isctty            844 kern/tty.c     		if (!isctty(p, tp) && suser(p, 0))
isctty            966 kern/tty.c     		if (p->p_ucred->cr_uid && !isctty(p, tp))
isctty            995 kern/tty.c     		if (!isctty(p, tp))
isctty            236 sys/tty.h      	(isctty((p), (tp)) && (p)->p_pgrp != (tp)->t_pgrp)