When the title of the article is "How debuggers work", I thought it might be more profitable to actually fulfill that premise, and not get side-tracked by the q

When the title of the article is "How debuggers work", I thought it might be more profitable to actually fulfill that premise, and not get side-tracked by the quirks of ptrace. (For example, no one could implement a debugger for, say, python scripts just reading this article.) A better title might have been "how to trace child processes under POSIX". Solving the general case is not just an academic exercise, it's also a richly rewarding learning experience. When people learn to think abstractly, none of these implementation details really matter. You can always specialize and learn the details of an specific instance; it's best to get a good grasp of the big-picture. [Edit: Instead of discussing "debuggers", in general, I hoped to narrow down and focus on just interruption mechanisms. Third-party execution tracing and stepping are usually outside language semantics, so there is some "art" to gaining control from an executing program. It would be nice to catalog the lore, and I hope others add to the three I have suggested above]