When emacs locks up

Question

Is there any keystroke combination that shuts down a process in emacs? Occasionally I make a newbie mistake at the Common Lisp REPL and my Emacs locks up. On Mac I just force-quit because I can't find a way to get control of Emacs back. But I'd prefer not close Emacs if I can avoid it.

Answer 1

1. Try C-g (keyboard-quit). Try repeating it multiple times.

2. Try C-] (abort-recursive-edit). Try repeating it multiple times.

3. Try ESC ESC ESC (keyboard-escape-quit). Try repeating it multiple times.

4. Give up and kill the process.