I would respectfully disagree here. I can't remember, and won't bother to look up, how to recursively use cp / mv / scp / rsync / whatever else... but I'd bet

I would respectfully disagree here. I can't remember, and won't bother to look up, how to recursively use cp / mv / scp / rsync / whatever else... but I'd bet it's -r, or -R. I'm not positive how to tell a shell program "I REALLY MEAN IT!", but I''d guess it's -f (unless it's kill, and I'm not going to sympathize with gripers over that one odd case :) ). There really is an (admittedly idiomatic, but still present) intuitive nature to these things. There are loads of counterexamples, for sure. But still - say I want to use extended Regexp in grep, or sed. I bet it's "-e" or "-E", right? Plus you can always search the man-page, without bothering to read it all. Reading man-pages does do a lot for you. And in my experience, I don't spend a lot of time while on the same engagement/project/whatever writing shell code across BSD/solaris/GNU-linux/etc. And honestly, if you can write a sophisticated sed substitution for BSD without reading the man page, is there really THAT big of a barrier lying between you and writing the same thing in GNU/Linux, or non-POSIX-compliant sed, or whatever else? You read the man page for 10 seconds and find the flag that means what you want to use. If it's different, you explore. This is totally not a rant at you, and I sincerely hope you don't take it that way - I just haven't found myself utterly foiled by the differences between say, RHEL v SUSE v BSD recently. There are differences, but hell - there are differences between versions of languages, between terminal emulators (scripts that work in bash but not in zsh and vice versa), etc.