Freeze/Melt

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(Created page with "{{FormatInfo |formattype=electronic |subcat=Compression |extensions={{ext|F}} }} '''Freeze''' is a file compression utility used from the command line in Unix-style operating...")
 
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'''Freeze''' is a file compression utility used from the command line in Unix-style operating systems. '''Melt''' is the corresponding decompressor. It is considered obsolete now in favor of [[gzip]].
 
'''Freeze''' is a file compression utility used from the command line in Unix-style operating systems. '''Melt''' is the corresponding decompressor. It is considered obsolete now in favor of [[gzip]].
  
A two-pass compression is done with a [[LZW|Lempel-Zev]] algorithm on the first pass and a dynamic [[Huffman encoding|Huffman algorithm]] on the second. The characteristics of the Huffman table used are added to the file. File attributes, ownership, etc., are preserved, and a .F extension is added. A two-byte magic number is prepended to the file (\037\236 octal for versions 1.x, and \037\237 for later versions).
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A two-pass compression is done with a [[Lempel-Zev]] algorithm on the first pass and a dynamic [[Huffman encoding|Huffman algorithm]] on the second. The characteristics of the Huffman table used are added to the file. File attributes, ownership, etc., are preserved, and a .F extension is added. A two-byte magic number is prepended to the file (\037\236 octal for versions 1.x, and \037\237 for later versions).
  
 
== References ==
 
== References ==
 
* [http://www.esrl.noaa.gov/gmd/dv/hats/cats/stations/qnxman/freeze.html Man page] (in NOAA site, which should know something about freezing!)
 
* [http://www.esrl.noaa.gov/gmd/dv/hats/cats/stations/qnxman/freeze.html Man page] (in NOAA site, which should know something about freezing!)
 
* [http://reality.sgiweb.org/freeware/source/freeze-2.3.1/ Source code]
 
* [http://reality.sgiweb.org/freeware/source/freeze-2.3.1/ Source code]

Revision as of 16:18, 28 December 2012

File Format
Name Freeze/Melt
Ontology
Extension(s) .F

Freeze is a file compression utility used from the command line in Unix-style operating systems. Melt is the corresponding decompressor. It is considered obsolete now in favor of gzip.

A two-pass compression is done with a Lempel-Zev algorithm on the first pass and a dynamic Huffman algorithm on the second. The characteristics of the Huffman table used are added to the file. File attributes, ownership, etc., are preserved, and a .F extension is added. A two-byte magic number is prepended to the file (\037\236 octal for versions 1.x, and \037\237 for later versions).

References

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