Terminal settings and background processes

Terminal settings and background processes

[Peter Stephenson]

I'm still getting my terminal settings messed up because of background
processes exiting on IRIX.  Did this patch not make it into zefram3?
I'm not sure I ever had the definitive version since there were numerous.

-- 
Peter Stephenson <pws@ifh.de>       Tel: +39 50 911239
WWW:  http://www.ifh.de/~pws/
Gruppo Teorico, Dipartimento di Fisica
Piazza Torricelli 2, 56100 Pisa, Italy

Re: Terminal settings and background processes

[Andrew Main]

Peter Stephenson wrote:
>I'm still getting my terminal settings messed up because of background
>processes exiting on IRIX.  Did this patch not make it into zefram3?
>I'm not sure I ever had the definitive version since there were numerous.

There were many patches on that issue, with several conflicting branches.
zefram3 contained the set of patches that there was eventually a consensus
on (at least, a consensus among those few of us that were actually paying
close attention).  zefram3 fixed the original problem in all cases I
tested (only on Linux, but I don't think this is system dependent).
What precisely is not working for you?

-zefram

Re: Terminal settings and background processes

[Peter Stephenson]

Andrew Main wrote:
> Peter Stephenson wrote:
> >I'm still getting my terminal settings messed up because of background
> >processes exiting on IRIX.  Did this patch not make it into zefram3?
> >I'm not sure I ever had the definitive version since there were numerous.
> 
> There were many patches on that issue, with several conflicting branches.

I certainly appreciate this:  any from me could certainly be ignored,
since I'm pretty sure the changes I suggested were incorporated into more
sophisticated variants.

> What precisely is not working for you?

After experimenting, it looks like killing a background job causes the
problem.  It doesn't matter if the job is running or suspended, and it
doesn't matter how simple the job is --- it's not just with emacs, it
happens even with sleep:

% stty -a
...
intr = ^C; quit = ^\; erase = ^?; kill = ^U; eof = ^D; eol = <undef>;
eol2 = <undef>; swtch = <undef>; start = ^Q; stop = ^S; susp = ^Z; dsusp = ^Y;
rprnt = ^R; werase = ^W; lnext = ^V; flush = ^O;
...
% sleep 10 &
[1] 3007
% kill %1
[1] + 3007 terminated sleep 10
% stty -a
...
intr = ^C; quit = <undef>; erase = ^?; kill = ^U; eof = ^A; eol = <undef>;
eol2 = <undef>; swtch = <undef>; start = ^Q; stop = ^S; susp = <undef>;
dsusp = <undef>; rprnt = ^R; werase = ^W; lnext = <undef>; flush = <undef>;
...

My terminal is reduced to a vt100, since the X terminal server is
down, so debugging is a little unrewarding at the moment and I haven't
looked any further yet.

-- 
Peter Stephenson <pws@ifh.de>       Tel: +39 50 911239
WWW:  http://www.ifh.de/~pws/
Gruppo Teorico, Dipartimento di Fisica
Piazza Torricelli 2, 56100 Pisa, Italy

Re: Terminal settings and background processes

[Andrew Main]

Peter Stephenson wrote:
>intr = ^C; quit = <undef>; erase = ^?; kill = ^U; eof = ^A; eol = <undef>;
>eol2 = <undef>; swtch = <undef>; start = ^Q; stop = ^S; susp = <undef>;
>dsusp = <undef>; rprnt = ^R; werase = ^W; lnext = <undef>; flush = <undef>;

Isn't this sort of thing a known system-dependent problem, and not the
shell's fault?  Particularly the eof = ^A -- IIRC this is caused by a
confusion between two flavours of termio structure.  Isn't this, in fact,
what ttyctl is for?

-zefram

Re: Terminal settings and background processes

[Peter Stephenson]

Andrew Main wrote:
> Peter Stephenson wrote:
> >intr = ^C; quit = <undef>; erase = ^?; kill = ^U; eof = ^A; eol = <undef>;
> >eol2 = <undef>; swtch = <undef>; start = ^Q; stop = ^S; susp = <undef>;
> >dsusp = <undef>; rprnt = ^R; werase = ^W; lnext = <undef>; flush = <undef>;
> 
> Isn't this sort of thing a known system-dependent problem, and not the
> shell's fault?

ttyctl -f certainly stops this, as it should, but I don't think it's
that simple, since I tried zsh 2.5 and the terminal modes weren't
altered even without the tty frozen, which suggests zsh is now still
reading terminal modes when it doesn't need to.

-- 
Peter Stephenson <pws@ifh.de>       Tel: +39 50 911239
WWW:  http://www.ifh.de/~pws/
Gruppo Teorico, Dipartimento di Fisica
Piazza Torricelli 2, 56100 Pisa, Italy