In POSIX -R is the recursion flag for ls, cp, rm, etc. So if you want to recurse, -R is probably a safer bet than -r. (ls -r just lists in reverse.)

Yeah, that may be it.. I'm wondering why they didn't just add a new option (aka --no-symlinks) or something

Annoying exception: scp only accepts -r as recursion flag, not -R.

Same here. I've been conditioned to use -R

Good point. Also, since you reminded me, chmod, chown, chgrp.

that's probably it

ever work on a non-gnu box? (old solaris, *bsd, stock os x, etc.) there's a decent chance they don't have -r at all.

*BSDs have (=> OS X probably too).

Solaris, HP-UX and OpenServer have not.

AIX is weird:

> -r Searches directories recursively. By default, links to directories are followed.

> -R Searches directories recursively. By default, links to directories are not followed.

Isn't the AIX behavior the one POSIX specifies?

Looking at MattJ100's link (http://pubs.opengroup.org/onlinepubs/009695399/utilities/gre...), it seems like POSIX grep actually does not have any recursion.

Hence, only lubutu's comment ("-R is the recursion flag for ls, cp, rm, etc") is true, while _delirium ("-R is the POSIX-standard flag for recursive grep") is wrong, which means AIX is free to do whatever it wants with both the -r and the -R flags.

That would be kind of perverse given how cp behaves for -r and -R