7z

Template: Infobox file format / Maintenance / default missing

377A.BCAF.271C hex 7z \ XBC \ XAF '\ x1c ( ASCII C notation )

7z is a compressed file format for archiving files, introduced with 7-Zip by Igor Pavlov Viktorovich. The file name extension is " 7z ".

Compared to other formats allows the LZMA a very high data compression rate. In addition, 7z is characterized by an open architecture, support for very large data sets and Unicode support as well as encryption by the AES -256 standard from. Due to the underlying architecture of the 7z format can easily be extended to other data compression methods.

In addition to 7 -Zip, the reference range of developer support numerous other programs to create and unpack 7z files.

Main features

  • Splitting of files: set Max size of the components manually.
  • Open architecture: This can be added such as support for any compression and conversion methods.
  • Large file support: By supporting file sizes of up to 16 exabytes ( ≈ 16 billion gigabytes) should be the size restriction in practice at the present time and also on the long term be irrelevant ( if the course of the hard disk capacities between 1980 to 2005 in the future extrapolated hard drives with a size of 1 EB will only be available from about 2035).
  • Unicode filenames
  • Progressive compression
  • Archive header compression
  • Strong Encryption: 7z implemented strong encryption using the Advanced Encryption Standard with key lengths of 256 bits (AES- 256). The keys are generated in a system based on SHA -256 method of a password provided by the user. Hashing is doing 218 (262144) times consecutively performed, which is a brute -force search for the key more difficult, since the time required for the testing of a key is multiplied (key Strengthening ). File names can be encrypted with.

Data compression methods

The open architecture of the 7z format, it can use any new compression method. Currently, the following methods are integrated into 7z:

Linux, Mac OS X and other Unix -like systems

The disclosure of the format makes porting to other operating systems like Linux possible. The open source reference implementation of 7-Zip is a pure Windows program. The console version was ported as p7zip on Linux. For real backup under Unix-like systems, the 7z format is not suitable alone as special files (devices, etc.) and file attributes such as owner and group of a file are not saved - here previous archive is recommended (eg with tar) and subsequent compression of the archive. At the mere disclosure of documents, the file attributes are generally irrelevant, so that a pure 7z file - created per $ 7z a archivname.7z files is sufficient.

7z is capable of multithreading ( mmt - option = ) to achieve multi-core computers, a considerable acceleration of the compression. The program is in relation to the 7z - compressed data stream is not streaming capable, that is, the options -si and-so only work for the uncompressed data (if such is required, can be found on the related program dodge xz, which is used as gzip may be ).

The console version can now be integrated by many applications with graphical user interface, including the pre-installed program archives of GNOME ( File Roller ) and KDE ( Ark ). In Mac OS X is available as graphical tool 7zX available.

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