ZLIB(3) ZLIB(3)
18 Aug 2023
NAME
zlib - compression/decompression library
SYNOPSIS
[see zlib.h for full description]
DESCRIPTION
The zlib library is a general purpose data compression library. The
code is thread safe, assuming that the standard library functions used
are thread safe, such as memory allocation routines. It provides in-
memory compression and decompression functions, including integrity
checks of the uncompressed data. This version of the library supports
only one compression method (deflation) but other algorithms may be
added later with the same stream interface. Compression can be done
in a single step if the buffers are large enough or can be done by
repeated calls of the compression function. In the latter case, the
application must provide more input and/or consume the output
(providing more output space) before each call. The library also
supports reading and writing files in gzip(1) (.gz) format with an
interface similar to that of stdio. The library does not install any
signal handler. The decoder checks the consistency of the compressed
data, so the library should never crash even in the case of corrupted
input. All functions of the compression library are documented in the
file zlib.h. The distribution source includes examples of use of the
library in the files test/example.c and test/minigzip.c, as well as
other examples in the examples/ directory. Changes to this version
are documented in the file ChangeLog that accompanies the source.
zlib is built in to many languages and operating systems, including
but not limited to Java, Python, .NET, PHP, Perl, Ruby, Swift, and Go.
An experimental package to read and write files in the .zip format,
written on top of zlib by Gilles Vollant (info@winimage.com), is
available at:
http://www.winimage.com/zLibDll/minizip.html and also in the
contrib/minizip directory of the main zlib source distribution.
SEE ALSO
The zlib web site can be found at:
http://zlib.net/ The data format used by the zlib library is
described by RFC (Request for Comments) 1950 to 1952 in the
files:
http://tools.ietf.org/html/rfc1950 (for the zlib header and
trailer format)
http://tools.ietf.org/html/rfc1951 (for the deflate compressed
data format)
http://tools.ietf.org/html/rfc1952 (for the gzip header and
trailer format) Mark Nelson wrote an article about zlib for the
Jan. 1997 issue of Dr. Dobb's Journal; a copy of the article is
available at:
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ZLIB(3) ZLIB(3)
18 Aug 2023
http://marknelson.us/1997/01/01/zlib-engine/
REPORTING PROBLEMS
Before reporting a problem, please check the zlib web site to verify
that you have the latest version of zlib; otherwise, obtain the latest
version and see if the problem still exists. Please read the zlib FAQ
at:
http://zlib.net/zlib_faq.html before asking for help. Send
questions and/or comments to zlib@gzip.org, or (for the Windows
DLL version) to Gilles Vollant (info@winimage.com).
AUTHORS AND LICENSE
Version 1.3 Copyright (C) 1995-2023 Jean-loup Gailly and Mark Adler
This software is provided 'as-is', without any express or implied
warranty. In no event will the authors be held liable for any damages
arising from the use of this software. Permission is granted to
anyone to use this software for any purpose, including commercial
applications, and to alter it and redistribute it freely, subject to
the following restrictions:
0step].
The origin of this software must not be misrepresented; you must
not claim that you wrote the original software. If you use this
software in a product, an acknowledgment in the product
documentation would be appreciated but is not required.
0step].
Altered source versions must be plainly marked as such, and must
not be misrepresented as being the original software.
0step].
This notice may not be removed or altered from any source
distribution. Jean-loup Gailly Mark Adler
jloup@gzip.org madler@alumni.caltech.edu The deflate
format used by zlib was defined by Phil Katz. The deflate and zlib
specifications were written by L. Peter Deutsch. Thanks to all the
people who reported problems and suggested various improvements in
zlib; who are too numerous to cite here. UNIX manual page by R. P.
C. Rodgers, U.S. National Library of Medicine
(rodgers@nlm.nih.gov).
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