Thread: Reading a binary file like a matrix of ints

Hi everyone,

I am trying to make a simple program that will read
a file like a matrix of ints.
The idea is that there is a binary file with ints:
1 2 3 4 5 6 7 8 9

and I want to read them in a buffer 3 ints at a time, and then print
them sepparated by spaces. Then I want to read then next 3 integers.
However when I try the reinterpret cast on a buffer of 12 chars.. I
get into problems. Any help appreciated.

Ted


I have this so far:

Code:

#include <iostream>
#include <fstream>
#include <vector>

const static int BUF_SIZE = 4;                    // 4 * num of ints
using std::ios_base;

int main(int argc, char** argv)
{
    std::ifstream file("InvDat.dat",
        ios_base::in | ios_base::binary);

    char buf[BUF_SIZE];

    if(file.is_open())
    {
        while (file.read(&buf[0], BUF_SIZE))
        {
            for (uint32_t i = 0; i < 3; ++i)
            {
                uint32_t *num = reinterpret_cast<uint32_t* >(&buf[0]);
                std::cout << (uint32_t) *num << " ";
            }
            std::cout << std::endl;
        }
        file.close();

    }
    return 0;
}