Thanks for the info. I'll check Proc::Killfam out, though I try to avoid non-core dependencies when I can on this box as it's an Ubuntu server.

I think BrowserUK identified why I was creating strawmen in Re^3: Handling badly behaved system calls in threads - I'm still working through the code examples he's posted for avoiding invoking the shell. Not relying to feeding backticked system calls through regular expressions appeals to me greatly.