I'm using file-notify-add-watch from filenotify.el to watch a dired directory so it can revert when a file is modified within the directory. This generally works, but I've noticed that it only works sometimes when renaming a file. Code is here.

When I watch two directories (~/ and ~/readings, for example) and add a file test.txt to ~/, filenotify catches that and reverts the buffer. When I run mv test.txt readings, the event passed to the filenotify callback contains the sexp '((<desc>) renamed "~/readings/test.txt" "~/readings/test.txt"). When I move it back with mv readings/test.txt . (while in ~/), the event passed to the callback is '((<desc>) renamed "~/test.txt" "~/test.txt"). So it seems to be passing not the previous and the new file, but just two of the new file's path. This could be a bug, but I'm not sure. For easier reading (=> indicates the events passed to the callback within emacs):

$ echo hey > test.txt
=> ((32) created "~/test.txt")
=> ((32) changed "~/test.txt")
$ mv test.txt readings
=> ((34) created "~/readings/test.txt")
$ mv readings/test.txt .
=> ((32) renamed "~/test.txt" "~/test.txt")

I'm pretty sure this is a bug, but I wanted to make sure I wasn't using filenotify incorrectly. Adding the watch, I do:

  (expand-file-name dired-directory)
  '(change attribute-change) #'my-callback)

Which returns 32 and 34, the two descriptors shown in the output above.

Is this a bug? Or is there some element of file-notify-add-watch I'm using incorrectly? I would expect mv <file> <folder> to create a rename notification with both the previous and current version, but it's not doing that. I'm using emacs 25.0.50 on linux with 'inotify as a file notification library.

  • I will check further whether it is an error in filenotify.el, but as first comment: since (a recent git checkout of) Emacs 25.0.50 you could also apply M-x auto-revert-mode on your dired buffer. Sep 4, 2015 at 7:38
  • I didn't know that! I have global-auto-revert-mode turned on; would that do the same thing, or is the local auto-revert-mode required? It doesn't seem to be auto-reverting (which would effectively do everything my code is supposed to do). Sep 4, 2015 at 7:45
  • Huh, it does seem that the local auto-revert-mode is doing exactly that. I wonder why the global version doesn't do the same thing. Sep 4, 2015 at 7:47
  • 1
    See the doc of global-auto-revert-mode: Global Auto Revert mode is a global minor mode that reverts any buffer associated with a file when the file changes on disk. Use auto-revert-mode to revert a particular buffer. A dired buffer is not "associated with a file". Sep 4, 2015 at 8:57
  • Oops, didn't catch that intricacy. If auto-revert-mode works, then I'll just use that instead of watching files manually; this behavior of filenotify is still strange though, I'll see if I can figure out what's happening. Sep 4, 2015 at 9:03

1 Answer 1


There was a problem in renaming of files over directory boundaries. Should be fixed now in filenotify.el. Pls try a recent rebuild of Emacs 25.0.50.

  • Using the method I tried above, the newest build seems to work! I'll just file an actual bug next time; I didn't here cause I wasn't sure if I was using it correctly. Thanks so much. Sep 6, 2015 at 21:43

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