It looks like the snippet checks whether a child is still running (by checking if the pipe is still open). system doesn't run a child in parallel, so your suggestion would help. It seems to me the solution would involve fork+exec (not recommended for Windows), system 1, ... (undocumented? Windows only), Win32::Process (Windows only), IPC::Open2, IPC::Open3, IPC::Run or IPC::Run3, but not system.