I've dealt a lot with forking processes, and got tired of dealing with all this. I have a bad memory apparently, and I could never do it without re-reading the man pages for wait() and waitpid() to understad the difference.

IAC, I just now default to using Parallel::ForkManager. It lets me write much easier to underastand forking code, and I've had no issues with it so far.

YMMV, and I can appreciate trying to understand this stuff in detail so you know what's going on under the hood, but these days I opt for keeping the hood shut.

~Jeff