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.
Because every system is setup differently, phpinfo() is commonly used to check configuration settings and for available predefined variables on a given system. Also, phpinfo() is a valuable debugging tool as it contains all EGPCS (Environment, GET, POST, Cookie, Server) data.
The output may be customized by passing one or more of the following constants bitwise values summed together in the optional what parameter. One can also combine the respective constants or bitwise values together with the or operator.
Table 1. phpinfo() options
| Name (constant) | Value | Description |
|---|---|---|
| INFO_GENERAL | 1 | The configuration line, php.ini location, build date, Web Server, System and more. |
| INFO_CREDITS | 2 | PHP 4 Credits. See also phpcredits(). |
| INFO_CONFIGURATION | 4 | Current Local and Master values for php directives. See also ini_get(). |
| INFO_MODULES | 8 | Loaded modules and their respective settings. |
| INFO_ENVIRONMENT | 16 | Environment Variable information that's also available in $_ENV. |
| INFO_VARIABLES | 32 | Shows all predefined variables from EGPCS (Environment, GET, POST, Cookie, Server). |
| INFO_LICENSE | 64 | PHP License information. See also the license faq. |
| INFO_ALL | -1 | Shows all of the above. This is the default value. |
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.
See also: phpversion(), phpcredits(), php_logo_guid(), ini_get(), ini_set(), and the section on Predefined Variables.