 ; DDD - swap attribute values: "" to "..." & vice versa.
 ; Copyright 1994 by Rocket Software
 ; One of the routines Captain Nemo used to design the Nautilus.

 (DEFUN DDD (enam / entt)
  (while (/= (cdr (assoc 0 (setq entt (entget (setq enam (entnext enam))))))
                                                                      "SEQEND")
         (cond ((or (= (cdr (assoc 1 entt)) "")
                    (= (cdr (assoc 1 entt)) " "))
                (entmod (subst (cons 1 "...") (assoc 1 entt) entt)))
               ((= (cdr (assoc 1 entt)) "...")
                (entmod (subst (cons 1 "") (assoc 1 entt) entt)))))
  (entupd enam)
 (princ))

 (DEFUN C:DDD (/ ss enam)
  (setq ss (ssget (list (cons 0 "insert"))))
  (setq num 0)
  (while (setq enam (ssname ss num))
         (setq num (1+ num))
         (ddd enam))
 (princ))