(PHP 4, PHP 5, PHP 7)
dl — Loads a PHP extension at runtime
$library
) : bool
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()).
This function was removed from most SAPIs in PHP 5.3.0, and was removed from PHP-FPM in PHP 7.0.0.
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:\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 (either by setting
enable_dl off 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.
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);
}
?>
Version | Description |
---|---|
7.0.0 | dl() is disabled in PHP-FPM. |
5.3.9 | dl() is enabled in PHP-FPM, albeit discouraged. |
5.3.0 | dl() is now disabled in some SAPIs due to stability issues. The only SAPIs that allow dl() are CLI and Embed. Use the Extension Loading Directives instead. |
Note:
dl() is not supported when PHP is built with ZTS support. Use the Extension Loading Directives instead.
Note:
dl() is case sensitive on Unix platforms.
Note: This function is disabled when PHP is running in safe mode.