Expert: Bill DeShawn - 4/27/2004

Question
Hello Bill, long time since I bothered You last time! ;)

Now I have a quite easy question for you, I think.

In a lisp I need to ask the drawing scale from the user, eg. 1:2, 12:100 or 100:12.
Both numbers can be whatever, but usually 1-3 digits (between 1 and 100). Now I need to separate those numbers (for later use) and I don´t want to ask them one by one.
I know I have to use getreal and substr functions, but how I calculate the place of the ":" mark? Before it there can be 1,2 or 3 (or even more) digits.

Thank you!

<<< Niko >>>  

Answer
I may be copping out, but I can't think of a way to identify the number of characters before and after another character.  I would use this approach:

(defun c:test ()
  (setq first (getreal "\nFirst number of ratio:  ")); could also use getint
  (setq second (getreal "\nSecond number of ratio:  ")); could also use getint
  (setq quotient (/ first second))
  (princ quotient)
  (princ)
)

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Bill DeShawn
http://my.sterling.net/~bdeshawn