tor_check_port_forwarding() in util.c contains both code specific to tor-fw-helper as well as generic code for launching a child process. It might be useful to make this more generic so it could be used for launching other processes. On this topic, in bug legacy/trac#1903, nickm said: > It seems that the code here does two things: one is a general task "Launch a > child process and see what it says" and another is a more specific task > "Launch a tor-fw-helper instance and act based on its output.)" It might be a > good idea to disentangle these eventually, in case we ever want to launch > anything else. > > It might be cleaner to move the static variables from > tor_check_port_forwarding into some kind of struct, in case we ever want to > launch two things in the future.