It saves last item in emacs kill ring into clipboard

emacs-copy-clipboard.el

(defun copy-clipboard()
  "Save last item in kill ring to clipboard"
  (interactive)
  (let ((tmp-file (make-temp-file "pbcopy")))
    (with-temp-buffer
      (yank)
      (when (file-writable-p tmp-file)
       (write-region (point-min)
                     (point-max)
                     tmp-file)
       (shell-command (concat "cat " tmp-file " | pbcopy")))
      (message "Selection is saved to clipboard"))))

(global-set-key (kbd "C-c C-c") 'copy-clipboard)