dl
(PHP 4, PHP 5)
dl — Loads a PHP extension at runtime
Description
Loads the PHP extension given by the parameter library .
Use extension_loaded() to test whether a given extension is already available or not. This works on both built-in extensions and dynamically loaded ones (either through php.ini or dl()).
Parameters
- library
-
This parameter is only the filename of the extension to load which also depends on your platform. For example, the sockets extension (if compiled as a shared module, not the default!) would be called sockets.so on Unix platforms whereas it is called php_sockets.dll on the Windows platform.
The directory where the extension is loaded from depends on your platform:
Windows - If not explicitly set in the php.ini, the extension is loaded from c:\php4\extensions\ by default.
Unix - If not explicitly set in the php.ini, the default extension directory depends on
- whether PHP has been built with --enable-debug or not
- whether PHP has been built with (experimental) ZTS (Zend Thread Safety) support or not
- the current internal ZEND_MODULE_API_NO (Zend internal module API number, which is basically the date on which a major module API change happened, e.g. 20010901)
Return Values
Επιστρέφει TRUE σε επιτυχία ή FALSE σε αποτυχία. If the functionality of loading modules is not available (see Note) or has been disabled (either by turning it off enable_dl or by enabling safe mode in php.ini) an E_ERROR is emitted and execution is stopped. If dl() fails because the specified library couldn't be loaded, in addition to FALSE an E_WARNING message is emitted.
Παραδείγματα
Example#1 dl() examples
<?php
// Example loading an extension based on OS
if (!extension_loaded('sqlite')) {
if (strtoupper(substr(PHP_OS, 0, 3)) === 'WIN') {
dl('php_sqlite.dll');
} else {
dl('sqlite.so');
}
}
// Or, the PHP_SHLIB_SUFFIX constant is available as of PHP 4.3.0
if (!extension_loaded('sqlite')) {
$prefix = (PHP_SHLIB_SUFFIX === 'dll') ? 'php_' : '';
dl($prefix . 'sqlite.' . PHP_SHLIB_SUFFIX);
}
?>
Notes
Note: dl() is not supported in multithreaded Web servers. Use the extensions statement in your php.ini when operating under such an environment. However, the CGI and CLI build are not affected !
Note: As of PHP 5, the dl() function is deprecated in every SAPI except CLI. Use Extension Loading Directives method instead.
Note: Since PHP 6 this function is disabled in all SAPIs, except CLI, CGI and embed.
Note: dl() is case sensitive on Unix platforms.
Note: Αυτή η συνάρτηση είναι απενεργοποιημένη στο safe mode.