Question

I’ve been working on a small programm that put all the images I need for my 3D engine into a single file, but for unknow reasons when I try to use fstream to write into a file, it doesn’t return any error, but still doesn’t write anything.

for exemple, I have a simple function that initialize a new file :

void initPAK(fstream& pakfile, image firstImg)
{
    PAKheader head;
    head.sign[0]    = 'P';
    head.sign[1]    = 'A';
    head.sign[2]    = 'K';
    head.nbdata     = 1;
    head.index.push_back(sizeof(head.sign)+sizeof(head.nbdata)+sizeof(uint32_t));

    if(pakfile.is_open())
    {
        pakfile.write(head.sign, sizeof(head.sign));
        pakfile.write((char*)&head.nbdata, sizeof(head.nbdata));
        for(uint32_t n=0; n<head.index.size(); n++)
        {
            pakfile.write((char*)&head.index[n], sizeof(head.index[n]));
        }

        pakfile.write((char*)&firstImg.width, sizeof(firstImg.width));
        pakfile.write((char*)&firstImg.height, sizeof(firstImg.height));
        pakfile.write((char*)&firstImg.channels, sizeof(firstImg.channels));
        for(uint32_t n=0; n<firstImg.data.size(); n++)
        {
            pakfile.write((char*)&firstImg.data[n], sizeof(firstImg.data[n]));
        }

    }
    else
    {
        cerr << "unable to open" << endl;
    }   
}

And I use it like that :

    fstream fileop;
    fileop.open("bin_file", fstream::in | fstream::out | fstream::trunc | fstream::binary);

    unsigned char zdata[] = {
        255, 0, 0,
        0, 255, 0,
        0, 0, 255,
    };

    image zimg;
    zimg.width = 3;
    zimg.height = 1;
    zimg.channels = 3;
    for(int i=0; i < 9; i++)
    {
        zimg.data.push_back(zdata[i]);
    }

    initPAK(fileop, zimg);

    fileop.close();

But the file “bin_file” his never write nor created. I saw in an other stackoverflow’s question that I should use flush() but I didn’t work either. The strangest thing his that this function use to work, until I replace ofstream to fstream I believe.
What am I doing wrong ?

Answer 1

Well, I’m a bit stupid. This function does work, my program was just so messy that the function was never called …
Thank anyway for your remarks who help me cleanup my code a bit.

Lesson learned : Never rush to code, even more if you should sleep.