tdev
void tdev(const struct pinfo *, VARENT *);
{"tdev", "TDEV", NULL, 0, tdev, 4},
ep->tdev = stp->st_rdev;
if (ep->tdev == 0) {
(void) sysctl(mib, 2, &ep->tdev, &size, NULL, 0);
} else if (ep->tdev == kp->p_tdev &&
dev_t tdev; /* dev_t of terminal */