in reply to killing child processes
Unless I have the wrong end of the stick, a module that will do what you want is Proc::Simple.
Have a peer on CPAN, and it's there. The documentation is simple, as is the implementation.
The only caveat I have with Proc::Simple is that in exceptional circumstances it can segfault due to it's reaper code (signals are painful in Perl).
HTH,
Malk