dl
(PHP 4, PHP 5, PHP 7, PHP 8)
dl — Loads a PHP extension at runtime
Description
$extension_filename): bool
Loads the PHP extension given by the parameter
extension_filename.
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()).
This function was removed from most SAPIs in PHP 5.3.0, and was removed from PHP-FPM in PHP 7.0.0.
Parameters
-
extension_filename -
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:\php5\ by default.
Unix - If not explicitly set in the php.ini, the default extension directory depends on
-
whether PHP has been built with
--enable-debugor 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)
<install-dir>/lib/php/extensions/ <debug-or-not>-<zts-or-not>-ZEND_MODULE_API_NO, e.g. /usr/local/php/lib/php/extensions/debug-non-zts-20010901 or /usr/local/php/lib/php/extensions/no-debug-zts-20010901. -
whether PHP has been built with
Return Values
Returns true on success or false on failure. If the functionality of loading modules is not available
or has been disabled (by setting
enable_dl off
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.
Examples
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 using PHP_SHLIB_SUFFIX constant
if (!extension_loaded('sqlite')) {
$prefix = (PHP_SHLIB_SUFFIX === 'dll') ? 'php_' : '';
dl($prefix . 'sqlite.' . PHP_SHLIB_SUFFIX);
}
?>
Notes
Note:
dl() is case sensitive on Unix platforms.
