Resource listing functions should show nothing if nothing piped in

[Mike Bailey]

$ instances nothing_found | instance-vpc | vpcs

[Mike Bailey]

This is tricky. How does a function know the difference between some "nothing" being piped in and there being no pipe involved?

[nitrocode]

I found this thread of solutions worth reading.

Could we simply check for args, if none, use a grep . to check for stdin and if neither, then show nothing?