#include <err.h>
#include <stdio.h>
#include <string.h>
#include <sysexits.h>
#include <netinet/in.h>
#include <sys/select.h>
#include <sys/socket.h>
#include <sys/types.h>

int
main(int argc, char *argv[])
{
    struct sockaddr_in sa_local, sa_remote;
    socklen_t sin_size = sizeof(struct sockaddr_in);
    fd_set exceptfds;
    struct timeval timeout;
    int fd_l, fd_c, fd_n, i;

    if ((fd_l = socket(PF_INET, SOCK_STREAM, 0)) == -1)
        err(EX_OSERR, "socket(2) failure");

    if ((fd_c = socket(PF_INET, SOCK_STREAM, 0)) == -1)
        err(EX_OSERR, "socket(2) failure");

    sa_local.sin_family = AF_INET;
    sa_local.sin_port = 0;
    sa_local.sin_addr.s_addr = htonl(INADDR_ANY);
    memset(&(sa_local.sin_zero), 0, sizeof(sa_local.sin_zero));

    if (bind(fd_l, (struct sockaddr *)&sa_local, sizeof(struct sockaddr)) == -1)
        err(EX_OSERR, "bind(2) failure");

    if (getsockname(fd_l, (struct sockaddr *)&sa_local, &sin_size) == -1)
        err(EX_OSERR, "getsockname(2) failure");

    if (listen(fd_l, 1) == -1)
        err(EX_OSERR, "listen(2) failure");

    if (connect(fd_c, (struct sockaddr *)&sa_local, sizeof(struct sockaddr)) == -1)
        err(EX_OSERR, "connect(2) failure");

    fd_n = accept(fd_l, (struct sockaddr *)&sa_remote, &sin_size);

    FD_ZERO(&exceptfds);
    FD_SET(fd_n, &exceptfds);

    if (send(fd_c, "x", 1, MSG_OOB) == -1)
        err(EX_OSERR, "send(2) failure");

    memset(&timeout, 0, sizeof(timeout));
    i = select(fd_n+1, NULL, NULL, &exceptfds, &timeout);

    if (i == 1)
        printf("ok\n");

    return (0);
}