Professional LAMP: Linux®, Apache, MySQL®, and PHP5 Web Development

5.2. PHP Configuration during Runtime

Checking and changing the settings of directives in php.ini directly is often a quick and easy solution to monitoring and modifying your installation, but many times you can't bring the server down to make a change, or you need to know a setting while a script is running. The techniques in this part of the chapter will help you make modifications while the server is still running.

5.2.1. Obtaining Current Runtime Settings

If you need to know the exact version of PHP installed, PHP provides the phpversion() function, which returns a string listing the full installed version. For example:

<?php

echo "The current version of PHP installed is: " . phpversion();

?>

This would output something like the following:

The current version of PHP installed is: 5.0.4

5.2.1.1. Retrieving Configuration Settings

There might be times when a simple version check isn't enough information, and you require a little more information about the way PHP is configured, but you don't have access to php.ini directly. To look up runtime configuration settings, you have three main choices: ini_get(), get_cfg_var(), and ini_get_all().

The first option, ini_get(), checks a given string against the current runtime configuration. If a setting matches, it returns the value of that setting; if no match is found, an empty string is returned:

<?php echo "Error reporting: " . ini_get('error_reporting') . "\n" . "Register globals: " . ini_get('register_globals') . "\n" . "Nonexistant ...