invisible to who(1)

Dave Cohrs dave at cs.wisc.edu
Fri Dec 30 01:30:08 AEST 1988


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. At the next login,
>ttyd0 is reported as name of the terminal-line with "Last login: ...".
>Furthermore, a DIALUP is recorded for ttyd0 in the syslog-file.

Get rid of the hard link.  The various programs, like ps, who and login
have problems with tty's with identity crises.  Either call the thing
"tty03" everywhere, including in /dev, or "ttyd0", but don't give it
two names.  The problem is that some programs use /etc/ttys (or whatever)
to map the tty name into things, and other programs search /dev until
they find a matching major/minor number.  The search stops on the *first*
file with the correct major/minor number, which might not have the same
name as the tty mentioned in /etc/ttys, and viola, the user doesn't show
up in "who".

Ultrix may have additional problems with skitzo tty's, but the above
is the basic problem.  I'd suggest "rm /dev/tty03" and treat the thing
like a dialup line.

dave cohrs
--
Dave Cohrs
+1 608 262-6617                        UW-Madison Computer Sciences Department
dave at cs.wisc.edu                       ...!{harvard,rutgers,ucbvax}!uwvax!dave



More information about the Comp.unix.wizards mailing list