atoi(str)
{
	local i;
	local sign;
	local out;
	out = 0;
	sign = 0;
	i = 0;
	loop {
		if ([str + i] == '-')
			sign = sign == 0;
		else if ([str + i] != '+')
			break;
		i = i + 1;
	}
	loop {
		if ([str + i] == 0 | isdigit([str + i]) == 0)
			break;
		out = out * 10 + [str + i] - '0';
		i = i + 1;
	}
	if (sign)
		return (0 - out);
	return out;
}