                    (re-search-backward "\\(^[0-9.,]+[A-Za-z]+\\).*total$")
                    (match-string 1))))))
 
+  (require 'cl-lib)
+
   (defun ar/dired-convert-audio-to-mp3 (&optional arg)
     "Convert audio file to mp3."
     (interactive "P")
-    (assert (executable-find "convert") nil "Install ffmpeg")
+    (cl-assert (executable-find "convert") nil "Install ffmpeg")
     (mapc
      (lambda (fpath)
        (let* ((src-fpath fpath)

            (kill-buffer (process-buffer process)))))
       (dired-map-over-marks (dired-get-filename) arg))))

  (defun ar/dired-create-icns-iconset (&optional arg)
    "Convert image ios icns and iconset (needs 1024x1024)."
    (interactive "P")
    (assert (executable-find "sips") nil "sips not installed")
    (mapc
     (lambda (fpath)
       (let* ((src-fpath fpath)

  (defun ar/dired-convert-image (&optional arg)
    "Convert image files to other formats."
    (interactive "P")
    (cl-assert (or (executable-find "convert") (executable-find "magick.exe")) nil "Install imagemagick")
    (let* ((dst-fpath)
           (src-fpath)
           (src-ext)
