on Emacs for OSX, how to keep kill ring and clipboard separate?

Question

In GNU Emacs for OSX, how can I keep the kill ring and OSX clipboard separate? (Such that I essentially have two separate kill rings.)

With desired behavior, this would work:
1. ⌘C to copy text from the web to OSX clipboard.
2. controlk to kill a line in Emacs.
3. controly to yank killed text from Emacs kill ring to current Emacs buffer.
4. ⌘v to paste original web text from OSX clipboard to current Emacs buffer.

This works out of the box in Aquamacs. How to make work in GNU Emacs?

This question was discussed as it pertains to Windows here: Emacs: How to separate the kill ring from the system clipboard?

and here: http://lists.gnu.org/archive/html/help-emacs-windows/2010-02/msg00001.HTML

...but this solution does not work in OSX. I would like a solution for Mac OSX.

Answer 1

The solution in Emacs: How to separate the kill ring from the system clipboard? does work, though not complete. You may call pbcopy yourself to get clipboard pasting right. For instance, try the following in your .emacs. Note that s-v is for Cmd+V in an OS X window system. Same goes for s-c.

;;; Tested on:
;;; 1.  GNU Emacs 24.3.1 (x86_64-apple-darwin13.0.0)
;;;     of 2013-12-22 on tennine-slave.macports.org
;;;     (MacPorts [email protected]_1)
;;;
;;; 2.  GNU Emacs 24.3.1 (x86_64-apple-darwin, NS apple-appkit-1038.36)
;;;     of 2013-03-12 on bob.porkrind.org
;;;     (Emacs For Mac OS X)

(defun isolate-kill-ring()
  "Isolate Emacs kill ring from OS X system pasteboard.
This function is only necessary in window system."
  (interactive)
  (setq interprogram-cut-function nil)
  (setq interprogram-paste-function nil))

(defun pasteboard-copy()
  "Copy region to OS X system pasteboard."
  (interactive)
  (shell-command-on-region
   (region-beginning) (region-end) "pbcopy"))

(defun pasteboard-paste()
  "Paste from OS X system pasteboard via `pbpaste' to point."
  (interactive)
  (shell-command-on-region
   (point) (if mark-active (mark) (point)) "pbpaste" nil t))

(defun pasteboard-cut()
  "Cut region and put on OS X system pasteboard."
  (interactive)
  (pasteboard-copy)
  (delete-region (region-beginning) (region-end)))

(if window-system
    (progn
      (isolate-kill-ring)
      ;; bind CMD+C to pasteboard-copy
      (global-set-key (kbd "s-c") 'pasteboard-copy)
      ;; bind CMD+V to pasteboard-paste
      (global-set-key (kbd "s-v") 'pasteboard-paste)
      ;; bind CMD+X to pasteboard-cut
      (global-set-key (kbd "s-x") 'pasteboard-cut))

  ;; you might also want to assign some keybindings for non-window
  ;; system usage (i.e., in your text terminal, where the
  ;; command->super does not work)
  )

If you ever run into problems with UTF-8, consider the following possible solution:

;; handle emacs utf-8 input
(set-terminal-coding-system 'utf-8)
(set-keyboard-coding-system 'utf-8)
(prefer-coding-system 'utf-8)
(setenv "LANG" "en_US.UTF-8")