ttymsg
if (ttymsg(&iovec, 1, tty, RING_WAIT - 5, true) != 0)
int ttymsg(struct iovec *, int, const char *, int, bool);
if (ttymsg(&iov, 1, utmp->ut_line, 60 * 5, 1) != 0)
if (ttymsg(iov, iovlen, ut->ut_line, TTYMSGTIME,
if (ttymsg(iov, iovlen, ut->ut_line, TTYMSGTIME,
ttymsg(iov, iovcnt, line, timeout)
if ((ret = ttymsg(iov, iovcnt, line, timeout, shout)) != 0)