1ZLIB(3)                    Library Functions Manual                    ZLIB(3)
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3
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NAME

6       zlib - compression/decompression library
7

SYNOPSIS

9       [see zlib.h for full description]
10

DESCRIPTION

12       The  zlib  library  is a general purpose data compression library.  The
13       code is thread safe, assuming that the standard library functions  used
14       are  thread  safe, such as memory allocation routines.  It provides in-
15       memory compression and  decompression  functions,  including  integrity
16       checks  of the uncompressed data.  This version of the library supports
17       only one compression method (deflation) but  other  algorithms  may  be
18       added later with the same stream interface.
19
20       Compression  can  be  done  in  a  single step if the buffers are large
21       enough or can be done by repeated calls of  the  compression  function.
22       In the latter case, the application must provide more input and/or con‐
23       sume the output (providing more output space) before each call.
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25       The library also supports reading and writing files  in  gzip(1)  (.gz)
26       format with an interface similar to that of stdio.
27
28       The  library  does  not install any signal handler.  The decoder checks
29       the consistency of the compressed data, so  the  library  should  never
30       crash even in the case of corrupted input.
31
32       All  functions  of  the  compression library are documented in the file
33       zlib.h.  The distribution  source  includes  examples  of  use  of  the
34       library  in  the  files  test/example.c and test/minigzip.c, as well as
35       other examples in the examples/ directory.
36
37       Changes to this version are  documented  in  the  file  ChangeLog  that
38       accompanies the source.
39
40       zlib is built in to many languages and operating systems, including but
41       not limited to Java, Python, .NET, PHP, Perl, Ruby, Swift, and Go.
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43       An experimental package to read and write files  in  the  .zip  format,
44       written on top of zlib by Gilles Vollant (info@winimage.com), is avail‐
45       able at:
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47              http://www.winimage.com/zLibDll/minizip.html  and  also  in  the
48              contrib/minizip directory of the main zlib source distribution.
49

SEE ALSO

51       The zlib web site can be found at:
52
53              http://zlib.net/
54
55       The  data  format used by the zlib library is described by RFC (Request
56       for Comments) 1950 to 1952 in the files:
57
58              http://tools.ietf.org/html/rfc1950  (for  the  zlib  header  and
59              trailer format)
60              http://tools.ietf.org/html/rfc1951  (for  the deflate compressed
61              data format)
62              http://tools.ietf.org/html/rfc1952  (for  the  gzip  header  and
63              trailer format)
64
65       Mark Nelson wrote an article about zlib for the Jan. 1997 issue of  Dr.
66       Dobb's Journal; a copy of the article is available at:
67
68              http://marknelson.us/1997/01/01/zlib-engine/
69

REPORTING PROBLEMS

71       Before reporting a problem, please check the zlib web  site  to  verify
72       that  you have the latest version of zlib; otherwise, obtain the latest
73       version and see if the problem still exists.  Please read the zlib  FAQ
74       at:
75
76              http://zlib.net/zlib_faq.html
77
78       before   asking   for   help.    Send   questions  and/or  comments  to
79       zlib@gzip.org, or (for the  Windows  DLL  version)  to  Gilles  Vollant
80       (info@winimage.com).
81

AUTHORS AND LICENSE

83       Version 1.2.11
84
85       Copyright (C) 1995-2017 Jean-loup Gailly and Mark Adler
86
87       This  software is provided 'as-is', without any express or implied war‐
88       ranty.  In no event will the authors be held  liable  for  any  damages
89       arising from the use of this software.
90
91       Permission  is  granted to anyone to use this software for any purpose,
92       including commercial applications, and to alter it and redistribute  it
93       freely, subject to the following restrictions:
94
95       1. The origin of this software must not be misrepresented; you must not
96          claim that you wrote the original software. If you use this software
97          in  a  product, an acknowledgment in the product documentation would
98          be appreciated but is not required.
99
100       2. Altered source versions must be plainly marked as such, and must not
101          be misrepresented as being the original software.
102
103       3. This  notice may not be removed or altered from any source distribu‐
104          tion.
105
106       Jean-loup Gailly        Mark Adler
107       jloup@gzip.org          madler@alumni.caltech.edu
108
109       The deflate format used by zlib was defined by Phil Katz.  The  deflate
110       and  zlib  specifications  were written by L. Peter Deutsch.  Thanks to
111       all the people who reported problems and suggested various improvements
112       in zlib; who are too numerous to cite here.
113
114       UNIX manual page by R. P. C. Rodgers, U.S. National Library of Medicine
115       (rodgers@nlm.nih.gov).
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119                                  15 Jan 2017                          ZLIB(3)
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