WinRAR

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WinRAR is a trialware file archiver utility for Windows, developed by Eugene Roshal of win.rar GmbH. It can create and view archives in RAR or ZIP file formats, and unpack numerous archive file formats. To enable the user to test the integrity of archives, WinRAR embeds CRC32 or BLAKE2 checksums for each file in each archive. WinRAR supports creating encrypted, multi-part and self-extracting archives.

WinRAR is a Windows-only app. The author has also released an Android app called "RAR for Android", and command-line utilities called "RAR" and "UNRAR" (widely released since autumn of 1993), available for macOS, Linux, FreeBSD, Windows, and MS-DOS.

Video WinRAR

Evolution

WinRAR and the RAR file format have evolved over time. Support for the archive format RAR5, using the same RAR file extension as earlier versions, was added in version 5.0; files in the older RAR file format have since been referred to as RAR4. WinRAR versions before 5.0 do not support RAR5 archives; only older versions of WinRAR run on Windows versions prior to XP, and cannot open RAR5 archives.

The RAR5 file format increased the maximum dictionary size to 1 GiB; 11 different compression directory sizes from 1 MiB to 1 GiB are available, with the default in version 5 increased from 4 MiB to 32 MiB, typically improving compression ratio. AES encryption, when used, was increased from 128- to 256-bit. Maximum path length for files in RAR and ZIP archives is increased to 2048 characters.

Options added in v5.0 include 256-bit BLAKE2 file-hashing algorithm instead of default 32-bit CRC32, duplicate file detection, NTFS hard and symbolic links, and Quick Open record to allow large archives to be opened faster.

The RAR5 file format removed comments for each file (though archive comment still remains), authenticity verification, and specialized compression algorithms for text and multimedia files. RAR5 also changed the file name for split volumes from "archivename.rNN" to "archivename.partNN.rar".

Maps WinRAR

Features

• Creation of packed RAR or ZIP archives.
• Unpacking of ACE, ARJ, BZIP2, CAB, GZ, ISO, JAR, LHA, RAR, TAR, UUE, XZ, Z, ZIP, ZIPX, 7z, 001 (split) archives, as well as EXE files containing these archive formats
• Checksum (integrity) verification for ACE, ARJ, BZIP2, CAB, GZ, BZIP2, RAR, XZ, ZIP and 7z archives
• Multithreaded CPU compression and decompression

When creating RAR archives:

• Support for maximum file size of 16 EiB, about 1.8 × 10¹⁹ bytes or 18 million TB
• Compression dictionary from 1 MiB to 1 GiB (It is limited to 256 MiB on 32-bit editions of Windows, although 32-bit Windows still can decompress archives with 1 GiB dictionary. Default size is 32 MiB.)
• Options, enabled by default, to optimise compression for executables for x86 processors and the obsolete 64-bit Itanium, and delta compression.
• Optional 256-bit BLAKE2 file hash can replace default 32-bit CRC32 file checksum
• Optional encryption using AES with a 256-bit key
• Optional data redundancy is provided in the form of Reed-Solomon recovery records and recovery volumes, allowing reconstruction of damaged archives (including reconstruction of entirely missed volumes)
• Optional "Quick Open Record" to open RAR files faster
• Ability to create multi-volume (split) archives
• Ability to create self-extracting files (Multi-volume self-extracting archives are supported. The self-extractor can execute commands, such as running a specified program before or after self-extraction.)
• Support for advanced NTFS file system options, such as NTFS hard and symbolic links
• Support for maximum path length up to 2048 characters (stored in the UTF-8 format)
• Optional archive comment (stored in the UTF-8 format)
• Optional file time stamp preservation: creation, last access, high precision modification times
• Optional file deduplication

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License

The software is distributed as "try before you buy"; it may be used without charge for 40 days. In China, a free-to-use personal edition has been provided officially since 2015.

Although archiving with the RAR format is proprietary, RarLab supplies as copyrighted freeware the C++ source code of the current UnRAR unpacker, with a license allowing it to be used in any software, thus enabling others to produce software capable of unpacking, but not creating, RAR archives.

RAR for Android is free of charge. It displays advertisements; for a payment they can be disabled. A license for WinRAR does not provide ad-suppression for RAR for Android.

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Security

Self-extracting archives created with versions before 5.31 (including the executable installer of WinRAR itself) are vulnerable to DLL hijacking: They may load and use DLLs named UXTheme.dll, RichEd32.dll and RichEd20.dll if they are in the same folder as the executable file.

It was widely reported that WinRAR v5.21 and earlier had a remote code execution (RCE) vulnerability which could allow a remote attacker to insert malicious code into a self-extracting executable (SFX) file being created by a user, "putting over 500 million users of the software at risk". However, examination of the claim revealed that, while the vulnerability existed, the result was merely an SFX which delivered its payload when executed; published responses dismissed the threat, one saying "If you can find suckers who will trust a .exe labelled as self-extracting archive ... then you can trick them into running your smuggled JavaScript".

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History

Versions

• Command line RAR and UNRAR were first released in autumn 1993.
• Early development version WinRAR 1.54b was released in 1995 as Windows 3.x software.
• Version 2.00 was released on September 6, 1996.
• Since version 3.00 (May 2002), the new RAR3 archive format is implemented. The new compressed archives cannot be managed by old versions of WinRAR.
• Since version 3.41 (December 2004), WinRAR adds support for Linux .Z archives like GZIP and BZIP2. New options include storing entire file paths and restoring compressed NTFS files.
• Since version 3.50 (August 2005), WinRAR adds support for interface skins and themes and support Windows XP Professional x64 Edition.
• Since version 3.60 (August 2006), WinRAR includes a multithreaded version of the compression algorithm, which improves compression speed on systems with multiple dual-core or Hyper-threading-enabled CPUs.
• Since version 3.70 (circa January 2007), WinRAR features support for Windows Vista.
• Since version 3.80 (September 2008), support for ZIP archives, which contain Unicode file names in UTF-8.
• Since version 3.90 (May 2009), WinRAR adds support for x64 architecture and Windows 7. It also enhanced support for multithreading.
• Version 3.91 is the last version that supports Valencian.
• Version 3.92 is the last version that supports Serbian Cyrillic and Serbian Latin.
• Version 4.00 (March 2011) speeds up decompression by up to 30%. Windows 98, Windows ME, and Windows NT are no longer supported; the minimum Windows version required is Windows 2000.
• Since version 4.10 (January 2012) WinRAR removes all ZIP limitations now allowing unlimited number of files and archive size. WinRAR now also allows creation of multivolume ZIP files. ZIP archives now include Unicode file names.
• Since version 4.20 (June 2012) Compression speed in SMP mode has been increased significantly, but this improvement was made at the expense of increased memory usage. ZIP compression now uses SMP as well. The default SMP mode cannot handle text; text compression is significantly worse unless additional switches are used. Also, Windows 2000 compatibility was removed.
• Since version 5.00 (September 2013) the later RAR5 archive format is implemented. RAR5 compressed archives cannot be managed by old versions of WinRAR. WinRAR 5 has better multicore processor support, and the RAR5 file format supports a larger dictionary size of up to 1 GiB with 64-bit WinRAR. Special optional compression algorithms optimised for RGB bitmaps, raw audio files, Itanium executables, and plain text, which were supported by earlier versions, are supported only in the older RAR format, not RAR5. Optional optimised compression of x86 executables and delta compression (for structured table data) are supported in both file formats.
• Version 5.50 (2017) adds support for a master password which can be used to encrypt passwords stored in WinRAR. The default RAR format is changed to version 5. Other additions include: support for decompressing Lzip archives; support for high precision file dates, longer file names and larger file sizes for TAR archives, and many minor changes and error fixes.

Operating systems support

More recent versions do not support many older operating systems. Versions supporting older operating systems may still be available, but not maintained:

• WinRAR v4.11 is the last version that supports Windows 2000.
• WinRAR v3.93 is the last version that supports Windows 95, 98, ME, and NT. RAR for Pocket PC 3.93 is the last version for Windows Mobile.
• RAR v3.93 for MS-DOS is the last version for MS-DOS and OS/2 on IA-32 CPUs (80386 equivalents and later). It supports file names longer than the MS-DOS standard of 8.3 characters, in a Windows DOS box (except under Windows NT), and uses the RSX DPMI extender.
• RAR v2.50 for MS-DOS (1999) is the last version that supports MS-DOS and OS/2 on 16-bit x86 CPUs (8086-compatible).

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Easter eggs

• In "About WinRAR" Help menu clicking on the WinRAR logo makes the ocean surf and waves move. Mouse clicking with Shift pressed on the logo generates a sailboat to the right of "WINRAR".
• In the same dialog pressing the book icon causes it to bounce like a ball until it comes to rest, with the Windows exclamation sound at each bounce.

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See also

• Comparison of file archivers
• Comparison of archive formats
• List of archive formats

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References

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Further reading

• "Data Compression". 2007. doi:10.1007/978-1-84628-603-2. ISBN 978-1-84628-602-5. 
• Fellows, G. (2010). "WinRAR temporary folder artefacts". Digital Investigation. 7: 9-13. doi:10.1016/j.diin.2009.12.001. 
• Yeo, G. S. -W.; Phan, R. C. -W. (2006). "On the security of the WinRAR encryption feature". International Journal of Information Security. 5 (2): 115. doi:10.1007/s10207-006-0086-3. 
• Metz, Cade (2004-11-16). "File Compression Beyond ZIP". PC Magazine. Vol. 23 no. 20. pp. 52-52. ISSN 0888-8507. 
• Qin, J. C.; Bai, Z. Y. (2011). "Design of new format for mass data compression". The Journal of China Universities of Posts and Telecommunications. 18: 121. doi:10.1016/S1005-8885(10)60037-4. 
• Spanbauer, Scott (December 2000). "Forget Napster-Usenet Is Where the Files Are". PC World. 18 (12): 254. ISSN 0737-8939. 
• Allen, Danny (February 2007). "Compression Apps Do More Than Shrink Files". PC World. 25 (2): 64-64. ISSN 0737-8939. 
• Sanjuàs-Cuxart, J.; Barlet-Ros, P.; Solé-Pareta, J. (2011). "Measurement Based Analysis of One-Click File Hosting Services". Journal of Network and Systems Management. 20 (2): 276. doi:10.1007/s10922-011-9202-4. 
• Jovanova, B.; Preda, M.; Preteux, F. O. (2009). "MPEG-4 Part 25: A graphics compression framework for XML-based scene graph formats". Signal Processing: Image Communication. 24: 101. doi:10.1016/j.image.2008.10.011. 
• Barr, K. C.; Asanovi?, K. (2006). "Energy-aware lossless data compression". ACM Transactions on Computer Systems. 24 (3): 250. doi:10.1145/1151690.1151692. 

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External links

• Official website
• List of WinRAR versions
• RAR 5.0 archive file format
• How to open, extract, create RAR files using WinRAR

Source of article : Wikipedia