main()
{
	int	childpid, pipe1[2], pipe2[2];

	if (pipe(pipe1) < 0 || pipe(pipe2) < 0)
		err_sys("can't create pipes");

	if ( (childpid = fork()) < 0) {
		err_sys("can't fork");

	} else if (childpid > 0) {			/* parent */
		close(pipe1[0]);
		close(pipe2[1]);

		client(pipe2[0], pipe1[1]);

		while (wait((int *) 0) != childpid)	/* wait for child */
			;

		close(pipe1[1]);
		close(pipe2[0]);
		exit(0);
	} else {					/* child */
		close(pipe1[1]);
		close(pipe2[0]);

		server(pipe1[0], pipe2[1]);

		close(pipe1[0]);
		close(pipe2[1]);
		exit(0);
	}
}