Serial line terminal size.

[Rodney W. Grimes]

> On 0529T1110, Rodney W. Grimes wrote:
> > [ Charset ISO-8859-2 unsupported, converting... ]
> > > On Mon, 2017-05-29 at 13:22 +0200, Ed Schouten wrote:
> > > > Hi Edward,
> > > > 
> > > > 2017-05-24 10:55 GMT+02:00 Edward Tomasz Napiera?a <trasz at freebsd.org
> > > > >:
> > > > > 
> > > > > There's a problem with serial consoles - after logging in, the
> > > > > terminal
> > > > > size is not set, ie it looks like this (notice the "0 rows; 0
> > > > > columns;"):
> > > > Wouldn't it make more sense for getty to set this up properly, as
> > > > opposed to putting it in all of the shell rc files?
> > > > 
> > > 
> > > I was thinking exactly the same thing a few days ago, but then I looked
> > > at the source code to getty and kinda backed away slowly and quietly,
> > > as one might do with any sleeping monster.
> > 
> > Now that I can agree with.   Getty has never been a friendly place.
> > 
> > I also think this belongs in Getty despite Warners concern that you
> > can not turn it off, as Getty alread does Termios stuff, which
> > you control via /etc/ttys, so there is a place to make a knob should
> > it be implemented in getty.
> 
> It's still something that the _user_ - as opposed to the system
> administrator - couldn't turn off.  Not sure it's actually important,
> though.
> 
> > This is a specific issue to hardwired terminals, which is what
> > getty was written for.
> > 
> > It could also fixes the issues that I have pointed out in
> > https://reviews.freebsd.org/D10642 with col/row not being
> > reset between logins which yields the propose patch ineffective.
> 
> If getty did reset the terminal size upon logoff, that would unbreak
> the mechanism.  Now, why doesn't it do that?  Isn't it expected to
> do so - to revert the terminal and serial port to some predefined
> initial state?  If it does - why doesn't this include the terminal
> size?

I have a feeling that issue is in the tty layer, or perhaps
getty is not closing the terminal so that the reset mechanism
can fire.


-- 
Rod Grimes                                                 rgrimes at freebsd.org