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Comment by TheSoftwareGuy | Hacker News Reader

> cat > Catenate

TIL the words concatenate and catenate exist, although they seem to have almost the same exact meaning

I'd heard of concatenate, but never catenate. I guess concatenate is a verb, and catenate is an adjective.

"Concatenate" seems redundant to me, as the Latin prefix "con" means "together" and the root "caten" is a chain. So technically it's "chain together", but a chain is already a thing that is linked together.

My Latin is rusty, but IIRC "con" can optionally just be added for emphasis, e.g. "iacere": to throw, but "conicere":to hurl. Maybe that's what was done here.

Links in a chain are already together. You absolutely can chain 2 things together that are not the chain itself. Where chain is used as a verb to describe the tying of things together. Saying chain together absolutely makes sence. Example "His ankles were chained together".

I thought maybe they chose "cat"enate to avoid a naming clash with a "con" command but looking back through the early Unix sources there doesn't appear to have been one.

Maybe it was to avoid confusion with Lisp's "cons" which conventionally (or always? It's been a while...) adds to the head of a list, whereas "cat" is a bit closer to adding to the tail. This is pure speculation on my part.

The dictionary defines it as "link together in a chain or series", but in practice on many UNIX systems it's come to mean simply, 'write to stdout' which unless you get into redirection, is just a user's terminal.

I get that the big metaphor was 'small pieces, loosely joined', but this one has always seemed half-baked to me - e.g, it's often too small to be useful without a bit more effort by you, the person typing things.

Hey, some people do use it to combine files!

I'm not arguing that, but to do what most people think of w.r.t what comes to mind when you talk about cat requires redirection.

From the man page:

The command:

           cat file1

will print the contents of file1 to the standard output.

The command:

           cat file1 file2 > file3

will sequentially print the contents of file1 and file2 to the file file3, truncating file3 if it already exists. See the manual page for your shell (i.e., sh(1)) for more information on redirection.

I'll have you know I had to use cat and tac in the way they were intended a few days ago.

I can't remember for the life of me why, but I was shocked.

Huzzah. You win this round.

To be fair, it's still linking one file together with... uh, nothing.

cat has been (ab)used to output files to a terminal for a long time. BSD 1 has a program cat3a [0] that Bill Joy wrote in 1977(!) to quickly write files to an ADM-3A terminal [1]. If you look at the keyboard it has arrows on the HJKL keys which is where vi got its navigation from. (Also the escape key was next to Q!)

[0] https://github.com/dspinellis/unix-history-repo/blob/BSD-1-S... [1] https://en.wikipedia.org/wiki/ADM-3A

And neither one is “obscure”, by a long shot.

I haven’t heard people use catenate much.

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