246 lines
6.2 KiB
Groff
246 lines
6.2 KiB
Groff
.\" $NetBSD: gzip.1,v 1.30 2017/10/22 17:36:49 abhinav Exp $
|
||
.\"
|
||
.\" Copyright (c) 1997, 2003, 2004, 2008, 2009, 2015, 2017 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.
|
||
.\"
|
||
.\" $FreeBSD$
|
||
.Dd November 21, 2017
|
||
.Dt GZIP 1
|
||
.Os
|
||
.Sh NAME
|
||
.Nm gzip ,
|
||
.Nm gunzip ,
|
||
.Nm zcat
|
||
.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.
|
||
.Pp
|
||
This version of
|
||
.Nm
|
||
is also capable of decompressing files compressed using
|
||
.Xr compress 1 ,
|
||
.Xr bzip2 1 ,
|
||
or
|
||
.Xr xz 1 .
|
||
.Sh OPTIONS
|
||
The following options are available:
|
||
.Bl -tag -width XXrXXXrecursiveX
|
||
.It Fl 1 , Fl Fl fast
|
||
.It Fl 2 , 3 , 4 , 5 , 6 , 7 , 8
|
||
.It Fl 9 , Fl Fl 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 , Fl Fl stdout , Fl Fl to-stdout
|
||
This option specifies that output will go to the standard output
|
||
stream, leaving files intact.
|
||
.It Fl d , Fl Fl decompress , Fl Fl uncompress
|
||
This option selects decompression rather than compression.
|
||
.It Fl f , Fl Fl 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 , Fl Fl help
|
||
This option prints a usage summary and exits.
|
||
.It Fl k , Fl Fl keep
|
||
This option prevents
|
||
.Nm
|
||
from deleting input files after (de)compression.
|
||
.It Fl L , -license
|
||
This option prints
|
||
.Nm
|
||
license.
|
||
.It Fl l , Fl Fl 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 , Fl Fl name
|
||
This option causes the stored filename in the input file to be used
|
||
as the output file.
|
||
.It Fl n , Fl Fl no-name
|
||
This option stops the filename and timestamp from being stored in
|
||
the output file.
|
||
.It Fl q , Fl Fl quiet
|
||
With this option, no warnings or errors are printed.
|
||
.It Fl r , Fl Fl 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 Fl suffix Ar suffix
|
||
This option changes the default suffix from .gz to
|
||
.Ar suffix .
|
||
.It Fl t , Fl Fl test
|
||
This option will test compressed files for integrity.
|
||
.It Fl V , Fl Fl version
|
||
This option prints the version of the
|
||
.Nm
|
||
program.
|
||
.It Fl v , Fl Fl 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 EXIT STATUS
|
||
The
|
||
.Nm
|
||
utility exits 0 on success,
|
||
1 on errors,
|
||
and 2 if a warning occurs.
|
||
.Sh SIGNALS
|
||
.Nm
|
||
responds to the following signals:
|
||
.Bl -tag -width indent
|
||
.It Dv SIGINFO
|
||
Report progress to standard error.
|
||
.El
|
||
.Sh SEE ALSO
|
||
.Xr bzip2 1 ,
|
||
.Xr compress 1 ,
|
||
.Xr xz 1 ,
|
||
.Xr fts 3 ,
|
||
.Xr zlib 3
|
||
.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
|
||
version 20170803,
|
||
and first appeared in
|
||
.Fx 7.0 .
|
||
.Sh AUTHORS
|
||
.An -nosplit
|
||
This implementation of
|
||
.Nm
|
||
was written by
|
||
.An Matthew R. Green Aq Mt mrg@eterna.com.au
|
||
with unpack support written by
|
||
.An Xin LI Aq Mt delphij@FreeBSD.org .
|
||
.Sh BUGS
|
||
According to RFC 1952, the recorded file size is stored in a 32-bit
|
||
integer, therefore, it cannot represent files larger than 4GB.
|
||
This limitation also applies to
|
||
.Fl l
|
||
option of
|
||
.Nm
|
||
utility.
|