Emacs Dired: Opening Files in External Apps

Xah Lee, 2012-01-10, …, 2012-04-10

Here's a simple elisp code that opens the current file or marked dired files in external app.

(defun open-in-external-app ()
  "Open the current file or dired marked files in external app.
Works in Microsoft Windows, Mac OS X, Linux."
  (interactive)
  (let ( doIt
         (myFileList
          (cond
           ((string-equal major-mode "dired-mode") (dired-get-marked-files))
           (t (list (buffer-file-name))) ) ) )

    (setq doIt (if (<= (length myFileList) 5)
                   t
                 (y-or-n-p "Open more than 5 files?") ) )
    
    (when doIt
      (cond
       ((string-equal system-type "windows-nt")
        (mapc (lambda (fPath) (w32-shell-execute "open" (replace-regexp-in-string "/" "\\" fPath t t)) ) myFileList)
        )
       ((string-equal system-type "darwin")
        (mapc (lambda (fPath) (let ((process-connection-type nil)) (start-process "" nil "open" fPath)) )  myFileList) )
       ((string-equal system-type "gnu/linux")
        (mapc (lambda (fPath) (let ((process-connection-type nil)) (start-process "" nil "xdg-open" fPath)) ) myFileList) ) ) ) ) )

You can give it a hotkey, see: Emacs: How to Define Keyboard Shortcuts.