strtol

long strtol(const char* s)
{
    bool sign = false;
    long i, r, base = 10;
    if(s[1] == 'x')
    {
        s+=2;
        base = 16;
    }
    else if(s[1] == 'b')
    {
        s+=2;
        base = 2;
    }
    if(s[0] == '-')
    {
        s+=1;
        sign = true;
    }
    for (i = 0, r = 0;s[i] != '\0';++i)
        r = r*base + s[i] - (s[i] >= '0' && s[i] <= '9' ? '0' :
                s[i] >= 'A' && s[i] <= 'Z' ? ('A' - 10) :  ('a' - 10));
    return (sign ? -r : r);
}