Matz writes: >Should I replace "vfork" by "fork"? I don't have enough knowledge to >decide. Any OS guru? Well, I just read "man vfork" on my Linux system, so I'm hardly a guru but ... The manpage describes a nightmare of undefined and incompatible (across systems) behaviour. It actually describes vfork as "a spectre from the past"! AFAICT vfork is just an optimisation to avoid unnecessary copying when the child process immediately does an execve. Due to Linux's copy-on-write implementation the overhead is small. In fact, for much of Linux's history vfork was identical to fork. I conclude you should use fork unless you know there is a real performance issue on some platform. This is unlikely to be the case on Linux. But then, I don't *really* know what I'm talking about. In which case, I hope a real guru will be prompted to shoot me down. That will be reward enough! :-) Regards, Jeremy -- http://www.rubygarden.com/ruby?JeremyHenty Ruby: programmer's best friend -- John Robson