How to read data in a specific memory address in c++

Question

I have created an integer variable using the following code in first.cpp :

#include <iostream>
using namespace std;

int main()
{
    int myvar = 10;
    cout << &myvar;

// I only need two steps above.
// The following steps are coded to make this program run continuously.

    cout << "Enter your name" << endl;
    string name;
    cin >> name;
    return 0;
}

Output of first.cpp is:

>0x6dfed4

While the above program is running, I also run the following program in second.cpp :

#include <iostream>
using namespace std;

int main()
{
    // I this program I want to read the content in myvar variable in first.cpp
    // How to do it ?

}

Using the second program, I want to read the content of the myvar variable in first.cpp.

How to do it?

Thank you.

Answer 1

To elaborate on my comment above:

As I wrote each program will run in a different process . Each process has a separate adddress space . Therefore using the address of a variable in another process doesn't make any sense.

In order to communicate between processes, you need some kind of IPC (inter-process communication): Inter-process communication

If you only need to share a variable, the first mechanism that comes to mind is to use shared memory : Shared memory

Shared-memory is very much OS dependent . You didn't mention which OS you are using. On Windows you can use Win API for managing shared memory: Windows shared memory

There's an equivalent on Linux, but I am not familiar with the details.

Alternatively you can use the boost solution which is cross platform: boost shared memory

If you'll delve into that it will be clear that these kind of solutions comes with some compilcations .

So the question is why do you need to do it? Maybe there's a better solution to your problem (you haven't described what it actually is, so there's not much more I can say).