compress(redirected from Z (file format))
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a bandage used for healing purposes.
A dry compress (usually cotton-gauze) is applied to a painful or injured part of the body (wound, burn) to protect it from chilling and other external irritants and to absorb any discharges. Wet compresses may be either cold (lotion) or hot (poultice). A heating compress (a damp material covered with waterproof paper or oilcloth and a layer of cotton) is used with inflammatory processes as a revulsive and resorptive. A medicinal compress is one in which medicinal substances (ointments, pastes, novocain) are added to the water.
Unix compress was written in C by Joseph M. Orost, James A. Woods et al., and was widely circulated via Usenet. It uses the Lempel-Ziv Welch algorithm and normally produces files with the suffix ".Z".
Compress uses variable length codes. Initially, nine-bit codes are output until they are all used. When this occurs, ten-bit codes are used and so on, until an implementation-dependent maximum is reached.
After every 10 kilobytes of input the compression ratio is checked. If it is decreasing then the entire string table is discarded and information is collected from scratch.
compress(1) To compact data to save space. See data compression and archive program.
(2) A Unix utility used to compress files. This is the perfect example of poor technical naming. When a common name is used to name a function, it becomes tedious to document the process. For example, "use gzip to compress the file instead of compress because..." See archive formats, tar, gzip and data compression.