Re: How to implement line sorting, uniquifying and counting function in emacs?

[Evgeny Roubinchtein <zhenya@freeshell.org>]

Oops... Just noticed I didn't really need to insert a dummy newline
when using a temp buffer.

(defun count-repeated-lines (&optional beg end)
  (let ((buf (current-buffer))
	(repeated-count 0)
	(unique-count 0)
	(cur-line nil)
	(prev-line nil))
    (with-temp-buffer
      (insert-buffer-substring buf 
			       (and beg 
				    (with-current-buffer buf
				      (save-excursion
					(goto-char beg)
					(line-beginning-position))))  
			       end)
      (sort-lines nil (point-min) (point-max))
      (goto-char (point-min))
      (while (/= (point) (point-max))
	(setq cur-line (buffer-substring-no-properties (point) 
						       (save-excursion (end-of-line) 
								       (point))))
	(if (and prev-line (string= prev-line cur-line))
	    (setq repeated-count (1+ repeated-count))
	  (setq unique-count (1+ unique-count)))
	(setq prev-line cur-line)
	(forward-line))
      (cons unique-count repeated-count))))