this atoi is actually works!

int     ft_atoi(char *str)
{
    int     sign;
    size_t  res;

    sign = 1;
    res = 0;
    while (((*str > 8) && (*str < 14)) || (*str == 32))
        str++;
    if (*str == '-' || *str == '+')
    {
        if (*str == '-')
            sign = -1;
        str++;
    }
    while ((*str >= '0') && (*str <= '9'))
    {
        if (res <= 9223372036854775807)
            res = (res * 10) + (*str - '0');
        else if (sign == -1)
            return (0);
        else
            return (-1);
        str++;
    }
    return (res * sign);
}