Continous polylines

Not looking for an answer, just direction. Also, I would prefer to stick
with lisp, as that is what I am learning currently. Next will be Vlisp.
This routine will be used to draw contour lines.

How do I do the following:

Code:

draw a polyline of unlimited length
when done (enter) ask to draw another one
if yes
reset a variable to another value (an integer)
perform a setvar
run another defun in the routine (possible layer change)
draw another polyline of unlimited length
if no - end program
repeat until a no is encountered

Thanks in advance to all,

Jeff

 

One approach:

(defun c:RPOLY (/ cmde p1)
(setq cmde (getvar "cmdecho"))
(setvar "cmdecho" 1)
(while (setq p1 (getpoint "\nStarting Point (ENTER when done): "))
(command "_.pline" p1)
(while (= (logand (getvar "cmdactive") 1) 1)
(command pause)
); while
); while
(setvar "cmdecho" cmde)
(princ)
)
___

 

Thank you Paul. I wasn't sure if I should use a while or a cond statement
to accomplish this. I haven't been able to get a good handle on making
while work just yet. I will keep plugging away.