PHP application aware of sockets are few, most of them will try to connect to a port, you will have to find a way to define the one you want to use for your particular app. Some let you put it in a variable, some will just need you to add it after the hostname or ip (localhost:3309), some will just assume 3306 and just ignore anything else.
+
+
Possible host strings (localhost can be replaced with 127.0.0.1 if needed):