Sort lines by length

line-length-sort.el

(defun sort-lines-by-length (b e)
  (interactive "r")
  (save-excursion
    (save-restriction
      (narrow-to-region b e)
      (let ((items (sort 
		    (split-string 
		     (buffer-substring (point-min) (point-max)) "[\n]")
		    (lambda(x y) (< (length x) (length y)))))
	    )
	(delete-region (point-min) (point-max))
	(save-excursion
	  (point-min)
	  (insert (apply 'concat (map 'list (lambda (x) (format "%s\n" x)) items))))))))