Getting user input without pausing

Is there a simple way to allow user input without having the program "wait" for it?

For example, I want to write a function that counts down from 100 to 0. The only way to stop it would be if the user enters a certain phrase. I want to make sure that the count down is absolutely uninterrupted unless the exact phrase is entered.

So, how would I have a variable ready to be changed by the user, and also a function running at "the same time" so to speak?

thanks!

Here's some mock code for what I can come up with so far.

Code:

---

for (int i = 100; i > 0; i--)
{
  cin >> password;
  if (password != 'stop')

    // pause for 1 second
    cout << i << "..." << endl;
}

---

So that's the basic idea of what I want, except in that example, the function will pause every time and "wait" for input right?

One way would require threads and thread synchronization.
There are other solutions, but none of them are easy ways.

It doesn't need threads. It just needs nonblocking input functions. Unfortunately there is no such thing in standard C++, but they certainly exist in other libraries. For example, Borland C++ used to have a function called kbhit() once upon a time, which would return true if there was data waiting to be read from the console and false otherwise.

Dev-C++ may have an implementation of kbhit() (it has getche() ...), and if not the web describes a number of ways of doing it. Here's one reference for using kbhit() without ncurses on Linux: Non-blocking user input in loop without ncurses. – c/c++ programming by examples
If you want to do this sort of thing seriously though you could look into ncurses (or pdcurses, which I hear is roughly equivalent but runs on Windows). Be warned that it might be quite a bit of work to learn a new API like ncurses, however.

The short answer is that it's not easy, and if you're just trying to write a program that displays "the nuke will go off in X seconds!" unless you type the password, just for fun . . . it's probably not worth the hassle. :)

[edit] More details:
http://www.gamedev.net/community/for...opic_id=538714
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