|| FreeBSD General Commands Manual
compression/decompression tool using Lempel-Ziv coding (LZ77)
|| [ -cdfhkLlNnqrtVv][ -S suffix] file [ file [ ...]]
|| [ -cfhkLNqrtVv][ -S suffix] file [ file [ ...]]
|| [ -fhV] file [ file [ ...]]
program compresses and decompresses files using Lempel-Ziv coding (LZ77). If no
will compress from standard input, or decompress to standard output. When in compression mode, each
will be replaced with another file with the suffix, set by the
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.
This version of gzip is also capable of decompressing files compressed using compress(1) or bzip2(1).
The following options are available:
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.
This option specifies that output will go to the standard output stream, leaving files intact.
This option selects decompression rather than compression.
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.
This option prints a usage summary and exits.
Keep (don't delete) input files during compression or decompression.
This option prints
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.
This option causes the stored filename in the input file to be used as the output file.
This option stops the filename and timestamp from being stored in the output file.
With this option, no warnings or errors are printed.
This option is used to
gzip the files in a directory tree individually, using the
This option changes the default suffix from .gz to
This option will test compressed files for integrity.
This option prints the version of the
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
program was originally written by Jean-loup Gailly, licensed under the GNU Public Licence. Matthew R. Green wrote a simple front end for
distribution media, based on the freely re-distributable zlib library. It was enhanced to be mostly feature-compatible with the original GNU
This implementation of gzip was ported based on the NetBSD gzip, and first appeared in FreeBSD 7.0.
This implementation of
gzip was written by
<email@example.com> with unpack support written by
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