File IO Sample with fprintf [writing ~1GB of data into text file]

FileIOSample.c

#include <stdio.h>
#include <string.h>
#include <windows.h>

long diff_micro(LARGE_INTEGER *start, LARGE_INTEGER *end)
{
    LARGE_INTEGER Frequency, elapsed;

    QueryPerformanceFrequency(&Frequency); 
    elapsed.QuadPart = end->QuadPart - start->QuadPart;

    elapsed.QuadPart *= 1000000;
    elapsed.QuadPart /= Frequency.QuadPart;

    return elapsed.QuadPart;
}

long diff_milli(LARGE_INTEGER *start, LARGE_INTEGER *end)
{
    LARGE_INTEGER Frequency, elapsed;

    QueryPerformanceFrequency(&Frequency); 
    elapsed.QuadPart = end->QuadPart - start->QuadPart;

    elapsed.QuadPart *= 1000;
    elapsed.QuadPart /= Frequency.QuadPart;

    return elapsed.QuadPart;
}


int main()
{
    /* time */
    /* http://stackoverflow.com/questions/17639213/millisecond-precision-timing-of-functions-in-c-crossplatform */
    LARGE_INTEGER StartingTime, EndingTime;

    QueryPerformanceCounter(&StartingTime);
	
	/* FILE *f = stdout; */
	FILE *f = NULL;
	
	errno_t result = fopen_s(&f, "output.txt", "w");
	
	if(result != 0)
	{
		char buffer[100];
		strerror_s(buffer, sizeof(buffer), result);
		
		printf("%s (%d)\n", buffer, result);
		return result;
	}
	
	//fprintf(f, "Fenerbahce is the best!\n");
	for(int i = 0; i < 10000000; i++)
		fprintf(f, "XXXXX.....IIIIIyyyyyGGGGG.....OOOOO33333nnnnneeeeefffffUUUUU--------##########9999999999nnnnnnnnn\n");
	fclose(f);
	
	QueryPerformanceCounter(&EndingTime);

    printf("DIFF in micro sec: %ld us\n", diff_micro(&StartingTime, &EndingTime));
    printf("DIFF in milli sec: %ld ms\n", diff_milli(&StartingTime, &EndingTime));
	
    return 0;
}