;;      UDB.LSP
;;      a routine to update a block by picking it

;;=======================================================

(defun C:UDB ( / _FLAG ss1 ent ent_typ blk_nm blk_pth)
 (setq _FLAG T)
 (while _FLAG
  (prompt "\n  Select BLOCK to update:  ")
  (setq ss1 (ssget))
  (cond
   ((= ss1 nil) (prompt "\nNothing selected, try again."))
   ((> (sslength ss1) 1) (prompt "\nPlease pick only one entity, try again."))
   ((= (sslength ss1) 1)
    (progn
     (setq ent (entget (ssname ss1 0)))
     (setq ent_typ (cdr (assoc 0 ent)))
     (if
      (= ent_typ "INSERT")
      (setq _FLAG nil)
      (prompt "\nEntity selected is not a BLOCK, try again.") 
     );if
    );progn
   );cond test #4
  );cond
 );while
 (setq blk_nm (strcat (cdr (assoc 2 ent)) ".DWG"))
 (setq blk_pth (findfile blk_nm))
 (if
  (= blk_pth nil)
  (prompt "\n  Program could not find a .DWG file for the block you picked.")
  (progn
   (setvar "CMDECHO" 0)
   (setq blk_nm (strcat (cdr (assoc 2 ent)) "="))
   (command "INSERT" blk_nm)
   (command)
   
  );progn
 );if
 (princ)
);defun