Some apps use ctrl++ and some ctrl+= to zoom in. Only some allow to customize. If all used same, I would just remap the keyboard not to use Shift. Can I make apps receive signals that both combinations are pressed when I press one of them?
I've tried web search for key generation and found QAs on bash solutions and that one advising writing c code: https://stackoverflow.com/questions/22262777/how-to-simulate-keyboard-key-press-code-ascii-of-alt-key. I know key bindings can be edited in /usr/share/X11/xkb/symbols and I can switch + and = as reaction to Shift. I realized I do not understand how the system processes Ctrl press as I have found neither ctrl not control in e.g. /usr/share/X11/xkb/symbols/us. Maybe the easy way to make my idea work is somewhere else...
Added:
I've found Custom xkb layout in which one key creates two unicode code points where answer proposes some workaround with comment "I dug through the source code, there doesn't seem to be any support for including multiple keystrokes in the key definitions of the keymap.", but it was in 2012, maybe now it is possible easier.
