- 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.
The conventional filename extension is a capitalized .Z.
Files begin with bytes
- SCO compress LZH - variant
- Quasijarus Strong Compression - variant
- pack (Unix) - predecessor
- compact (Unix) - predecessor
- Squash (RISC OS)
- compact (Gene Olson)
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.
||pack (Unix) - old format|
||Freeze/Melt - old format|
||Freeze/Melt - new format|
||SCO compress LZH|
||Quasijarus Strong Compression|