CTF_WRTTN
if ((sc->sc_flags & (CTF_WRT|CTF_WRTTN)) == (CTF_WRT|CTF_WRTTN) &&
sc->sc_flags &= ~(CTF_OPEN | CTF_WRT | CTF_WRTTN);
sc->sc_flags |= (CTF_WRT | CTF_WRTTN);
if ((sc->sc_flags & (CTF_WRT|CTF_WRTTN)) == (CTF_WRT|CTF_WRTTN) &&
sc->sc_flags &= ~(CTF_OPEN | CTF_WRT | CTF_WRTTN);
sc->sc_flags |= (CTF_WRT | CTF_WRTTN);