zlib

Frequently Asked Questions

  1. Is zlib Y2K-compliant?

    Yes. zlib doesn't handle dates.

  2. Where can I get a Windows DLL version?

    The zlib sources can be compiled without change to produce a DLL. If you want a precompiled DLL, see http://www.winimage.com/zLibDll/ . Questions about the zlib DLL should be sent to Gilles Vollant (info@winimage.com).

  3. Where can I get a Visual Basic interface to zlib?

    See

  4. compress() returns Z_BUF_ERROR

    Make sure that before the call of compress, the length of the compressed buffer is equal to the total size of the compressed buffer and not zero. For Visual Basic, check that this parameter is passed by reference ("as any"), not by value ("as long").

  5. deflate() or inflate() returns Z_BUF_ERROR

    Before making the call, make sure that avail_in and avail_out are not zero. When setting the parameter flush equal to Z_FINISH, also make sure that avail_out is big enough to allow processing all pending input.

  6. Where's the zlib documentation (man pages, etc.)?

    It's in zlib.h for the moment, and Francis S. Lin has converted it to a web page. Volunteers to transform this to Unix-style man pages, please contact Jean-loup Gailly (jloup@gzip.org). Examples of zlib usage are in the files example.c and minigzip.c.

  7. Why don't you use GNU autoconf or libtool or ...?

    Because we would like to keep zlib as a very small and simple package. zlib is rather portable and doesn't need much configuration.

  8. I found a bug in zlib.

    Most of the time, such problems are due to an incorrect usage of zlib. Please try to reproduce the problem with a small program and send the corresponding source to us at zlib@gzip.org . Do not send multi-megabyte data files without prior agreement.

  9. Why do I get "undefined reference to gzputc"?

    If "make test" produces something like 

       example.o(.text+0x154): undefined reference to `gzputc'

    check that you don't have old files libz.* in /usr/lib, /usr/local/lib or /usr/X11R6/lib. Remove any old versions, then do "make install".

  10. I need a Delphi interface to zlib.

    See the directories contrib/delphi and contrib/delphi2 in the zlib distribution.

  11. Can zlib handle .zip archives?

    See the directory contrib/minizip in the zlib distribution.

  12. Can zlib handle .Z files?

    No, sorry. You have to spawn an uncompress or gunzip subprocess, or adapt the code of uncompress on your own.

  13. How can I make a Unix shared library?

    make clean
    ./configure -s
    make

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Last modified 9 January 2000 by newt@pobox.com , you betcha.

Copyright © 1998-2000 Jean-loup Gailly and Greg Roelofs.