Getting the tables of a db by using _query()

hi, I'm trying to get the tables of a db (and fields of the tables) by first using mysql_query("show tables"), but this doesn't seem to return anything useful. How can I do this? Note that I don't want to use mysql_list_tables or mysql_list_fields because I'll probably have to port this script to another scripting languages, too. The existence of these functions made me think there must be a sql query that does the same trick. - markus