Filtering out objects in ssget

hey guys!

So i'm trying to build a lisp that will prompt the user to select some objects, filter out which ones are polylines and resize the width of the polylines.

I am able to get it to iterate through the selection but I am having a hard time with getting it to filter out polylines.

Any and all help is appreciated!

(I have ;;; where my attempt was to figure it out on my own)

(defun c:test (/)

 (setq a (ssget))

 (setq counter 0)

 ;;;(setq b (ssname a counter))

 (while (< counter (sslength a))

   ;;;add of object is not a polyline, skip

 ;;;(setq blist (entget b))

 ;;;(setq bname (cdr(assoc 0 (ssname b counter))))

 ;;;(if (= (cdr(assoc 0 (b))) "POLYLINE")

   ;;;(progn

 (command "pedit" (ssname a counter) "width" 1 "")

 (setq counter (+ counter 1))

   ;;;;end progn
   
   ;;;(setq counter (+ counter 1))
   ;;;;end if

  );;end while

 );;end defun

I haven't error checked my code or done the variable list at the start yet, was saving it until I've figured out this piece of the code.

I would suggest filtering at the ssget prompt so that the user is aware which objects will be processed by the program.

Here are some resources to assist you:

http://lee-mac.com/ssget.html

http://www.afralisp.net/autolisp/tutorials/selection-sets.php

http://www.afralisp.net/autolisp/tutorials/selection-set-filters.php

Try this version of your program

test.LSP

An example of directly changing a pline width rather than use pedit.

(setq obj (vlax-ename->vla-object (car (entsel "\nPick Pline"))))
(val-put-constantwidth obj val) ; val is the width of the pline