openwith seems to kill replying in mu4e.

Is there a similar/alternative solution for easy defining default apps per extensions in dired?

  • Can you clarify what you mean when you say that "openwith seems to kill replying in mu4e"? I use both and have no problem with them. Does this problem persist if you start Emacs without your init file (emacs -Q)?
    – Dan
    Apr 23, 2016 at 16:54
  • Hi Dan. when i hit 'R' the reply dosent launch and i get this error: error in process filter: Opening input file. any clue?
    – zeltak
    Apr 23, 2016 at 17:25
  • Try (add-to-list 'mm-inhibit-file-name-handlers 'openwith-file-handler) . Sep 8, 2016 at 10:37

4 Answers 4


You might find that dired-launch is of some value. I developed it as a launcher specifically for dired-mode (unlike openwith... which tries to work in a variety of settings). dired-launch provides a keybinding (J) which allows one to launch the default external application corresponding to that file.


On Debian, this is how I do it:

(defun mu-open-in-external-app ()
  "Open the file where point is or the marked files in Dired in external
app. The app is chosen from your OS's preference."
  (let* ((file-list
     (lambda (file-path)
       (let ((process-connection-type nil))
         (start-process "" nil "xdg-open" file-path))) file-list)))

And then I have this:

(define-key dired-mode-map (kbd "C-<return>") #'mu-open-in-external-app)

You can bind RET instead.

(define-key dired-mode-map (kbd "RET") #'mu-open-in-external-app)

Yes, vanilla Dired has help for this, and Dired+ provides some more help.

  1. You can use ! on a file (or marked files) to run a shell program on it. Use M-n to cycle among possible commands. These commands to choose from come from the MIME type of the file (see non-option variable mailcap-mime-data). They can also come from entries that you make in user option dired-guess-shell-alist-user (you will need to load standard library dired-x.el for this).

  2. If you use Emacs on MS Windows and you have both Dired+ and library w32-browser.el (see Ms Shell Execute) then you can use M-RET in Dired to open a file or directory using its Windows file association (i.e., its "open" program).

  • thx Drew! i use linux (arch linux). I have been using ! with the dired-x and it works great but what i really want is to press ENTER and launch the app (im lazy i guess). openwith works great in that sense. best, Z
    – zeltak
    Apr 23, 2016 at 17:34
  • Then bind a key that does that: invokes the app. Usually the question is which app? That's what dired-guess-default is about. It is used by dired-guess-shell-command which is used by via M-n (dired-read-shell-command) from ! (dired-do-shell-command). It just looks through dired-guess-shell-alist-user and dired-guess-shell-alist-default` for a match for your filename, to get the app. If you know the shell command you want for a given file, then do (dired-do-shell-command THE-SHELL-COMMAND current-prefix-arg THE-FILES-TO-ACT-ON) in the Emacs command you bind to a key.
    – Drew
    Apr 23, 2016 at 21:18

I'd like to expand on Manuel Uberti's answer.

I use EWXM, and I don't want to accidentally open another Emacs instance. Before running xdg-open, I first run xdg-mime a couple of times to check whether the application that will open the file is Emacs. If it is, skip the current file.

I'm new to Elisp, and I appreciate suggestions for improvement!

(defun my/open-in-external-app ()
  "Open the file where point is or the marked files in Dired in external
app. The app is chosen from your OS's preference."
  (let ((file-list (dired-get-marked-files))
    (cl-flet ((without-newline (str)
                (substring str 0 (1- (length str)))))
       (lambda (file-path)
         (setq mime-type (without-newline (shell-command-to-string (concat "xdg-mime query filetype " file-path))))
         (setq default-application (without-newline (shell-command-to-string (concat "xdg-mime query default " mime-type))))
         (unless (equal default-application "emacs.desktop")
           (let ((process-connection-type nil))
             (start-process "" nil "xdg-open" file-path)))) file-list))))

One more thing: When I attempted to load the define-key sexp on startup, I got an error about dired-mode-map being unbound. So I wrapped it with with-eval-after-load:

(with-eval-after-load 'dired
  (define-key dired-mode-map (kbd "C-<return>") #'my/open-in-external-app))

EDIT: Instead of with-temp-buffer, the function now uses shell-command-to-string. Also, I changed let to let* at the beginning.

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