php man page for extension_loaded

EXTENSION_LOADED(3)							 1						       EXTENSION_LOADED(3)

extension_loaded - Find out whether an extension is loaded

SYNOPSIS
       bool extension_loaded (string  $name)

DESCRIPTION
	Finds out whether the extension is loaded.

PARAMETERS
	      o $name
		-  The	extension name. This parameter is case-insensitive.  You can see the names of various extensions by using phpinfo(3) 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(3) example

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

SEE ALSO
       get_loaded_extensions(3), get_extension_funcs(3), phpinfo(3), dl(3), function_exists(3).

PHP Documentation Group 												       EXTENSION_LOADED(3)