Emacs - 在外部修改文件时通知

Question

如何让emacs通知我一个或多个访问过的文件是从其他地方更改的？以下是Gedit中如何实现此功能:

我已经看过EmacsWiki 的"Revert Buffer"文档中解释的方法,并找到了一种解决方法(根据个人喜好进行了一些修改):

(global-set-key (kbd "<f5>") (lambda ()
  (interactive)
  (if (string= (buffer-name) ecb-directories-buffer-name)
    (refresh-ecb)
    (if (buffer-modified-p)
      (revert-buffer) ; ask for confirmation
      (revert-buffer t t))))) ; don't ask for confirmation - it's unnecessary, since the buffer hasn't been modified

这很好,但我想要的是拥有一个自动解决方案.也许,在缓冲区内嵌一些嘈杂的消息(如截图中所示).也许,即使是在Visual Studio中实现的模态对话框(这很烦人,但它毕竟是诀窍).你的建议是什么？

Answer 1

这就是我能想到的 - 非常感谢来自 EmacsWiki 的人提供的提示。我创建了一个每隔几秒触发一次的回调 - 它检查修改时间并在文件被修改时显示一条恼人的消息。

从好的方面来说，该解决方案基本上可以工作并通知我有关更改的信息，无论缓冲区是否被修改。不利的一面是，它涉及不断轮询当前文件的修改时间，但我的工作场景可以容忍这一点。

;(global-auto-revert-mode 1)
(defun ask-user-about-supersession-threat (fn) "blatantly ignore files that changed on disk")
(run-with-timer 0 2 'my-check-external-modifications)
(add-hook 'after-save-hook 'my-check-external-modifications)
(add-hook 'after-revert-hook 'my-check-external-modifications)

(defun my-load-external-modifications ()
  (interactive)
  (if (string= (buffer-name) ecb-directories-buffer-name)
    (refresh-ecb)
    (if (buffer-modified-p)
      (revert-buffer) ; ask for confirmation
      (revert-buffer t t)) ; don't ask for confirmation - it's unnecessary, since the buffer hasn't been modified
    (my-check-external-modifications))) 

(defun my-overwrite-external-modifications ()
  (interactive)
  (clear-visited-file-modtime)
  (set-buffer-modified-p (current-buffer))
  (save-buffer)
  (my-check-external-modifications))

(defun my-check-external-modifications ()
  (if (verify-visited-file-modtime (current-buffer))
    (progn
      (global-set-key (kbd "<f5>") 'my-load-external-modifications)
      (global-set-key (kbd "C-s") 'save-buffer)
      (setq header-line-format tabbar-header-line-format))
    (progn
      (global-set-key (kbd "<f5>") 'my-load-external-modifications)
      (global-set-key (kbd "C-s") 'my-overwrite-external-modifications)
      (setq header-line-format (format "%s. Press F5 to load external changes, C-s to overwrite them"
        (propertize "This file has been changed externally" 'face '(:foreground "#f00")))))))