New to PHP : How to develop/use external APIs ?

A question from a PHP newbie : Can somebody point me to the pertinent chunks of documentation to read to quickly learn how I will be able to call custom programming of my own from php4 ? To better define my needs, suppose I have some C routines which I should be able to execute from PHP4 code to access and use some service. It could for instance be some entry point APIs to an existing interface for some old legacy application. Let's assume I have the source code and control over those pieces of external code. Is there some special way to go to build shared-libraries (if Unix) or DLLs (if Win32) so I will be able to call those APIs from PHP4 web pages ? I will start reading as much of the docs as I can in between, but if any of you had some recommendations so I can quick start my learning curve, I'd be really happy ! To specify what will be my platform, I intend to use PHP4 on Apache on Win32 thanks to the excellent opensa.org porting job. Thank you all, --------------------------------------------------------------------- Olivier Mascia T.I.P. Group SA om@tipgroup.com www.tipgroup.com Director, Chief Software Architect +32 65 401111