You have now successfully created your new PHP shared extension. To activate it you have to load the extension into PHP.

To load the extension at startup so that it is always available with PHP you have to add an extension directive to your php.ini file:

...
extension=x1.so
...

To load the extension at runtime only where it is really needed you may use PHPs dl() function:

<?php
dl("x1.so");
...
?>