+++ /dev/null
-\input texinfo @c -*-texinfo-*-
-@c %**start of header
-@setfilename gzip.info
-@include version.texi
-@settitle Gzip User's Manual
-@finalout
-@setchapternewpage odd
-@c %**end of header
-@copying
-This manual is for Gzip
-(version @value{VERSION}, @value{UPDATED}),
-and documents commands for compressing and decompressing data.
-
-Copyright @copyright{} 1998, 1999, 2001, 2002 Free Software
-Foundation, Inc.
-
-Copyright @copyright{} 1992, 1993 Jean-loup Gailly
-
-@quotation
-Permission is granted to copy, distribute and/or modify this document
-under the terms of the GNU Free Documentation License, Version 1.1 or
-any later version published by the Free Software Foundation; with no
-Invariant Sections, with the Front-Cover texts being ``A GNU Manual,''
-and with the Back-Cover Texts as in (a) below. A copy of the
-license is included in the section entitled ``GNU Free Documentation
-License.''
-
-(a) The FSF's Back-Cover Text is: ``You have freedom to copy and modify
-this GNU Manual, like GNU software. Copies published by the Free
-Software Foundation raise funds for GNU development.''
-@end quotation
-@end copying
-
-@c Debian install-info (up through at least version 1.9.20) uses only the
-@c first dircategory. Put this one first, as it is more useful in practice.
-@dircategory Individual utilities
-@direntry
-* gzip: (gzip)Invoking gzip. Compress files.
-@end direntry
-
-@dircategory Utilities
-@direntry
-* Gzip: (gzip). The gzip command for compressing files.
-@end direntry
-
-@titlepage
-@title gzip
-@subtitle The data compression program
-@subtitle for Gzip Version @value{VERSION}
-@subtitle @value{UPDATED}
-@author by Jean-loup Gailly
-
-@page
-@vskip 0pt plus 1filll
-@insertcopying
-@end titlepage
-
-@contents
-
-@ifnottex
-@node Top, , , (dir)
-@top Compressing Files
-
-@insertcopying
-@end ifnottex
-
-@menu
-* Overview:: Preliminary information.
-* Sample:: Sample output from @code{gzip}.
-* Invoking gzip:: How to run @code{gzip}.
-* Advanced usage:: Concatenated files.
-* Environment:: The @code{GZIP} environment variable
-* Tapes:: Using @code{gzip} on tapes.
-* Problems:: Reporting bugs.
-* Copying This Manual:: How to make copies of this manual.
-* Concept Index:: Index of concepts.
-@end menu
-
-@node Overview, Sample, , Top
-@chapter Overview
-@cindex overview
-
-@code{gzip} reduces the size of the named files using Lempel-Ziv coding
-(LZ77). Whenever possible, each file is replaced by one with the
-extension @samp{.gz}, while keeping the same ownership modes, access and
-modification times. (The default extension is @samp{-gz} for VMS,
-@samp{z} for MSDOS, OS/2 FAT and Atari.) If no files are specified or
-if a file name is "-", the standard input is compressed to the standard
-output. @code{gzip} will only attempt to compress regular files. In
-particular, it will ignore symbolic links.
-
-If the new file name is too long for its file system, @code{gzip}
-truncates it. @code{gzip} attempts to truncate only the parts of the
-file name longer than 3 characters. (A part is delimited by dots.) If
-the name consists of small parts only, the longest parts are truncated.
-For example, if file names are limited to 14 characters, gzip.msdos.exe
-is compressed to gzi.msd.exe.gz. Names are not truncated on systems
-which do not have a limit on file name length.
-
-By default, @code{gzip} keeps the original file name and timestamp in
-the compressed file. These are used when decompressing the file with the
-@samp{-N} option. This is useful when the compressed file name was
-truncated or when the time stamp was not preserved after a file
-transfer.
-
-Compressed files can be restored to their original form using @samp{gzip -d}
-or @code{gunzip} or @code{zcat}. If the original name saved in the
-compressed file is not suitable for its file system, a new name is
-constructed from the original one to make it legal.
-
-@code{gunzip} takes a list of files on its command line and replaces
-each file whose name ends with @samp{.gz}, @samp{.z}, @samp{.Z},
-@samp{-gz}, @samp{-z} or @samp{_z} and which begins with the correct
-magic number with an uncompressed file without the original extension.
-@code{gunzip} also recognizes the special extensions @samp{.tgz} and
-@samp{.taz} as shorthands for @samp{.tar.gz} and @samp{.tar.Z}
-respectively. When compressing, @code{gzip} uses the @samp{.tgz}
-extension if necessary instead of truncating a file with a @samp{.tar}
-extension.
-
-@code{gunzip} can currently decompress files created by @code{gzip},
-@code{zip}, @code{compress} or @code{pack}. The detection of the input
-format is automatic. When using the first two formats, @code{gunzip}
-checks a 32 bit CRC (cyclic redundancy check). For @code{pack},
-@code{gunzip} checks the uncompressed length. The @code{compress} format
-was not designed to allow consistency checks. However @code{gunzip} is
-sometimes able to detect a bad @samp{.Z} file. If you get an error when
-uncompressing a @samp{.Z} file, do not assume that the @samp{.Z} file is
-correct simply because the standard @code{uncompress} does not complain.
-This generally means that the standard @code{uncompress} does not check
-its input, and happily generates garbage output. The SCO @samp{compress
--H} format (@code{lzh} compression method) does not include a CRC but
-also allows some consistency checks.
-
-Files created by @code{zip} can be uncompressed by @code{gzip} only if
-they have a single member compressed with the 'deflation' method. This
-feature is only intended to help conversion of @code{tar.zip} files to
-the @code{tar.gz} format. To extract a @code{zip} file with a single
-member, use a command like @samp{gunzip <foo.zip} or @samp{gunzip -S
-.zip foo.zip}. To extract @code{zip} files with several
-members, use @code{unzip} instead of @code{gunzip}.
-
-@code{zcat} is identical to @samp{gunzip -c}. @code{zcat}
-uncompresses either a list of files on the command line or its standard
-input and writes the uncompressed data on standard output. @code{zcat}
-will uncompress files that have the correct magic number whether they
-have a @samp{.gz} suffix or not.
-
-@code{gzip} uses the Lempel-Ziv algorithm used in @code{zip} and PKZIP.
-The amount of compression obtained depends on the size of the input and
-the distribution of common substrings. Typically, text such as source
-code or English is reduced by 60-70%. Compression is generally much
-better than that achieved by LZW (as used in @code{compress}), Huffman
-coding (as used in @code{pack}), or adaptive Huffman coding
-(@code{compact}).
-
-Compression is always performed, even if the compressed file is slightly
-larger than the original. The worst case expansion is a few bytes for
-the @code{gzip} file header, plus 5 bytes every 32K block, or an expansion
-ratio of 0.015% for large files. Note that the actual number of used
-disk blocks almost never increases. @code{gzip} preserves the mode,
-ownership and timestamps of files when compressing or decompressing.
-
-The @code{gzip} file format is specified in P. Deutsch, @sc{gzip} file
-format specification version 4.3,
-@uref{ftp://ftp.isi.edu/in-notes/rfc1952.txt, Internet RFC 1952} (May
-1996). The @code{zip} deflation format is specified in P. Deutsch,
-@sc{deflate} Compressed Data Format Specification version 1.3,
-@uref{ftp://ftp.isi.edu/in-notes/rfc1951.txt, Internet RFC 1951} (May
-1996).
-
-@node Sample, Invoking gzip, Overview, Top
-@chapter Sample Output
-@cindex sample
-
-Here are some realistic examples of running @code{gzip}.
-
-This is the output of the command @samp{gzip -h}:
-
-@example
-gzip 1.3
-(1999-12-21)
-usage: gzip [-cdfhlLnNrtvV19] [-S suffix] [file ...]
- -c --stdout write on standard output, keep original files unchanged
- -d --decompress decompress
- -f --force force overwrite of output file and compress links
- -h --help give this help
- -l --list list compressed file contents
- -L --license display software license
- -n --no-name do not save or restore the original name and time stamp
- -N --name save or restore the original name and time stamp
- -q --quiet suppress all warnings
- -r --recursive operate recursively on directories
- -S .suf --suffix .suf use suffix .suf on compressed files
- -t --test test compressed file integrity
- -v --verbose verbose mode
- -V --version display version number
- -1 --fast compress faster
- -9 --best compress better
- file... files to (de)compress. If none given, use standard input.
-Report bugs to <bug-gzip@@gnu.org>.
-@end example
-
-This is the output of the command @samp{gzip -v texinfo.tex}:
-
-@example
-texinfo.tex: 69.7% -- replaced with texinfo.tex.gz
-@end example
-
-The following command will find all @code{gzip} files in the current
-directory and subdirectories, and extract them in place without
-destroying the original:
-
-@example
-find . -name '*.gz' -print | sed 's/^\(.*\)[.]gz$/gunzip < "&" > "\1"/' | sh
-@end example
-
-@node Invoking gzip, Advanced usage, Sample, Top
-@chapter Invoking @code{gzip}
-@cindex invoking
-@cindex options
-
-The format for running the @code{gzip} program is:
-
-@example
-gzip @var{option} @dots{}
-@end example
-
-@code{gzip} supports the following options:
-
-@table @samp
-@item --stdout
-@itemx --to-stdout
-@itemx -c
-Write output on standard output; keep original files unchanged.
-If there are several input files, the output consists of a sequence of
-independently compressed members. To obtain better compression,
-concatenate all input files before compressing them.
-
-@item --decompress
-@itemx --uncompress
-@itemx -d
-Decompress.
-
-@item --force
-@itemx -f
-Force compression or decompression even if the file has multiple links
-or the corresponding file already exists, or if the compressed data
-is read from or written to a terminal. If the input data is not in
-a format recognized by @code{gzip}, and if the option @samp{--stdout} is also
-given, copy the input data without change to the standard output: let
-@code{zcat} behave as @code{cat}. If @samp{-f} is not given, and
-when not running in the background, @code{gzip} prompts to verify
-whether an existing file should be overwritten.
-
-@item --help
-@itemx -h
-Print an informative help message describing the options then quit.
-
-@item --list
-@itemx -l
-For each compressed file, list the following fields:
-
-@example
-compressed size: size of the compressed file
-uncompressed size: size of the uncompressed file
-ratio: compression ratio (0.0% if unknown)
-uncompressed_name: name of the uncompressed file
-@end example
-
-The uncompressed size is given as @samp{-1} for files not in @code{gzip}
-format, such as compressed @samp{.Z} files. To get the uncompressed size for
-such a file, you can use:
-
-@example
-zcat file.Z | wc -c
-@end example
-
-In combination with the @samp{--verbose} option, the following fields are also
-displayed:
-
-@example
-method: compression method (deflate,compress,lzh,pack)
-crc: the 32-bit CRC of the uncompressed data
-date & time: time stamp for the uncompressed file
-@end example
-
-The crc is given as ffffffff for a file not in gzip format.
-
-With @samp{--verbose}, the size totals and compression ratio for all files
-is also displayed, unless some sizes are unknown. With @samp{--quiet},
-the title and totals lines are not displayed.
-
-The @code{gzip} format represents the the input size modulo
-@math{2^32}, so the uncompressed size and compression ratio are listed
-incorrectly for uncompressed files 4 GB and larger. To work around
-this problem, you can use the following command to discover a large
-uncompressed file's true size:
-
-@example
-zcat file.gz | wc -c
-@end example
-
-@item --license
-@itemx -L
-Display the @code{gzip} license then quit.
-
-@item --no-name
-@itemx -n
-When compressing, do not save the original file name and time stamp by
-default. (The original name is always saved if the name had to be
-truncated.) When decompressing, do not restore the original file name
-if present (remove only the @code{gzip}
-suffix from the compressed file name) and do not restore the original
-time stamp if present (copy it from the compressed file). This option
-is the default when decompressing.
-
-@item --name
-@itemx -N
-When compressing, always save the original file name and time stamp; this
-is the default. When decompressing, restore the original file name and
-time stamp if present. This option is useful on systems which have
-a limit on file name length or when the time stamp has been lost after
-a file transfer.
-
-@item --quiet
-@itemx -q
-Suppress all warning messages.
-
-@item --recursive
-@itemx -r
-Travel the directory structure recursively. If any of the file names
-specified on the command line are directories, @code{gzip} will descend
-into the directory and compress all the files it finds there (or
-decompress them in the case of @code{gunzip}).
-
-@item --suffix @var{suf}
-@itemx -S @var{suf}
-Use suffix @samp{@var{suf}} instead of @samp{.gz}. Any suffix can be
-given, but suffixes other than @samp{.z} and @samp{.gz} should be
-avoided to avoid confusion when files are transferred to other systems.
-A null suffix forces gunzip to try decompression on all given files
-regardless of suffix, as in:
-
-@example
-gunzip -S "" * (*.* for MSDOS)
-@end example
-
-Previous versions of gzip used the @samp{.z} suffix. This was changed to
-avoid a conflict with @code{pack}.
-
-@item --test
-@itemx -t
-Test. Check the compressed file integrity.
-
-@item --verbose
-@itemx -v
-Verbose. Display the name and percentage reduction for each file compressed.
-
-@item --version
-@itemx -V
-Version. Display the version number and compilation options, then quit.
-
-@item --fast
-@itemx --best
-@itemx -@var{n}
-Regulate the speed of compression using the specified digit @var{n},
-where @samp{-1} or @samp{--fast} indicates the fastest compression
-method (less compression) and @samp{--best} or @samp{-9} indicates the
-slowest compression method (optimal compression). The default
-compression level is @samp{-6} (that is, biased towards high compression at
-expense of speed).
-@end table
-
-@node Advanced usage, Environment, Invoking gzip, Top
-@chapter Advanced usage
-@cindex concatenated files
-
-Multiple compressed files can be concatenated. In this case,
-@code{gunzip} will extract all members at once. If one member is
-damaged, other members might still be recovered after removal of the
-damaged member. Better compression can be usually obtained if all
-members are decompressed and then recompressed in a single step.
-
-This is an example of concatenating @code{gzip} files:
-
-@example
-gzip -c file1 > foo.gz
-gzip -c file2 >> foo.gz
-@end example
-
-Then
-
-@example
-gunzip -c foo
-@end example
-
-is equivalent to
-
-@example
-cat file1 file2
-@end example
-
-In case of damage to one member of a @samp{.gz} file, other members can
-still be recovered (if the damaged member is removed). However,
-you can get better compression by compressing all members at once:
-
-@example
-cat file1 file2 | gzip > foo.gz
-@end example
-
-compresses better than
-
-@example
-gzip -c file1 file2 > foo.gz
-@end example
-
-If you want to recompress concatenated files to get better compression, do:
-
-@example
-zcat old.gz | gzip > new.gz
-@end example
-
-If a compressed file consists of several members, the uncompressed
-size and CRC reported by the @samp{--list} option applies to the last member
-only. If you need the uncompressed size for all members, you can use:
-
-@example
-zcat file.gz | wc -c
-@end example
-
-If you wish to create a single archive file with multiple members so
-that members can later be extracted independently, use an archiver such
-as @code{tar} or @code{zip}. GNU @code{tar} supports the @samp{-z}
-option to invoke @code{gzip} transparently. @code{gzip} is designed as a
-complement to @code{tar}, not as a replacement.
-
-@node Environment, Tapes, Advanced usage, Top
-@chapter Environment
-@cindex Environment
-
-The environment variable @code{GZIP} can hold a set of default options for
-@code{gzip}. These options are interpreted first and can be overwritten by
-explicit command line parameters. For example:
-
-@example
-for sh: GZIP="-8v --name"; export GZIP
-for csh: setenv GZIP "-8v --name"
-for MSDOS: set GZIP=-8v --name
-@end example
-
-On Vax/VMS, the name of the environment variable is @code{GZIP_OPT}, to
-avoid a conflict with the symbol set for invocation of the program.
-
-@node Tapes, Problems, Environment, Top
-@chapter Using @code{gzip} on tapes
-@cindex tapes
-
-When writing compressed data to a tape, it is generally necessary to pad
-the output with zeroes up to a block boundary. When the data is read and
-the whole block is passed to @code{gunzip} for decompression,
-@code{gunzip} detects that there is extra trailing garbage after the
-compressed data and emits a warning by default if the garbage contains
-nonzero bytes. You have to use the
-@samp{--quiet} option to suppress the warning. This option can be set in the
-@code{GZIP} environment variable, as in:
-
-@example
-for sh: GZIP="-q" tar -xfz --block-compress /dev/rst0
-for csh: (setenv GZIP "-q"; tar -xfz --block-compress /dev/rst0)
-@end example
-
-In the above example, @code{gzip} is invoked implicitly by the @samp{-z}
-option of GNU @code{tar}. Make sure that the same block size (@samp{-b}
-option of @code{tar}) is used for reading and writing compressed data on
-tapes. (This example assumes you are using the GNU version of
-@code{tar}.)
-
-@node Problems, Copying This Manual, Tapes, Top
-@chapter Reporting Bugs
-@cindex bugs
-
-If you find a bug in @code{gzip}, please send electronic mail to
-@email{bug-gzip@@gnu.org}. Include the version number,
-which you can find by running @w{@samp{gzip -V}}. Also include in your
-message the hardware and operating system, the compiler used to compile
-@code{gzip},
-a description of the bug behavior, and the input to @code{gzip} that triggered
-the bug.@refill
-
-@node Copying This Manual, Concept Index, Problems, Top
-@appendix Copying This Manual
-
-@menu
-* GNU Free Documentation License:: License for copying this manual.
-@end menu
-
-@include fdl.texi
-
-@node Concept Index, , Copying This Manual, Top
-@appendix Concept Index
-
-@printindex cp
-
-@bye
projects / debian / gzip / blobdiff