1.\" $NetBSD: gzip.1,v 1.32 2024/02/04 05:43:07 mrg Exp $ 2.\" 3.\" Copyright (c) 1997, 2003, 2004, 2008, 2009, 2015, 2017 Matthew R. Green 4.\" All rights reserved. 5.\" 6.\" Redistribution and use in source and binary forms, with or without 7.\" modification, are permitted provided that the following conditions 8.\" are met: 9.\" 1. Redistributions of source code must retain the above copyright 10.\" notice, this list of conditions and the following disclaimer. 11.\" 2. Redistributions in binary form must reproduce the above copyright 12.\" notice, this list of conditions and the following disclaimer in the 13.\" documentation and/or other materials provided with the distribution. 14.\" 15.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 16.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 17.\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 18.\" IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 19.\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 20.\" BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 21.\" LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 22.\" AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 23.\" OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25.\" SUCH DAMAGE. 26.\" 27.Dd January 8, 2017 28.Dt GZIP 1 29.Os 30.Sh NAME 31.Nm gzip , 32.Nm gunzip , 33.Nm zcat 34.Nd compression/decompression tool using Lempel-Ziv coding (LZ77) 35.Sh SYNOPSIS 36.Nm 37.Op Fl cdfhlNnqrtVv 38.Op Fl S Ar suffix 39.Ar file 40.Oo 41.Ar file Oo ... 42.Oc 43.Oc 44.Nm gunzip 45.Op Fl cfhNqrtVv 46.Op Fl S Ar suffix 47.Ar file 48.Oo 49.Ar file Oo ... 50.Oc 51.Oc 52.Nm zcat 53.Op Fl fhV 54.Ar file 55.Oo 56.Ar file Oo ... 57.Oc 58.Oc 59.Sh DESCRIPTION 60The 61.Nm 62program compresses and decompresses files using Lempel-Ziv coding 63(LZ77). 64If no 65.Ar files 66are specified, 67.Nm 68will compress from standard input, or decompress to standard output. 69When in compression mode, each 70.Ar file 71will be replaced with another file with the suffix, set by the 72.Fl S Ar suffix 73option, added, if possible. 74In decompression mode, each 75.Ar file 76will be checked for existence, as will the file with the suffix 77added. 78.Pp 79If invoked as 80.Nm gunzip 81then the 82.Fl d 83option is enabled. 84If invoked as 85.Nm zcat 86or 87.Nm gzcat 88then both the 89.Fl c 90and 91.Fl d 92options are enabled. 93.Pp 94This version of 95.Nm 96is also capable of decompressing files compressed using 97.Xr compress 1 , 98.Xr bzip2 1 , 99.Ar lzip , 100or 101.Xr xz 1 . 102.Sh OPTIONS 103The following options are available: 104.Bl -tag -width XXrXXXrecursiveX 105.It Fl 1 , Fl Fl fast 106.It Fl 2 107.It Fl 3 108.It Fl 4 109.It Fl 5 110.It Fl 6 111.It Fl 7 112.It Fl 8 113.It Fl 9 , Fl Fl best 114These options change the compression level used, with the 115.Fl 1 116option being the fastest, with less compression, and the 117.Fl 9 118option being the slowest, with optimal compression. 119The default compression level is 6. 120.It Fl c , Fl Fl stdout , Fl Fl to-stdout 121This option specifies that output will go to the standard output 122stream, leaving files intact. 123.It Fl d , Fl Fl decompress , Fl Fl uncompress 124This option selects decompression rather than compression. 125.It Fl f , Fl Fl force 126This option turns on force mode. 127This allows files with multiple links, overwriting of pre-existing 128files, reading from or writing to a terminal, and when combined 129with the 130.Fl c 131option, allowing non-compressed data to pass through unchanged. 132.It Fl h , Fl Fl help 133This option prints a usage summary and exits. 134.It Fl k , Fl Fl keep 135This option prevents 136.Nm 137from deleting input files after (de)compression. 138.It Fl l , Fl Fl list 139This option displays information about the file's compressed and 140uncompressed size, ratio, uncompressed name. 141With the 142.Fl v 143option, it also displays the compression method, CRC, date and time 144embedded in the file. 145.It Fl N , Fl Fl name 146This option causes the stored filename in the input file to be used 147as the output file. 148.It Fl n , Fl Fl no-name 149This option stops the filename and timestamp from being stored in 150the output file. 151.It Fl q , Fl Fl quiet 152With this option, no warnings or errors are printed. 153.It Fl r , Fl Fl recursive 154This option is used to 155.Nm 156the files in a directory tree individually, using the 157.Xr fts 3 158library. 159.It Fl S Ar suffix , Fl Fl suffix Ar suffix 160This option changes the default suffix from .gz to 161.Ar suffix . 162.It Fl t , Fl Fl test 163This option will test compressed files for integrity. 164.It Fl V , Fl Fl version 165This option prints the version of the 166.Nm 167program. 168.It Fl v , Fl Fl verbose 169This option turns on verbose mode, which prints the compression 170ratio for each file compressed. 171.El 172.Sh ENVIRONMENT 173If the environment variable 174.Ev GZIP 175is set, it is parsed as a white-space separated list of options 176handled before any options on the command line. 177Options on the command line will override anything in 178.Ev GZIP . 179.Sh EXIT STATUS 180The 181.Nm 182utility exits 0 on success, 1831 on errors, 184and 2 if a warning occurs. 185.Sh SIGNALS 186.Nm 187responds to the following signals: 188.Bl -tag -width indent 189.It Dv SIGINFO 190Report progress to standard error. 191.El 192.Sh SEE ALSO 193.Xr bzip2 1 , 194.Xr compress 1 , 195.Xr xz 1 , 196.Xr fts 3 , 197.Xr zlib 3 198.Sh HISTORY 199The 200.Nm 201program was originally written by Jean-loup Gailly, licensed under 202the GNU Public Licence. 203Matthew R. Green wrote a simple front end for 204.Nx 1.3 205distribution media, based on the freely re-distributable zlib library. 206It was enhanced to be mostly feature-compatible with the original 207GNU 208.Nm 209program for 210.Nx 2.0 . 211.Pp 212This manual documents 213.Nx 214.Nm 215version 20170803. 216.Sh AUTHORS 217This implementation of 218.Nm 219was written by 220.An Matthew R. Green Aq Mt mrg@eterna23.net . 221