emacs snippet for batch reformatting

.emacs

(defun buffer-untabify ()
  "Untabify an entire buffer"
  (interactive)
  (untabify (point-min) (point-max))
  (delete-trailing-whitespace))

(defun buffer-indent()
  "Reindent an entire buffer"
  (interactive)
  (indent-region (point-min) (point-max) nil))

(defun buffer-cleanup()
  "Untabify and re-indent an entire buffer"
  (interactive)
  (if (equal buffer-file-coding-system 'undecided-unix )
      nil
    (set-buffer-file-coding-system 'undecided-unix))
  (buffer-untabify)
  (buffer-indent)
  (delete-trailing-whitespace))