Thread: evaluating strings

I am trying to evaluate a string entered by the user. I want to do something similar to the eval function in Matlab. For example, if the user enters :

p OR NOT q

I would then prompt them for the values of p and q. The user would enter either a 1 or 0 for each, then I would display if the expression is either true or false. I already know how to use the or, and, and not operators in C. My problem is if I trace through the input string and make a new string which would be:

p | ! q

How do I evaluate this expression if it is still a string?

Thanks

I guess you will have to write code to parse the string yourself and calculate the result via code only.