interactive and non-interactive use should diverge as little as possible. Personal, I like it, when a program directs me to its help-command, when I give it a

interactive and non-interactive use should diverge as little as possible. Personal, I like it, when a program directs me to its help-command, when I give it a bad option, like > openssl blabla Invalid command 'blabla'; type "help" for a list.