state_machine.c

int		get_token(char input)
{
    if (input == '%')
        return (TK_PERCENTAGE);
    else if (input >= '1' && input <= '9')
        return (TK_ONE_NINE);
    else if (input == '\0')
        return (TK_NULL);
    else if (input == '.')
        return (TK_DOT);
    else if (input == '*')
        return (TK_ASTERISK);
    else if (input == '-')
        return (TK_HYPEN);
    else if (input == '0')
        return (TK_ZERO);
    else if (input == 'c' || input == 'd' || input == 's' ||
             input == 'x' || input == 'X' || input == 'u' ||
             input == 'i' || input == 'p')
        return (TK_SPECIFIER);
    else
        return (TK_ELSE);
    return (-1);
}

int		get_state(int state, int input)
{
	int	arr[81] = {	2, 1, 10, 1, 1, 1, 1, 1, 1,
	  				2, 1, 10, 1, 1, 1, 1, 1, 1,
					8, 3, -1, 5, 4, 2, 2, 8, -1,
	               	8, 3, -1, 5, -1, -1, 3, 8, -1,
	               	8, -1, -1, 5, -1, -1, -1, 8, -1,
	               	8, 6, -1, -1, 7, -1, 6, 8, -1,
	               	8, 6, -1, -1, -1, -1, 6, 8, -1,
	               	8, -1, -1, -1, -1, -1, -1, 8, -1
				};
  
    return (arr[(state * 9) + input]);
}

while (*str)
	{
		token = get_token(*str);
		state = get_state(state, token);
		if (state == 1)
			write(1, str, 1);
		if (state == 2)
		{
			if (*str == '-')
			{
				opt->hypen = 1;
				opt->padc = ' ';
			}
			else if (*str == '0' && opt->hypen != 1)
				opt->padc = '0';
		}
		if (state == 3)
		{
			opt->width *= 10;
			opt->width += (*str - '0');
		}
		if (state == 4)
		{
			opt->width = va_arg(ap, int);
			if (opt->width < 0 && !opt->hypen)
			{
				opt->hypen = 1;
				opt->padc = ' ';
			}
			if (opt->width < 0)
				opt->width = -opt->width;
		}
		if (state == 5)
		{
			opt->dot = 1;
			opt->length = 0;
		}
		if (state == 6)
		{
			opt->length *= 10;
			opt->length += (*str - '0');
		}
		if (state == 7)
			opt->length = va_arg(ap, int);
		if (state == 8 || state == 10) // 현재 % 에 대한 것들은 다 읽은 거니까 종료해야지
			break ;
		if (state == -1)
			return (-1);
		str++;
	}