Have postgresql 9.0 notify a running process

Greetings,
I have written a daemon the runs on a ubuntu box. This box has the postgresql installed on it and has a database. When the user modifies certain tables in the database, I would like postgresql to notify the running daemon. I assume that I would have to use notify/listen in some way, but am unsure of this. The daemon was developed in C++. What would I have to put into the daemon code to listen for the notify from Postgresql ?

any help/ideas greatly appreciated.