Exits the loop after a certain amount of time if there's no input

Question

I\'m just wondering whether is it possible and how do I implement this feature, where we exit from the loop if there\'s no input from the user. For example, I want to exit t

Answer 1

Use select() function to set a timeout for your scanf

The following code is an example of how use it.

#include 
#include 
#include 

int main(void)
{
    int x;
    fd_set          set;
    struct          timeval timeout = {0};

    FD_ZERO(&set);


   while(1)
   {
        timeout.tv_sec = 30;
        FD_SET(fileno( stdin ), &set);
        printf ("enter a number:");
        fflush (stdout);
        if (select(FD_SETSIZE, &set, NULL, NULL, &timeout))
        {

           scanf("%d", &x);
           printf("The number you put is %d\r\n",x);

        }
        else
        {
                printf("\r\nTimeout: Stop reading\r\n");
                break;
        }
    }
}