As I just said, the session_set_save_handler() function will allow us to override the default method of storing data.  According to the documentation, here is the format for this function:

bool session_set_save_handler ( callback $open, callback $close, callback $read, callback $write, callback $destroy, callback $gc );

In our example, I'm going to create a session class that can be used to store information to the database instead of to a file.

For starters, create a new file called "sessions.php."  Inside this file, put the following code:

class SessionManager {

   var $life_time;

   function SessionManager() {

      // Read the maxlifetime setting from PHP
      $this->life_time = get_cfg_var("session.gc_maxlifetime");

      // Register this object as the session handler
      session_set_save_handler( 
        array( &$this, "open" ), 
        array( &$this, "close" ),
        array( &$this, "read" ),
        array( &$this, "write"),
        array( &$this, "destroy"),
        array( &$this, "gc" )
      );

   }

}

In the above example, the SessionManager() class and its constructor are created.  You will notice that instead of merely passing function names into the session_set_save_handler() function, I sent arrays allowing me to identify class methods as the intercepts for the session actions.