How to assign File path to variable in c++

Question

I have a program which calculates md5 hash. I can enter the text and it will generate the md5 code. I want to get files from computer, for example text file and generate md5 for that. The problem is that i don't know how to get the file location and assign it to variable so i can put that variable in md5 generator function.

cout << "md5 of 'grape': " << md5("example") << endl;

as you can see in the above code i enter the md5 function argument which is "example" string, so i want something like this

string foo = "C:\\Users\\User\\Downloads\\1.txt";   
cout << "md5 of 'grape': " << md5(foo) << endl;

so this will calculate md5 for "C:\\Users\\User\\Downloads\\1.txt" string, but i want to calculate the 1.txt file's md5.

Answer 1

One way to do it is by reading the whole file into a string and passing it to md5 function like this (I assume you are using zedwood's md5 ):

#include <iostream>
#include <fstream>
#include <sstream>
#include <string>
#include "md5.h"

int main()
{
    MD5 md5;
    std::ifstream ifs("C:\\Users\\User\\Downloads\\1.txt", std::ios::binary);
    if (ifs)
    {
        std::ostringstream oss;
        oss << ifs.rdbuf();
        std::string s(oss.str());
        md5.update(s.data(), s.size());
        md5.finalize();
        std::cout << md5.hexdigest() << std::endl;
    }

    return 0;
}

This should work with non-text files too.