Breaking on an API programmatically

[Iwarez]

For a softwrap dumper I plan to work on I want to receive a breakpoint when the program calls writeprocessmemory. Does anyone of you know how to achieve this? I tried using readprocessmemory and writeprocessmemory with valid processhandle but the funtion fails on reading anything outside the image of the exe. Help appreciated.

[Iwarez]

I found out I passed a parameter wrong so the function would fail anyway.... Sorry. I now found I could succesfully write my own bytes in the API's code

[squidge]

ISTR, nikolatesla20 wrote a sample program that did this a bit ago and submitted it to the board as an attachment. It was basically for patching IsDebuggerPresent on Armadillo'd apps. I believe the filename was "genericdebug".