This problem has absolutely nothing to do with Perl. It's a matter of communication between your program and your web server. It's your web server that needs to think the program has finished. If your web server does that why watching for eof on stdout and stderr, you need to close them. Don't forget than on a fork(), filedescriptors get dupped.

Did you know this issue if even pointed out in perldoc -f fork?

Abigail