;;作者：John Uhden
;;功能：图块重命名
;;参数：old:旧图块名称；new:重命名后的名称
;;返回：重新命名后的图块

(defun renameblock (old new / ent)
  (and
    (= (type old)(type new) 'STR)
    (/= new old)
    (snvalid new 0)
    (setq ent (tblobjname "block" old))
    (or
      ;; allow changing case of block name
      (= (strcase old)(strcase new))
      (not (tblobjname "block" new))
    )
    ;; then get the block record...
    (setq ent (cdr (assoc 330 (entget ent))))
    (setq ent (entget ent))
    (entmod (subst (cons 2 new)(assoc 2 ent) ent))
  )
)