# extension_loaded

(PHP 4, PHP 5)

extension_loaded — Find out whether an extension is loaded

### Description

bool extension_loaded ( string `$name` )

Finds out whether the extension is loaded.

### Parameters

`name`

  The extension name.

  You can see the names of various extensions by using phpinfo() or if you're using the CGI or CLI version of PHP you can use the -m switch to list all available extensions:

      $ php -m
      [PHP Modules]
      xml
      tokenizer
      standard
      sockets
      session
      posix
      pcre
      overload
      mysql
      mbstring
      ctype

      [Zend Modules]

### Return Values

Returns `TRUE` if the extension identified by `name` is loaded, `FALSE` otherwise.

### Examples

Example#1 extension_loaded() example

`<?php
if (!extension_loaded('gd')) {
if (!dl('gd.so')) {
exit;
}
}
?>`

### Notes

> Note: extension_loaded() uses the internal extension name to test whether a certain extension is available or not. Most internal extension names are written in lower case but there may be extension available which also use uppercase letters. Be warned that this function compares case sensitive !

### See Also

- get_loaded_extensions()
- get_extension_funcs()
- phpinfo()
- dl()