字串判斷

// ConsoleApplication1.cpp : 定義主控台應用程式的進入點。
//

#include "stdafx.h"
#include <iostream>
#include <fstream>
#include <string>
#include <cctype>
using namespace std;


int main()
{
	fstream file;
	file.open("C:\\nmea_sample.txt", ios_base::in);

	if (!file)
	{
		cout << "開起失敗" << endl;
	}
	string temp, checkstr = "$GPGGA";

	while (!file.eof())
	{
		bool isGPGGA = 0;
		file >> temp;
		if (temp.find(checkstr) != string::npos)
		{
			cout << temp << endl;
			isGPGGA = 1;
		}
		if (isGPGGA)
		{
			char checkchar = temp[1];
			for (int i = 2; temp[i] != '*'; i++)
			{
				checkchar ^= temp[i];
			}

			int checknum = 0;

			if (isalpha(temp[temp.find_first_of('*') + 1]) == 1)
				checknum += ((temp[temp.find_first_of('*') + 1] - 'A') + 10) * 16;
			else
				checknum += (temp[temp.find_first_of('*') + 1] - '0') * 16;

			if (isalpha(temp[temp.find_first_of('*') + 2]) == 1)
				checknum += ((temp[temp.find_first_of('*') + 2] - 'A') + 10);
			else
				checknum += (temp[temp.find_first_of('*') + 2] - '0');


			if (int(checkchar) == checknum)
			{
				cout << "PASS" << endl;
				unsigned int k = temp.find(',');
				while (k!= string::npos)
				{
					cout << "時間" << temp[k + 1] << temp[k + 2] << ":" << temp[k + 3] << temp[k + 4] << ":" << temp[k + 5] << temp[k + 6] << endl;
					k = string::npos;
				}
			}

			else
				cout << "ERROR" << endl;
		}


	}

}