Add missing documentation; build and install it.

3 files changed, 887 insertions, 1 deletions

diff --git a/gnu/usr.bin/gzip/Makefile b/gnu/usr.bin/gzip/Makefile
index ffc6dc2abc1..ecfe2e21a52 100644
--- a/gnu/usr.bin/gzip/Makefile
+++ b/gnu/usr.bin/gzip/Makefile
@@ -1,4 +1,4 @@
-#	$OpenBSD: Makefile,v 1.5 1996/09/16 10:21:32 downsj Exp $
+#	$OpenBSD: Makefile,v 1.6 1997/01/26 09:53:18 downsj Exp $
 #	$NetBSD: Makefile,v 1.17 1995/10/24 22:18:34 jtc Exp $
 
 PROG=	gzip
@@ -12,8 +12,12 @@ SRCS+=	match.S
 CFLAGS+=-DASMV
 .endif
 
+CLEANFILES+=	gzip.info
+
 LDSTATIC= ${STATIC}
 
+MAKEINFO=	makeinfo
+
 MLINKS+= gzip.1 gunzip.1 gzip.1 gzcat.1 gzip.1 zcat.1
 MLINKS+= zdiff.1 zcmp.1
 #MLINKS+= gzip.1 uncompress.1
@@ -23,6 +27,15 @@ LINKS+= ${BINDIR}/gzip ${BINDIR}/zcat
 LINKS+=	${BINDIR}/zdiff ${BINDIR}/zcmp
 #LINKS+= ${BINDIR}/gzip ${BINDIR}/uncompress
 
+all:	gzip.info
+
+gzip.info:	gzip.texi
+	${MAKEINFO} -I${.CURDIR} ${.CURDIR}/gzip.texi
+
+beforeinstall:
+	${INSTALL} ${COPY} -m 444 -o ${BINOWN} -g ${BINGRP} *.info* \
+		${DESTDIR}/usr/share/info
+
 afterinstall:
 	install -c -o ${BINOWN} -g ${BINGRP} -m ${BINMODE} \
 	   ${.CURDIR}/zforce ${.CURDIR}/gzexe ${.CURDIR}/znew \
diff --git a/gnu/usr.bin/gzip/gpl.texinfo b/gnu/usr.bin/gzip/gpl.texinfo
new file mode 100644
index 00000000000..6fb0afb4c06
--- /dev/null
+++ b/gnu/usr.bin/gzip/gpl.texinfo
@@ -0,0 +1,394 @@
+@setfilename gpl.info
+
+@unnumbered GNU GENERAL PUBLIC LICENSE
+@center Version 2, June 1991
+
+@display
+Copyright @copyright{} 1989, 1991 Free Software Foundation, Inc.
+675 Mass Ave, Cambridge, MA 02139, USA
+
+Everyone is permitted to copy and distribute verbatim copies
+of this license document, but changing it is not allowed.
+@end display
+
+@unnumberedsec Preamble
+
+  The licenses for most software are designed to take away your
+freedom to share and change it.  By contrast, the GNU General Public
+License is intended to guarantee your freedom to share and change free
+software---to make sure the software is free for all its users.  This
+General Public License applies to most of the Free Software
+Foundation's software and to any other program whose authors commit to
+using it.  (Some other Free Software Foundation software is covered by
+the GNU Library General Public License instead.)  You can apply it to
+your programs, too.
+
+  When we speak of free software, we are referring to freedom, not
+price.  Our General Public Licenses are designed to make sure that you
+have the freedom to distribute copies of free software (and charge for
+this service if you wish), that you receive source code or can get it
+if you want it, that you can change the software or use pieces of it
+in new free programs; and that you know you can do these things.
+
+  To protect your rights, we need to make restrictions that forbid
+anyone to deny you these rights or to ask you to surrender the rights.
+These restrictions translate to certain responsibilities for you if you
+distribute copies of the software, or if you modify it.
+
+  For example, if you distribute copies of such a program, whether
+gratis or for a fee, you must give the recipients all the rights that
+you have.  You must make sure that they, too, receive or can get the
+source code.  And you must show them these terms so they know their
+rights.
+
+  We protect your rights with two steps: (1) copyright the software, and
+(2) offer you this license which gives you legal permission to copy,
+distribute and/or modify the software.
+
+  Also, for each author's protection and ours, we want to make certain
+that everyone understands that there is no warranty for this free
+software.  If the software is modified by someone else and passed on, we
+want its recipients to know that what they have is not the original, so
+that any problems introduced by others will not reflect on the original
+authors' reputations.
+
+  Finally, any free program is threatened constantly by software
+patents.  We wish to avoid the danger that redistributors of a free
+program will individually obtain patent licenses, in effect making the
+program proprietary.  To prevent this, we have made it clear that any
+patent must be licensed for everyone's free use or not licensed at all.
+
+  The precise terms and conditions for copying, distribution and
+modification follow.
+
+@iftex
+@unnumberedsec TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION
+@end iftex
+@ifinfo
+@center TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION
+@end ifinfo
+
+@enumerate
+@item
+This License applies to any program or other work which contains
+a notice placed by the copyright holder saying it may be distributed
+under the terms of this General Public License.  The ``Program'', below,
+refers to any such program or work, and a ``work based on the Program''
+means either the Program or any derivative work under copyright law:
+that is to say, a work containing the Program or a portion of it,
+either verbatim or with modifications and/or translated into another
+language.  (Hereinafter, translation is included without limitation in
+the term ``modification''.)  Each licensee is addressed as ``you''.
+
+Activities other than copying, distribution and modification are not
+covered by this License; they are outside its scope.  The act of
+running the Program is not restricted, and the output from the Program
+is covered only if its contents constitute a work based on the
+Program (independent of having been made by running the Program).
+Whether that is true depends on what the Program does.
+
+@item
+You may copy and distribute verbatim copies of the Program's
+source code as you receive it, in any medium, provided that you
+conspicuously and appropriately publish on each copy an appropriate
+copyright notice and disclaimer of warranty; keep intact all the
+notices that refer to this License and to the absence of any warranty;
+and give any other recipients of the Program a copy of this License
+along with the Program.
+
+You may charge a fee for the physical act of transferring a copy, and
+you may at your option offer warranty protection in exchange for a fee.
+
+@item
+You may modify your copy or copies of the Program or any portion
+of it, thus forming a work based on the Program, and copy and
+distribute such modifications or work under the terms of Section 1
+above, provided that you also meet all of these conditions:
+
+@enumerate a
+@item
+You must cause the modified files to carry prominent notices
+stating that you changed the files and the date of any change.
+
+@item
+You must cause any work that you distribute or publish, that in
+whole or in part contains or is derived from the Program or any
+part thereof, to be licensed as a whole at no charge to all third
+parties under the terms of this License.
+
+@item
+If the modified program normally reads commands interactively
+when run, you must cause it, when started running for such
+interactive use in the most ordinary way, to print or display an
+announcement including an appropriate copyright notice and a
+notice that there is no warranty (or else, saying that you provide
+a warranty) and that users may redistribute the program under
+these conditions, and telling the user how to view a copy of this
+License.  (Exception: if the Program itself is interactive but
+does not normally print such an announcement, your work based on
+the Program is not required to print an announcement.)
+@end enumerate
+
+These requirements apply to the modified work as a whole.  If
+identifiable sections of that work are not derived from the Program,
+and can be reasonably considered independent and separate works in
+themselves, then this License, and its terms, do not apply to those
+sections when you distribute them as separate works.  But when you
+distribute the same sections as part of a whole which is a work based
+on the Program, the distribution of the whole must be on the terms of
+this License, whose permissions for other licensees extend to the
+entire whole, and thus to each and every part regardless of who wrote it.
+
+Thus, it is not the intent of this section to claim rights or contest
+your rights to work written entirely by you; rather, the intent is to
+exercise the right to control the distribution of derivative or
+collective works based on the Program.
+
+In addition, mere aggregation of another work not based on the Program
+with the Program (or with a work based on the Program) on a volume of
+a storage or distribution medium does not bring the other work under
+the scope of this License.
+
+@item
+You may copy and distribute the Program (or a work based on it,
+under Section 2) in object code or executable form under the terms of
+Sections 1 and 2 above provided that you also do one of the following:
+
+@enumerate a
+@item
+Accompany it with the complete corresponding machine-readable
+source code, which must be distributed under the terms of Sections
+1 and 2 above on a medium customarily used for software interchange; or,
+
+@item
+Accompany it with a written offer, valid for at least three
+years, to give any third party, for a charge no more than your
+cost of physically performing source distribution, a complete
+machine-readable copy of the corresponding source code, to be
+distributed under the terms of Sections 1 and 2 above on a medium
+customarily used for software interchange; or,
+
+@item
+Accompany it with the information you received as to the offer
+to distribute corresponding source code.  (This alternative is
+allowed only for noncommercial distribution and only if you
+received the program in object code or executable form with such
+an offer, in accord with Subsection b above.)
+@end enumerate
+
+The source code for a work means the preferred form of the work for
+making modifications to it.  For an executable work, complete source
+code means all the source code for all modules it contains, plus any
+associated interface definition files, plus the scripts used to
+control compilation and installation of the executable.  However, as a
+special exception, the source code distributed need not include
+anything that is normally distributed (in either source or binary
+form) with the major components (compiler, kernel, and so on) of the
+operating system on which the executable runs, unless that component
+itself accompanies the executable.
+
+If distribution of executable or object code is made by offering
+access to copy from a designated place, then offering equivalent
+access to copy the source code from the same place counts as
+distribution of the source code, even though third parties are not
+compelled to copy the source along with the object code.
+
+@item
+You may not copy, modify, sublicense, or distribute the Program
+except as expressly provided under this License.  Any attempt
+otherwise to copy, modify, sublicense or distribute the Program is
+void, and will automatically terminate your rights under this License.
+However, parties who have received copies, or rights, from you under
+this License will not have their licenses terminated so long as such
+parties remain in full compliance.
+
+@item
+You are not required to accept this License, since you have not
+signed it.  However, nothing else grants you permission to modify or
+distribute the Program or its derivative works.  These actions are
+prohibited by law if you do not accept this License.  Therefore, by
+modifying or distributing the Program (or any work based on the
+Program), you indicate your acceptance of this License to do so, and
+all its terms and conditions for copying, distributing or modifying
+the Program or works based on it.
+
+@item
+Each time you redistribute the Program (or any work based on the
+Program), the recipient automatically receives a license from the
+original licensor to copy, distribute or modify the Program subject to
+these terms and conditions.  You may not impose any further
+restrictions on the recipients' exercise of the rights granted herein.
+You are not responsible for enforcing compliance by third parties to
+this License.
+
+@item
+If, as a consequence of a court judgment or allegation of patent
+infringement or for any other reason (not limited to patent issues),
+conditions are imposed on you (whether by court order, agreement or
+otherwise) that contradict the conditions of this License, they do not
+excuse you from the conditions of this License.  If you cannot
+distribute so as to satisfy simultaneously your obligations under this
+License and any other pertinent obligations, then as a consequence you
+may not distribute the Program at all.  For example, if a patent
+license would not permit royalty-free redistribution of the Program by
+all those who receive copies directly or indirectly through you, then
+the only way you could satisfy both it and this License would be to
+refrain entirely from distribution of the Program.
+
+If any portion of this section is held invalid or unenforceable under
+any particular circumstance, the balance of the section is intended to
+apply and the section as a whole is intended to apply in other
+circumstances.
+
+It is not the purpose of this section to induce you to infringe any
+patents or other property right claims or to contest validity of any
+such claims; this section has the sole purpose of protecting the
+integrity of the free software distribution system, which is
+implemented by public license practices.  Many people have made
+generous contributions to the wide range of software distributed
+through that system in reliance on consistent application of that
+system; it is up to the author/donor to decide if he or she is willing
+to distribute software through any other system and a licensee cannot
+impose that choice.
+
+This section is intended to make thoroughly clear what is believed to
+be a consequence of the rest of this License.
+
+@item
+If the distribution and/or use of the Program is restricted in
+certain countries either by patents or by copyrighted interfaces, the
+original copyright holder who places the Program under this License
+may add an explicit geographical distribution limitation excluding
+those countries, so that distribution is permitted only in or among
+countries not thus excluded.  In such case, this License incorporates
+the limitation as if written in the body of this License.
+
+@item
+The Free Software Foundation may publish revised and/or new versions
+of the General Public License from time to time.  Such new versions will
+be similar in spirit to the present version, but may differ in detail to
+address new problems or concerns.
+
+Each version is given a distinguishing version number.  If the Program
+specifies a version number of this License which applies to it and ``any
+later version'', you have the option of following the terms and conditions
+either of that version or of any later version published by the Free
+Software Foundation.  If the Program does not specify a version number of
+this License, you may choose any version ever published by the Free Software
+Foundation.
+
+@item
+If you wish to incorporate parts of the Program into other free
+programs whose distribution conditions are different, write to the author
+to ask for permission.  For software which is copyrighted by the Free
+Software Foundation, write to the Free Software Foundation; we sometimes
+make exceptions for this.  Our decision will be guided by the two goals
+of preserving the free status of all derivatives of our free software and
+of promoting the sharing and reuse of software generally.
+
+@iftex
+@heading NO WARRANTY
+@end iftex
+@ifinfo
+@center NO WARRANTY
+@end ifinfo
+
+@item
+BECAUSE THE PROGRAM IS LICENSED FREE OF CHARGE, THERE IS NO WARRANTY
+FOR THE PROGRAM, TO THE EXTENT PERMITTED BY APPLICABLE LAW.  EXCEPT WHEN
+OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES
+PROVIDE THE PROGRAM ``AS IS'' WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED
+OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.  THE ENTIRE RISK AS
+TO THE QUALITY AND PERFORMANCE OF THE PROGRAM IS WITH YOU.  SHOULD THE
+PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY SERVICING,
+REPAIR OR CORRECTION.
+
+@item
+IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING
+WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY AND/OR
+REDISTRIBUTE THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES,
+INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING
+OUT OF THE USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED
+TO LOSS OF DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY
+YOU OR THIRD PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER
+PROGRAMS), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE
+POSSIBILITY OF SUCH DAMAGES.
+@end enumerate
+
+@iftex
+@heading END OF TERMS AND CONDITIONS
+@end iftex
+@ifinfo
+@center END OF TERMS AND CONDITIONS
+@end ifinfo
+
+@page
+@unnumberedsec How to Apply These Terms to Your New Programs
+
+  If you develop a new program, and you want it to be of the greatest
+possible use to the public, the best way to achieve this is to make it
+free software which everyone can redistribute and change under these terms.
+
+  To do so, attach the following notices to the program.  It is safest
+to attach them to the start of each source file to most effectively
+convey the exclusion of warranty; and each file should have at least
+the ``copyright'' line and a pointer to where the full notice is found.
+
+@smallexample
+@var{one line to give the program's name and an idea of what it does.}
+Copyright (C) 19@var{yy}  @var{name of author}
+
+This program is free software; you can redistribute it and/or
+modify it under the terms of the GNU General Public License
+as published by the Free Software Foundation; either version 2
+of the License, or (at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program; if not, write to the Free Software
+Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+@end smallexample
+
+Also add information on how to contact you by electronic and paper mail.
+
+If the program is interactive, make it output a short notice like this
+when it starts in an interactive mode:
+
+@smallexample
+Gnomovision version 69, Copyright (C) 19@var{yy} @var{name of author}
+Gnomovision comes with ABSOLUTELY NO WARRANTY; for details
+type `show w'.  This is free software, and you are welcome
+to redistribute it under certain conditions; type `show c' 
+for details.
+@end smallexample
+
+The hypothetical commands @samp{show w} and @samp{show c} should show
+the appropriate parts of the General Public License.  Of course, the
+commands you use may be called something other than @samp{show w} and
+@samp{show c}; they could even be mouse-clicks or menu items---whatever
+suits your program.
+
+You should also get your employer (if you work as a programmer) or your
+school, if any, to sign a ``copyright disclaimer'' for the program, if
+necessary.  Here is a sample; alter the names:
+
+@example
+Yoyodyne, Inc., hereby disclaims all copyright
+interest in the program `Gnomovision'
+(which makes passes at compilers) written 
+by James Hacker.
+
+@var{signature of Ty Coon}, 1 April 1989
+Ty Coon, President of Vice
+@end example
+
+This General Public License does not permit incorporating your program into
+proprietary programs.  If your program is a subroutine library, you may
+consider it more useful to permit linking proprietary applications with the
+library.  If this is what you want to do, use the GNU Library General
+Public License instead of this License.
diff --git a/gnu/usr.bin/gzip/gzip.texi b/gnu/usr.bin/gzip/gzip.texi
new file mode 100644
index 00000000000..07be37187d7
--- /dev/null
+++ b/gnu/usr.bin/gzip/gzip.texi
@@ -0,0 +1,479 @@
+\input texinfo @c -*-texinfo-*-
+@c %**start of header
+@setfilename gzip.info
+@settitle Gzip User's Manual
+@finalout
+@setchapternewpage odd
+@c %**end of header
+
+@ifinfo
+This file documents the the GNU @code{gzip} command for compressing files.
+
+Copyright (C) 1992-1993 Jean-loup Gailly
+
+Permission is granted to make and distribute verbatim copies of
+this manual provided the copyright notice and this permission notice
+are preserved on all copies.
+
+@ignore
+Permission is granted to process this file through TeX and print the
+results, provided the printed document carries copying permission
+notice identical to this one except for the removal of this paragraph
+(this paragraph not being relevant to the printed manual).
+
+@end ignore
+Permission is granted to copy and distribute modified versions of this
+manual under the conditions for verbatim copying, provided that the entire
+resulting derived work is distributed under the terms of a permission
+notice identical to this one.
+
+Permission is granted to copy and distribute translations of this manual
+into another language, under the above conditions for modified versions,
+except that this permission notice may be stated in a translation approved
+by the Foundation.
+@end ifinfo
+
+@titlepage
+@title gzip
+@subtitle The data compression program
+@subtitle Edition 1.2.4, for Gzip Version 1.2.4
+@subtitle July 1993
+@author by Jean-loup Gailly
+
+@page
+@vskip 0pt plus 1filll
+Copyright @copyright{} 1992-1993 Jean-loup Gailly
+
+Permission is granted to make and distribute verbatim copies of
+this manual provided the copyright notice and this permission notice
+are preserved on all copies.
+
+Permission is granted to copy and distribute modified versions of this
+manual under the conditions for verbatim copying, provided that the entire
+resulting derived work is distributed under the terms of a permission
+notice identical to this one.
+
+Permission is granted to copy and distribute translations of this manual
+into another language, under the above conditions for modified versions,
+except that this permission notice may be stated in a translation approved
+by the Foundation.
+@end titlepage
+
+@node Top, , , (dir)
+
+@ifinfo
+This file documents the @code{gzip} command to compress files.
+@end ifinfo
+
+@menu
+* Copying::		How you can copy and share @code{gzip}.
+* 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.
+* Concept Index::	Index of concepts.
+@end menu
+
+@node Copying, Overview, , Top
+@include gpl.texinfo
+
+@node Overview, Sample, Copying, 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 @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.
+
+@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 1.2.4 (18 Aug 93)
+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.
+@end example
+
+This is the output of the command @samp{gzip -v texinfo.tex}:
+
+@example
+texinfo.tex:             71.6% -- 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 --stdout is also
+given, copy the input data without change to the standard ouput: 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 --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 --verbose, the size totals and compression ratio for all files
+is also displayed, unless some sizes are unknown. With --quiet,
+the title and totals lines are not displayed.
+
+@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. 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, Concept Index, Tapes, Top
+@chapter Reporting Bugs
+@cindex bugs
+
+If you find a bug in @code{gzip}, please send electronic mail to
+@w{@samp{jloup@@chorus.fr}} or, if this fails, to
+@w{@samp{bug-gnu-utils@@prep.ai.mit.edu}}.  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 Concept Index, , Problems, Top
+@unnumbered Concept Index
+
+@printindex cp
+
+@contents
+@bye