code: public static int
  intValue(String option) {
  	String s = value(option);
  	if (s != null) {
  		try {
  			int val = Integer.parseInt(s);
  			if (val > 0)
  				return (val);
  		}
  		catch (NumberFormatException e) {
  		}
  	}
  	return (-1);
  }
docs: Returns the value of an option as an integer, or -1 if not defined.