Hey guys, it's the first time for me posting on Perlmonks, I really hope I didn't chose the wrong area to do this. If so, please let me know.

Well, I'm actual trying to get www.Gearman.org running and it seems like I have to fork on some point. When I was researching about forking how it works, and how it should be done, I read something about exit_value, signal_num and dump_core. Maybe a little code example here:

You can check all the failure possibilities by
               inspecting "$?" like this:

                   $exit_value  = $? >> 8;
                   $signal_num  = $? & 127;
                   $dumped_core = $? & 128;
[download]

Best method to capture return code from system calls?

I know what bitwise is and how it works, but I don't get what this three variables should tell me. I mean I know what an exit_value is, but this signal num or dumped_core ... what does it brings to me to bitwise $? (= return value by a fork) with 127 or 128? Regards.