While "perldoc -f open" is very handy, looking at prior art would also be educational. Me, I'd look at
querying CPAN for 'stdout' - the first result is probably a good one to read the source code of. In fact, you may find that using that module solves your problems. It certainly has solved a few of mine.
My criteria for good software:
- Does it work?
- Can someone else come in, make a change, and be reasonably certain no bugs were introduced?