You need to have two rather than one handle if you want to know when the process is finishing outputting. Otherwise its output filehandle will never reach EOF.

Actually hIsEOF only looks at the read side of a read/write Handle, so this would still work.

Generally you won't want to close the output and input Handles simultaneously.

Good point. However, closing just one side of a read/write Handle is something we've wanted before IIRC: it's useful when dealing with sockets. Cheers, Simon