path: root/archivers/libarchive/files/doc/text/bsdtar.1.txt

TAR(1)			  BSD General Commands Manual			TAR(1)

1mNAME0m
     1mtar 22m— manipulate tape archives

1mSYNOPSIS0m
     1mtar 22m[4mbundled-flags24m ⟨args⟩] [⟨4mfile24m⟩ | ⟨4mpattern24m⟩ ...]
     1mtar 22m{1m-c22m} [4moptions24m] [4mfiles24m | 4mdirectories24m]
     1mtar 22m{1m-r 22m| 1m-u22m} 1m-f 4m22marchive-file24m [4moptions24m] [4mfiles24m | 4mdirectories24m]
     1mtar 22m{1m-t 22m| 1m-x22m} [4moptions24m] [4mpatterns24m]

1mDESCRIPTION0m
     1mtar 22mcreates 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.

     The first synopsis form shows a “bundled” option word.  This usage is
     provided for compatibility with historical implementations.  See COMPATI‐
     BILITY below for details.

     The other synopsis forms show the preferred usage.  The first option to
     1mtar 22mis a mode indicator from the following list:
     1m-c      22mCreate a new archive containing the specified items.	The long
	     option form is 1m--create22m.
     1m-r      22mLike 1m-c22m, but new entries are appended to the archive.  Note that
	     this only works on uncompressed archives stored in regular files.
	     The 1m-f 22moption is required.  The long option form is 1m--append22m.
     1m-t      22mList archive contents to stdout.  The long option form is 1m--list22m.
     1m-u      22mLike 1m-r22m, but new entries are added only if they have a modifica‐
	     tion date newer than the corresponding entry in the archive.
	     Note that this only works on uncompressed archives stored in reg‐
	     ular files.  The 1m-f 22moption is required.  The long form is
	     1m--update22m.
     1m-x      22mExtract 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 1m--extract22m.

     In 1m-c22m, 1m-r22m, or 1m-u 22mmode, each specified file or directory is added to the
     archive in the order specified on the command line.  By default, the con‐
     tents of each directory are also archived.

     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 tcsh(1).

1mOPTIONS0m
     Unless specifically stated otherwise, options are applicable in all oper‐
     ating modes.

     1m@4m22marchive0m
	     (c and r modes only) The specified archive is opened and the
	     entries in it will be appended to the current archive.  As a sim‐
	     ple example,
		   1mtar -c -f 4m22m-24m 4mnewfile24m 1m@4m22moriginal.tar0m
	     writes a new archive to standard output containing a file 4mnewfile0m
	     and all of the entries from 4moriginal.tar24m.  In contrast,
		   1mtar -c -f 4m22m-24m 4mnewfile24m 4moriginal.tar0m
	     creates a new archive with only two entries.  Similarly,
		   1mtar -czf 4m22m-24m 1m--format pax @4m22m-0m
	     reads an archive from standard input (whose format will be deter‐
	     mined automatically) and converts it into a gzip-compressed pax-
	     format archive on stdout.	In this way, 1mtar 22mcan be used to con‐
	     vert archives from one format to another.

     1m-a22m, 1m--auto-compress0m
	     (c mode only) Use the archive suffix to decide a set of the for‐
	     mat and the compressions.	As a simple example,
		   1mtar -a -cf 4m22marchive.tgz24m 4msource.c24m 4msource.h0m
	     creates a new archive with restricted pax format and gzip com‐
	     pression,
		   1mtar -a -cf 4m22marchive.tar.bz2.uu24m 4msource.c24m 4msource.h0m
	     creates a new archive with restricted pax format and bzip2 com‐
	     pression and uuencode compression,
		   1mtar -a -cf 4m22marchive.zip24m 4msource.c24m 4msource.h0m
	     creates a new archive with zip format,
		   1mtar -a -jcf 4m22marchive.tgz24m 4msource.c24m 4msource.h0m
	     ignores the “-j” option, and creates a new archive with
	     restricted pax format and gzip compression,
		   1mtar -a -jcf 4m22marchive.xxx24m 4msource.c24m 4msource.h0m
	     if it is unknown suffix or no suffix, creates a new archive with
	     restricted pax format and bzip2 compression.

     1m--acls  22m(c, r, u, x modes only) Archive or extract POSIX.1e or NFSv4
	     ACLs. This is the reverse of 1m--no-acls 22mand the default behavior
	     in c, r, and u modes (except Mac OS X) or if 1mtar 22mis run in x mode
	     as root. On Mac OS X this option translates extended ACLs to
	     NFSv4 ACLs. To store extended ACLs the 1m--mac-metadata 22moption is
	     preferred.

     1m-B22m, 1m--read-full-blocks0m
	     Ignored for compatibility with other tar(1) implementations.

     1m-b 4m22mblocksize24m, 1m--block-size 4m22mblocksize0m
	     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.

     1m-C 4m22mdirectory24m, 1m--cd 4m22mdirectory24m, 1m--directory 4m22mdirectory0m
	     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.

     1m--chroot0m
	     (x mode only) 1mchroot22m() to the current directory after processing
	     any 1m-C 22moptions and before extracting any files.

     1m--clear-nochange-fflags0m
	     (x mode only) Before removing file system objects to replace
	     them, clear platform-specific file flags that might prevent
	     removal.

     1m--exclude 4m22mpattern0m
	     Do not process files or directories that match the specified pat‐
	     tern.  Note that exclusions take precedence over patterns or
	     filenames specified on the command line.

     1m--fflags0m
	     (c, r, u, x modes only) Archive or extract file flags. This is
	     the reverse of 1m--no-fflags 22mand the default behavior in c, r, and
	     u modes or if 1mtar 22mis run in x mode as root.

     1m--format 4m22mformat0m
	     (c, r, u mode only) Use the specified format for the created ar‐
	     chive.  Supported formats include “cpio”, “pax”, “shar”, and
	     “ustar”.  Other formats may also be supported; see
	     libarchive-formats(5) for more information about currently-sup‐
	     ported formats.  In r and u modes, when extending an existing ar‐
	     chive, the format specified here must be compatible with the for‐
	     mat of the existing archive on disk.

     1m-f 4m22mfile24m, 1m--file 4m22mfile0m
	     Read the archive from or write the archive to the specified file.
	     The filename can be 4m-24m for standard input or standard output.	The
	     default varies by system; on FreeBSD, the default is 4m/dev/sa024m; on
	     Linux, the default is 4m/dev/st024m.

     1m--gid 4m22mid0m
	     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 1m--gname 22mis not also specified, the group name will be set to
	     match the group id.

     1m--gname 4m22mname0m
	     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
	     1m--gid 22moption) 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.

     1m-H      22m(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.

     1m-h      22m(c and r modes only) Synonym for 1m-L22m.

     1m-I      22mSynonym for 1m-T22m.

     1m--help  22mShow usage.

     1m--hfsCompression0m
	     (x mode only) Mac OS X specific (v10.6 or later). Compress
	     extracted regular files with HFS+ compression.

     1m--ignore-zeros0m
	     An alias of 1m--options read_concatenated_archives 22mfor compatibil‐
	     ity with GNU tar.

     1m--include 4m22mpattern0m
	     Process only files or directories that match the specified pat‐
	     tern.  Note that exclusions specified with 1m--exclude 22mtake prece‐
	     dence over inclusions.  If no inclusions are explicitly speci‐
	     fied, all entries are processed by default.  The 1m--include 22moption
	     is especially useful when filtering archives.  For example, the
	     command
		   1mtar -c -f 4m22mnew.tar24m 1m--include='*foo*' @4m22mold.tgz0m
	     creates a new archive 4mnew.tar24m containing only the entries from
	     4mold.tgz24m containing the string ‘foo’.

     1m-J22m, 1m--xz0m
	     (c mode only) Compress the resulting archive with xz(1).  In
	     extract or list modes, this option is ignored.  Note that, unlike
	     other 1mtar 22mimplementations, this implementation recognizes XZ com‐
	     pression automatically when reading archives.

     1m-j22m, 1m--bzip22m, 1m--bzip222m, 1m--bunzip20m
	     (c mode only) Compress the resulting archive with bzip2(1).  In
	     extract or list modes, this option is ignored.  Note that, unlike
	     other 1mtar 22mimplementations, this implementation recognizes bzip2
	     compression automatically when reading archives.

     1m-k22m, 1m--keep-old-files0m
	     (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.

     1m--keep-newer-files0m
	     (x mode only) Do not overwrite existing files that are newer than
	     the versions appearing in the archive being extracted.

     1m-L22m, 1m--dereference0m
	     (c and r modes only) All symbolic links will be followed.	Nor‐
	     mally, symbolic links are archived as such.  With this option,
	     the target of the link will be archived instead.

     1m-l22m, 1m--check-links0m
	     (c and r modes only) Issue a warning message unless all links to
	     each file are archived.

     1m--lrzip0m
	     (c mode only) Compress the resulting archive with lrzip(1).  In
	     extract or list modes, this option is ignored.

     1m--lz4   22m(c mode only) Compress the archive with lz4-compatible compres‐
	     sion before writing it.  In input mode, this option is ignored;
	     lz4 compression is recognized automatically on input.

     1m--lzma  22m(c mode only) Compress the resulting archive with the original
	     LZMA algorithm.  Use of this option is discouraged and new ar‐
	     chives should be created with 1m--xz 22minstead.  Note that, unlike
	     other 1mtar 22mimplementations, this implementation recognizes LZMA
	     compression automatically when reading archives.

     1m--lzop  22m(c mode only) Compress the resulting archive with lzop(1).  In
	     extract or list modes, this option is ignored.

     1m-m22m, 1m--modification-time0m
	     (x mode only) Do not extract modification time.  By default, the
	     modification time is set to the time stored in the archive.

     1m--mac-metadata0m
	     (c, r, u and x mode only) Mac OS X specific. Archive or extract
	     extended ACLs and extended attributes using copyfile(3) in Apple‐
	     Double format. This is the reverse of 1m--no-mac-metadata22m.  and the
	     default behavior in c, r, and u modes or if 1mtar 22mis run in x mode
	     as root.

     1m-n22m, 1m--norecurse22m, 1m--no-recursion0m
	     (c, r, u modes only) Do not recursively archive the contents of
	     directories.

     1m--newer 4m22mdate0m
	     (c, r, u modes only) Only include files and directories newer
	     than the specified date.  This compares ctime entries.

     1m--newer-mtime 4m22mdate0m
	     (c, r, u modes only) Like 1m--newer22m, except it compares mtime
	     entries instead of ctime entries.

     1m--newer-than 4m22mfile0m
	     (c, r, u modes only) Only include files and directories newer
	     than the specified file.  This compares ctime entries.

     1m--newer-mtime-than 4m22mfile0m
	     (c, r, u modes only) Like 1m--newer-than22m, except it compares mtime
	     entries instead of ctime entries.

     1m--nodump0m
	     (c and r modes only) Honor the nodump file flag by skipping this
	     file.

     1m--nopreserveHFSCompression0m
	     (x mode only) Mac OS X specific(v10.6 or later). Do not compress
	     extracted regular files which were compressed with HFS+ compres‐
	     sion before archived.  By default, compress the regular files
	     again with HFS+ compression.

     1m--null  22m(use with 1m-I 22mor 1m-T22m) Filenames or patterns are separated by null
	     characters, not by newlines.  This is often used to read file‐
	     names output by the 1m-print0 22moption to find(1).

     1m--no-acls0m
	     (c, r, u, x modes only) Do not archive or extract POSIX.1e or
	     NFSv4 ACLs. This is the reverse of 1m--acls 22mand the default behav‐
	     ior if 1mtar 22mis run as non-root in x mode (on Mac OS X also in c, r
	     and u modes).

     1m--no-fflags0m
	     (c, r, u, x modes only) Do not archive or extract file flags.
	     This is the reverse of 1m--fflags 22mand the default behavior if 1mtar0m
	     is run as non-root in x mode.

     1m--no-mac-metadata0m
	     (x mode only) Mac OS X specific. Do not archive or extract ACLs
	     and extended attributes using copyfile(3) in AppleDouble format.
	     This is the reverse of 1m--mac-metadata22m.  and the default behavior
	     if 1mtar 22mis run as non-root in x mode.

     1m-n22m, 1m--norecurse22m, 1m--no-recursion0m

     1m--no-same-owner0m
	     (x mode only) Do not extract owner and group IDs.	This is the
	     reverse of 1m--same-owner 22mand the default behavior if 1mtar 22mis run as
	     non-root.

     1m--no-same-permissions0m
	     (x mode only) Do not extract full permissions (SGID, SUID, sticky
	     bit, ACLs, extended attributes or extended file flags).  This is
	     the reverse of 1m-p 22mand the default behavior if 1mtar 22mis run as non-
	     root and can be overridden by also specifying 1m--acls22m, 1m--fflags22m,
	     1m--mac-metadata, --same-owner22m, 1m--same-permissions 22mand 1m--xattrs22m.

     1m--no-xattrs0m
	     (c, r, u, x modes only) Do not archive or extract extended
	     attributes. This is the reverse of 1m--xattrs 22mand the default
	     behavior if 1mtar 22mis run as non-root in x mode.

     1m--numeric-owner0m
	     This is equivalent to 1m--uname 22m"" 1m--gname 22m"".  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.

     1m-O22m, 1m--to-stdout0m
	     (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.

     1m-o      22m(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 1m-p 22mis 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.

     1m-o      22m(c, r, u mode) A synonym for 1m--format 4m22mustar0m

     1m--older 4m22mdate0m
	     (c, r, u modes only) Only include files and directories older
	     than the specified date.  This compares ctime entries.

     1m--older-mtime 4m22mdate0m
	     (c, r, u modes only) Like 1m--older22m, except it compares mtime
	     entries instead of ctime entries.

     1m--older-than 4m22mfile0m
	     (c, r, u modes only) Only include files and directories older
	     than the specified file.  This compares ctime entries.

     1m--older-mtime-than 4m22mfile0m
	     (c, r, u modes only) Like 1m--older-than22m, except it compares mtime
	     entries instead of ctime entries.

     1m--one-file-system0m
	     (c, r, and u modes) Do not cross mount points.

     1m--options 4m22moptions0m
	     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:
	     4mkey=value0m
		     The key will be set to the specified value in every mod‐
		     ule that supports it.  Modules that do not support this
		     key will ignore it.
	     4mkey24m	  The key will be enabled in every module that supports it.
		     This is equivalent to 4mkey24m1m=122m.
	     4m!key24m	  The key will be disabled in every module that supports
		     it.
	     4mmodule:key=value24m, 4mmodule:key24m, 4mmodule:!key0m
		     As above, but the corresponding key and value will be
		     provided only to modules whose name matches 4mmodule24m.
	     The currently supported modules and keys are:
	     1miso9660:joliet0m
		     Support Joliet extensions.  This is enabled by default,
		     use 1m!joliet 22mor 1miso9660:!joliet 22mto disable.
	     1miso9660:rockridge0m
		     Support Rock Ridge extensions.  This is enabled by
		     default, use 1m!rockridge 22mor 1miso9660:!rockridge 22mto disable.
	     1mgzip:compression-level0m
		     A decimal integer from 1 to 9 specifying the gzip com‐
		     pression level.
	     1mgzip:timestamp0m
		     Store timestamp. This is enabled by default, use
		     1m!timestamp 22mor 1mgzip:!timestamp 22mto disable.
	     1mlrzip:compression22m=4mtype0m
		     Use 4mtype24m as compression method.  Supported values are
		     bzip2, gzip, lzo (ultra fast), and zpaq (best, extremely
		     slow).
	     1mlrzip:compression-level0m
		     A decimal integer from 1 to 9 specifying the lrzip com‐
		     pression level.
	     1mlz4:compression-level0m
		     A decimal integer from 1 to 9 specifying the lzop com‐
		     pression level.
	     1mlz4:stream-checksum0m
		     Enable stream checksum. This is by default, use
		     1mlz4:!stream-checksum 22mto disable.
	     1mlz4:block-checksum0m
		     Enable block checksum (Disabled by default).
	     1mlz4:block-size0m
		     A decimal integer from 4 to 7 specifying the lz4 compres‐
		     sion block size (7 is set by default).
	     1mlz4:block-dependence0m
		     Use the previous block of the block being compressed for
		     a compression dictionary to improve compression ratio.
	     1mlzop:compression-level0m
		     A decimal integer from 1 to 9 specifying the lzop com‐
		     pression level.
	     1mxz:compression-level0m
		     A decimal integer from 0 to 9 specifying the xz compres‐
		     sion level.
	     1mmtree:4m22mkeyword0m
		     The mtree writer module allows you to specify which mtree
		     keywords will be included in the output.  Supported key‐
		     words include: 1mcksum22m, 1mdevice22m, 1mflags22m, 1mgid22m, 1mgname22m, 1mindent22m,
		     1mlink22m, 1mmd522m, 1mmode22m, 1mnlink22m, 1mrmd16022m, 1msha122m, 1msha25622m, 1msha38422m,
		     1msha51222m, 1msize22m, 1mtime22m, 1muid22m, 1muname22m.  The default is equiva‐
		     lent to: “device, flags, gid, gname, link, mode, nlink,
		     size, time, type, uid, uname”.
	     1mmtree:all0m
		     Enables all of the above keywords.  You can also use
		     1mmtree:!all 22mto disable all keywords.
	     1mmtree:use-set0m
		     Enable generation of 1m/set 22mlines in the output.
	     1mmtree:indent0m
		     Produce human-readable output by indenting options and
		     splitting lines to fit into 80 columns.
	     1mzip:compression22m=4mtype0m
		     Use 4mtype24m as compression method.  Supported values are
		     store (uncompressed) and deflate (gzip algorithm).
	     1mzip:encryption0m
		     Enable encryption using traditional zip encryption.
	     1mzip:encryption22m=4mtype0m
		     Use 4mtype24m as encryption type.	Supported values are
		     zipcrypt (traditional zip encryption), aes128 (WinZip
		     AES-128 encryption) and aes256 (WinZip AES-256 encryp‐
		     tion).
	     1mread_concatenated_archives0m
		     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 con‐
		     catenated archive would be read.  This option is compara‐
		     ble to the 1m-i22m, 1m--ignore-zeros 22moption of GNU tar.
	     If a provided option is not supported by any module, that is a
	     fatal error.

     1m-P22m, 1m--absolute-paths0m
	     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, 1mtar 22mwill
	     refuse to extract archive entries whose pathnames contain 4m..24m or
	     whose target directory would be altered by a symlink.  This
	     option suppresses these behaviors.

     1m-p22m, 1m--insecure22m, 1m--preserve-permissions0m
	     (x mode only) Preserve file permissions.  Attempt to restore the
	     full permissions, including owner, file modes, ACLs, extended
	     atributes and extended file flags, if available, for each item
	     extracted from the archive. This is the default, if 1mtar 22mis being
	     run by root and can be overridden by also specifying 1m--no-acls22m,
	     1m--no-fflags22m, 1m--no-mac-metadata, --no-same-owner22m,
	     1m--no-same-permissions 22mand 1m--no-xattrs22m.

     1m--passphrase 4m22mpassphrase0m
	     The 4mpassphrase24m is used to extract or create an encrypted archive.
	     Currently, zip is the only supported format that supports encryp‐
	     tion.  You shouldn't use this option unless you realize how inse‐
	     cure use of this option is.

     1m--posix0m
	     (c, r, u mode only) Synonym for 1m--format 4m22mpax0m

     1m-q22m, 1m--fast-read0m
	     (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.

     1m-S      22m(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.

     1m-s 4m22mpattern0m
	     Modify file or archive member names according to 4mpattern24m.  The
	     pattern has the format 4m/old/new/24m[ghHprRsS] where 4mold24m is a basic
	     regular expression, 4mnew24m is the replacement string of the matched
	     part, and the optional trailing letters modify how the replace‐
	     ment is handled.  If 4mold24m is not matched, the pattern is skipped.
	     Within 4mnew24m, ~ is substituted with the match, \1 to \9 with the
	     content of the corresponding captured group.  The optional trail‐
	     ing 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.	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 4mhrs24m which applies substitutions to all names.	In
	     particular, it is never necessary to specify h, r, or s.

     1m--same-owner0m
	     (x mode only) Extract owner and group IDs.  This is the reverse
	     of 1m--no-same-owner 22mand the default behavior if 1mtar 22mis run as
	     root.

     1m--strip-components 4m22mcount0m
	     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.

     1m-T 4m22mfilename24m, 1m--files-from 4m22mfilename0m
	     In x or t mode, 1mtar 22mwill read the list of names to be extracted
	     from 4mfilename24m.  In c mode, 1mtar 22mwill read names to be archived
	     from 4mfilename24m.  The special name “-C” on a line by itself will
	     cause the current directory to be changed to the directory speci‐
	     fied on the following line.  Names are terminated by newlines
	     unless 1m--null 22mis specified.  Note that 1m--null 22malso disables the
	     special handling of lines containing “-C”.  Note:	If you are
	     generating lists of files using find(1), you probably want to use
	     1m-n 22mas well.

     1m--totals0m
	     (c, r, u modes only) After archiving all files, print a summary
	     to stderr.

     1m-U22m, 1m--unlink22m, 1m--unlink-first0m
	     (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 1mtar 22mto remove intervening directory symlinks
	     instead of reporting an error.  See the SECURITY section below
	     for more details.

     1m--uid 4m22mid0m
	     Use the provided user id number and ignore the user name from the
	     archive.  On create, if 1m--uname 22mis not also specified, the user
	     name will be set to match the user id.

     1m--uname 4m22mname0m
	     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 1m--uid 22moption) 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.

     1m--use-compress-program 4m22mprogram0m
	     Pipe the input (in x or t mode) or the output (in c mode) through
	     4mprogram24m instead of using the builtin compression support.

     1m-v22m, 1m--verbose0m
	     Produce verbose output.  In create and extract modes, 1mtar 22mwill
	     list each file name as it is read from or written to the archive.
	     In list mode, 1mtar 22mwill produce output similar to that of ls(1).
	     An additional 1m-v 22moption will also provide ls-like details in cre‐
	     ate and extract mode.

     1m--version0m
	     Print version of 1mtar 22mand 1mlibarchive22m, and exit.

     1m-w22m, 1m--confirmation22m, 1m--interactive0m
	     Ask for confirmation for every action.

     1m-X 4m22mfilename24m, 1m--exclude-from 4m22mfilename0m
	     Read a list of exclusion patterns from the specified file.  See
	     1m--exclude 22mfor more information about the handling of exclusions.

     1m--xattrs0m
	     (c, r, u, x modes only) Archive or extract extended attributes.
	     This is the reverse of 1m--no-xattrs 22mand the default behavior in c,
	     r, and u modes or if 1mtar 22mis run in x mode as root.

     1m-y      22m(c mode only) Compress the resulting archive with bzip2(1).  In
	     extract or list modes, this option is ignored.  Note that, unlike
	     other 1mtar 22mimplementations, this implementation recognizes bzip2
	     compression automatically when reading archives.

     1m-Z22m, 1m--compress22m, 1m--uncompress0m
	     (c mode only) Compress the resulting archive with compress(1).
	     In extract or list modes, this option is ignored.	Note that,
	     unlike other 1mtar 22mimplementations, this implementation recognizes
	     compress compression automatically when reading archives.

     1m-z22m, 1m--gunzip22m, 1m--gzip0m
	     (c mode only) Compress the resulting archive with gzip(1).  In
	     extract or list modes, this option is ignored.  Note that, unlike
	     other 1mtar 22mimplementations, this implementation recognizes gzip
	     compression automatically when reading archives.

1mENVIRONMENT0m
     The following environment variables affect the execution of 1mtar22m:

     TAR_READER_OPTIONS
		The default options for format readers and compression read‐
		ers.  The 1m--options 22moption overrides this.

     TAR_WRITER_OPTIONS
		The default options for format writers and compression writ‐
		ers.  The 1m--options 22moption overrides this.

     LANG	The locale to use.  See environ(7) for more information.

     TAPE	The default device.  The 1m-f 22moption overrides this.  Please see
		the description of the 1m-f 22moption above for more details.

     TZ 	The timezone to use when displaying dates.  See environ(7) for
		more information.

1mEXIT STATUS0m
     The 1mtar 22mutility exits 0 on success, and >0 if an error occurs.

1mEXAMPLES0m
     The following creates a new archive called 4mfile.tar.gz24m that contains two
     files 4msource.c24m and 4msource.h24m:
	   1mtar -czf 4m22mfile.tar.gz24m 4msource.c24m 4msource.h0m

     To view a detailed table of contents for this archive:
	   1mtar -tvf 4m22mfile.tar.gz0m

     To extract all entries from the archive on the default tape drive:
	   1mtar -x0m

     To examine the contents of an ISO 9660 cdrom image:
	   1mtar -tf 4m22mimage.iso0m

     To move file hierarchies, invoke 1mtar 22mas
	   1mtar -cf 4m22m-24m 1m-C 4m22msrcdir24m 4m.24m | 1mtar -xpf 4m22m-24m 1m-C 4m22mdestdir0m
     or more traditionally
	   cd srcdir ; 1mtar -cf 4m22m-24m 4m.24m | (4mcd24m 4mdestdir24m 4m;24m 1mtar -xpf 4m22m-24m)

     In create mode, the list of files and directories to be archived can also
     include directory change instructions of the form 1m-C4m22mfoo/baz24m and archive
     inclusions of the form 1m@4m22marchive-file24m.  For example, the command line
	   1mtar -c -f 4m22mnew.tar24m 4mfoo124m 1m@4m22mold.tgz24m 1m-C4m22m/tmp24m 4mfoo20m
     will create a new archive 4mnew.tar24m.  1mtar 22mwill read the file 4mfoo124m from the
     current directory and add it to the output archive.  It will then read
     each entry from 4mold.tgz24m and add those entries to the output archive.
     Finally, it will switch to the 4m/tmp24m directory and add 4mfoo224m to the output
     archive.

     An input file in mtree(5) format can be used to create an output archive
     with arbitrary ownership, permissions, or names that differ from existing
     data on disk:

	   $ 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

     The 1m--newer 22mand 1m--newer-mtime 22mswitches accept a variety of common date
     and time specifications, including “12 Mar 2005 7:14:29pm”, “2005-03-12
     19:14”, “5 minutes ago”, and “19:14 PST May 1”.

     The 1m--options 22margument can be used to control various details of archive
     generation or reading.  For example, you can generate mtree output which
     only contains 1mtype22m, 1mtime22m, and 1muid 22mkeywords:
	   1mtar -cf 4m22mfile.tar24m 1m--format=mtree --options='!all,type,time,uid' 4m22mdir0m
     or you can set the compression level used by gzip or xz compression:
	   1mtar -czf 4m22mfile.tar24m 1m--options='compression-level=9'22m.
     For more details, see the explanation of the 1marchive_read_set_options22m()
     and 1marchive_write_set_options22m() API calls that are described in
     archive_read(3) and archive_write(3).

1mCOMPATIBILITY0m
     The bundled-arguments format is supported for compatibility with historic
     implementations.  It consists of an initial word (with no leading - char‐
     acter) 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,
	   1mtar tbf 32 4m22mfile.tar0m
     specifies three flags 1mt22m, 1mb22m, and 1mf22m.	The 1mb 22mand 1mf 22mflags both require argu‐
     ments, so there must be two additional items on the command line.	The 4m320m
     is the argument to the 1mb 22mflag, and 4mfile.tar24m is the argument to the 1mf0m
     flag.

     The mode options c, r, t, u, and x and the options b, f, l, m, o, v, and
     w comply with SUSv2.

     For maximum portability, scripts that invoke 1mtar 22mshould use the bundled-
     argument format above, should limit themselves to the 1mc22m, 1mt22m, and 1mx 22mmodes,
     and the 1mb22m, 1mf22m, 1mm22m, 1mv22m, and 1mw 22moptions.

     Additional long options are provided to improve compatibility with other
     tar implementations.

1mSECURITY0m
     Certain security issues are common to many archiving programs, including
     1mtar22m.	In particular, carefully-crafted archives can request that 1mtar0m
     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 supe‐
     ruser, any file on the system can potentially be overwritten.  There are
     three ways this can happen.  Although 1mtar 22mhas mechanisms to protect
     against each one, savvy users should be aware of the implications:

     1m·       22mArchive entries can have absolute pathnames.	By default, 1mtar0m
	     removes the leading 4m/24m character from filenames before restoring
	     them to guard against this problem.

     1m·       22mArchive entries can have pathnames that include 4m..24m components.
	     By default, 1mtar 22mwill not extract files containing 4m..24m components
	     in their pathname.

     1m·       22mArchive 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, 1mtar 22mchecks each extracted path
	     for symlinks.  If the final path element is a symlink, it will be
	     removed and replaced with the archive entry.  If 1m-U 22mis specified,
	     any intermediate symlink will also be unconditionally removed.
	     If neither 1m-U 22mnor 1m-P 22mis specified, 1mtar 22mwill refuse to extract the
	     entry.
     To protect yourself, you should be wary of any archives that come from
     untrusted sources.  You should examine the contents of an archive with
	   1mtar -tf 4m22mfilename0m
     before extraction.  You should use the 1m-k 22moption to ensure that 1mtar 22mwill
     not overwrite any existing files or the 1m-U 22moption to remove any pre-
     existing files.  You should generally not extract archives while running
     with super-user privileges.  Note that the 1m-P 22moption to 1mtar 22mdisables the
     security checks above and allows you to extract an archive while preserv‐
     ing any absolute pathnames, 4m..24m components, or symlinks to other directo‐
     ries.

1mSEE ALSO0m
     bzip2(1), compress(1), cpio(1), gzip(1), mt(1), pax(1), shar(1), xz(1),
     libarchive(3), libarchive-formats(5), tar(5)

1mSTANDARDS0m
     There is no current POSIX standard for the tar command; it appeared in
     ISO/IEC 9945-1:1996 (“POSIX.1”) but was dropped from IEEE Std 1003.1-2001
     (“POSIX.1”).  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.

     The ustar and pax interchange file formats are defined by IEEE Std
     1003.1-2001 (“POSIX.1”) for the pax command.

1mHISTORY0m
     A 1mtar 22mcommand 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 1mpdtar 22mpublic-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
     FreeBSD beginning with FreeBSD 1.0.

     This is a complete re-implementation based on the libarchive(3) library.
     It was first released with FreeBSD 5.4 in May, 2005.

1mBUGS0m
     This program follows ISO/IEC 9945-1:1996 (“POSIX.1”) for the definition
     of the 1m-l 22moption.  Note that GNU tar prior to version 1.15 treated 1m-l 22mas
     a synonym for the 1m--one-file-system 22moption.

     The 1m-C 4m22mdir24m option may differ from historic implementations.

     All archive output is written in correctly-sized blocks, even if the out‐
     put 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 com‐
     pressors, including gzip(1) and bzip2(1), complain about the null padding
     when decompressing an archive created by 1mtar22m, although they still extract
     it correctly.

     The compression and decompression is implemented internally, so there may
     be insignificant differences between the compressed output generated by
	   1mtar -czf 4m22m-24m 4mfile0m
     and that generated by
	   1mtar -cf 4m22m-24m 4mfile24m | 1mgzip0m

     The default should be to read and write archives to the standard I/O
     paths, but tradition (and POSIX) dictates otherwise.

     The 1mr 22mand 1mu 22mmodes require that the archive be uncompressed and located in
     a regular file on disk.  Other archives can be modified using 1mc 22mmode with
     the 4m@archive-file24m extension.

     To archive a file called 4m@foo24m or 4m-foo24m you must specify it as 4m./@foo24m or
     4m./-foo24m, respectively.

     In create mode, a leading 4m./24m is always removed.  A leading 4m/24m is stripped
     unless the 1m-P 22moption is specified.

     There needs to be better support for file selection on both create and
     extract.

     There is not yet any support for multi-volume archives.

     Converting between dissimilar archive formats (such as tar and cpio)
     using the 1m@4m22m-24m convention can cause hard link information to be lost.
     (This is a consequence of the incompatible ways that different archive
     formats store hardlink information.)

BSD			       February 24, 2017			   BSD