1  .TH ZLIB 3 "15 Jan 2017"
  2  .SH NAME
  3  zlib \- compression/decompression library
  4  .SH SYNOPSIS
  5  [see
  6  .I zlib.h
  7  for full description]
  8  .SH DESCRIPTION
  9  The
 10  .I zlib
 11  library is a general purpose data compression library.
 12  The code is thread safe, assuming that the standard library functions
 13  used are thread safe, such as memory allocation routines.
 14  It provides in-memory compression and decompression functions,
 15  including integrity checks of the uncompressed data.
 16  This version of the library supports only one compression method (deflation)
 17  but other algorithms may be added later
 18  with the same stream interface.
 19  .LP
 20  Compression can be done in a single step if the buffers are large enough
 21  or can be done by repeated calls of the compression function.
 22  In the latter case,
 23  the application must provide more input and/or consume the output
 24  (providing more output space) before each call.
 25  .LP
 26  The library also supports reading and writing files in
 27  .IR gzip (1)
 28  (.gz) format
 29  with an interface similar to that of stdio.
 30  .LP
 31  The library does not install any signal handler.
 32  The decoder checks the consistency of the compressed data,
 33  so the library should never crash even in the case of corrupted input.
 34  .LP
 35  All functions of the compression library are documented in the file
 36  .IR zlib.h .
 37  The distribution source includes examples of use of the library
 38  in the files
 39  .I test/example.c
 40  and
 41  .IR test/minigzip.c,
 42  as well as other examples in the
 43  .IR examples/
 44  directory.
 45  .LP
 46  Changes to this version are documented in the file
 47  .I ChangeLog
 48  that accompanies the source.
 49  .LP
 50  .I zlib
 51  is built in to many languages and operating systems, including but not limited to
 52  Java, Python, .NET, PHP, Perl, Ruby, Swift, and Go.
 53  .LP
 54  An experimental package to read and write files in the .zip format,
 55  written on top of
 56  .I zlib
 57  by Gilles Vollant (info@winimage.com),
 58  is available at:
 59  .IP
 60  http://www.winimage.com/zLibDll/minizip.html
 61  and also in the
 62  .I contrib/minizip
 63  directory of the main
 64  .I zlib
 65  source distribution.
 66  .SH "SEE ALSO"
 67  The
 68  .I zlib
 69  web site can be found at:
 70  .IP
 71  http://zlib.net/
 72  .LP
 73  The data format used by the
 74  .I zlib
 75  library is described by RFC
 76  (Request for Comments) 1950 to 1952 in the files:
 77  .IP
 78  http://tools.ietf.org/html/rfc1950 (for the zlib header and trailer format)
 79  .br
 80  http://tools.ietf.org/html/rfc1951 (for the deflate compressed data format)
 81  .br
 82  http://tools.ietf.org/html/rfc1952 (for the gzip header and trailer format)
 83  .LP
 84  Mark Nelson wrote an article about
 85  .I zlib
 86  for the Jan. 1997 issue of  Dr. Dobb's Journal;
 87  a copy of the article is available at:
 88  .IP
 89  http://marknelson.us/1997/01/01/zlib-engine/
 90  .SH "REPORTING PROBLEMS"
 91  Before reporting a problem,
 92  please check the
 93  .I zlib
 94  web site to verify that you have the latest version of
 95  .IR zlib ;
 96  otherwise,
 97  obtain the latest version and see if the problem still exists.
 98  Please read the
 99  .I zlib
100  FAQ at:
101  .IP
102  http://zlib.net/zlib_faq.html
103  .LP
104  before asking for help.
105  Send questions and/or comments to zlib@gzip.org,
106  or (for the Windows DLL version) to Gilles Vollant (info@winimage.com).
107  .SH AUTHORS AND LICENSE
108  Version 1.2.11
109  .LP
110  Copyright (C) 1995-2017 Jean-loup Gailly and Mark Adler
111  .LP
112  This software is provided 'as-is', without any express or implied
113  warranty.  In no event will the authors be held liable for any damages
114  arising from the use of this software.
115  .LP
116  Permission is granted to anyone to use this software for any purpose,
117  including commercial applications, and to alter it and redistribute it
118  freely, subject to the following restrictions:
119  .LP
120  .nr step 1 1
121  .IP \n[step]. 3
122  The origin of this software must not be misrepresented; you must not
123  claim that you wrote the original software. If you use this software
124  in a product, an acknowledgment in the product documentation would be
125  appreciated but is not required.
126  .IP \n+[step].
127  Altered source versions must be plainly marked as such, and must not be
128  misrepresented as being the original software.
129  .IP \n+[step].
130  This notice may not be removed or altered from any source distribution.
131  .LP
132  Jean-loup Gailly        Mark Adler
133  .br
134  jloup@gzip.org          madler@alumni.caltech.edu
135  .LP
136  The deflate format used by
137  .I zlib
138  was defined by Phil Katz.
139  The deflate and
140  .I zlib
141  specifications were written by L. Peter Deutsch.
142  Thanks to all the people who reported problems and suggested various
143  improvements in
144  .IR zlib ;
145  who are too numerous to cite here.
146  .LP
147  UNIX manual page by R. P. C. Rodgers,
148  U.S. National Library of Medicine (rodgers@nlm.nih.gov).
149  .\" end of man page