invisible to who(1)

[Peter Rowell]

In article <1499 at tuhold> gfl at tuhold (Gerhard Fleischanderl) writes:
>
>On a dial-in line at a MicroVAX-II (Ultrix 2.0), we encounter
>a strange phenomenon:
>A login on this line (tty03) is not recognized by who(1) nor finger(1).
>However, the login-shell is shown for TTY 03 by ps(1).
>
>There is a hard link between /dev/tty03 and /dev/ttyd0.
> ...
>who(1) had worked correctly before ttyd0 has been created (renamed from
>tty03 by uucpsetup(8), manually installed as a hard-link to tty03).
>If /dev/ttyd0 is renamed, everything works fine again. ("Last login:"
>reports tty03, there is nothing recorded to the syslog-file.)
>
>Does Ultrix handle a device with name "ttyd0" in a special way?
>This "invisible login" isn't threatening, nevertheless we want to fix it.

Ah indeed.  We have had the same problems under both 4.2 and 4.3, so
I guess the problem is generic, rather than Ultrix specific.

The "fix" (at least for us) is to *rename* /dev/tty03 to /dev/ttyd0,
not just link it (which seems like the perfectly reasonable thing to
do).  There appears to be something funny about how "who" figures out
what is going on and it seems to be upset if there is more than one
device with the same major/minor numbers.

Are there any guru's who can explain this? Fix this?

----------------------------------------------------------------------
Peter Rowell				"He found the missing link!"
Third Eye Software, Inc.		(415) 321-0967
Menlo Park, CA  94025			peter at thirdi.UUCP