This is a list of
file format
A file format is a standard way that information is encoded for storage in a computer file. It specifies how bits are used to encode information in a digital storage medium. File formats may be either proprietary or free.
Some file formats ...
s used by
archiver
An archive is an accumulation of historical records or materials – in any medium – or the physical facility in which they are located.
Archives contain primary source documents that have accumulated over the course of an individual or ...
s and
compressor
A compressor is a mechanical device that increases the pressure of a gas by reducing its volume. An air compressor is a specific type of gas compressor.
Compressors are similar to pumps: both increase the pressure on a fluid and both can transp ...
s used to create
archive files.
Archiving only
Compression only
Archiving and compression
Data recovery
Comparison
Containers and compression
Notes
While the original
tar format uses the
ASCII character encoding, current implementations use the
UTF-8 (Unicode) encoding, which is backwards compatible with ASCII.
Supports the external Parchive program (par2).
From 3.20 release RAR can store modification, creation and last access time with the precision up to 0.0000001 second (= 0.1 µs)
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The PAQ family (with its lighter weight derivative LPAQ) went through many revisions, each revision suggested its own extension. For example: ".paq9a".
WIM can store the ciphertext of encrypted files on an NTFS volume, but such files can only by decrypted if an administrator extracts the file to an NTFS volume, and the decryption key is available (typically from the file's original owner on the same Windows installation). Microsoft has also distributed some download versions of the Windows operating system as encrypted WIM files, but via an external encryption process and not a feature of WIM.
*Purpose: Archive formats are used for backups, mobility, and archiving. Many archive formats compress the data to consume less storage space and result in quicker transfer times as the same data is represented by fewer bytes. Another benefit is that files are combined into one archive file which has less overhead for managing or transferring. There are numerous compression algorithms available to losslessly compress archived data and some algorithms work better (smaller archive or faster compression) with particular data types. Archive formats are also used by most operating systems to package software for easier distribution and installation than binary executables.
*Filename extension: The DOS and Windows operating systems required filenames to include an extension (of at least one, and typically 3 characters) to identify the file type and use. Filename extensions must be unique for each type of file. Many operating systems
An operating system (OS) is system software that manages computer hardware, software resources, and provides common services for computer programs.
Time-sharing operating systems schedule tasks for efficient use of the system and may also inc ...
identify a file's type from its contents without the need for an extension in its name. However, the use of three-character extensions has been embraced as a useful and efficient shorthand for identifying file types.
*Integrity check: Archive files are often stored on magnetic media, which is subject to data storage
Data storage is the recording (storing) of information (data) in a storage medium. Handwriting, phonographic recording, magnetic tape, and optical discs are all examples of storage media. Biological molecules such as RNA and DNA are conside ...
errors. Early tape media had a higher rate of errors than they do today. Many archive formats contain extra error-correction information to detect storage or transmission errors, and the software used to read the archive files contains logic to detect and possibly correct errors.
*Recovery record: Many archive formats contain redundant data embedded in the files in order to detect data storage or transmission errors, and the software used to read the archive files contains logic to detect and correct errors.
*Encryption: In order to protect the data being stored or transferred from being read if intercepted, many archive formats include the capability to encrypt the data. There are multiple mathematical algorithms available to encrypt data.
Software packaging and distribution
Notes
Not to be confused with the archiver JAR written by Robert K. Jung, which produces ".j" files.
Features
Notes
Compression is not a built-in feature of the formats, however, the resulting archive can be compressed with any algorithm of choice. Several implementations include functionality to do this automatically
Most implementations can optionally produce a self-extracting executable
Per-file compression with gzip, bzip2, lzo, xz, lzma (as opposed to compressing the whole archive). An individual can choose not to compress already compressed filenames based on their suffix as well.
See also
* Archive file
* Comparison of file archivers
* Comparison of file systems
* List of file systems
* Solid compression
* zlib
Footnotes
{{DEFAULTSORT:Archive Formats
Lists of file formats
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