HAVE_IP
show_prerequisites(&flags, HAVE_IP, 0);
show_prerequisites(&flags, HAVE_IP | HAVE_OPTIONS, 0);
show_prerequisites(&flags, HAVE_IP, 0);
if ( (*flags & HAVE_IP) == HAVE_IP)
flags = HAVE_IP; /* avoid printing anything else */
flags |= HAVE_IP | HAVE_OPTIONS;