7-Zip is a free file archiver with a high degree of data compression . It supports several compression algorithms and many data formats, including its own 7z format with a highly efficient LZMA compression algorithm . The program has been developed since 1999, it is free and has open source code, most of which is freely distributed under the terms of the GNU LGPL license, with the exception of the UnRAR unpacker code, which has limitations. The main platform is Windows (including Windows CE ), where two versions of the program are available: with a graphical interface and a version for the command line. The console version was ported by the community of developers for POSIX standard systems under the general name p7zip [6] . Ported versions for other systems, as well as the original 7-Zip program, are available on the SourceForge system website (as of September 5, 2017 , the program was downloaded from the site more than 412 million times [7] ). 7-Zip is the winner of the 2007 SourceForge.net Community Choice Awards in the categories of "Best Project" and "Best Technical Design" [8] .
| 7-zip | |
|---|---|
 | |
| Type of | Archiver |
| Developer | |
| Written on | and |
| Interface | graphic command line |
| operating system | Windows p7zip port for Linux , macOS , etc. UNIX-like [1] , ReactOS |
| Interface languages | Multilingual |
| First edition | |
| Latest version | |
| Readable File Formats | , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , and |
| File Formats Created | , , , , , and |
| condition | Topical |
| License | |
| Site | |
Content
Key Features of 7-Zip
- Supported Algorithms:
- LZMA , LZMA2, PPMd , Bzip2 , Deflate and Deflate64
- Supported Formats:
- packing and unpacking: 7z , BZIP2 ( BZ2 , TB2 , TBZ , TBZ2 ), GZIP ( GZ , TGZ ), TAR , ZIP ( JAR ), XZ , WIM ;
- unpacking only: ARJ , CAB , CHM , CPIO , CramFS , DEB , DMG , FAT , HFS , MBR , ISO , LZH (LHA), LZMA , MSI , NSIS , NTFS , RAR , RPM , SquashFS , UDF , VHD , XAR , Z ( TAR ).
- 7-Zip also has its own plug-in system, which allows third-party developers to add support for additional file formats in 7-Zip. There are plugins [9] that allow you to unpack the following formats: LZIP , ASAR, CCD / IMG, CDI, CHD (v4), CSO, CUE / BIN , ECM, GDI, ISZ , MDS / MDF , NRG, S01, E01, Ex01, L01, Lx01, AFF, AD1, MIME , UUE , XXE, yEnc .
- Very high compression ratio in 7z format thanks to the use of the advanced Lempel-Ziv algorithm .
- For ZIP and GZIP formats, the compression ratio is 2-10% higher than PKZIP and WinZip .
- Ability to create self-extracting archives for the 7z format.
- Ability to create multi-volume (cut into pieces) archives (except for self-extracting) for 7z format.
- AES- 256 encryption capability for 7z and ZIP formats.
- Supports hardware acceleration available on processors that implement the AES-NI instruction set.
- Integration into the shell of Microsoft Windows and Windows NT .
- Plugins for the programs FAR Manager , Total Commander and Unreal Commander .
- Built-in utility for performance testing.
- Multilingual graphical interface (for Windows only) with two-window file manager functions.
- Powerful command line version.
- Special version for 64-bit Windows operating systems.
- Unicode encoding support for file names.
7-Zip does not provide a way to manage the order of files within archives. It ignores the file name order on the command line. Therefore, 7-Zip cannot be used in cases where the order of file names is of great importance. For example, the EPUB format, which is based on Zip and HTML formats, requires a certain order of files in archives: a file named “MimeType” should be the first file in a ZIP archive.
Compression
7-Zip uses multithreading and allows you to use for compression, depending on the algorithm or format, a different number of threads. When creating archives in which files are compressed independently from each other (for example, ZIP ), the program can use up to eight streams at a time. For the LZMA compression algorithm, the archiver can simultaneously use up to two streams. The inability to use more of them is due to the consistent nature of continuous compression . The LZMA2 compression algorithm does not have this drawback.
When compressing in 7z format, special normalizer filters are also used. So, for more optimal compression of 32-bit x86-code, normalizing converters BCJ and BCJ2 are used. In addition, the program has an optimizing delta converter for some types of multimedia data, for example, uncompressed 24-bit images.
The degree of packaging is highly dependent on the nature of the data being compressed. Typically, the 7z format provides 4–25% better compression than the ZIP format.
In the final rating of the MaximumCompression.com site, the 7-Zip v9.25a archiver took 24th place in terms of compression ratio, beating WinRAR v4.1 beta 3 (by 3.6%) and WinZip v14 (by 4.2%). The rating leaders - PAQ8PX and WinRK - outperform 7-Zip in compression by 28% and 24% respectively, but spend much more time on packaging [10] .
Notes
- ↑ Download page.
- ↑ History of the 7-Zip
- ↑ 1 2 https://sourceforge.net/projects/sevenzip/
- ↑ https://www.7-zip.org/download.html
- ↑ 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 http: // www. 7-zip.org/
- ↑ p7zip
- ↑ SourceForge.net: Project Statistics For 7-Zip Archived on September 20, 2005.
- ↑ SourceForge.net: 2007 Community Choice Awards
- ↑ Plug-ins for the 7-Zip archiver
- ↑ Best overall compression program .
Literature
- Salomon, D. and Bryant, D. and Motta, G. Handbook of Data Compression. - Springer London, 2010 .-- P. 411-414. - 1361 p. - ISBN 9781848829039 .
Links
- Official website
- 7-Zip on SourceForge
- Download 7-Zip at SourceForge
- Links to the alpha version in the Open Discussion section on the SourceForge website of the 7-Zip project forum, you can also get advice from the developer there - (Alpha and Beta versions of 7-Zip are often the development of “stable” versions with improvements and fixes bugs).