nm
first creates a unique temporary file, then writes the new contents to
the temporary file, and finally renames the temporary file to its final
name atomically using
Xr rename 2 .
This guarantees that an application accessing the file, will either see
the old contents or the new contents at all times.
It Fl Fl same-owner
(x mode only)
Extract owner and group IDs.
This is the reverse of
Fl Fl no-same-owner
and the default behavior if
Nm
is run as root.
It Fl Fl strip-components Ar count
Remove the specified number of leading path elements.
Pathnames with fewer elements will be silently skipped.
Note that the pathname is edited after checking inclusion/exclusion patterns
but before security checks.
It Fl T Ar filename , Fl Fl files-from Ar filename
In x or t mode,
Nm
will read the list of names to be extracted from
Pa filename .
In c mode,
Nm
will read names to be archived from
Pa filename .
The special name
Dq -C
on a line by itself will cause the current directory to be changed to
the directory specified on the following line.
Names are terminated by newlines unless
Fl Fl null
is specified.
Note that
Fl Fl null
also disables the special handling of lines containing
Dq -C .
Note:  If you are generating lists of files using
Xr find 1 ,
you probably want to use
Fl n
as well.
It Fl Fl totals
(c, r, u modes only)
After archiving all files, print a summary to stderr.
It Fl U , Fl Fl unlink , Fl Fl unlink-first
(x mode only)
Unlink files before creating them.
This can be a minor performance optimization if most files
already exist, but can make things slower if most files
do not already exist.
This flag also causes
Nm
to remove intervening directory symlinks instead of
reporting an error.
See the SECURITY section below for more details.
It Fl Fl uid Ar id
Use the provided user id number and ignore the user
name from the archive.
On create, if
Fl Fl uname
is not also specified, the user name will be set to
match the user id.
It Fl Fl uname Ar name
Use the provided user name.
On extract, this overrides the user name in the archive;
if the provided user name does not exist on the system,
it will be ignored and the user id
(from the archive or from the
Fl Fl uid
option)
will be used instead.
On create, this sets the user name that will be stored
in the archive;
the name is not verified against the system user database.
It Fl Fl use-compress-program Ar program
Pipe the input (in x or t mode) or the output (in c mode) through
Pa program
instead of using the builtin compression support.
It Fl Fl owner Ar name Ns Op : Ns Ar uid
Use the provided user, if
Ar uid
is not provided,
Ar name
can be either an username or numeric id.
See the
Fl Fl uname
option for details.
It Fl v , Fl Fl verbose
Produce verbose output.
In create and extract modes,
Nm
will list each file name as it is read from or written to
the archive.
In list mode,
Nm
will produce output similar to that of
Xr ls 1 .
An additional
Fl v
option will also provide ls-like details in create and extract mode.
It Fl Fl version
Print version of
Nm
and
Nm libarchive ,
and exit.
It Fl w , Fl Fl confirmation , Fl Fl interactive
Ask for confirmation for every action.
It Fl X Ar filename , Fl Fl exclude-from Ar filename
Read a list of exclusion patterns from the specified file.
See
Fl Fl exclude
for more information about the handling of exclusions.
It Fl Fl xattrs
(c, r, u, x modes only)
Archive or extract extended file attributes.
This is the reverse of
Fl Fl no-xattrs
and the default behavior in c, r, and u modes or if
Nm
is run in x mode as root.
It Fl y
(c mode only)
Compress the resulting archive with
Xr bzip2 1 .
In extract or list modes, this option is ignored.
Note that this
Nm tar
implementation recognizes bzip2 compression automatically when reading
archives.
It Fl Z , Fl Fl compress , Fl Fl uncompress
(c mode only)
Compress the resulting archive with
Xr compress 1 .
In extract or list modes, this option is ignored.
Note that this
Nm tar
implementation recognizes compress compression automatically when reading
archives.
It Fl z , Fl Fl gunzip , Fl Fl gzip
(c mode only)
Compress the resulting archive with
Xr gzip 1 .
In extract or list modes, this option is ignored.
Note that this
Nm tar
implementation recognizes gzip compression automatically when reading
archives.
El
Sh ENVIRONMENT
The following environment variables affect the execution of
Nm :
Bl -tag -width indent
It Ev TAR_READER_OPTIONS
The default options for format readers and compression readers.
The
Fl Fl options
option overrides this.
It Ev TAR_WRITER_OPTIONS
The default options for format writers and compression writers.
The
Fl Fl options
option overrides this.
It Ev LANG
The locale to use.
See
Xr environ 7
for more information.
It Ev TAPE
The default device.
The
Fl f
option overrides this.
Please see the description of the
Fl f
option above for more details.
It Ev TZ
The timezone to use when displaying dates.
See
Xr environ 7
for more information.
El
Sh EXIT STATUS
Ex -std
Sh EXAMPLES
The following creates a new archive
called
Ar file.tar.gz
that contains two files
Ar source.c
and
Ar source.h :
Dl Nm Fl czf Pa file.tar.gz Pa source.c Pa source.h
Pp
To view a detailed table of contents for this
archive:
Dl Nm Fl tvf Pa file.tar.gz
Pp
To extract all entries from the archive on
the default tape drive:
Dl Nm Fl x
Pp
To examine the contents of an ISO 9660 cdrom image:
Dl Nm Fl tf Pa image.iso
Pp
To move file hierarchies, invoke
Nm
as
Dl Nm Fl cf Pa - Fl C Pa srcdir \&. | Nm Fl xpf Pa - Fl C Pa destdir
or more traditionally
Dl cd srcdir \&; Nm Fl cf Pa - \&. | ( cd destdir \&; Nm Fl xpf Pa - )
Pp
In create mode, the list of files and directories to be archived
can also include directory change instructions of the form
Cm -C Ns Pa foo/baz
and archive inclusions of the form
Cm @ Ns Pa archive-file .
For example, the command line
Dl Nm Fl c Fl f Pa new.tar Pa foo1 Cm @ Ns Pa old.tgz Cm -C Ns Pa /tmp Pa foo2
will create a new archive
Pa new.tar .
Nm
will read the file
Pa foo1
from the current directory and add it to the output archive.
It will then read each entry from
Pa old.tgz
and add those entries to the output archive.
Finally, it will switch to the
Pa /tmp
directory and add
Pa foo2
to the output archive.
Pp
An input file in
Xr mtree 5
format can be used to create an output archive with arbitrary ownership,
permissions, or names that differ from existing data on disk:
Bd -literal -offset indent
$ cat input.mtree
#mtree
usr/bin uid=0 gid=0 mode=0755 type=dir
usr/bin/ls uid=0 gid=0 mode=0755 type=file content=myls
$ tar -cvf output.tar @input.mtree
Ed
Pp
The
Fl Fl newer
and
Fl Fl newer-mtime
switches accept a variety of common date and time specifications, including
Dq 12 Mar 2005 7:14:29pm ,
Dq 2005-03-12 19:14 ,
Dq 5 minutes ago ,
and
Dq 19:14 PST May 1 .
Pp
The
Fl Fl options
argument can be used to control various details of archive generation
or reading.
For example, you can generate mtree output which only contains
Cm type , Cm time ,
and
Cm uid
keywords:
Dl Nm Fl cf Pa file.tar Fl Fl format=mtree Fl Fl options='!all,type,time,uid' Pa dir
or you can set the compression level used by gzip or xz compression:
Dl Nm Fl czf Pa file.tar Fl Fl options='compression-level=9' .
For more details, see the explanation of the
Fn archive_read_set_options
and
Fn archive_write_set_options
API calls that are described in
Xr archive_read 3
and
Xr archive_write 3 .
Sh COMPATIBILITY
The bundled-arguments format is supported for compatibility
with historic implementations.
It consists of an initial word (with no leading - character) in which
each character indicates an option.
Arguments follow as separate words.
The order of the arguments must match the order
of the corresponding characters in the bundled command word.
For example,
Dl Nm Cm tbf 32 Pa file.tar
specifies three flags
Cm t ,
Cm b ,
and
Cm f .
The
Cm b
and
Cm f
flags both require arguments,
so there must be two additional items
on the command line.
The
Ar 32
is the argument to the
Cm b
flag, and
Ar file.tar
is the argument to the
Cm f
flag.
Pp
The mode options c, r, t, u, and x and the options
b, f, l, m, o, v, and w comply with SUSv2.
Pp
For maximum portability, scripts that invoke
Nm tar
should use the bundled-argument format above, should limit
themselves to the
Cm c ,
Cm t ,
and
Cm x
modes, and the
Cm b ,
Cm f ,
Cm m ,
Cm v ,
and
Cm w
options.
Pp
Additional long options are provided to improve compatibility with other
tar implementations.
Sh SECURITY
Certain security issues are common to many archiving programs, including
Nm .
In particular, carefully-crafted archives can request that
Nm
extract files to locations outside of the target directory.
This can potentially be used to cause unwitting users to overwrite
files they did not intend to overwrite.
If the archive is being extracted by the superuser, any file
on the system can potentially be overwritten.
There are three ways this can happen.
Although
Nm
has mechanisms to protect against each one,
savvy users should be aware of the implications:
Bl -bullet -width indent
It
Archive entries can have absolute pathnames.
By default,
Nm
removes the leading
Pa /
character from filenames before restoring them to guard against this problem.
It
Archive entries can have pathnames that include
Pa ..
components.
By default,
Nm
will not extract files containing
Pa ..
components in their pathname.
It
Archive entries can exploit symbolic links to restore
files to other directories.
An archive can restore a symbolic link to another directory,
then use that link to restore a file into that directory.
To guard against this,
Nm
checks each extracted path for symlinks.
If the final path element is a symlink, it will be removed
and replaced with the archive entry.
If
Fl U
is specified, any intermediate symlink will also be unconditionally removed.
If neither
Fl U
nor
Fl P
is specified,
Nm
will refuse to extract the entry.
El
To protect yourself, you should be wary of any archives that
come from untrusted sources.
You should examine the contents of an archive with
Dl Nm Fl tf Pa filename
before extraction.
You should use the
Fl k
option to ensure that
Nm
will not overwrite any existing files or the
Fl U
option to remove any pre-existing files.
You should generally not extract archives while running with super-user
privileges.
Note that the
Fl P
option to
Nm
disables the security checks above and allows you to extract
an archive while preserving any absolute pathnames,
Pa ..
components, or symlinks to other directories.
Sh SEE ALSO
Xr bzip2 1 ,
Xr compress 1 ,
Xr cpio 1 ,
Xr gzip 1 ,
Xr mt 1 ,
Xr pax 1 ,
Xr shar 1 ,
Xr xz 1 ,
Xr libarchive 3 ,
Xr libarchive-formats 5 ,
Xr tar 5
Sh STANDARDS
There is no current POSIX standard for the tar command; it appeared
in
St -p1003.1-96
but was dropped from
St -p1003.1-2001 .
The options supported by this implementation were developed by surveying a
number of existing tar implementations as well as the old POSIX specification
for tar and the current POSIX specification for pax.
Pp
The ustar and pax interchange file formats are defined by
St -p1003.1-2001
for the pax command.
Sh HISTORY
A
Nm tar
command appeared in Seventh Edition Unix, which was released in January, 1979.
There have been numerous other implementations,
many of which extended the file format.
John Gilmore's
Nm pdtar
public-domain implementation (circa November, 1987)
was quite influential, and formed the basis of GNU tar.
GNU tar was included as the standard system tar
in
Fx
beginning with
Fx 1.0 .
Pp
This is a complete re-implementation based on the
Xr libarchive 3
library.
It was first released with
Fx 5.4
in May, 2005.
Sh BUGS
This program follows
St -p1003.1-96
for the definition of the
Fl l
option.
Note that GNU tar prior to version 1.15 treated
Fl l
as a synonym for the
Fl Fl one-file-system
option.
Pp
The
Fl C Pa dir
option may differ from historic implementations.
Pp
All archive output is written in correctly-sized blocks, even
if the output is being compressed.
Whether or not the last output block is padded to a full
block size varies depending on the format and the
output device.
For tar and cpio formats, the last block of output is padded
to a full block size if the output is being
written to standard output or to a character or block device such as
a tape drive.
If the output is being written to a regular file, the last block
will not be padded.
Many compressors, including
Xr gzip 1
and
Xr bzip2 1 ,
complain about the null padding when decompressing an archive created by
Nm ,
although they still extract it correctly.
Pp
The compression and decompression is implemented internally, so
there may be insignificant differences between the compressed output
generated by
Dl Nm Fl czf Pa - file
and that generated by
Dl Nm Fl cf Pa - file | Nm gzip
Pp
The default should be to read and write archives to the standard I/O paths,
but tradition (and POSIX) dictates otherwise.
Pp
The
Cm r
and
Cm u
modes require that the archive be uncompressed
and located in a regular file on disk.
Other archives can be modified using
Cm c
mode with the
Pa @archive-file
extension.
Pp
To archive a file called
Pa @foo
or
Pa -foo
you must specify it as
Pa ./@foo
or
Pa ./-foo ,
respectively.
Pp
In create mode, a leading
Pa ./
is always removed.
A leading
Pa /
is stripped unless the
Fl P
option is specified.
Pp
There needs to be better support for file selection on both create
and extract.
Pp
There is not yet any support for multi-volume archives.
Pp
Converting between dissimilar archive formats (such as tar and cpio) using the
Cm @ Ns Pa -
convention can cause hard link information to be lost.
(This is a consequence of the incompatible ways that different archive
formats store hardlink information.)

You are viewing proxied material from ftp.icm.edu.pl. The copyright of proxied material belongs to its original authors. Any comments or complaints in relation to proxied material should be directed to the original authors of the content concerned. Please see the disclaimer for more details.