How can I tell the program to stop using freopen

Question

I am beginner in C++ and I have a question that is beyond my limits. I compile under GNU GCC. I use

#include

also known as:

Answer 1

The same question has been asked about stdout: How to redirect the output back to the screen after freopen("out.txt", "a", stdout), but the answer is the same for both - there's no clean way of doing this: http://c-faq.com/stdio/undofreopen.html

Since you do need to read from the console later in the program, I'd suggest you just open the file as, well, a file. If the reason you wanted to use stdin to read from a file is the convenience of not having to pass the file handle to functions like fscanf, you could consider using fstream facilities instead - the code can look exactly as when reading from the console:

#include 
#include 

using namespace std;
int main()
{
    int x;
    cin >> x; // reading from console
    {
        ifstream cin("input.txt");
        cin >> x; // reading from file
    }
    cin >> x; // again from console

    return 0;
}