strcmp performs a case-sensitive comparison of the two argument strings. strcmp(arg1,arg2) returns a number.
There are three cases :
1. If is lexicographically less than, the `strcmp()' returns a negative number.
2. If the two strings are identical, `strcmp()' returns zero.
3. Otherwise, `strcmp()' returns a positive number.
So in your case, like SilentRage said, you have to test if strcmp(r,b) !=0
Peace !