Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!csd4.csd.uwm.edu!cs.utexas.edu!uunet!ibmpa!bullhead!brunner
From: brunner@bullhead.uucp
Newsgroups: comp.sys.ibm.pc.rt
Subject: Re: rlogin to an RT prevents using vi
Keywords: TCP, vi, rlogin
Message-ID: <1934@ibmpa.UUCP>
Date: 29 Aug 89 01:15:01 GMT
References: <396@ifcom.UUCP>
Sender: news@ibmpa.UUCP
Reply-To: brunner@ibmsupt.UUCP ()
Organization: IBM AWD Palo Alto
Lines: 51

>In article <396@ifcom.UUCP> hst@ifcom.UUCP (Hartmut Streppel) writes:
>If we use rlogin to login from one of the machines mentioned
>above to the RT, and then try to use  vi on the RT, vi fails giving 
>the message: "Don't know enough your terminal to use visual"

The error is due to an initial sanity check in the vok routine in ex_v.c,
the portion of the ex/vi code which checks for terminal characteristics.

If the global WCOLS hasn't been set prior to entry into this routine,
then there is insufficient info to divide the screen buffer into lines.

So, why hasn't WCOLS been set? Both rlogin and telnet make an effort to
determin the TERM shell variable in the local environment and pass it to
the remote host, where it may be reset during the remote host login. Check
your .cshrc/.login on the remote host for settings, you may want to have
your term variable host dependent, set in a switch statement in .login

switch ($host) # ibmpa lan hosts
	case ibmsupt:
		set	TERM = "ibmaed"
		breaksw
	case dumbbunny:
		set	TERM = "dumb"
		breaksw
	case dialbunny:
		set	TERM = "dialup"
		breaksw
	default:
		set	TERM = "vt100"
endsw

P.S. Your mailage may vary with AIX, check ttys(5) for supported types
and echo $term (or $TERM) on both ends of the pipe.

An equivalent problem was reported as an APAR, xterm via telnet didn't
force the remote host to use the local host's notion of the term shell
variable. This is NOT a bug. Telnet/rlogin are general remote terminal
routines, if the local setting for term were forced on the remote host
it would be very inconvient, passing vt100 is always safe (even to TOPS
and VMS hosts on the Internet), but the remote host may not support X
or the Advanced Experimental Display or whatever. It is preferable to
have a screen-oriented application (e.g., vi) bail out to line mode when
the environment is either unsupported or not available during telnet/rlogin
initiation. One can always set term in the login environment or "by hand".




Eric Brunner, IBM AWD Palo Alto
inet: brunner@monet.berkeley.edu or brunner%ibmsupt@uunet.uu.net
uucp: uunet!ibmsupt!brunner		(415) 855-4486