This directory contains a Pascal (Delphi, Kylix) interface to the

zlib data compression library.

Directory listing

=================

zlibd32.mak     makefile for Borland C++

example.pas     usage example of zlib

zlibpas.pas     the Pascal interface to zlib

readme.txt      this file

Compatibility notes

===================

- Although the name "zlib" would have been more normal for the

  zlibpas unit, this name is already taken by Borland's ZLib unit.

  This is somehow unfortunate, because that unit is not a genuine

  interface to the full-fledged zlib functionality, but a suite of

  class wrappers around zlib streams.  Other essential features,

  such as checksums, are missing.

  It would have been more appropriate for that unit to have a name

  like "ZStreams", or something similar.

- The C and zlib-supplied types int, uInt, long, uLong, etc. are

  translated directly into Pascal types of similar sizes (Integer,

  LongInt, etc.), to avoid namespace pollution.  In particular,

  there is no conversion of unsigned int into a Pascal unsigned

  integer.  The Word type is non-portable and has the same size

  (16 bits) both in a 16-bit and in a 32-bit environment, unlike

  Integer.  Even if there is a 32-bit Cardinal type, there is no

  real need for unsigned int in zlib under a 32-bit environment.

- Except for the callbacks, the zlib function interfaces are

  assuming the calling convention normally used in Pascal

  (__pascal for DOS and Windows16, __fastcall for Windows32).

  Since the cdecl keyword is used, the old Turbo Pascal does

  not work with this interface.

- The gz* function interfaces are not translated, to avoid

  interfacing problems with the C runtime library.  Besides,

    gzprintf(gzFile file, const char *format, ...)

  cannot be translated into Pascal.

Legal issues

============

The zlibpas interface is:

  Copyright (C) 1995-2003 Jean-loup Gailly and Mark Adler.

  Copyright (C) 1998 by Bob Dellaca.

  Copyright (C) 2003 by Cosmin Truta.

The example program is:

  Copyright (C) 1995-2003 by Jean-loup Gailly.

  Copyright (C) 1998,1999,2000 by Jacques Nomssi Nzali.

  Copyright (C) 2003 by Cosmin Truta.

  This software is provided 'as-is', without any express or implied

  warranty.  In no event will the author 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:

  1. 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.

  2. Altered source versions must be plainly marked as such, and must not be

     misrepresented as being the original software.

  3. This notice may not be removed or altered from any source distribution.