R_FLAG
if ((pmtab->p_ttyflags & (R_FLAG|A_FLAG)) ||
if (pmtab->p_ttyflags & R_FLAG) { /* wait_read is needed */
if (pmptr->p_ttyflags & R_FLAG) {
*ttyflags |= R_FLAG;
if (flags & R_FLAG) {
if (pmptr->p_ttyflags & R_FLAG)