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

[Karl O. Pinc]

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.

Karl <kop@meme.com>
Free Software:  "You don't pay back, you pay forward."
                 -- Robert A. Heinlein