[apple/file_cmds.git] / gzip / gzip.1

.\"	$NetBSD: gzip.1,v 1.21 2011/06/19 02:22:36 christos Exp $
.\"
.\" Copyright (c) 1997, 2003, 2004 Matthew R. Green
.\" All rights reserved.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\"    notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\"    notice, this list of conditions and the following disclaimer in the
.\"    documentation and/or other materials provided with the distribution.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
.\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
.\" IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
.\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
.\" BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
.\" LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
.\" AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
.\" OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
.\" SUCH DAMAGE.
.\"
.\" $FreeBSD: src/usr.bin/gzip/gzip.1,v 1.11 2011/10/10 06:37:32 delphij Exp $
.Dd October 9, 2011
.Dt GZIP 1
.Os
.Sh NAME
.Nm gzip
.Nd compression/decompression tool using Lempel-Ziv coding (LZ77)
.Sh SYNOPSIS
.Nm
.Op Fl cdfhkLlNnqrtVv
.Op Fl S Ar suffix
.Ar file
.Oo
.Ar file Oo ...
.Oc
.Oc
.Nm gunzip
.Op Fl cfhkLNqrtVv
.Op Fl S Ar suffix
.Ar file
.Oo
.Ar file Oo ...
.Oc
.Oc
.Nm zcat
.Op Fl fhV
.Ar file
.Oo
.Ar file Oo ...
.Oc
.Oc
.Sh DESCRIPTION
The
.Nm
program compresses and decompresses files using Lempel-Ziv coding
(LZ77).
If no
.Ar files
are specified,
.Nm
will compress from standard input, or decompress to standard output.
When in compression mode, each
.Ar file
will be replaced with another file with the suffix, set by the
.Fl S Ar suffix
option, added, if possible.
.Pp
In decompression mode, each
.Ar file
will be checked for existence, as will the file with the suffix
added.
Each
.Ar file
argument must contain a separate complete archive;
when multiple
.Ar files
are indicated, each is decompressed in turn.
.Pp
In the case of
.Nm gzcat
the resulting data is then concatenated in the manner of
.Xr cat 1 .
.Pp
If invoked as
.Nm gunzip
then the
.Fl d
option is enabled.
If invoked as
.Nm zcat
or
.Nm gzcat
then both the
.Fl c
and
.Fl d
options are enabled.
When invoked as
.Nm zcat ,
.Dq .Z
will be appended to all filenames that do not have that suffix.
.Pp
This version of
.Nm
is also capable of decompressing files compressed using
.Xr compress 1
or
.Xr bzip2 1 .
.Sh OPTIONS
The following options are available:
.Bl -tag -width XXrXXXrecursiveX
.It Fl 1 , -fast
.It Fl 2 , 3 , 4 , 5 , 6 , 7 , 8
.It Fl 9 , -best
These options change the compression level used, with the
.Fl 1
option being the fastest, with less compression, and the
.Fl 9
option being the slowest, with optimal compression.
The default compression level is 6.
.It Fl c , -stdout , -to-stdout
This option specifies that output will go to the standard output
stream, leaving files intact.
.It Fl d , -decompress , -uncompress
This option selects decompression rather than compression.
.It Fl f , -force
This option turns on force mode.
This allows files with multiple links, symbolic links to regular files,
overwriting of pre-existing files, reading from or writing to a terminal,
and when combined with the
.Fl c
option, allowing non-compressed data to pass through unchanged.
.It Fl h , -help
This option prints a usage summary and exits.
.It Fl k , -keep
Keep (don't delete) input files during compression
or decompression.
.It Fl L , -license
This option prints
.Nm
license.
.It Fl l , -list
This option displays information about the file's compressed and
uncompressed size, ratio, uncompressed name.
With the
.Fl v
option, it also displays the compression method, CRC, date and time
embedded in the file.
.It Fl N , -name
This option causes the stored filename in the input file to be used
as the output file.
.It Fl n , -no-name
This option stops the filename and timestamp from being stored in
the output file.
.It Fl q , -quiet
With this option, no warnings or errors are printed.
.It Fl r , -recursive
This option is used to
.Nm
the files in a directory tree individually, using the
.Xr fts 3
library.
.It Fl S Ar suffix , Fl -suffix Ar suffix
This option changes the default suffix from .gz to
.Ar suffix .
.It Fl t , -test
This option will test compressed files for integrity.
.It Fl V , -version
This option prints the version of the
.Nm
program.
.It Fl v , -verbose
This option turns on verbose mode, which prints the compression
ratio for each file compressed.
.El
.Sh ENVIRONMENT
If the environment variable
.Ev GZIP
is set, it is parsed as a white-space separated list of options
handled before any options on the command line.
Options on the command line will override anything in
.Ev GZIP .
.Sh SEE ALSO
.Xr bzip2 1 ,
.Xr compress 1 ,
.Xr xz 1 ,
.Xr fts 3 ,
.Xr zlib 3 ,
.Xr compat 5
.Sh HISTORY
The
.Nm
program was originally written by Jean-loup Gailly, licensed under
the GNU Public Licence.
Matthew R. Green wrote a simple front end for
.Nx 1.3
distribution media, based on the freely re-distributable zlib library.
It was enhanced to be mostly feature-compatible with the original
GNU
.Nm
program for
.Nx 2.0 .
.Pp
This implementation of
.Nm
was ported based on the
.Nx
.Nm ,
and first appeared in
.Fx 7.0 .
.Sh AUTHORS
.An -nosplit
This implementation of
.Nm
was written by
.An Matthew R. Green Aq mrg@eterna.com.au
with unpack support written by
.An Xin LI Aq delphij@FreeBSD.org .
.Sh BUGS
According to RFC 1952, the recorded file size is stored in a 32-bit
integer, therefore, it can not represent files larger than 4GB.
This limitation also applies to
.Fl l
option of
.Nm
utility.
Commit	Line	Data
00337e45 A	1	.\" $NetBSD: gzip.1,v 1.21 2011/06/19 02:22:36 christos Exp $
	2	.\"
	3	.\" Copyright (c) 1997, 2003, 2004 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	.\" $FreeBSD: src/usr.bin/gzip/gzip.1,v 1.11 2011/10/10 06:37:32 delphij Exp $
	28	.Dd October 9, 2011
	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 cdfhkLlNnqrtVv
	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 cfhkLNqrtVv
	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
	59	The
	60	.Nm
	61	program compresses and decompresses files using Lempel-Ziv coding
	62	(LZ77).
	63	If no
	64	.Ar files
65	are specified,
66	.Nm
67	will compress from standard input, or decompress to standard output.
68	When in compression mode, each
69	.Ar file
70	will be replaced with another file with the suffix, set by the
71	.Fl S Ar suffix
72	option, added, if possible.
73	.Pp
74	In decompression mode, each
75	.Ar file
76	will be checked for existence, as will the file with the suffix
77	added.
78	Each
79	.Ar file
80	argument must contain a separate complete archive;
81	when multiple
82	.Ar files
83	are indicated, each is decompressed in turn.
84	.Pp
85	In the case of
86	.Nm gzcat
87	the resulting data is then concatenated in the manner of
88	.Xr cat 1 .
89	.Pp
90	If invoked as
91	.Nm gunzip
92	then the
93	.Fl d
94	option is enabled.
95	If invoked as
96	.Nm zcat
97	or
98	.Nm gzcat
99	then both the
100	.Fl c
101	and
102	.Fl d
103	options are enabled.
104	When invoked as
105	.Nm zcat ,
106	.Dq .Z
107	will be appended to all filenames that do not have that suffix.
108	.Pp
109	This version of
110	.Nm
111	is also capable of decompressing files compressed using
112	.Xr compress 1
113	or
114	.Xr bzip2 1 .
115	.Sh OPTIONS
116	The following options are available:
117	.Bl -tag -width XXrXXXrecursiveX
118	.It Fl 1 , -fast
119	.It Fl 2 , 3 , 4 , 5 , 6 , 7 , 8
120	.It Fl 9 , -best
121	These options change the compression level used, with the
122	.Fl 1
123	option being the fastest, with less compression, and the
124	.Fl 9
125	option being the slowest, with optimal compression.
126	The default compression level is 6.
127	.It Fl c , -stdout , -to-stdout
128	This option specifies that output will go to the standard output
129	stream, leaving files intact.
130	.It Fl d , -decompress , -uncompress
131	This option selects decompression rather than compression.
132	.It Fl f , -force
133	This option turns on force mode.
134	This allows files with multiple links, symbolic links to regular files,
135	overwriting of pre-existing files, reading from or writing to a terminal,
136	and when combined with the
137	.Fl c
138	option, allowing non-compressed data to pass through unchanged.
139	.It Fl h , -help
140	This option prints a usage summary and exits.
141	.It Fl k , -keep
142	Keep (don't delete) input files during compression
143	or decompression.
144	.It Fl L , -license
145	This option prints
146	.Nm
147	license.
148	.It Fl l , -list
149	This option displays information about the file's compressed and
150	uncompressed size, ratio, uncompressed name.
151	With the
152	.Fl v
153	option, it also displays the compression method, CRC, date and time
154	embedded in the file.
155	.It Fl N , -name
156	This option causes the stored filename in the input file to be used
157	as the output file.
158	.It Fl n , -no-name
159	This option stops the filename and timestamp from being stored in
160	the output file.
161	.It Fl q , -quiet
162	With this option, no warnings or errors are printed.
163	.It Fl r , -recursive
164	This option is used to
165	.Nm
166	the files in a directory tree individually, using the
167	.Xr fts 3
168	library.
169	.It Fl S Ar suffix , Fl -suffix Ar suffix
170	This option changes the default suffix from .gz to
171	.Ar suffix .
172	.It Fl t , -test
173	This option will test compressed files for integrity.
174	.It Fl V , -version
175	This option prints the version of the
176	.Nm
177	program.
178	.It Fl v , -verbose
179	This option turns on verbose mode, which prints the compression
180	ratio for each file compressed.
181	.El
182	.Sh ENVIRONMENT
183	If the environment variable
184	.Ev GZIP
185	is set, it is parsed as a white-space separated list of options
186	handled before any options on the command line.
187	Options on the command line will override anything in
188	.Ev GZIP .
189	.Sh SEE ALSO
190	.Xr bzip2 1 ,
191	.Xr compress 1 ,
192	.Xr xz 1 ,
193	.Xr fts 3 ,
194	.Xr zlib 3 ,
195	.Xr compat 5
196	.Sh HISTORY
197	The
198	.Nm
199	program was originally written by Jean-loup Gailly, licensed under
200	the GNU Public Licence.
201	Matthew R. Green wrote a simple front end for
202	.Nx 1.3
203	distribution media, based on the freely re-distributable zlib library.
204	It was enhanced to be mostly feature-compatible with the original
205	GNU
206	.Nm
207	program for
208	.Nx 2.0 .
209	.Pp
210	This implementation of
211	.Nm
212	was ported based on the
213	.Nx
214	.Nm ,
215	and first appeared in
216	.Fx 7.0 .
217	.Sh AUTHORS
218	.An -nosplit
219	This implementation of
220	.Nm
221	was written by
222	.An Matthew R. Green Aq mrg@eterna.com.au
223	with unpack support written by
224	.An Xin LI Aq delphij@FreeBSD.org .
225	.Sh BUGS
226	According to RFC 1952, the recorded file size is stored in a 32-bit
227	integer, therefore, it can not represent files larger than 4GB.
228	This limitation also applies to
229	.Fl l
230	option of
231	.Nm
232	utility.