Thread: Reading in an unknown number of numbers

I hit a little barrier while trying to implement an RPN calculator today. I want to have expressions like this in a file:

Code:

33 10 +

But that could be any number of numbers and I have no idea how to read them in.

Code:

int main (int argc, char *argv[])
{
        FILE            *f = 0;
        int             ch = 0;
        Stack           *stk = new Stack (256);

        f = fopen ("z:\\test.rpn", "r");
        if (! f) {
                cout << "Error opening file\n";
                return 1;
        }

        while ((ch = fgetc (f)) != EOF) {  // The offending line
                switch (ch) {
                        case '+': {
                                        char    one, two, ans;

                                        one = stk->pop ();
                                        two = stk->pop ();
                                        ans = one + two;
                                        stk->push (ans);

                                        break;
                                  }
                        case '-':
                                break;
                        case '/':
                                break;
                        case '*':
                                break;
                        default: // assumed to be a literal to push
                                stk->push (ch);
                }
        }

        fclose (f);
        delete stk;
         return 0;
}

I don't have a clue how to read in an unknown number of numbers, as the title suggests.