extension_loaded
(PHP 4, PHP 5)
extension_loaded — Find out whether an extension is loaded
说明
bool extension_loaded
( string $name
)
Finds out whether the extension is loaded.
参数
-
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]
返回值
Returns TRUE if the extension identified by name
is loaded, FALSE otherwise.
范例
Example#1 extension_loaded() example
<?php
if (!extension_loaded('gd')) {
if (!dl('gd.so')) {
exit;
}
}
?>
注释
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 !