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From: pphillip@cs.ubc.ca (Peter Phillips)
Newsgroups: comp.sys.mips
Subject: Re: Patches to RISC/OS 4.5 for MIT X11R4
Message-ID: <1991Feb18.222802.2669@cs.ubc.ca>
Date: 18 Feb 91 22:28:02 GMT
References: <1991Feb15.211308.27835@convex.com>
Sender: news@cs.ubc.ca (Usenet News)
Organization: University of British Columbia, Vancouver, B.C., Canada
Lines: 38


We've been using the libraries and clients from X11R4 on our R3260
under RiscOS 4.51 for quite some time now but have run into a small
problem with xterm.

If an xterm is started from a login which has no controlling tty (like
from /usr/ucb/rsh) then the xterm will not get a controlling tty.  The
lack of a controlling tty breaks programs like "su" and "script".
This problem doesn't occur under other UNIX machines running X11R4 nor
does it occur using xterm from RiscWindows 3.21.

Has anyone else run into or solved this problem?  Our X11R4 was
installed using the BSD compiler/libraries.  The only patch applied to
xterm was to make sure that HAS_UTMP_UT_HOST was undefined.

You can see if your xterm has this bug by doing something like:

/usr/ucb/rsh mips-host xterm -display display:0.0

From the resulting xterm doing something like:

echo foo >/dev/tty

Should give you:

/dev/tty: No such device or address

I've been trying to debug this but I'm more than a little confused
about how a controlling tty is set.  In termio(7-SysV) it implies that
opening a tty device will make that tty the process' controlling tty
but this isn't true in all situations.  Under SunOS there is an
ioctl() call which will make an open tty device the controlling tty
but I can't seem to find any corresponding system call in RiscOS 4.51.
(I suspect there isn't one).  Help!

--
Peter Phillips, pphillip@cs.ubc.ca | "It's worse than that ... He has
{alberta,uunet}!ubc-cs!pphillip    | no brain." -- McCoy, "Spock's Brain"