Registering session handlers
Finally, the handlers implemented in Example D-3 through Example D-8 need to be registered as callback functions with PHP. Example D-9 shows the call to session_set_save_handler( ) with the names of each handler function.
Example D-9. Registering the user-defined session handlers with PHP
// Call to register user call back functions.
session_set_save_handler("sessionOpen",
"sessionClose",
"sessionRead",
"sessionWrite",
"sessionDestroy",
"sessionGC");