#define LISTEN_SOCKET "/var/tmp/mysocket"

static int listen_fd;

BOOL listen_socket (HWND hwnd)
{
 if ((listen_fd = serv_listen (LISTEN_SOCKET)) < 0)
 return FALSE;
 return RegisterListenFD (fd, POLL_IN, hwnd, NULL);
}

/*
 * When the server receives the request to connect from a client,
 * the window hwnd will receive a MSG_FDEVENT message.
 * Now the server can accept the request.
 */
LRESULT MyWndProc (HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
{
 switch (message) {

 ...

 case MSG_FDEVENT:
 if (LOWORD (wParam) == listen_fd) {
 /* This message comes from the listen socket fd. */
 pid_t pid;
 uid_t uid;
 int conn_fd;
 conn_fd = serv_accept (listen_fd, &pid, &uid);
 if (conn_fd >= 0) {
 RegisterListenFD (conn_fd, POLL_IN, hwnd, NULL);
 }
 }
 else {
 /* Client send a request. */
 int fd = LOWORD(wParam);
 /* Handle the request from client. */
 sock_read_t (fd, ...);
 sock_write_t (fd, ....);
 }
 break;

 ...

 }
}

/*
 * Clients can use the following code to connect itself to the server.
 */

 int conn_fd;

 if ((conn_fd = cli_conn (LISTEN_SOCKET, 'b')) >= 0) {
 /* Send a request to the server. */
 sock_write_t (fd, ....);
 /* Get the reply from the server. */
 sock_read_t (fd, ....);
 }