dired-buffer-stale-p

dired-buffer-stale-p is a compiled Lisp function in `dired.el'.

(dired-buffer-stale-p &optional NOCONFIRM)

Return non-nil if current Dired buffer needs updating.
If NOCONFIRM is non-nil, then this function always returns nil
for a remote directory. This feature is used by Auto Revert mode.