keyd
keyd is a key remapping daemon that allows the user to map keys per application and globally with support for both Xorg and Wayland.
Instalación
Emerge
keyd is currently only available on the GURU ebuild repository.
If the overlay is not enabled, run:
root #eselect repository enable guru
root #emaint sync -r guru
After activating the overlay, keyd can be installed:
root #emerge --ask app-misc/keydUtilización
There is global config file at /etc/keyd/default.conf that define "layers", are packs of keys, that may be activated sequentially or at the same time with keys that activate layer.
For per application usage there is separate config at ~/.config/keyd/app.conf that define layers per applications. In this layers you define additional keys to global. Key here may be double in form of <layer>.<key>.
Global configuration activated with "keyd service".
keyd distributed with "keyd-application-mapper" script for usage in window environment. To use this script user require permission to "keyd goup", that may be granted with following command:
root #usermod -aG keyd larry
Configuration cases for per application usage
Three keys like Alt+Shift+v
There are two predefined layers here alt and shift. You should define global combined layer "[alt+shift]", after that you may use this as name for layer.
.config/keyd/app.confalt+shift.v = C-endTwo action at one key
If you need several keys to be pressed you may use "macro" action with several expressions separated by space.
If you need some internal action like "clear()" you should look for "clearm()" action that execute expression before "clear()" call.
Chords
Implemented with "oneshot()" action for example "Ctrl+x key":
control.x = oneshot(<gloval layer with some key>)
Clear other layer
Only "clearm()" working for current stable version, that breaks all layers.
Security concerns
When a user is granted access to the keyd group, and thereby to /run/keyd.socket, which allows them to send keys system-wide, it creates a breach that may be exploited by any malicious program within that user's environment. This could potentially lead to elevated root access. This vulnerability affects all uinput-based applications that allow arbitrary keys to be sent from user space.
Wayland security
This vulnerability may be may be closed if we run script this way with Wayland environment variables:
user $sudo --preserve-env=WAYLAND_DISPLAY,XDG_RUNTIME_DIR /usr/bin/keyd-application-mapper
For this command add sudo permission for current user:
larry ALL=(root) SETENV:NOPASSWD:/usr/bin/keyd-application-mapper
Copy user configuration to root folder:
root #mkdir -p /root/.config/keyd
root #cp /home/larry/.config/keyd/app.conf /root/.config/keyd/app.conf
Withdraw permits by removing user from "keyd" group:
root #gpasswd -d larry keyd
Example of configuration of Emacs keys for Firefox
.config/keyd/app.confFor Firefox[firefox-esr|*]
# Firefox
alt.x = C-l
alt.a = C-pageup
alt.e = C-pagedown
control.s = C-f
# - Firefox built-in:
# control.[ - back
# control.] - forward
# F3 - search forward
# shift.F3 - search backward
# - enter, escape
control.g = clearm(escape)
control.m = enter
# - begin, end of string
control.a = home
control.e = end
# - edit
control.h = backspace
control.d = delete
control.l = left
control.f = right
control.n = down
control.k = up
alt.l = C-left
alt.f = C-right
control.slash = C-z
# - scroll
alt.v = pageup
control.v = pagedown
alt.z = up
control.z = down
# - copy, paste
control.w = clearm(C-x)
alt.w = clearm(C-c)
control.y = clearm(C-v)
alt.c = C-v
# - selection mode - remember: C+h and C+d don't work with
control.space = toggle(shift)
control.c = clearm(C-c)
# - select all
control.x = oneshot(control_x)/etc/keyd/default.confGlobal[ids]
*
# - Firefox copy text
[control+alt]
w = C-w
[alt+shift]
dot = C-end
comma = C-home
[control_x]
h = C-a