Compress (Unix)

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Formats that could be considered to be the successors of ''compress'' include [[Freeze/Melt]], and (especially) [[Gzip]].
 
Formats that could be considered to be the successors of ''compress'' include [[Freeze/Melt]], and (especially) [[Gzip]].
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== The 0x1f compression family ==
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There are several compressed file formats, with similar features, that begin with byte value {{magic|0x1f}} (octal 037; decimal 31). We arbitrarily choose ''compress'' as the representative example, and list the formats here.
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{| class="wikitable"
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! Signature (hex) !! Format
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|-
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| <code>1f 1e</code> || [[pack (Unix)]]
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|-
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| <code>1f 1f</code> || [[pack (Unix)]] - old format
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|-
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| <code>1f 8b</code> || [[gzip]]
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|-
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| <code>1f 9d</code> || compress
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|-
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| <code>1f 9e</code> || [[Freeze/Melt]] - old format
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|-
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| <code>1f 9f</code> || [[Freeze/Melt]] - new format
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|-
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| <code>1f a0</code> || [[SCO compress LZH]]
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|-
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| <code>1f a1</code> || [[Quasijarus Strong Compression]]
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|-
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| <code>1f ff</code> or <code>ff 1f</code> || [[compact (Unix)]]
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|}
  
 
== Software ==
 
== Software ==

Latest revision as of 14:40, 18 September 2020

File Format
Name compress (Unix)
Ontology
Extension(s) .Z
MIME Type(s) application/x-compress
Wikidata ID Q29209269
Released ~1984
This article is about a specific file format. For compression in general, see Compression.

compress is a Unix command line utility, and a general-purpose compressed file format. Its compression algorithm is based on LZW.

Contents

[edit] Identifiers

The conventional filename extension is a capitalized .Z.

[edit] Identification

Files begin with bytes 1f 9d.

[edit] See also

Formats that could be considered to be the successors of compress include Freeze/Melt, and (especially) Gzip.

[edit] The 0x1f compression family

There are several compressed file formats, with similar features, that begin with byte value 0x1f (octal 037; decimal 31). We arbitrarily choose compress as the representative example, and list the formats here.

Signature (hex) Format
1f 1e pack (Unix)
1f 1f pack (Unix) - old format
1f 8b gzip
1f 9d compress
1f 9e Freeze/Melt - old format
1f 9f Freeze/Melt - new format
1f a0 SCO compress LZH
1f a1 Quasijarus Strong Compression
1f ff or ff 1f compact (Unix)

[edit] Software

[edit] External links

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