[jshb]

Why does cat need the ability to add line numbers anyway? It seems outside the scope of it's purpose. Next it'll need ability to translate Russian to English.

If I ever needed line numbering, I would output into a file and open it in a far more capable text editor/viewer that was designed for doing that well.

[AlecSchueler]

Indeed - `nl` should be preferable to `cat -n` for that reason even if for no others. People have been actually saying this since at least 1983 (http://harmful.cat-v.org/cat-v/).

I'm often surprised that cat is anywhere near as popular as it is. I think I've used it for actual file concatenation maybe two times in the past three years.