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c++fwrite

Some wrong with fwrite() in c++

I'm wrote function which count time of multiplying matrix. That is code:

if ((file = fopen("../logs.txt","w")) != NULL)
{
    for(int i = 0; i < 5; ++i)
    {   
        if(QueryPerformanceCounter(&start) !=0)
        {
            mult(m1, m2, m3);
            QueryPerformanceCounter(&finish);
            double temp = (double)(finish.QuadPart - start.QuadPart)/frequency.QuadPart;
            if(temp<=min || min == 0)
                min = temp;
        }
    }
    fwrite(&min, sizeof(min), 1, file);
    fclose(file);   
}

When i debug it, I saw that my min time equal 0.26336317888614069, but in file it was written "2W<сЪР?". Tell me please what is wrong.

Solution

  • You are writing the binary representation to the file, rather than the human-readable one.

    Use:

    fprintf(file, "%f", min);