utility to determine rlogin?

[Jerry Peek]

In article <204 at ge1cbx.UUCP> gerald at ge1cbx.UUCP (Gerald Aden) writes:
> Is there a utility that returns an indication as to whether or not
> I am remotely logged in.  I want to put it in my .login file where
> I want to perform certain functions if I am remotely logged in.  My
> home directory is NFS mounted on all the machines on our network.

You didn't say what OS you're using.  And I don't know how it's configured.
But I can tell you how I did the same kind of thing on a 4.3BSD system.  It
turned out to be really useful.  Most of our terminals were connected to:
	- a dataswitch (like Sytek, Develcon, etc.) or
	- a network (for rlogin, telnet, etc.)
So, we couldn't make the same kinds of assumptions (like "ttyG3 is always a
vt100") that sites with hardwired terminals did.

First, we labeled all the entries in the /etc/ttys file to tell what sort of
device was hooked to each one.  (Our /etc/ttys used to label all terminals as
"plugboard".  We changed them to read "dw3", "develcon", "sytek", "network",
etc.)  So, all the rlogin-able ports were labelled "network" in /etc/ttys.

Then, I wrote a shell script named "ttykind".  It took a tty name on the
commandline (default: current terminal) and output the tty kind from the
/etc/ttys file.  For example, let's say I'm remotely logged in on /dev/ttyp3,
and /etc/ttys shows it as a "network" tty.  Running "ttykind" will give:
	% ttykind
	network

So, setting up my .login was easy.  I put a test like this one in it:

	switch ("`ttykind`")
	case network:
		# do stuff for network login
	case xxx:
		# do stuff for xxx login
	default:

DISCLAIMERS: The /etc/ttys file is important; you shouldn't edit it without
thinking about what else will be affected.  Also, on some non-4.3BSD systems,
there are two files named (I think) /etc/ttys and /etc/ttytype; they work in a
different way than the 4.3BSD /etc/ttys file.  Finally, it's been quite a
while since I used that system; I hope I haven't forgotten any details.

--Jerry Peek, Northeast Parallel Architectures Center, Syracuse, NY 13244-1260
  jerryp at cmx.npac.syr.edu
  +1 315 423-4120