meta key switch

mac-switch-meta.el

;; Keybonds
(global-set-key [(hyper a)] 'mark-whole-buffer)
(global-set-key [(hyper v)] 'yank)
(global-set-key [(hyper c)] 'kill-ring-save)
(global-set-key [(hyper s)] 'save-buffer)
(global-set-key [(hyper l)] 'goto-line)
(global-set-key [(hyper w)]
                (lambda () (interactive) (delete-window)))
(global-set-key [(hyper z)] 'undo)

;; mac switch meta key
(defun mac-switch-meta nil 
  "switch meta between Option and Command"
  (interactive)
  (if (eq mac-option-modifier nil)
      (progn
	(setq mac-option-modifier 'meta)
	(setq mac-command-modifier 'hyper)
	)
    (progn 
      (setq mac-option-modifier nil)
      (setq mac-command-modifier 'meta)
      )
    )
  )

@FeiSun @yyz1989 AFAICT there's no way to fully enable the default command-key behaviors, but you can add the ones you need to the snippet above. For example, (global-set-key [(hyper q)] 'save-buffers-kill-emacs) will make cmd-q quit emacs

Not sure when/what emacs version this was added, but something like this now works:

       ;; Do not have emacs capture right alt/option key and command keys
       (setq ns-right-command-modifier 'none)   ;; original value is 'left'
       (setq ns-right-alternate-modifier 'none) ;; original value is 'left'
       ;;(setq ns-right-option-modifier nil)      ;; alias for ns-right-alternate-modifier

@idcrook I don't know about you, but for my Emacs Mac Port these ns-* commands are still not available. However, for everyone searching to get something like that to work, there exists now a mac-right-{alternate|command}-modifier command!

I am sorry, but how do you use this?
I included the contents of the file in the beginning of this thread in my setup but I still can't have them swapped.
I am on Catalina by the way. I am also using terminal mode (emacs -nw)

@hisnawi This setup does not work for emacs -nw, since it is your terminal emulator(iTerm2, Terminal.app etc) who controls the cmd and option key behavior.