C++ sample code to read Sound card buffer from Line In (mic)

[breezed]

i need my program to read soundcard buffer in realtime, the way i need my program works is pretty simple, it monitor the sounds that came from mic (Line in),and if the program get some tone with "2 second length" and "x height of frequency" it wites text file with timestamp data in it.

can you guys gimme sum lite on this?