Re: Suggestion for terminal package maintainers

[Ken Brown <kbrown at cornell dot edu>]

On 6/2/2009 10:09 AM, Corinna Vinschen wrote:
> On Jun  2 09:39, Ken Brown wrote:
> > On 6/2/2009 9:28 AM, Ken Brown wrote:
> > > On 6/2/2009 8:48 AM, Corinna Vinschen wrote:
> > > > On Jun  1 17:03, Ken Brown wrote:
> > > > > The Cygwin console, after some changes made this past weekend, now  
> > > > > uses  ^? as the default erase character, and this is what is sent 
> > > > > by the  backspace key instead of ^H   
> > > > > [...]
> > > > What makes me a bit concerned about this change is that, while we can
> > > > change Cygwin's terminfo and termcap files, we can't do that for
> > > > existing non-Cygwin installations.  Is it really safe to change the BS
> > > > key to ^? now that the "cygwin" terminal type is known to return ^H for
> > > > so many years?
> > > Applications like emacs that use ncurses should have no problem.  Are  
> > > there applications that rely on the historical behavior of the cygwin  
> > > terminal type rather than querying terminfo?  Apart from cygwin, such  
> > > applications would have problems with any terminal type that decides to 
> > > change its behavior.
> > Sorry, I think I misinterpreted what you meant by "non-Cygwin  
> > installations".  But wouldn't the issue be resolved by pushing the  
> > change to the cygwin terminal type in terminfo upstream?
>
> It would solve it over time when non-Cygwin systems pick up the
> latest terminfo/termcap.  I'm just wondering if it's not a bit
> surprising for remote apps when started in a Cygwin console window
> via ssh/rsh/telnet/etc.

OK, I get it now.  With the latest snapshot installed, I just started a 
Cygwin console and logged into a Redhat linux system via ssh.  Terminfo 
has the wrong information, of course:

$ tput -T cygwin kbs | cat -v
^H

/etc/termcap doesn't have an entry for cygwin, so that's not an issue. 
But stty gets it right, inheriting the setting from the Cygwin console I 
guess:

$ stty -a | grep erase
... erase = ^? ...

And when I start emacs, both the backspace key and C-h work as expected.

That's just emacs.  I don't know what will happen with other applications.

Ken