Movatterモバイル変換

[0]ホーム
URL:

Jump to content
WikipediaThe Free Encyclopedia
Search

RAR (file format)

From Wikipedia, the free encyclopedia
Archive file format
For “RAR” usage in Jakarta Connectors, seeResource Adapter Archive.
This article has multiple issues. Please helpimprove it or discuss these issues on thetalk page.(Learn how and when to remove these messages)
This articlemay containoriginal research. Pleaseimprove it byverifying the claims made and addinginline citations. Statements consisting only of original research should be removed.(February 2016) (Learn how and when to remove this message)
icon
This articlerelies excessively onreferences toprimary sources. Please improve this article by addingsecondary or tertiary sources.
Find sources: "RAR" file format – news ·newspapers ·books ·scholar ·JSTOR(October 2008) (Learn how and when to remove this message)
(Learn how and when to remove this message)
RAR file format
Filename extension
.rar, .rev, .r00, .r01
Internet media type
application/vnd.rar
Uniform Type Identifier (UTI)com.rarlab.rar-archive
Magic number52 61 72 21 1A 07 00
(RAR 1.5 to 4.0)
52 61 72 21 1A 07 01 00
(RAR 5+)[1]
Size limitation263-1 bytes (almost 8exbibytes)
Developed byEugene Roshal
Initial releaseMarch 1993; 32 years ago (1993-03)[2]
Type of formatarchive format
Free format?No (decompression source code publicly available, but notfree software, with restriction that it "cannot be used to develop RAR (WinRAR) compatible archiver")[3]
Websiterarlab.com

RAR is aproprietaryarchive file format that supportsdata compression,error correction andfile spanning.[4] It was developed in 1993 by Russian software engineerEugene Roshal and the software is licensed bywin.rar GmbH.[4] The nameRAR stands forRoshal Archive.

File format

[edit]

Thefilename extensions used by RAR are.rar for the data volume set and.rev for the recovery volume set. Previous versions of RAR split large archives into several smaller files, creating a "multi-volume archive". Numbers were used in the file extensions of the smaller files to keep them in the proper sequence. The first file used the extension.rar, then.r00 for the second, and then.r01,.r02, etc.

RAR compression applications and libraries (including GUI basedWinRAR application for Windows, console rar utility for different OSes and others) are proprietary software, to which Alexander L. Roshal,[4] the elder brother ofEugene Roshal, holds the copyright. Version 3 of RAR is based onLempel-Ziv (LZSS) andprediction by partial matching (PPM) compression, specifically the PPMd implementation of PPMII by Dmitry Shkarin.[5]

The minimum size of a RAR file is 20 bytes. The maximum size of a RAR file is9,223,372,036,854,775,807 (263−1) bytes, which is one byte less than 8EiB.[6]

Versions

[edit]

The RAR file format revision history:

  • 1.3 – the first public version, does not have the "Rar!" signature.
  • 1.5 – changes are not known.
  • 2.0 – released with WinRAR 2.0 and Rar for MS-DOS 2.0; features the following changes:
    • Multimedia compression for true color bitmap images and uncompressed audio.
    • Up to 1MB compression dictionary.
    • Introduces archives data recovery protection record.
  • 2.9[note 1] – released in WinRAR version 3.00. Feature changes in this version include:
    • File extensions is changed from{volume name}.rar, {volume name}.r00, {volume name}.r01, etc. to{volume name}.part001.rar, {volume name}.part002.rar, etc.
    • Encryption of both file data and file headers.
    • Improves compression algorithm using 4MB dictionary size, Dmitry Shkarin'sPPMII algorithm for file data.
    • Optional creation of "recovery volumes" (.rev files) forerror correction, which can be used to reconstruct missing files in a volume set.
    • Support for archive files larger than 9GB.
    • Support forUnicode file names stored inUTF-16 little endian format.
  • 5.0 – supported by WinRAR 5.0 (released April 2013) and later.[7] Changes in this version:
    • Maximum compression dictionary size increased to 1GB (default for WinRAR 5.x is 32MB and 4 MB for WinRAR 4.x).
    • Maximum path length for files in RAR and ZIP archives is increased up to 2048 characters.
    • Support forUnicode file names stored inUTF-8 format.
    • Faster compression and decompression.
    • Multicore decompression support.
    • Greatly improves recovery.
    • OptionalAES encryption increased from 128-bit to 256-bit.
    • Optional 256-bitBLAKE2 file hash instead of a default 32-bitCRC-32 file checksum.
    • Optional duplicate file detection.
    • OptionalNTFS hard and symbolic links.
    • Optional Quick Open Record. Rar4 archives had to be parsed before opening as file names were spread throughout the archive, slowing operation particularly with slower devices such as optical drives, and reducing the integrity of damaged archives. Rar5 can optionally create a "quick open record", a special archive block at the end of the file that contains the names of files included, allowing archives to be opened faster.
    • Removes specialized compression algorithms for Itanium executables, text, raw audio (WAV), and raw image (BMP) files; consequently some files of these types compress better in the older RAR (4) format with these options enabled than in RAR5.
  • 5.0+ – partially supported by WinRAR 5.0 and later. Fully supported by WinRAR 7.0 (released February 2024[8]) and later. Changes in this version:
    • Compression dictionary up to 64GB.
    • Improved compression by the addition of "Alternate search algorithm".
    • Maximum path length limit increased from 2047 to 65535 characters.
Notes
  1. ^WinRAR 5.0 and RAR for Android refer to this format as RAR4.

Software

[edit]
Main article:Comparison of file archivers

Native operating system support

[edit]

RARlab's native software is available forMicrosoft Windows (named WinRAR),Linux,FreeBSD,macOS, andAndroid; archive extraction is supported natively inChromeOS. WinRAR and RAR for Android support thegraphical user interface (GUI); other versions named RAR run as console commands.

Creating RAR files

[edit]

RAR files can only be created with proprietaryWinRAR (Windows), RAR[9] for Android,command-line RAR (available for Windows, macOS, Linux, and FreeBSD), and other software that has written permission from Alexander Roshal or uses copyrighted code under license from Roshal. The software license agreements forbid reverse engineering.[4]

Third-party software for extracting RAR files

[edit]

Several programs can unpack the file format.

  • RARLAB distributes theC++ source code and binaries for a command-lineunrar program.[10] The license permits its use to produce software capable of unpacking, but not creating, RAR archives, without having to pay a fee. It is not afree software license.
  • 7-Zip, afree and open-source program, starting from 7-Zip version 15.06 beta[11] can unpack RAR5 archives, using the RARLAB unrar code.
  • PeaZip is a free RAR unarchiver, licensed under theLGPLv3-or-later and via 7-Zip can unpack RAR archives, using RARLAB unrar.[12]
  • The Unarchiver is a proprietary freeware software unarchiver for Mac for RAR and other formats. It was previouslyfree software licensed under theLGPLv2.1-or-later, up to version 3.11.1 (released 2016), which at the time provided a free-software implementation of extraction of RAR versions up to RAR5.[13][14][15][16] There is a free software (LGPLv2.1-or-later) command-line version,unar, forked from 2016, which runs on Mac, Windows, and Linux.[17][18]
  • UNRARLIB (UniquE RAR File Library)[19] was an obsolete free software unarchiving library called "unrarlib", licensed under theGPLv2-or-later. It could only decompress archives created by RAR versions prior to 2.9; archives created by RAR 2.9 and later use different formats not supported by this library. The original development-team ended work on this library in 2007.[20][21][19]
  • libarchive, a free and open-source library for reading and writing a variety of archive formats, with partial support for all RAR versions, including RAR5.[22] The code was written from scratch using RAR's “technote.txt” format description.[23]
  • Windows 11 natively supports RAR extraction since version 23H2[24] using thelibarchive open-source project.[25]

Other uses ofrar

[edit]

The filename extensionrar is also used by the unrelatedResource Adapter aRchive file format.[26][27][28][29][30][31]

See also

[edit]

References

[edit]
  1. ^RAR 5.0 technote
  2. ^"Interview by correspondence" (in Russian). 1997–2002. Retrieved26 April 2010.
  3. ^Roshal, Alexander."UnRAR License".Fedora Project wiki. Red Hat. Archived fromthe original on 9 June 2019. Retrieved9 June 2019.
  4. ^abcdwin.rar GmbH."RAR and WinRAR END USER LICENSE AGREEMENT (EULA)".RARLAB.The author and holder of the copyright of the software is Alexander L. Roshal. [...] Neither RAR binary code, WinRAR binary code, UnRAR source or UnRAR binary code may be used or reverse engineered to re-create the RAR compression algorithm, which is proprietary, without written permission.
  5. ^Christian Scheurer (2006-12-17)."unrarlib FAQ".
  6. ^"WinRAR description". Archived fromthe original on 2013-07-20. Retrieved2013-05-01.
  7. ^WinRAR 5.0 introduces the new RAR 5 format. What you need to know - ghacks.net
  8. ^WinRAR News: WinRAR 7.00 Final released
  9. ^"RAR - Apps on Google Play".play.google.com. Retrieved2019-01-31.
  10. ^"RarLab downloads: freeware UnRAR source and binaries download".RarLab.com. The license states: "The source code of UnRAR utility isfreeware".
  11. ^"7-Zip / Discussion / Open Discussion: 7-Zip 15.06 beta".sourceforge.net. Retrieved2015-10-24.
  12. ^PeaZip website with info about RAR5 extraction.
  13. ^"The Unarchiver".The Unarchiver. Archived fromthe original on 2017-06-21.
  14. ^"Another High Priority Project done: The Unarchiver provides free RARv3 extraction tools".Free Software Foundation. Retrieved2024-02-18.
  15. ^"The Unarchiver changes".The Unarchiver. Archived fromthe original on 2017-07-06.
  16. ^"The Unarchiver source code from 2016 is licensed under the GNU Lesser General Public License v2.1".GitHub. 2011-05-11. Retrieved2024-02-18.
  17. ^"Unar and Lsar - Command Line Tools for The Unarchiver".The Unarchiver. Retrieved2024-02-18., including The Unarchiver source code from 2016.
  18. ^"MacPaw/XADMaster is licensed under the GNU Lesser General Public License v2.1".GitHub. 2018-03-21. Retrieved2021-11-23.
  19. ^ab"Home".UnRarLib.org. UniquE RAR File Library. 2007.
  20. ^"Features".UnRarLib.org. UniquE RAR File Library. 2002.
  21. ^"FAQ".UnRarLib.org. UniquE RAR File Library. December 2011.
  22. ^"List of formats supported by libarchive".GitHub. Retrieved2021-05-01.
  23. ^"Support for RAR · Issue #151 · libarchive/Libarchive".GitHub.
  24. ^Bowden, Zac (2023-06-07)."Windows 11 version 23H2: All the new features in Microsoft's big OS update".Windows Central. Retrieved2025-07-04.
  25. ^Panay, Panos (2023-05-23)."Bringing the power of AI to Windows 11 – unlocking a new era of productivity for customers and developers with Windows Copilot and Dev Home".Windows Developer Blog. Retrieved2023-05-26.
  26. ^"The Java EE 5 Tutorial". Retrieved2017-12-02.
  27. ^"RAR abbreviation stands for Resource Adapter Archive". Retrieved2017-12-02.
  28. ^"Resource Adapter aRchive - How is Resource Adapter aRchive abbreviated?". Retrieved2017-12-02.
  29. ^"9 Packaging and Deploying Resource Adapters". Retrieved2017-12-02.
  30. ^"Apache Maven RAR Plugin". Retrieved2017-12-02.
  31. ^"java - Is Resource Adapter Archive (RAR) the same as Roshal ARchive (RAR)? - Stack Overflow". Retrieved2017-12-02.

External links

[edit]
Archiving only
Compressing only
Archiving
and compressing
Software packaging
and distributing
Document packaging
and distributing
Archivers with
compression
(comparison)
Free and
open-source
Freeware
Commercial
Non-archiving
compressors
Generic
For code
Audio
compression
(comparison)
Lossy
Lossless
Video
compression
(comparison)
Lossy
MPEG-4 ASP
H.264
HEVC
Others
Lossless
Retrieved from "https://en.wikipedia.org/w/index.php?title=RAR_(file_format)&oldid=1322029406"
Categories:
Hidden categories:
[8]ページ先頭
©2009-2026 Movatter.jp