| 1 | .TH ZLIB 3 "27 Mar 2022"
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| 2 | .SH NAME
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| 3 | zlib \- compression/decompression library
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| 4 | .SH SYNOPSIS
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| 5 | [see
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| 6 | .I zlib.h
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| 7 | for full description]
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| 8 | .SH DESCRIPTION
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| 9 | The
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| 10 | .I zlib
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| 11 | library is a general purpose data compression library.
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| 12 | The code is thread safe, assuming that the standard library functions
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| 13 | used are thread safe, such as memory allocation routines.
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| 14 | It provides in-memory compression and decompression functions,
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| 15 | including integrity checks of the uncompressed data.
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| 16 | This version of the library supports only one compression method (deflation)
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| 17 | but other algorithms may be added later
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| 18 | with the same stream interface.
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| 19 | .LP
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| 20 | Compression can be done in a single step if the buffers are large enough
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| 21 | or can be done by repeated calls of the compression function.
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| 22 | In the latter case,
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| 23 | the application must provide more input and/or consume the output
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| 24 | (providing more output space) before each call.
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| 25 | .LP
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| 26 | The library also supports reading and writing files in
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| 27 | .IR gzip (1)
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| 28 | (.gz) format
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| 29 | with an interface similar to that of stdio.
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| 30 | .LP
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| 31 | The library does not install any signal handler.
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| 32 | The decoder checks the consistency of the compressed data,
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| 33 | so the library should never crash even in the case of corrupted input.
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| 34 | .LP
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| 35 | All functions of the compression library are documented in the file
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| 36 | .IR zlib.h .
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| 37 | The distribution source includes examples of use of the library
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| 38 | in the files
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| 39 | .I test/example.c
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| 40 | and
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| 41 | .IR test/minigzip.c,
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| 42 | as well as other examples in the
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| 43 | .IR examples/
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| 44 | directory.
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| 45 | .LP
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| 46 | Changes to this version are documented in the file
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| 47 | .I ChangeLog
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| 48 | that accompanies the source.
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| 49 | .LP
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| 50 | .I zlib
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| 51 | is built in to many languages and operating systems, including but not limited to
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| 52 | Java, Python, .NET, PHP, Perl, Ruby, Swift, and Go.
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| 53 | .LP
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| 54 | An experimental package to read and write files in the .zip format,
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| 55 | written on top of
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| 56 | .I zlib
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| 57 | by Gilles Vollant (info@winimage.com),
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| 58 | is available at:
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| 59 | .IP
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| 60 | http://www.winimage.com/zLibDll/minizip.html
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| 61 | and also in the
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| 62 | .I contrib/minizip
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| 63 | directory of the main
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| 64 | .I zlib
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| 65 | source distribution.
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| 66 | .SH "SEE ALSO"
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| 67 | The
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| 68 | .I zlib
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| 69 | web site can be found at:
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| 70 | .IP
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| 71 | http://zlib.net/
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| 72 | .LP
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| 73 | The data format used by the
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| 74 | .I zlib
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| 75 | library is described by RFC
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| 76 | (Request for Comments) 1950 to 1952 in the files:
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| 77 | .IP
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| 78 | http://tools.ietf.org/html/rfc1950 (for the zlib header and trailer format)
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| 79 | .br
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| 80 | http://tools.ietf.org/html/rfc1951 (for the deflate compressed data format)
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| 81 | .br
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| 82 | http://tools.ietf.org/html/rfc1952 (for the gzip header and trailer format)
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| 83 | .LP
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| 84 | Mark Nelson wrote an article about
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| 85 | .I zlib
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| 86 | for the Jan. 1997 issue of Dr. Dobb's Journal;
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| 87 | a copy of the article is available at:
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| 88 | .IP
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| 89 | http://marknelson.us/1997/01/01/zlib-engine/
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| 90 | .SH "REPORTING PROBLEMS"
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| 91 | Before reporting a problem,
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| 92 | please check the
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| 93 | .I zlib
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| 94 | web site to verify that you have the latest version of
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| 95 | .IR zlib ;
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| 96 | otherwise,
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| 97 | obtain the latest version and see if the problem still exists.
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| 98 | Please read the
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| 99 | .I zlib
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| 100 | FAQ at:
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| 101 | .IP
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| 102 | http://zlib.net/zlib_faq.html
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| 103 | .LP
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| 104 | before asking for help.
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| 105 | Send questions and/or comments to zlib@gzip.org,
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| 106 | or (for the Windows DLL version) to Gilles Vollant (info@winimage.com).
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| 107 | .SH AUTHORS AND LICENSE
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| 108 | Version 1.2.12
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| 109 | .LP
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| 110 | Copyright (C) 1995-2022 Jean-loup Gailly and Mark Adler
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| 111 | .LP
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| 112 | This software is provided 'as-is', without any express or implied
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| 113 | warranty. In no event will the authors be held liable for any damages
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| 114 | arising from the use of this software.
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| 115 | .LP
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| 116 | Permission is granted to anyone to use this software for any purpose,
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| 117 | including commercial applications, and to alter it and redistribute it
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| 118 | freely, subject to the following restrictions:
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| 119 | .LP
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| 120 | .nr step 1 1
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| 121 | .IP \n[step]. 3
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| 122 | The origin of this software must not be misrepresented; you must not
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| 123 | claim that you wrote the original software. If you use this software
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| 124 | in a product, an acknowledgment in the product documentation would be
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| 125 | appreciated but is not required.
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| 126 | .IP \n+[step].
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| 127 | Altered source versions must be plainly marked as such, and must not be
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| 128 | misrepresented as being the original software.
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| 129 | .IP \n+[step].
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| 130 | This notice may not be removed or altered from any source distribution.
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| 131 | .LP
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| 132 | Jean-loup Gailly Mark Adler
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| 133 | .br
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| 134 | jloup@gzip.org madler@alumni.caltech.edu
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| 135 | .LP
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| 136 | The deflate format used by
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| 137 | .I zlib
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| 138 | was defined by Phil Katz.
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| 139 | The deflate and
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| 140 | .I zlib
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| 141 | specifications were written by L. Peter Deutsch.
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| 142 | Thanks to all the people who reported problems and suggested various
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| 143 | improvements in
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| 144 | .IR zlib ;
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| 145 | who are too numerous to cite here.
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| 146 | .LP
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| 147 | UNIX manual page by R. P. C. Rodgers,
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| 148 | U.S. National Library of Medicine (rodgers@nlm.nih.gov).
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| 149 | .\" end of man page
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