;; Make dired open certain file types externally when pressing RET on a file.
(defvar unsupported-mime-types
  '("application/pdf"
    "image/png"
	"image/jpeg"
	"image/x-xcf"))

(load "subr-x")

(defun get-mimetype (filepath)
  (string-trim
   (shell-command-to-string (concat "file -b --mime-type " filepath))))

(defun dired-find-file-dwim ()
  (interactive)
  (let ((file (dired-get-filename nil t)))
    (if (member (get-mimetype file) unsupported-mime-types)
      (call-process "xdg-open" nil 0 nil file)
      (find-file file))))

(with-eval-after-load 'dired
  (define-key dired-mode-map (kbd "RET") #'dired-find-file-dwim))