Honestly a surprisingly dogshit aspect of a lot of CLI software is lack of good feedback. Imo any invocation of any app should print something to stdout or stderr if only just to make sure the user knows something just happened, even in non-verbose mode. If a user really wants to not know what's going on they can redirect them both to /dev/null but I think it's insane that by default if I permanently delete a file it just sorta happens with no feedback at all.
Obligatory: Ed, man! !man ed
Let's look at a typical novice's session with the mighty ed:
golem$ ed ? help ? ? ? quit ? exit ? bye ? hello? ? eat flaming death ? ^C ? ^C ? ^D ?Note the consistent user interface and error reportage. Ed is generous enough to flag errors, yet prudent enough not to overwhelm the novice with verbosity.