Outputs a large amount of information about the current state of PHP. This includes information about PHP compilation options and extensions, the PHP version, server information and environment (if compiled as a module), the PHP environment, OS version information, paths, master and local values of configuration options, HTTP headers, and the PHP License.
The output may be customized by passing one or more of the following values sumed together in the optional parameter what (one can also combine them together with the or operator.
Note: Parts of the information displayed are disabled when the expose_php configuration setting is set to off. This includes the PHP and Zend logos, and the credits.