1.\" $NetBSD: gzip.1,v 1.20 2009/04/01 08:15:37 mrg Exp $ 2.\" $DragonFly: src/usr.bin/gzip/gzip.1,v 1.2 2007/12/06 19:54:52 hasso Exp $ 3.\" 4.\" Copyright (c) 1997, 2003, 2004 Matthew R. Green 5.\" All rights reserved. 6.\" 7.\" Redistribution and use in source and binary forms, with or without 8.\" modification, are permitted provided that the following conditions 9.\" are met: 10.\" 1. Redistributions of source code must retain the above copyright 11.\" notice, this list of conditions and the following disclaimer. 12.\" 2. Redistributions in binary form must reproduce the above copyright 13.\" notice, this list of conditions and the following disclaimer in the 14.\" documentation and/or other materials provided with the distribution. 15.\" 16.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 17.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 18.\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 19.\" IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 20.\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 21.\" BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 22.\" LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 23.\" AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 24.\" OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26.\" SUCH DAMAGE. 27.\" 28.Dd July 28, 2009 29.Dt GZIP 1 30.Os 31.Sh NAME 32.Nm gzip 33.Nd compression/decompression tool using Lempel-Ziv coding (LZ77) 34.Sh SYNOPSIS 35.Nm 36.Op Fl cdfhklNnqrtVv 37.Op Fl S Ar suffix 38.Ar file 39.Oo 40.Ar file Oo ... 41.Oc 42.Oc 43.Nm gunzip 44.Op Fl cfhkNqrtVv 45.Op Fl S Ar suffix 46.Ar file 47.Oo 48.Ar file Oo ... 49.Oc 50.Oc 51.Nm zcat 52.Op Fl fhV 53.Ar file 54.Oo 55.Ar file Oo ... 56.Oc 57.Oc 58.Sh DESCRIPTION 59The 60.Nm 61program compresses and decompresses files using Lempel-Ziv coding 62(LZ77). 63If no 64.Ar files 65are specified, 66.Nm 67will compress from standard input, or decompress to standard output. 68When in compression mode, each 69.Ar file 70will be replaced with another file with the suffix, set by the 71.Fl S Ar suffix 72option, added, if possible. 73In decompression mode, each 74.Ar file 75will be checked for existence, as will the file with the suffix 76added. 77.Pp 78If invoked as 79.Nm gunzip 80then the 81.Fl d 82option is enabled. 83If invoked as 84.Nm zcat 85or 86.Nm gzcat 87then both the 88.Fl c 89and 90.Fl d 91options are enabled. 92.Pp 93This version of 94.Nm 95is also capable of decompressing files compressed using 96.Xr pack 1 , 97.Xr compress 1 98or 99.Xr bzip2 1 . 100.Sh OPTIONS 101The following options are available: 102.Bl -tag -width XXrXXXrecursiveX 103.It Fl 1 , -fast 104.It Fl 2 105.It Fl 3 106.It Fl 4 107.It Fl 5 108.It Fl 6 109.It Fl 7 110.It Fl 8 111.It Fl 9 , -best 112These options change the compression level used, with the 113.Fl 1 114option being the fastest, with less compression, and the 115.Fl 9 116option being the slowest, with optimal compression. 117The default compression level is 6. 118.It Fl c , -stdout , -to-stdout 119This option specifies that output will go to the standard output 120stream, leaving files intact. 121.It Fl d , -decompress , -uncompress 122This option selects decompression rather than compression. 123.It Fl f , -force 124This option turns on force mode. 125This allows files with multiple links, overwriting of pre-existing 126files, reading from or writing to a terminal, and when combined 127with the 128.Fl c 129option, allowing non-compressed data to pass through unchanged. 130.It Fl h , -help 131This option prints a usage summary and exits. 132.It Fl k , -keep 133Keep (don't delete) input files during compression 134or decompression. 135.It Fl l , -list 136This option displays information about the file's compressed and 137uncompressed size, ratio, uncompressed name. 138With the 139.Fl v 140option, it also displays the compression method, CRC, date and time 141embedded in the file. 142.It Fl N , -name 143This option causes the stored filename in the input file to be used 144as the output file. 145.It Fl n , -no-name 146This option stops the filename and timestamp from being stored in 147the output file. 148.It Fl q , -quiet 149With this option, no warnings or errors are printed. 150.It Fl r , -recursive 151This option is used to 152.Nm 153the files in a directory tree individually, using the 154.Xr fts 3 155library. 156.It Fl S Ar suffix , Fl -suffix Ar suffix 157This option changes the default suffix from .gz to 158.Ar suffix . 159.It Fl t , -test 160This option will test compressed files for integrity. 161.It Fl V , -version 162This option prints the version of the 163.Nm 164program. 165.It Fl v , -verbose 166This option turns on verbose mode, which prints the compression 167ratio for each file compressed. 168.El 169.Sh ENVIRONMENT 170If the environment variable 171.Ev GZIP 172is set, it is parsed as a white-space separated list of options 173handled before any options on the command line. 174Options on the command line will override anything in 175.Ev GZIP . 176.Sh SEE ALSO 177.Xr bzip2 1 , 178.Xr compress 1 , 179.Xr fts 3 , 180.Xr zlib 3 181.Sh HISTORY 182The 183.Nm 184program was originally written by Jean-loup Gailly, licensed under 185the GNU Public Licence. 186Matthew R. Green wrote a simple front end for 187.Nx 1.3 188distribution media, based on the freely re-distributable zlib library. 189It was enhanced to be mostly feature-compatible with the original 190GNU 191.Nm 192program for 193.Nx 2.0 . 194.Pp 195This manual documents 196.Nx 197.Nm 198version 20040427. 199.Sh AUTHORS 200This implementation of 201.Nm 202was written by 203.An Matthew R. Green Aq mrg@eterna.com.au . 204