bug#3540: Please reserve a ctrl-key combination for interoperability

[Marcin Borkowski <mbork@mbork.pl>]

On 2019-10-06, at 06:56, Stefan Kangas <stefan@marxist.se> wrote:

> "Karl O. Pinc" <kop@meme.com> writes:
>
>> Hello,
>>
>> I want emacs to keep one control key combination unbound
>> so that emacs can be run inside other programs that
>> need an escape character to enter a control mode.
>> Examples of such programs are screen and minicom.
>>
>> Screen is a full-screen window manager  that  multiplexes
>> a physical terminal between several processes
>> (typically interactive shells).  Minicom  is  a
>> serial communication program, a terminal emulator.
>>
>> It is difficult to use emacs inside such programs because
>> these programs (by default) bind a commonly used emacs control
>> key sequence as their escape key.  Emacs users should be able to
>> re-configure such programs to use an unbound emacs ctrl keypress.
>>
>> Sure, each emacs user could chose their own key combination (I used
>> ctrl-\, but I recently upgraded from emacs 21 and see it's
>> now bound in emacs 22), but this makes it almost
>> impossible to, e.g., publish tutorials/recipies on how to
>> use, say, screen, with emacs.  The person following the
>> tutorial might need the particular emacs feature that
>> is no longer bound to the standard emacs key combination.
>>
>> As things stand emacs users have a bar over which they
>> must jump to use such useful programs as screen; each
>> user must figure out what emacs keypress they wish
>> to sacrifice, taking into account the key combinations
>> used by screen at a time when they are unfamiliar with
>> screen.  At minimum if a control key combination was
>> reserved the choice would be obvious, at best either
>> emacs or the screen documentation would describe
>> what configuration and usage changes were necessary
>> to allow the two programs to interoperate.
>>
>> Frankly, Ctrl-\ was perfect because it was not otherwise
>> bound in either screen or minicom.  The choice of a key
>> that's already bound in these programs means that yet more
>> reconfiguration of screen/minicom must be done to retain
>> functionality, the lost functionality must be bound to
>> a non-standard key.  This introduces yet more incompatibility
>> between emacs users and the rest of the universe.
>>
>> Thank you for your time.
>
> This wishlist request is now 10 years old.  If I understand it
> correctly, it is asking for a mandate to never use a particular Ctrl-key
> combination (within Emacs core, I assume), in order that people could
> then use that key within screen.
>
> I think this is not the best way to go about it.  Users of screen or
> tmux or whatever could easily just rebind whatever key they find
> conflicts with their keybinding for screen or tmux commands.
>
> Since this hasn't garnered support from more than one other user in the
> last 10 years, I'm therefore proposing to close this as wontfix.  If
> anyone disagrees with that, please protest now, or I'll do that in a
> couple of weeks.

As a partial solution, the manual *might* suggest to use C-z for that,
especially that is is bounded to a 99.99% useless command by default
(and using e.g. screen or tmux makes it 100% useless).

Best,

--
Marcin Borkowski
http://mbork.pl