cppBinFileBasics

#include <iostream>
#include <fstream>
#include <chrono>

//ofstream - output stream
//ifstream - input stream
//fstream - input/output stream

// std::ios::app
// std::ios::trunc
// std::ios::out
// std::ios::in
// std::ios::binary


int main()
{
    srand(time(nullptr));

    std::fstream iofile;

    iofile.open("d:\\file.dat", std::ios::trunc | std::ios::out | std::ios::in | std::ios::binary);

    if ( !iofile)
    {
        std::cout << "IOERROR: can't create/open file!\n";
        return 1;
    }
    int val{};

    for (int i{ 0 }; i < 10; ++i)
    {

        //val = rand() % 10000;

        //for (int i{ 0 }; i < sizeof(int); ++i)
        //{
        //  uint8_t dec{ ((uint8_t*)&val)[i] };
        //  uint8_t hex{ (uint8_t)(dec % 16) };

        //  char L{ hex < 10 ? '0' + hex : 'A' + (hex - 10) };

        //  dec /= 16;
        //  hex = dec % 16;

        //  char H{ hex < 10 ? '0' + hex : 'A' + (hex - 10) };
        //
        //  std::cout << H << L << ' ';
        //}
        //std::cout << '\n';

        iofile.write((char*)&i, sizeof(int));
    }

    iofile.seekg(0, std::ios::beg);


    while (!iofile.eof())
    {
        iofile.read((char*)&val, sizeof(int));
        if (iofile.fail())
        {
            break;
        }
        std::cout << val << '\n';
        iofile.seekg(1 * sizeof(int), std::ios::beg);
    }

    iofile.close();

    return 0;
}