The reference Wikipedia gives for that does not actually say that the original “cat” only took one file name. What is says is that “cat”s predecessor, “pr”, only took one file name, and that “cat” subsumed it.

How’s that for pedantry?

Excellent!

Good to know. Reading definitions of concatenate and catenate, I was confused about whether there actually was a difference or not.

Edit: that wikipedia page makes it sound like the program it replaced was the one that prints a single file to the screen.