gistfile1.c

int connection_refused()
{
    int sockfd = async_net("127.0.0.1", 11111);
    struct pollfd pfd;
    pfd.fd = sockfd;
    pfd.events = POLLIN|POLLOUT;
    int ready = poll(&pfd, 1, -1);
    printf("ready=%d, POLLIN=%d, POLLOUT=%d, POLLERR=%d\n",
            ready,
            ( pfd.revents&POLLIN ) != 0,
            ( pfd.revents&POLLOUT ) != 0,
            ( pfd.revents&POLLERR ) != 0);

    int error;
    socklen_t errlen = sizeof(error);
    getsockopt(sockfd, SOL_SOCKET, SO_ERROR, &error, &errlen);
    printf("error=%d, msg=%s\n", error, strerror(error) );
    return 0;
}