Is there a cross platform way of accessing the GUI clipboard from emacs lisp?

Question

I run emacs with a common configuration on osx and linux. I have some custom functions that need to get access to the GUI clipboard. I find interacting with the clipboard a bit of pain - so I've resorted to things like

 (shell-command-to-string "pbpaste || xclip -o")

before.

Is there a correct way of doing this (i.e. a single function that intends to work across all GUIs which someone else maintains?).

This came up again in the context of working on a script that might in theory become a library that is shared with other people - so I would prefer not to use hacks in it (though I am currently putting a hack into it).

Answer 1

If configured correctly emacs will access the gui clipboard when you run (yank) and update the kill-ring. This is triggered by (current-kill 0) which you can use to get at the clipboard.

(defun show-clipboard ()
    (message (current-kill 0)))

Though not that current-kill adds an entry to the kill-ring.

Having a look at the documentation for current-kill

Rotate the yanking point by N places, and then return that kill.
If N is zero and `interprogram-paste-function' is set to a
function that returns a string or a list of strings, and if that
function doesn't return nil, then that string (or list) is added
to the front of the kill ring and the string (or first string in
the list) is returned as the latest kill.

On my machine interprogram-paste-function contains gui-selection-value... however if you call gui-selection-value twice it returns nil the section time, so I think current-kill shoud be used instead).