my-mac-key-mode.el

(defun do-applescript+ (&rest scripts)
  "Like `do-applescript', but execute concatenated SCRIPTS.
In case the execution fails, return an error."
  (condition-case err
      (do-applescript
       (apply 'concat scripts))
    (error err)))

(defun show-in-finder (&optional path behind)
  "Display current file/directory in a Finder window"
  (interactive)
  (let ((item (or path
                  buffer-file-name
                  (and (eq major-mode 'dired-mode) default-directory))))
    (cond
     ((not (stringp item)))
     ((file-remote-p item)
      (error "This item is located on a remote system."))
     (t
      (setq item (expand-file-name item))
      (do-applescript+
       "tell application \"Finder\" to select (\""
       item
       "\" as POSIX file)\n"
       (unless behind
         "tell application \"Finder\" to activate"))))))

(defun open-terminal (&optional path behind)
  "Launch Terminal and go to the relevant directory"
  (interactive)
  (let ((item (or path default-directory)))
    (cond
     ((not (stringp item)))
     ((file-remote-p item)
      (error "This item is located on a remote system."))
     ((file-directory-p item)
      (setq item (expand-file-name item))
      (do-applescript+
       "tell application \"Terminal\" to do script "
       "with command \"cd \" & quoted form of \""
       item
       "\"\n"
       (unless behind
         "tell application \"Terminal\" to activate")))
     (t
      (error "An error occured")))))