It's most definitely catenate. I understand catenate to mean chain and concatenate to be to chain together. Since "cat foo bar xyzzy" doesn't modify the files to join them in any way I don't think they're chained together.
Besides, ken & Co. aren't daft. con would be short for concatenate. :-)
Do they mean the same thing?
As for cat, the utility, I'm afraid we'll never stop seeing people doing
even when it makes absolutely no sense whatsoever.If it did, I might as well do
I mean, why not? It "looks nicer" than Programmers love their cats.