(PHP 4, PHP 5, PHP 7, PHP 8)
dl — Loads a PHP extension at runtime
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 is only available for the CLI and embed SAPIs, and the CGI SAPI when run from the command line.
extension_filenameThis 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
--enable-debug
or not
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.
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.
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);
}
?>Note:
dl() is case sensitive on Unix platforms.