Copy/paste with system clipboard, support Chinese or other unicode.

osx_copy_paste_with_chinese.el

(defun copy-from-osx ()
  (shell-command-to-string "pbpaste"))

(defun paste-to-osx (text &optional push)
  (let ((process-connection-type nil)
        (lang (getenv "LANG"))
        (default-directory "~"))
    (setenv "LANG" "en_US.UTF-8")
    (let ((proc (start-process "pbcopy" "*Messages*" "pbcopy")))
      (process-send-string proc text)
      (process-send-eof proc))
    (setenv "LANG" lang)))

(setq interprogram-cut-function 'paste-to-osx)
(setq interprogram-paste-function 'copy-from-osx)