prefork is a utility to prefork inetd-style wait services which itself
runs as an inetd-style wait service. prefork expects to be passed file
descriptor zero (0) as a listening socket on which accept(2) can be
called and will spawn children, passing them file descriptor zero (0)
under the expectation that these children will service the incoming
connexions. The children should then service connexions by calling
accept(2) on the socket.
