cad怎么算各线段长度总和

(defun c:ZC ()
(setvar "cmdecho" 0)
(prompt"统计总长")(terpri)
(setq en (ssget '((0 . "ARC,ELLIPSE,CIRCLE,*LINE"))))
(setq i 0)
(setq ll 0)
(repeat (sslength en)
(setq ss (ssname en i))
(setq endata (entget ss))
(command "lengthen" ss "")
(setq dd (getvar "perimeter"))
(setq ll (+ dd ll))
(setq i (1+ i))
)
(princ "\n 所选线条总长为:")(princ ll)
(setq p1 (getpoint "\n 文字标注点:"))
(command "layer" "m" "6文字层" "c" 3 "6文字层" "l" "continuous" "6文字层" "");6文字层
(command "text" "m" p1 60 0 "总长mm")
(command "text" "m" (polar p1 (* 1.5 pi) 65) 60 0 (rtos LL 2 2))
(princ)
)

我有CAD里计算线段长度总和的插件