#include <sys/types.h>

#include <netdb.h>

#define MAXLEN 80

int server_write (int client_socket, char *s)

{

    return write (client_socket, s, strlen (s));

}

int server_init (char *port)

{

    int server_socket, status;

    struct addrinfo hints;

    struct addrinfo *result, *rp;

    int yes = 1;

    memset (&hints, 0, sizeof (hints));

    hints.ai_family = AF_UNSPEC;

    hints.ai_socktype = SOCK_STREAM;

    hints.ai_flags = AI_PASSIVE;

    if (getaddrinfo (NULL, "4000", &hints, &result) < 0) {

        perror ("GETADDRINFO");

        return -1;

    }

    server_socket = -1;

    for (rp = result; rp != NULL; rp = rp->ai_next) {

        if ((server_socket = socket (rp->ai_family, rp->ai_socktype, rp->ai_protocol)) < 0) {

            perror ("SOCKET");

            continue;

        }

        if (setsockopt (server_socket, SOL_SOCKET, SO_REUSEADDR, &yes, sizeof (int)) == -1) {

            perror ("setsockopt");

            return -1;

        }

        if ((bind (server_socket, rp->ai_addr, rp->ai_addrlen)) == -1) {

            perror ("BIND");

            close (server_socket);

            server_socket = -1;

        } else {

            printf ("bound to an %s socket\n", (rp->ai_family == AF_INET6) ? "IPv6" : "IPv4");

        }

    }

    status = listen (server_socket, 10);

    if (status != 0) {

        perror ("LISTEN");

        return -1;

    }

    if (result != NULL)

        freeaddrinfo (result);

    return server_socket;

}

    char message[MAXLEN + 1];

    if ((server_socket = server_init ("4000")) < 0)

        client_socket = accept (server_socket, NULL, NULL);

            if ((len = read (client_socket, message, MAXLEN)) == -1)

            message[len] = '\0';

            len = server_write (client_socket, "Please wait...\r\n");

             * server is still alive and will continue when resources are available