tar (computing)

tar (software)
Original author	Bell Laboratories
Developers	Various open-source and commercial developers
Release	January 1979 (1979-01)
Stable release(s)
BSD tar 3.7.2 / 2023-09-12 GNU tar 1.35  / 2023-07-18 pdtar 1986-10-29 / 1986-10-29 Plan 9 tar ? / ? star 2023-09-28 / 2023-09-28
Written in	pdtar, star, Plan 9, GNU: C
Operating system	Unix, Unix-like, Plan 9, Microsoft Windows, IBM i
Included with	Windows 10 version 1803 and later macOS FreeBSD
Type	Lossless data compression, file archiver
License	BSD tar: BSD-2-Clause GNU tar: GPL-3.0-or-later pdtar: Public domain Plan 9: MIT star: CDDL-1.0
Website	BSD tar: libarchive.org GNU tar: gnu.org/software/tar
Repository	BSD tar: github.com/libarchive/libarchive GNU tar: savannah.gnu.org/projects/tar star: codeberg.org/schilytools/schilytools

tar (file format)
Filename extension	.tar
Internet media type	application/x-tar
Uniform Type Identifier (UTI)	public.tar-archive
Magic number	u s t a r \0 0 0  at byte offset 257 for POSIX versions u s t a r \040 \040 \0  for old GNU tar format Absent in pre-POSIX versions
Type of format	Archive file
Compression	None
Standard	POSIX since POSIX.1, presently in the definition of pax
Open format?	Yes

tar is a file format and a file archiver program. The program combines multiple files into a single archive file in the tar file format. It was originally developed for magnetic tape computer storage – reading and writing data for a sequential I/O device with no file system, and the name is short for the format description "tape archive". When stored in a file system, a file that tar reads and writes is often called a tarball.

A tarball contains metadata for the contained files including the name, ownership, timestamps, permissions and directory organization. As a file containing other files with associated metadata, a tarball is useful for software distribution and backup.

POSIX abandoned tar in favor of pax, yet tar continues to have widespread use.