パリティチェック？

fcc.cpp

#include <stdlib.h>
#include <iostream>
#include <string>
#include <sstream>


bool CheckFCC(std::string &buf, int start, size_t byte_count)
{
	char fcc = buf[byte_count + 4];
	char calc_fcc;

	for (size_t i = 0; i < byte_count + 4; i++)
	{
		calc_fcc ^= buf[start + i];
	}

	std::stringstream ss;
	ss << "Recieved fcc: " << (int)fcc << " Calculated fcc: " << (int)calc_fcc;

	return fcc == calc_fcc ? true : false;

}


bool CheckFCC(unsigned char buf[], int start, size_t byte_count)
{
	unsigned char fcc = buf[byte_count + 4];
	unsigned char calc_fcc = 0x00;

	for (size_t i = 0; i < byte_count + 4; i++)
	{
		calc_fcc ^= buf[start + i];
	}

	std::stringstream ss;
	ss << "Recieved fcc: " << (int)fcc << " Calculated fcc: " << (int)calc_fcc;

	return fcc == calc_fcc ? true : false;

}

int main(int argc, char *argv[])
{
	unsigned char data[] = { 0x01, 0x40, 0x0c, 0x0d,
							 0x81, 0xd5, 0x40, 0x01,
							 0x00, 0x00, 0x00, 0x00,
							 0x00, 0x01, 0xff, 0x02,
							 0xf0, 0x59 };

	std::string s1;
	for (size_t i = 0; i < sizeof(data); i++) {
		s1.push_back(data[i]);
	}

	unsigned char data2[] = { 0x02, 0x40, 0x0c, 0x09,
							  0x81, 0xd4, 0x40, 0x01,
							  0x00, 0x00, 0x00, 0x00,
							  0x00, 0x53 };

	std::string s2;
	for (size_t i = 0; i < sizeof(data2); i++) {
		s1.push_back(data2[i]);
	}

	bool fcc = CheckFCC(data, 0, data[3]);
	if (!fcc)
	{
		std::cout << "fcc error." << std::endl;
	}
	else
	{
		std::cout << "ok." << std::endl;
	}


	 fcc = CheckFCC(data2, 0, data2[3]);
	if (!fcc)
	{
		std::cout << "fcc error." << std::endl;
	}
	else
	{
		std::cout << "ok." << std::endl;
	}

	fcc = CheckFCC(s1, 0, s1[3]);
	if (!fcc)
	{
		std::cout << "fcc error." << std::endl;
	}
	else
	{
		std::cout << "ok." << std::endl;
	}
	
	fcc = CheckFCC(s2, 0, s2[3]);
	if (!fcc)
	{
		std::cout << "fcc error." << std::endl;
	}
	else
	{
		std::cout << "ok." << std::endl;
	}

	return EXIT_SUCCESS;
}