Store file in unsigned char array and print it - c++

Question

I've used the code below to read a binary file (in my case .docx file) and storing it in unsigned char array instead of just char (took reference from here Reading and writing binary file)
#include <fstream>
#include <iterator>
#include <vector>
int main()
{
std::ifstream input("C:\\test.docx", std::ios::binary);
std::vector<unsigned char> buffer((std::istreambuf_iterator<unsigned char>(input)),
(std::istreambuf_iterator<unsigned char>()));
}
Now I got two questions.
First thing I wanna know, is this a correct way to read a .docx file in an unsigned char array? Or are there better options available?
Secondly, I need to print the contents of file that are read in the unsigned char array, just to verify if it has correctly read the file or not. How can that be achieved?

Answer 1

That is an OK way if you're fine having the whole file in memory. If you want to read the file in parts, you should iterate over it. A use-case for it would be for transmitting it over the network - there, you won't need the whole file in memory.
About printing the file, it's possible to print the bytes read, for example, like this:
#include <fstream>
#include <iterator>
#include <vector>
#include <iostream>
#include <iomanip>
int main()
{
std::ifstream input("C:\\test.docx", std::ios::binary);
std::vector<unsigned char> buffer((std::istreambuf_iterator<unsigned char>(input)),
(std::istreambuf_iterator<unsigned char>()));
std::cout << std::hex;
for (unsigned char b : buffer)
std::cout << "0x" << std::setfill('0') << std::setw(2) << (int)b << " ";
std::cout << std::dec << std::endl;
}
If you meant printing the contents of the file to see some familiar text, that's not going to work directly. docx files use the Open XML File Format, which first of all, makes them a zip file. Inside the zip file, you will find XML representations of the data in the document, which are readable.