Lisp Question

I have a lisp question for you guys.

I am making a simple gcode generator. When I come to an arc I want to get
the end point by clicking on it, then I want to click the arc so I can
extract the radius information. I do this two step end then radius so that
I make sure I'm getting the endpoint I want and not the one Autocad thinks
it should be.

Here is how I am doing it:
(setq point (getpoint "Select Arc End:")) ;Prompt the
user to specify the arcs end point
(setq px (car point))
;Extract the X dimension
(setq py (cadr point))
;Extract the Y dimension
(setq pz (caddr point))
;Extract the Z dimension
(setq enam (car (entsel "\nSelect ARC: "))) ;Prompt the
user to select the arc
(Setq pr (cdr (assoc 40 (entget(entlast))))) ;Extract the
Radius dimension of selected arc

The darned thing isn't working though. Well it does and it doesn't.
When I select the arc with the entsel command it pretends to do something.
I don't get a nil or an error.
If I type in (entget(entlast)) I see whatever I edited last. If it was a
line I see the line, if it was mtext I see that.

If I type in (entsel "\nselect an object") then select an object, it still
doesn't choose that object. It gives no error, just keeps hanging onto
whatever I'd edited last.

So tell me, what the heck is the deal? Is it some environment variable I
need to set? Is my aperature to large? Why the heck will this stupid thing
not entsel what the heck I'm clicking on.
I even click on the arc using the midpoint osnap and it still
(entget(entlast)) whatever I last edited.

If you guys could help me with this I would be greatly appreciative. I'm
sure I've left some important info out, if so let me know.

Thanks,
John

 

Try this:

(setq pr (cdr (assoc 40 (entget enam))))


HTH
Juergen

 

Yup, that did it. I kept trying to do the same thing, but in my ignorance I
kept trying to do it as:
(setq pr (cdr (assoc 40 (entget(enam))))) I see now why I shouldn't have
been putting teh variable into the parenthesis.

Thanks for your help. It did the trick for me.

John

 

You're welcome

Juergen