Whatever it is, it will be listed among the [man]MySQL[/man] functions, then.
Lessee....
[man]mysql_affected_rows[/man] -- Get number of affected rows in previous MySQL operation
[man]mysql_change_user[/man] -- Change logged in user of the active connection
[man]mysql_client_encoding[/man] -- Returns the name of the character set
....
Oh, whatever. I'd be bound to come across it sooner or later if it's there.