1.\" $NetBSD: gzip.1,v 1.30 2017/10/22 17:36:49 abhinav 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 , 99or 100.Xr xz 1 . 101.Sh OPTIONS 102The following options are available: 103.Bl -tag -width XXrXXXrecursiveX 104.It Fl 1 , Fl Fl fast 105.It Fl 2 106.It Fl 3 107.It Fl 4 108.It Fl 5 109.It Fl 6 110.It Fl 7 111.It Fl 8 112.It Fl 9 , Fl Fl best 113These options change the compression level used, with the 114.Fl 1 115option being the fastest, with less compression, and the 116.Fl 9 117option being the slowest, with optimal compression. 118The default compression level is 6. 119.It Fl c , Fl Fl stdout , Fl Fl to-stdout 120This option specifies that output will go to the standard output 121stream, leaving files intact. 122.It Fl d , Fl Fl decompress , Fl Fl uncompress 123This option selects decompression rather than compression. 124.It Fl f , Fl Fl force 125This option turns on force mode. 126This allows files with multiple links, overwriting of pre-existing 127files, reading from or writing to a terminal, and when combined 128with the 129.Fl c 130option, allowing non-compressed data to pass through unchanged. 131.It Fl h , Fl Fl help 132This option prints a usage summary and exits. 133.It Fl k , Fl Fl keep 134This option prevents 135.Nm 136from deleting input files after (de)compression. 137.It Fl l , Fl Fl list 138This option displays information about the file's compressed and 139uncompressed size, ratio, uncompressed name. 140With the 141.Fl v 142option, it also displays the compression method, CRC, date and time 143embedded in the file. 144.It Fl N , Fl Fl name 145This option causes the stored filename in the input file to be used 146as the output file. 147.It Fl n , Fl Fl no-name 148This option stops the filename and timestamp from being stored in 149the output file. 150.It Fl q , Fl Fl quiet 151With this option, no warnings or errors are printed. 152.It Fl r , Fl Fl recursive 153This option is used to 154.Nm 155the files in a directory tree individually, using the 156.Xr fts 3 157library. 158.It Fl S Ar suffix , Fl Fl suffix Ar suffix 159This option changes the default suffix from .gz to 160.Ar suffix . 161.It Fl t , Fl Fl test 162This option will test compressed files for integrity. 163.It Fl V , Fl Fl version 164This option prints the version of the 165.Nm 166program. 167.It Fl v , Fl Fl verbose 168This option turns on verbose mode, which prints the compression 169ratio for each file compressed. 170.El 171.Sh ENVIRONMENT 172If the environment variable 173.Ev GZIP 174is set, it is parsed as a white-space separated list of options 175handled before any options on the command line. 176Options on the command line will override anything in 177.Ev GZIP . 178.Sh EXIT STATUS 179The 180.Nm 181utility exits 0 on success, 1821 on errors, 183and 2 if a warning occurs. 184.Sh SIGNALS 185.Nm 186responds to the following signals: 187.Bl -tag -width indent 188.It Dv SIGINFO 189Report progress to standard error. 190.El 191.Sh SEE ALSO 192.Xr bzip2 1 , 193.Xr compress 1 , 194.Xr xz 1 , 195.Xr fts 3 , 196.Xr zlib 3 197.Sh HISTORY 198The 199.Nm 200program was originally written by Jean-loup Gailly, licensed under 201the GNU Public Licence. 202Matthew R. Green wrote a simple front end for 203.Nx 1.3 204distribution media, based on the freely re-distributable zlib library. 205It was enhanced to be mostly feature-compatible with the original 206GNU 207.Nm 208program for 209.Nx 2.0 . 210.Pp 211This manual documents 212.Nx 213.Nm 214version 20170803. 215.Sh AUTHORS 216This implementation of 217.Nm 218was written by 219.An Matthew R. Green Aq Mt mrg@eterna.com.au . 220