Emacs可以跟踪像BBEdit这样的文件吗？

Question

引用Sublime Text的功能请求:

BBEdit在OS X上具有此功能:
- 在BBEdit中,打开"myfile.txt"
- 在Finder中,将"myfile.txt"重命名为"myfile2.txt"
- 现在,在BBEdit中,文档显示为"myfile2.txt" ,并保存文件更新"myfile2.txt"

这比ST2用例好得多:
- 在Sublime Text 2中,打开"myfile.txt"
- 在Finder中,将"myfile.txt"重命名为"myfile2.txt"
- 现在,将文档保存在ST2中会以静默方式创建重复文件"myfile.txt".这导致我的工作区中同一文件的两个略有不同的版本,导致后来的麻烦.

与Sublime Text一样,Emacs也会发生类似的事情.所以,我很想找到一种方法让Emacs做BBEdit正在做的事情.

我搜索了谷歌,但我真的不确定在这里搜索什么.这是否有特定的艺术术语？无论哪种方式,我都没有发现任何兴趣.

有没有现成的方法呢？还是会变得相当复杂？这篇文章说"书签"功能NSURL就是这里使用的.

Answer 1

来自NEWS最新的emacs trunk文件(未发布)

(require 'filenotify)
(require 'cl-lib)

(defvar my-file-to-fd-hash (make-hash-table))

(defun my-file-notify-add-rename-watch (&optional file)
  (let ((file-name (or file buffer-file-name)))
    (when file-name
      (puthash file-name
               (file-notify-add-watch file-name
                          '(change)
                          'my-handle-file-change)
               my-file-to-fd-hash))))

(defun my-file-notify-rm-rename-watch (&optional file)
  (let* ((file-name (or file
                buffer-file-name))
         (fd (gethash file-name my-file-to-fd-hash)))
    ;; Stop watching the file
    (when fd
      (file-notify-rm-watch fd)
      (remhash file-name my-file-to-fd-hash))))

(add-to-list 'find-file-hook 'my-file-notify-add-rename-watch)
(add-to-list 'kill-buffer-hook 'my-file-notify-rm-rename-watch)

(defun my-handle-file-change (event)
  (let* ((fd (cl-first event))
         (action (cl-second event))
         (file (cl-third event))
         (renamed-to (cl-fourth event))
         (visiting-buffer (get-file-buffer file)))
    ;; Ignore events other than `rename` and also the `rename` events
    ;; generated due to emacs backing up file
    (when (and (eq action 'renamed)
           (not (backup-file-name-p renamed-to)))
      (message (format "File %s was renamed" file))

      ;; If file is not open ignore the notification
      (when visiting-buffer
        (with-current-buffer visiting-buffer
          (set-visited-file-name renamed-to))
        (my-file-notify-rm-rename-watch file)
        (my-file-notify-add-rename-watch renamed-to)))))

因此,对于GNU/Linux和Windows用户来说,您要求的功能很可能,但是在OS X上生成的文件通知似乎没有(在Emacs中)支持.

下面的代码应该做你想要的(虽然它没有经过彻底的测试),它需要最新的(未发布的)emacs

(require 'filenotify)
(require 'cl-lib)

(defvar my-file-to-fd-hash (make-hash-table))

(defun my-file-notify-add-rename-watch (&optional file)
  (let ((file-name (or file buffer-file-name)))
    (when file-name
      (puthash file-name
               (file-notify-add-watch file-name
                          '(change)
                          'my-handle-file-change)
               my-file-to-fd-hash))))

(defun my-file-notify-rm-rename-watch (&optional file)
  (let* ((file-name (or file
                buffer-file-name))
         (fd (gethash file-name my-file-to-fd-hash)))
    ;; Stop watching the file
    (when fd
      (file-notify-rm-watch fd)
      (remhash file-name my-file-to-fd-hash))))

(add-to-list 'find-file-hook 'my-file-notify-add-rename-watch)
(add-to-list 'kill-buffer-hook 'my-file-notify-rm-rename-watch)

(defun my-handle-file-change (event)
  (let* ((fd (cl-first event))
         (action (cl-second event))
         (file (cl-third event))
         (renamed-to (cl-fourth event))
         (visiting-buffer (get-file-buffer file)))
    ;; Ignore events other than `rename` and also the `rename` events
    ;; generated due to emacs backing up file
    (when (and (eq action 'renamed)
           (not (backup-file-name-p renamed-to)))
      (message (format "File %s was renamed" file))

      ;; If file is not open ignore the notification
      (when visiting-buffer
        (with-current-buffer visiting-buffer
          (set-visited-file-name renamed-to))
        (my-file-notify-rm-rename-watch file)
        (my-file-notify-add-rename-watch renamed-to)))))