Holding the console-screen when end-of-file is involved

Question

Here's the scaled down version of the program which accepts an unknown no. of Integer inputs. I used cin.get() before but to no avail, finally used this but unfortunately it too didn't worked. I am using Notepad++ spawning command prompt to run my programs. Is this something to do with Notepad++ OR the CTRL-Z (end-of-file) character?

EDIT : Works fine using cmd.exe

vector<int> vint;
int val = 0;

cout << "Enter integers..... Press CTRL and \'Z\' when done entering!"
     << "\n GO... : ";  

while(cin >> val)   
    vint.push_back(val);

if (vint.size() > 1)
{
    ...
}
else
{
    ...
}

std::cin.ignore (std::numeric_limits<std::streamsize>::max(), '\n' );
std::cin.get(); 

Answer 1

When you enter Ctrl+Z in a console programme you tell that it's the end of the file. Any subsequent reading from cin is then doomed to fail.

It works from the command line, because the command processor doesn't close the window when the programme is over.

Possible solutions:

The portable approach would be to interupt the loop cleanly by checking for a special value (for example 0).

If this is not possible, another approach would be to gain more control on the user input and read lines into a string. You could then end the loop when an empty line is entered. This is I think for the user the most intuitive approach. All you have to do is to parse non empty strings with stringstreams (and eventually complain if non numeric values were entered).

An less perfect approach could be to instruct the user to enter some non numeric value to end the loop. You then have to clear the failure that invalid input would generate:

 while (std::cin >> val ) {
   ...
 }
 if (std::cin.eof())     // display the special case 
    std::cout <<"End of file encountered !" << std::endl; 

 std::cout << "Press a key...";

 std::cin.clear();    // clear the error state of cin
 std::cin.ignore(std::numeric_limits<std::streamsize>::max(), '\n');
 std::cin.get(); 

Surprisingly, this works compiled with MSVC2015 on windows when entering Ctr+Z: once the end of file state cleared the console is magically restored and you can continue to read. However you can't assume this to work with console front-ends like Notepad++, nor with other implementations of the standard library, nor on other OS.