GZIP(1) 						    BSD General Commands Manual 						   GZIP(1)

NAME

     gzip -- compression/decompression tool using Lempel-Ziv coding (LZ77)

SYNOPSIS

     gzip [-cdfhkLlNnqrtVv] [-S suffix] file [file [...]]
     gunzip [-cfhkLNqrtVv] [-S suffix] file [file [...]]
     zcat [-fhV] file [file [...]]

DESCRIPTION

     The gzip program compresses and decompresses files using Lempel-Ziv coding (LZ77).  If no files are specified, gzip will compress from stan-
     dard input, or decompress to standard output.  When in compression mode, each file will be replaced with another file with the suffix, set by
     the -S suffix option, added, if possible.

     In decompression mode, each file will be checked for existence, as will the file with the suffix added.  Each file argument must contain a
     separate complete archive; when multiple files are indicated, each is decompressed in turn.

     In the case of gzcat the resulting data is then concatenated in the manner of cat(1).

     If invoked as gunzip then the -d option is enabled.  If invoked as zcat or gzcat then both the -c and -d options are enabled.  When invoked
     as zcat, ``.Z'' will be appended to all filenames that do not have that suffix.

     This version of gzip is also capable of decompressing files compressed using compress(1) or bzip2(1).

OPTIONS

     The following options are available:

     -1, --fast

     -2, -3, -4, -5, -6, -7, -8

     -9, --best        These options change the compression level used, with the -1 option being the fastest, with less compression, and the -9
		       option being the slowest, with optimal compression.  The default compression level is 6.

     -c, --stdout, --to-stdout
		       This option specifies that output will go to the standard output stream, leaving files intact.

     -d, --decompress, --uncompress
		       This option selects decompression rather than compression.

     -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 -c option, allowing non-compressed
		       data to pass through unchanged.

     -h, --help        This option prints a usage summary and exits.

     -k, --keep        Keep (don't delete) input files during compression or decompression.

     -L, --license     This option prints gzip license.

     -l, --list        This option displays information about the file's compressed and uncompressed size, ratio, uncompressed name.  With the -v
		       option, it also displays the compression method, CRC, date and time embedded in the file.

     -N, --name        This option causes the stored filename in the input file to be used as the output file.

     -n, --no-name     This option stops the filename and timestamp from being stored in the output file.

     -q, --quiet       With this option, no warnings or errors are printed.

     -r, --recursive   This option is used to gzip the files in a directory tree individually, using the fts(3) library.

     -S suffix, --suffix suffix
		       This option changes the default suffix from .gz to suffix.

     -t, --test        This option will test compressed files for integrity.

     -V, --version     This option prints the version of the gzip program.

     -v, --verbose     This option turns on verbose mode, which prints the compression ratio for each file compressed.

ENVIRONMENT

     If the environment variable 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 GZIP.

SEE ALSO

     bzip2(1), compress(1), xz(1), fts(3), zlib(3), compat(5)

HISTORY

     The gzip program was originally written by Jean-loup Gailly, licensed under the GNU Public Licence.  Matthew R. Green wrote a simple front
     end for NetBSD 1.3 distribution media, based on the freely re-distributable zlib library.	It was enhanced to be mostly feature-compatible
     with the original GNU gzip program for NetBSD 2.0.

     This implementation of gzip was ported based on the NetBSD gzip, and first appeared in FreeBSD 7.0.

AUTHORS

     This implementation of gzip was written by Matthew R. Green <mrg@eterna.com.au> with unpack support written by Xin LI <delphij@FreeBSD.org>.

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 -l option of gzip utility.

BSD
								  October 9, 2011							       BSD