bsdtar

NAME

SYNOPSIS

DESCRIPTION

-c

Create a new archive containing the specified items. The long option form is --create.

-r

Like -c, but new entries are appended to the archive. Note that this only works on uncompressed archives stored in regular files. The -f option is required. The long option form is --append.

-t

List archive contents to stdout. The long option form is --list.

-u

Like -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 -f option is required. The long form is --update.

-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 --extract.

OPTIONS

@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,

tar -c -f - newfile @original.tar

writes a new archive to standard output containing a file newfile and all of the entries from original.tar. In contrast,

tar -c -f - newfile original.tar

creates a new archive with only two entries. Similarly,

tar -czf - --format pax @-

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, tar can be used to convert archives from one format to another.

-a, --auto-compress

(c mode only) Use the archive suffix to decide a set of the format and the compressions. As a simple example,

tar -a -cf archive.tgz source.c source.h

creates a new archive with restricted pax format and gzip compression,

tar -a -cf archive.tar.bz2.uu source.c source.h

creates a new archive with restricted pax format and bzip2 compression and uuencode compression,

tar -a -cf archive.zip source.c source.h

creates a new archive with zip format,

tar -a -jcf archive.tgz source.c source.h

ignores the “-j” option, and creates a new archive with restricted pax format and gzip compression,

tar -a -jcf 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.

--acls

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

-B, --read-full-blocks

Ignored for compatibility with other tar(1) implementations.

-b blocksize, --block-size 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.

-C directory, --cd directory, --directory 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.

--chroot

(x mode only) chroot() to the current directory after processing any -C options and before extracting any files.

--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.

--exclude 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.

--exclude-vcs

Do not process files or directories internally used by the version control systems ‘Arch’, ‘Bazaar’, ‘CVS’, ‘Darcs’, ‘Mercurial’, ‘RCS’, ‘SCCS’, ‘SVN’ and ‘git’.

--fflags

(c, r, u, x modes only) Archive or extract platform-specific file attributes or file flags. This is the reverse of --no-fflags and the default behavior in c, r, and u modes or if tar is run in x mode as root.

--format format

(c, r, u mode only) Use the specified format for the created archive. Supported formats include “cpio”, “pax”, “shar”, and “ustar”. Other formats may also be supported; see 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.

-f file, --file file

Read the archive from or write the archive to the specified file. The filename can be - for standard input or standard output. The default varies by system; on FreeBSD, the default is /dev/sa0; on Linux, the default is /dev/st0.

--gid 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 --gname is not also specified, the group name will be set to match the group id.

--gname 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 --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.

-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.

-h

(c and r modes only) Synonym for -L.

-I

Synonym for -T.

--help

Show usage.

--hfsCompression

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

--ignore-zeros

An alias of --options read_concatenated_archives for compatibility with GNU tar.

--include pattern

Process only files or directories that match the specified pattern. Note that exclusions specified with - -exclude take precedence over inclusions. If no inclusions are explicitly specified, all entries are processed by default. The --include option is especially useful when filtering archives. For example, the command

tar -c -f new.tar --include='*foo*' @old.tgz

creates a new archive new.tar containing only the entries from old.tgz containing the string ‘foo’.

-J, --xz

(c mode only) Compress the resulting archive with xz(1). In extract or list modes, this option is ignored. Note that this tar implementation recognizes XZ compression automatically when reading archives.

-j, --bzip, --bzip2, --bunzip2

(c mode only) Compress the resulting archive with bzip2(1). In extract or list modes, this option is ignored. Note that this tar implementation recognizes bzip2 compression automatically when reading archives.

-k, --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.

--keep-newer-files

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

-L, --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.

-l, --check-links

(c and r modes only) Issue a warning message unless all links to each file are archived.

--lrzip

(c mode only) Compress the resulting archive with lrzip(1). In extract or list modes, this option is ignored. Note that this tar implementation recognizes lrzip compression automatically when reading archives.

--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 tar implementation recognizes lz4 compression automatically when reading archives.

--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 tar implementation recognizes zstd compression automatically when reading archives.

--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 --xz instead. Note that this tar implementation recognizes LZMA compression automatically when reading archives.

--lzop

(c mode only) Compress the resulting archive with lzop(1). In extract or list modes, this option is ignored. Note that this tar implementation recognizes LZO compression automatically when reading archives.

-m, --modification-time

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

--mac-metadata

(c, r, u and x mode only) Mac OS X specific. Archive or extract extended ACLs and extended file attributes using copyfile(3) in AppleDouble format. This is the reverse of --no-mac-metadata. and the default behavior in c, r, and u modes or if tar is run in x mode as root.

-n, --norecurse, --no-recursion

Do not operate recursively on the content of directories.

--newer date

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

--newer-mtime date

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

--newer-than file

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

--newer-mtime-than file

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

--nodump

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

--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.

--null

(use with -I or -T) Filenames or patterns are separated by null characters, not by newlines. This is often used to read filenames output by the -print0 option to find(1).

--no-acls

(c, r, u, x modes only) Do not archive or extract POSIX.1e or NFSv4 ACLs. This is the reverse of --acls and the default behavior if tar is run as non-root in x mode (on Mac OS X as any user in c, r, u and x modes).

--no-fflags

(c, r, u, x modes only) Do not archive or extract file attributes or file flags. This is the reverse of --fflags and the default behavior if tar is run as non-root in x mode.

--no-mac-metadata

(x mode only) Mac OS X specific. Do not archive or extract ACLs and extended file attributes using copyfile(3) in AppleDouble format. This is the reverse of --mac-metadata. and the default behavior if tar is run as non-root in x mode.

--no-read-sparse

(c, r, u modes only) Do not read sparse file information from disk. This is the reverse of --read-sparse.

--no-safe-writes

(x mode only) Do not create temporary files and use rename(2) to replace the original ones. This is the reverse of --safe-writes.

--no-same-owner

(x mode only) Do not extract owner and group IDs. This is the reverse of --same-owner and the default behavior if tar is run as non-root.

--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 -p and the default behavior if tar is run as non-root.

--no-xattrs

(c, r, u, x modes only) Do not archive or extract extended file attributes. This is the reverse of --xattrs and the default behavior if tar is run as non-root in x mode.

--numeric-owner

This is equivalent to --uname “” --gname “”. 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.

-O, --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.

-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 -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.

-o

(c, r, u mode) A synonym for --format ustar

--older date

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

--older-mtime date

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

--older-than file

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

--older-mtime-than file

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

--one-file-system

(c, r, and u modes) Do not cross mount points.

--options 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:

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.

key

The key will be enabled in every module that supports it. This is equivalent to key=1.

!key

The key will be disabled in every module that supports it.

module:key=value, module:key, module:!key

As above, but the corresponding key and value will be provided only to modules whose name matches module.

The complete list of supported modules and keys for create and append modes is in archive_write_set_options(3) and for extract and list modes in archive_read_set_options(3).

Examples of supported options:

iso9660:joliet

Support Joliet extensions. This is enabled by default, use !joliet or iso9660:!joliet to disable.

iso9660:rockridge

Support Rock Ridge extensions. This is enabled by default, use !rockridge or iso9660:!rockridge to disable.

gzip:compression-level

A decimal integer from 1 to 9 specifying the gzip compression level.

gzip:timestamp

Store timestamp. This is enabled by default, use !timestamp or gzip:!timestamp to disable.

lrzip:compression=type

Use type as compression method. Supported values are bzip2, gzip, lzo (ultra fast), and zpaq (best, extremely slow).

lrzip:compression-level

A decimal integer from 1 to 9 specifying the lrzip compression level.

lz4:compression-level

A decimal integer from 1 to 9 specifying the lzop compression level.

lz4:stream-checksum

Enable stream checksum. This is by default, use lz4:!stream-checksum to disable.

lz4:block-checksum

Enable block checksum (Disabled by default).

lz4:block-size

A decimal integer from 4 to 7 specifying the lz4 compression block size (7 is set by default).

lz4:block-dependence

Use the previous block of the block being compressed for a compression dictionary to improve compression ratio.

zstd:compression-level

A decimal integer specifying the zstd compression level. Supported values depend on the library version, common values are from 1 to 22.

zstd:threads

Specify the number of worker threads to use. Setting threads to a special value 0 makes zstd(1) use as many threads as there are CPU cores on the system.

lzop:compression-level

A decimal integer from 1 to 9 specifying the lzop compression level.

xz:compression-level

A decimal integer from 0 to 9 specifying the xz compression level.

xz:threads

Specify the number of worker threads to use. Setting threads to a special value 0 makes xz(1) use as many threads as there are CPU cores on the system.

mtree:keyword

The mtree writer module allows you to specify which mtree keywords will be included in the output. Supported keywords include: cksum, device, flags, gid, gname, indent, link, md5, mode, nlink, rmd160, sha1, sha256, sha384, sha512, size, time, uid, uname. The default is equivalent to: “device, flags, gid, gname, link, mode, nlink, size, time, type, uid, uname”.

mtree:all

Enables all of the above keywords. You can also use mtree:!all to disable all keywords.

mtree:use-set

Enable generation of /set lines in the output.

mtree:indent

Produce human-readable output by indenting options and splitting lines to fit into 80 columns.

zip:compression=type

Use type as compression method. Supported values are store (uncompressed) and deflate (gzip algorithm).

zip:encryption

Enable encryption using traditional zip encryption.

zip:encryption=type

Use type as encryption type. Supported values are zipcrypt (traditional zip encryption), aes128 (WinZip AES-128 encryption) and aes256 (WinZip AES-256 encryption).

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 -i, --ignore-zeros option of GNU tar.

If a provided option is not supported by any module, that is a fatal error.

-P, --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, tar will refuse to extract archive entries whose pathnames contain .. or whose target directory would be altered by a symlink. This option suppresses these behaviors.

-p, --insecure, --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 --no-same-permissions and the default if tar is being run as root. It can be partially overridden by also specifying --no-acls, --no-fflags, --no-mac-metadata or --no-xattrs.

--passphrase passphrase

The 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.

--posix

(c, r, u mode only) Synonym for - -format pax

-q, --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.

--read-sparse

(c, r, u modes only) Read sparse file information from disk. This is the reverse of --no-read-sparse and the default behavior.

-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.

-s pattern

Modify file or archive member names according to pattern. The pattern has the format /old/new/[ghHprRsS] where old is a basic regular expression, new is the replacement string of the matched part, and the optional trailing letters modify how the replacement is handled. If old is not matched, the pattern is skipped. Within new, ~ is substituted with the match, \1 to \9 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. 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 hrs which applies substitutions to all names. In particular, it is never necessary to specify h, r, or s.

--safe-writes

(x mode only) Extract files atomically. By default tar 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 --safe-writes is enabled, tar 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 rename(2). This guarantees that an application accessing the file, will either see the old contents or the new contents at all times.

--same-owner

(x mode only) Extract owner and group IDs. This is the reverse of --no-same-owner and the default behavior if tar is run as root.

--strip-components 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.

-T filename, --files-from filename

In x or t mode, tar will read the list of names to be extracted from filename. In c mode, tar will read names to be archived from filename. The special name “-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 --null is specified. Note that --null also disables the special handling of lines containing “-C”. Note: If you are generating lists of files using find(1), you probably want to use -n as well.

--totals

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

-U, --unlink, --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 tar to remove intervening directory symlinks instead of reporting an error. See the SECURITY section below for more details.

--uid id

Use the provided user id number and ignore the user name from the archive. On create, if --uname is not also specified, the user name will be set to match the user id.

--uname 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 --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.

--use-compress-program program

Pipe the input (in x or t mode) or the output (in c mode) through program instead of using the builtin compression support.

-v, --verbose

Produce verbose output. In create and extract modes, tar will list each file name as it is read from or written to the archive. In list mode, tar will produce output similar to that of ls(1). An additional -v option will also provide ls-like details in create and extract mode.

--version

Print version of tar and libarchive, and exit.

-w, --confirmation, --interactive

Ask for confirmation for every action.

-X filename, --exclude-from filename

Read a list of exclusion patterns from the specified file. See --exclude for more information about the handling of exclusions.

--xattrs

(c, r, u, x modes only) Archive or extract extended file attributes. This is the reverse of --no-xattrs and the default behavior in c, r, and u modes or if tar is run in x mode as root.

-y

(c mode only) Compress the resulting archive with bzip2(1). In extract or list modes, this option is ignored. Note that this tar implementation recognizes bzip2 compression automatically when reading archives.

-Z, --compress, --uncompress

(c mode only) Compress the resulting archive with compress(1). In extract or list modes, this option is ignored. Note that this tar implementation recognizes compress compression automatically when reading archives.

-z, --gunzip, --gzip

(c mode only) Compress the resulting archive with gzip(1). In extract or list modes, this option is ignored. Note that this tar implementation recognizes gzip compression automatically when reading archives.

ENVIRONMENT

TAR_READER_OPTIONS

The default options for format readers and compression readers. The --options option overrides this.

TAR_WRITER_OPTIONS

The default options for format writers and compression writers. The --options option overrides this.

LANG

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

TAPE

The default device. The -f option overrides this. Please see the description of the -f option above for more details.

TZ

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

EXIT STATUS

EXAMPLES

$ 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

COMPATIBILITY

SECURITY

• Archive entries can have absolute pathnames. By default, tar removes the leading / character from filenames before restoring them to guard against this problem.
• Archive entries can have pathnames that include .. components. By default, tar will not extract files containing .. components in their pathname.
• 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, tar 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 -U is specified, any intermediate symlink will also be unconditionally removed. If neither -U nor -P is specified, tar will refuse to extract the entry.

SEE ALSO

STANDARDS

HISTORY

BUGS