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PACK(1) General Commands Manual PACK(1) NAME pack, unpack, pcat, compress, uncompress, zcat - compress and expand files SYNOPSIS pack [ - ] file ... unpack file ... pcat [ file ... ] compress [ option ... ] [ file ... ] uncompress [ option ... ] [ file ... ] zcat [ -V ] [ file ... ] DESCRIPTION Pack attempts to compress the files and places the results in corre- sponding files named file.z with the same access modes, dates, and owner as the originals. Successfully packed files are removed. Unpack reverses the process. Pcat unpacks files to the standard output. The .z suffix may be omitted from the name of the input file for unpack or pcat. Pack encodes individual characters in a Huffman code. Option - causes statistics of the encoding to be printed. The option toggles on and off at each appearance among the list of files. Compress, uncompress, and zcat work like pack, unpack, and pcat, putting each compressed file into file.Z. The options are -f (force) Compress even when it doesn't save space. -c Write to the standard output; change no files. Zcat is identi- cal to uncompress -c. -bbits Compress uses a modified Lempel-Ziv encoding. Common substrings in the file are replaced by variable-length codes up to size bits (default 16). Smaller limits devour less address space. -v Print percent reduction for each file. -V Print program version number. Compress-uncompress pack better and are faster overall; pack-unpack work on smaller machines and are much more widely available. SEE ALSO T. A. Welch, `A Technique for High Performance Data Compression,' IEEE Computer, 17 (1984) 8-19. DIAGNOSTICS The exit code of pack, unpack, or pcat is the number of files it failed to process. The exit code of compress, uncompress, or zcat is 0 normally, 1 for er- ror, 2 for ineffective compression (i.e. expansion). PACK(1)