Assuming you have read the previous post, lets discuss on how to build our first PHP extension: every PHP extension is built out of minimum of 2 files, a configuration file (config.m4) which tells us what files to build and what external libraries are needed and source File(s) which will contain the actual functionality.

He builds up an example skeleton for an extension (the config.m4) and explains how the file will be phpized and configured. Next up is the php_sample.h header file where the needed modules are loaded and the sample.c file to define them. Last, but not least, comes the extension code itself that calls the printf function to output the "hello world" message.

While Core does ship with a large list of extensions (which are all QA'd and supported by Zend) there are times when you would like to include non-official extensions from PECL for various reasons.

He breaks it down into a few simple steps - download, "phpize" the extension, compile it and add the extension to the php.ini. He details the second step of the process (the phpize) because of some of the differences there are between doing it for a normal PHP install and a Zend Core install.

He also provides directions for an exception to the rule - compiling a PDO driver for your ZC install. You'll have to trick the Zend Core installation into using the right files, though. Full instructions are included.