Re: [Resolved]Re: OT: M-S-$ Not Working

[Maxim Nikulin]

On 06/02/2021 00:38, Bo Grimes wrote:
> I have no idea what 3rd level is, but before I ticked it I turned off
> my number lock, and C-S-$ worked!  So I ticked it and it stopped
> working.  So I unticked it and ticked Number keypad always enters
> digits, which is, of course, why I use Num Lock to begin with.

Definitely "xev" is your friend if your want to realize actual effect of 
such changes, along with "setxkbmap -query" (or "setxkbmap -print") and 
"xkbcomp -xkb :0 -".

3rd level is intended to type some characters absent in regular layout 
using a special modifier key. Personally I use 2 keyboard layouts and 
compose key for some symbols that are not directly available, so I do 
not need 3rd level as well.

> With that ticked Emacs behaves as expected.  I have always used Num
> Lock and never had that problems

You could have a look into /usr/share/X11/xkb/rules/evdev.lst 
/usr/share/X11/xkb/symbols/keypad /usr/share/X11/xkb/types/numpad files. 
If I do not mistake, $ is mapped for keypad with keypad:oss_wang option. 
Likely you could achieve what you want with custom Xkb configuration. I 
have not tried such tricks however. The most comprehensive guide on Xkb, 
I have seen, was in Russian. Its English variant is incomplete, the 
author's site is down. 
https://web.archive.org/web/20121108145326/http://pascal.tsu.ru/en/xkb/

X Keyboard Extension Protocol and library specifications could be hard 
to read, XKB Configuration Guide hosted on x.org is too brief.

P.S. Have you checked that it is possible to swap Ctrl and Caps in 
wayland session? If not it is likely worth filing a bug. It seems 
wayland will be default soon. Some Xkb stuff is already broken in gnome 
(rather intentionally). My first experience with wayland was that it 
took enough time to realize why I could not authenticate. Gdm was using 
wayland by default and in password fields (hidden input!) shift does not 
allow several capital letters in a row.