One of the most powerful features of PHP is the ability to customize its behavior through a configuration file. In this article, we're going to cover some of the ways the php.ini file can be used and how it might help you. This article will outline in detail many of the more frequently used directives of the php.ini file.

Using the PHP configuration file can make administration of PHP as simple as administration of Apache! The php.ini file is used by PHP to simplify post-installation configuration of PHP and gives you one place for all of PHP's runtime configurations. When PHP fires up its engines, one of the first thing it does is to look for the php.ini file so that it can read into memory the directives defined therein. It looks for php.ini in the current working directory, the path designated by the environmental variable PHPRC, and in the path defined at compile time.

As I said before, the php.ini file provides the advantage of allowing you to dynamically customize PHP. Well, dynamically is only half true. If you're running PHP as an Apache module, the configuration directives reside in memory until a new Apache process has been started. Since a CGI program starts a new process each time, the configuration information is re-read each time PHP is used as a CGI program, thus giving the impression of dynamic configuration. Otherwise, the PHP configuration remains unchanged until the web server is restarted.

• What is php.ini? - The PHP configuration file

• Setting parser options