pg_port returns the port number that the given PostgreSQL connection instance is connected to.
An PgSql\Connection instance. When connection is null, the default connection is used. The default connection is the last connection made by pg_connect or pg_pconnect.
A string containing the port number of the database server the connection is to, or empty string on error.
|8.1.0||The connection parameter expects an PgSql\Connection instance now; previously, a resource was expected.|
|8.0.0||connection is now nullable.|