ttycheckoutq      433 kern/subr_prf.c 	if (sess && sess->s_ttyvp && ttycheckoutq(sess->s_ttyp, 0)) {
ttycheckoutq     2051 kern/tty.c     	if (ttycheckoutq(tp,0) == 0)
ttycheckoutq      279 sys/tty.h      int	 ttycheckoutq(struct tty *tp, int wait);