Make emacs explicitly copy to/from the X11 selection and clipboard buffers?

Question

In vim you can explicitly copy/paste to/from the X11 selection buffer and clipboard buffer by using "*y and "+y, respectively.

My emacs is (apparently -- it's not intentional on my part) set up to use the selection buffer for C-w, C-y, and friends.

Are there functions that I can call, analogous to kill-region and yank which use the clipboard buffer?

To be clear, I want selective access to both buffers at the same time. Based on some quick web searches, it looks like there are configuration variables I can set which will globally change yank to use one buffer or the other. I want to be able to select, just like vim's * and + registers allow.

(Hopefully I've gotten the terminology right: when I say "selection buffer", I mean the buffer where you can highlight text with the mouse and middle-click to paste. When I say "clipboard buffer", I mean the place where text goes when copied by ctrl-c in non-emacs apps.)

Edit: bzg's answer is really close.

In gnome-terminal, I select ~/projects with the mouse, then right-mouse -> copy. Then I select /home. Still in gnome-terminal, when I do:

• middle-mouse: /home
• right-mouse -> paste: ~/projects

When I move into emacs and do:

• middle-mouse: /home
• M-y (yank): /home
• C-S-y (my-yank): ~/projects

Great! yank uses the selection buffer and my-yank uses the clipboard.

Now, still in emacs, I do:

• C-SPC M-f M-f C-w (make region "regular kill", and kill it)

then go to gnome-terminal and do:

• middle-mouse: "regular kill"
• right-mouse -> paste: ~/projects

Great! Only the selection buffer was changed, not the clipboard.

Then, back in emacs, I do:

• C-SPC M-f M-f C-S-w (make region "my kill", and kill it)

then go to gnome-terminal and do:

• middle-mouse: regular kill
• right-mouse -> paste: ~/projects

That's wrong, the clipboard buffer should contain "my kill".

My interprogram-cut-function is x-select-text. My x-select-enable-clipboard is nil.

Answer 1

This code will map C-S-y and C-S-w to customized versions of yank and kill-region that will temporarily toggle the use of clipboard:

(defun my-yank (&optional arg)
  (interactive "*P")
  (let ((x-select-enable-clipboard (not x-select-enable-clipboard)))
    (yank arg)))

(defun my-kill-region (beg end)
  (interactive "r")
  (let ((interprogram-cut-function
     (when (not (eq interprogram-cut-function 'x-select-text))
       'x-select-text)))
    (kill-region beg end)))

(define-key global-map (kbd "C-S-w") 'my-kill-region)
(define-key global-map (kbd "C-S-y") 'my-yank)

So if you copied something in X and don't want it when yanking in Emacs, use C-S-y. If you kill something in Emacs and don't want it in the X clipboard, use C-S-w.

All this assuming you are using the default values for x-select-enable-clipboard' andinterprogram-cut-function', of course.

Answer 2

bzg's answer comes really close, but the toggling of interprogram-cut-function doesn't quite do the trick -- I believe it ends up nil because that variable has a value when the function starts.

This revised set of functions does exactly what I want, by explicitly setting the clipboard/primary enables in each one. Big hat tip to bzg for getting me on the right track!

(defun my-yank (&optional arg)
  "Yank from the clipboard, not the primary selection."
  (interactive "*P")
  (let ((x-select-enable-clipboard t)
        (x-select-enable-primary nil))
    (yank arg)))

(defun my-kill-region (beg end)
  "Kill to the clipboard, not the primary selection."
  (interactive "r")
  (let ((x-select-enable-clipboard t)
        (x-select-enable-primary nil))
    (kill-region beg end)))

(defun my-kill-ring-save (beg end)
  "Save to the clipboard, not the primary selection."
  (interactive "r")
  (let ((x-select-enable-clipboard t)
        (x-select-enable-primary nil))
    (kill-ring-save beg end)))

(define-key global-map (kbd "C-S-w") 'my-kill-region)
(define-key global-map (kbd "C-M-S-w") 'my-kill-ring-save)
(define-key global-map (kbd "C-S-y") 'my-yank)

Answer 3

Emacs provides some useful functions in menu-bar.el, of all places. So I have:

 (global-set-key [(control shift ?w)] 'clipboard-kill-ring-save)
 (global-set-key [(control shift ?y)] 'clipboard-yank)