How to stop waiting for user input in c++?

Question

I have a simple code as below.

    int a, b;
    cin >> a >> b;

If the user only inputs one number, the program will hang there waiting for another input. How do I stop the situation automatically and let the user to enter two numbers again if there is no input for a time, like 30 seconds?

possible duplicate of [Possible to stop cin from waiting input?](http://stackoverflow.com/questions/8569027/possible-to-stop-cin-from-waiting-input) — OldProgrammer, Sep 04 '15 at 16:00
The solution depends on the platform. What platform, OS and IDE/Compiler are you using? — Thomas Matthews, Sep 04 '15 at 16:05

score 0 · Answer 1 · answered Sep 04 '15 at 16:11

There is no easy / universal way to do so. There are separate methods for Linux (alarm, signal handlers, followed by manual stream flushing and resetting) and Windows (not sure -- implement your own readline using raw keyboard input?), but they are all quite complicated and hard to get right.

How to stop waiting for user input in c++?

1 Answers1