Mac – How to clear the screen when using shell mode in emacs

M-p does the job

Emacs shell-mode buffers are not terminals (i.e., they do not use ptys (pseudo-terminals)), so no program running in such a buffer (the shell, the programs run by the shell, etc.) can perform character-at-a-time input. Each line is typed in full and only sent when ENTER is pressed. To see proof, run the tty command in a shell-mode buffer, and it's output will be not a tty.