How to copy text from Emacs to another application on Linux

Insert the following into your .emacs file:

(setq x-select-enable-clipboard t)

I stick this in my .emacs:

(setq x-select-enable-clipboard t)
(setq interprogram-paste-function 'x-cut-buffer-or-selection-value)

I subsequently have basically no problems cutting and pasting back and forth from anything in Emacs to any other X11 or Gnome application.

Bonus: to get these things to happen in Emacs without having to reload your whole .emacs, do C-x C-e with the cursor just after the close paren of each of those expressions in the .emacs buffer.

Good luck!

Let's be careful with our definitions here

• An Emacs copy is the command kill-ring-save (usually bound to M-w).
• A system copy is what you typically get from pressing C-c (or choosing "Edit->Copy" in a application window).
• An X copy is "physically" highlighting text with the mouse cursor.
• An Emacs paste is the command yank (usually bound to C-y).
• A system paste is what you typically get from pressing C-v (or choosing "Edit-Paste" in an application window).
• An X paste is pressing the "center mouse button" (simulated by pressing the left and right mouse buttons together).

In my case (on GNOME):

• Both Emacs and system copy usually work with X paste.
• X copy usually works with Emacs paste.

• To make system copy work with Emacs paste and Emacs copy work with system paste, you need to add (setq x-select-enable-clipboard t) to your .emacs. Or try

  META-X set-variable RET x-select-enable-clipboard RET t
  

I think this is pretty standard modern Unix behavior.

It's also important to note (though you say you're using Emacs in a separate window) that when Emacs is running in a console, it is completely divorced from the system and X clipboards: cut and paste in that case is mediated by the terminal. For example, "Edit->Paste" in your terminal window should act exactly as if you typed the text from the clipboard into the Emacs buffer.

The difficulty with copy and paste in Emacs is that you want it to work independently from the internal kill/yank, and you want it to work both in terminal and the gui. There are existing robust solutions for either terminal or gui, but not both. After installing xsel (e.g. sudo apt-get install xsel), here is what I do for copy and paste to combine them:

(defun copy-to-clipboard ()
  (interactive)
  (if (display-graphic-p)
      (progn
        (message "Yanked region to x-clipboard!")
        (call-interactively 'clipboard-kill-ring-save)
        )
    (if (region-active-p)
        (progn
          (shell-command-on-region (region-beginning) (region-end) "xsel -i -b")
          (message "Yanked region to clipboard!")
          (deactivate-mark))
      (message "No region active; can't yank to clipboard!")))
  )

(defun paste-from-clipboard ()
  (interactive)
  (if (display-graphic-p)
      (progn
        (clipboard-yank)
        (message "graphics active")
        )
    (insert (shell-command-to-string "xsel -o -b"))
    )
  )

(global-set-key [f8] 'copy-to-clipboard)
(global-set-key [f9] 'paste-from-clipboard)