Network-Programming-in-C/Advanced_Technique/poll_func.c

#include <stdio.h>
#include <poll.h>

int main(){

    struct pollfd pfds[1]; // More if you want to monitor more

    pfds[0].fd = 0;         //Standard input
    pfds[0].events = POLLIN;// Tell me when ready to read

    //  If you needed to monitor other things, as well:
    // pfds[1].fd = some_socket; // Some socket descriptor
    // pfds[1].events = POLLIN;  // Tell me when ready to read

    printf("Hit RETURN or wait 2.5 seconds for timeout\n");

    int num_events = poll(pfds, 1, 2500); // 2.5 second timeout
 
    if(num_events == 0){
        printf("Poll timed out!\n");
    }
    else{
        int pollin_happened = pfds[0].revents & POLLIN;

        if( pollin_happened ){
            printf("File descriptor %d is ready to read\n", pfds[0].fd);
        }
        else{
            printf("Unexpected event occured: %d\n", pfds[0].revents);
        }
    }
    return 0;
}