Emacs: what is the shortcut key to clear buffer?

Question

Like, Control-A (select all) followed by delete?

Answer 1

Old folks might like to call it hk rather than clear-buffer-permanently, and assign it to the nostalgic key sequence like so:

(define-key esc-map "\^[hk" 'hk)

That's the pre-Gnu TECO EMACS command to clear the buffer (ESC ESC wHole Kill).