strace is a very good first tool to use. It's extremely quick and easy to run, and gives a wonderful view of how the process interacts with the system or other

strace is a very good first tool to use. It's extremely quick and easy to run, and gives a wonderful view of how the process interacts with the system or other processes. You also notice quickly if you can't find your answer with strace, if what you are interested in is not done with a syscall. In the source code you are looking at layers over layers of abstraction, variables being passed around and mangled and substituted into strings, maybe get into a dependency tree of various libraries. Not to say that you are wrong, the source the ultimate most powerful tool and absolutely you should learn to use it. But I disagree with what tool to use first, if you have zero knowledge about the process.