Re: cannot disable output processing in pseudo-terminal (between openpty(3) parent and child)

[Valery Ushakov <uwe%stderr.spb.ru@localhost>]

On Mon, Jul 31, 2023 at 06:41:13 +0000, pouya+lists.netbsd%nohup.io@localhost wrote:

> One difference I see with your code is that you don't seem to change
> the controlling terminal in the child with setsid(2) and a TIOCSCTTY
> ioctl(2).

I only need to feed some input to the terminal emulation code, so the
scaffolding is minimal :).  The child programs are usually just cat,
printf, tputs.


> It made no difference.  In both cases running stty(1) with operands
> "raw" or "-opost" are ineffective and OPOST remains set after
> running them.
[...]
> I'm still puzzled as to why I can't disable OPOST programmatically
> or using stty.
> 
> FWIW I have set TERM=dumb in my terminal and that also seems to
> affect input and output processing.

The fact that TERM affects this is a sign that you likely have
something like a shell with line-editing interfering as RVP suggested
in another message.


-uwe