My understanding is that Valgrind does a number of different kinds of error checking, for example validating the parameters to system calls, memory bounds checking and so on. Perhaps then a better proposal would be to implement just one kind of such error checking. Memory bounds checking could be implemented independently of system call discipline; perhaps some other student could then do the system call stuff. How modular is its codebase? Mike -- Michael David Crawford mdcrawford at gmail dot com GoingWare's Bag of Programming Tricks http://www.goingware.com/tips/