Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!ucbvax!decwrl!sun-barr!apple!claris!sts!roy
From: roy@sts.sts.UUCP
Newsgroups: comp.sources.bugs
Subject: Re: atty on Sun 3
Message-ID: <68400002@sts>
Date: 4 Jun 89 16:24:00 GMT
References: <280@kurz-ai.UUCP>
Lines: 47
Nf-ID: #R:kurz-ai.UUCP:280:sts:68400002:000:1956
Nf-From: sts.sts.UUCP!roy    Jun  4 09:24:00 1989


/* Written  4:49 pm  Jun  3, 1989 by guy@auspex.UUCP in sts:comp.sources.bugs */
>Atty core dumps because it calls abort. It calls abort because an pty
>ioctl fails. The ioctl fails because it tries to set terminal modes
>on the master side of the pty instead of on the slave side.
>
>I don't know if that's possible on other systems but it won't work on
>SunOS 4.0 suns, see the enclosed program:

OK, here's the scoop.
.
.
.

	   However, there is a truly slimy kludge in the 4.0 pseudo-tty
	   driver that lets it work *most* of the time for the *BSD*
	   terminal "ioctl"s.  It does *not* work for the System V-style
.
.
.

The following patch to "atty.c" seemed to fix the problem (I was able to
start "atty" up, and type at it a bit, at least); it moves the setting
of the initial pseudo-tty modes from code in the parent which bangs on
the master side to code in the child that bangs on the slave side after
it's opened):

*** atty.c.ORIG	Sat Jun  3 16:25:00 1989
--- atty.c	Sat Jun  3 16:34:32 1989
/* End of text from sts:comp.sources.bugs */

I applied the patch to atty.c and re-compiled with gcc.  The result
was that I'm able to get the initial prompt and type a few characters,
but when I hit Return, I get the same core dump as before and,
apparently, for the same reason.  Naturally, since atty(1) is not
meant to run under System V and SunOS 4.0 is partially based on System
V, it doesn't work too well here.

My fix is to run ash(1) under the cmushell in GNU Emacs.  That way, I
get the Emacs editing power as well as command history.

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