Question

For example: I have a file longest_substring_no_repeating_chars.cc. One day I want to rename it to longest_substr_no_repeating_chars.cc. How do I do it by editing the old name? Or is there any convenient way to do it?

Answer 1

Assuming you want to rename the file you’re currently editing you can define a function like this one:

(defun rename-file-and-buffer ()
  "Renames current buffer and file it is visiting."
  (interactive)
  (let ((name (buffer-name))
        (filename (buffer-file-name)))
    (if (not (and filename (file-exists-p filename)))
        (message "Buffer '%s' is not visiting a file!" name)
      (let ((new-name (read-file-name "New name: " filename)))
        (cond ((get-buffer new-name)
               (message "A buffer named '%s' already exists!" new-name))
              (t
               (rename-file name new-name 1)
               (rename-buffer new-name)
               (set-visited-file-name new-name)
               (set-buffer-modified-p nil)))))))

And the you can bind it to a key combo like C-c r

(global-set-key (kbd "C-c r") 'rename-file-and-buffer)

Otherwise, @Oleg’s suggestion to use dired is a great option.