How do I rename an open file in Emacs?

Question

Yes, with dired mode, you can:

• C-x d to open dired
• RET to select directory of current file
• C-x C-j (dired-jump to the name of the current file, in Dired)
• R to rename the file (or dired-do-rename).
• q to go back to the (renamed) file buffer

The rename is equivalent to a shell mv, but it will also update any open buffers, and unlike mv it will not change the access and modify times on the file in the filesystem.

Just for completeness, since some folks may visit this page thinking they will get an answer for the "save as" feature of Emacs, that's C-x C-w for an open file.

Try this function from Steve Yegge's .emacs:

;; source: http://steve.yegge.googlepages.com/my-dot-emacs-file
(defun rename-file-and-buffer (new-name)
  "Renames both current buffer and file it's visiting to NEW-NAME."
  (interactive "sNew name: ")
  (let ((name (buffer-name))
        (filename (buffer-file-name)))
    (if (not filename)
        (message "Buffer '%s' is not visiting a file!" name)
      (if (get-buffer new-name)
          (message "A buffer named '%s' already exists!" new-name)
        (progn
          (rename-file filename new-name 1)
          (rename-buffer new-name)
          (set-visited-file-name new-name)
          (set-buffer-modified-p nil))))))

Take a look at that page, there's another really useful related function there, called "move-buffer-file".

My favorite is the one from Magnars (of emacs rocks screencasts fame.)

Unlike the other alternatives, you don't have to type the name out from scratch - you get the current name to modify.

(defun rename-current-buffer-file ()
  "Renames current buffer and file it is visiting."
  (interactive)
  (let* ((name (buffer-name))
        (filename (buffer-file-name))
        (basename (file-name-nondirectory filename)))
    (if (not (and filename (file-exists-p filename)))
        (error "Buffer '%s' is not visiting a file!" name)
      (let ((new-name (read-file-name "New name: " (file-name-directory filename) basename nil basename)))
        (if (get-buffer new-name)
            (error "A buffer named '%s' already exists!" new-name)
          (rename-file filename new-name 1)
          (rename-buffer new-name)
          (set-visited-file-name new-name)
          (set-buffer-modified-p nil)
          (message "File '%s' successfully renamed to '%s'"
                   name (file-name-nondirectory new-name)))))))

Thanks to James Yang for a correct version.

Here's a more robust version adapted from stevey.

;; Originally from stevey, adapted to support moving to a new directory.
(defun rename-file-and-buffer (new-name)
  "Renames both current buffer and file it's visiting to NEW-NAME."
  (interactive
   (progn
     (if (not (buffer-file-name))
         (error "Buffer '%s' is not visiting a file!" (buffer-name)))
     ;; Disable ido auto merge since it too frequently jumps back to the original
     ;; file name if you pause while typing. Reenable with C-z C-z in the prompt.
     (let ((ido-auto-merge-work-directories-length -1))
       (list (read-file-name (format "Rename %s to: " (file-name-nondirectory
                                                       (buffer-file-name))))))))
  (if (equal new-name "")
      (error "Aborted rename"))
  (setq new-name (if (file-directory-p new-name)
                     (expand-file-name (file-name-nondirectory
                                        (buffer-file-name))
                                       new-name)
                   (expand-file-name new-name)))
  ;; Only rename if the file was saved before. Update the
  ;; buffer name and visited file in all cases.
  (if (file-exists-p (buffer-file-name))
      (rename-file (buffer-file-name) new-name 1))
  (let ((was-modified (buffer-modified-p)))
    ;; This also renames the buffer, and works with uniquify
    (set-visited-file-name new-name)
    (if was-modified
        (save-buffer)
      ;; Clear buffer-modified flag caused by set-visited-file-name
      (set-buffer-modified-p nil)))

  (setq default-directory (file-name-directory new-name))

  (message "Renamed to %s." new-name))

Here's another version, that's pretty robust and VC aware:

(defun rename-file-and-buffer ()
  "Rename the current buffer and file it is visiting."
  (interactive)
  (let ((filename (buffer-file-name)))
    (if (not (and filename (file-exists-p filename)))
        (message "Buffer is not visiting a file!")
      (let ((new-name (read-file-name "New name: " filename)))
        (cond
         ((vc-backend filename) (vc-rename-file filename new-name))
         (t
          (rename-file filename new-name t)
          (set-visited-file-name new-name t t)))))))

You can read more about it here.

If you're using Spacemacs then you get this behavior for free since it comes with an implementation of rename-current-buffer-file (based on magnars) that by default bound to SPC-f-R.

https://github.com/syl20bnr/spacemacs/blob/bd7ef98e4c35fd87538dd2a81356cc83f5fd02f3/layers/%2Bdistributions/spacemacs-base/funcs.el#L294