Tjyylli

I want CapsLock key on my keyboard to act like the left mouse button. I want to be able to perform clicks, double clicks, send mouse down and mouse up events etc.

Now I am using AutoHotkey and the following script

Capslock::LButton

Return

The script works but not in every app and not every time. For example, it doesn't work in Task Manager, it usually doesn't work in installer UIs and some other places.

The script / AutoHotkey also doesn't work in windows of apps under some load. For example, if the app is performing heavy IO then the script might or might not work.

This is annoying to have intermittent issues with the approach.

So, please provide some advice on how to improve the script or maybe recommend some better alternatives than AutoHotkey.

The question does not specify the Windowing/Operating system (although one might be tempted to guess...), so for completeness this is the answer in (modern) X11:

1) find keycode corresponding to CapsLock - e.g. bu running xev and looking for keycode in the output while pressing CapsLock:

$ xev | grep keycode

state 0x10, keycode 66 (keysym 0xffe5, Caps_Lock), same_screen YES,

state 0x12, keycode 66 (keysym 0xffe5, Caps_Lock), same_screen YES,

If you are using "normal" (i.e. PC) keyboard it should be 66

2) enable mousekeys:

$ xkbset m

3) map the keys you want:

xmodmap  -e 'keycode 66 = Pointer_Button1'

or, if you want to be fancy, keep Caps_Lock with some modifier:

xmodmap  -e 'keycode 66 = Pointer_Button1 Caps_Lock'

will keep the CapsLock functionality if you press Shift+CapsLock

For an easy solution, I suggest to set up mouse keys: Control PanelAll Control Panel ItemsEase of Access CenterSet up Mouse Keys

This will enable to use your keyboard as a mouse by using the numpad area.
How to use guide.

If You want to customize it, by altering the keys, than I suggest using NeatMouse.

NeatMouse has English, French, German, Greek, Italian, Polish and
Ukrainian translations. Both regular and portable versions are
available. It is small, convenient, efficient and completely free!

Ok, it turns out there is a hack that enables AutoHotkey to work in Task Manager etc.

Enable interaction with administrative programs

Tried that. It worked. So far so good.

In the spirit of Radovan Garabik's answer (for those of us using an X11 based OS, e.g. Kubuntu .. if you are using Windows this is not for you, stick with the AutoHotKey solutions.) I got this to work without disabling my numpad by doing this:

In my ~/.bashrc (or whatever startup script is appropriate to your system) I added these lines:

/usr/bin/xmodmap -e "remove lock = Caps_Lock"

/usr/bin/xmodmap -e "keycode 66 ="

/usr/bin/xbindkeys -f ~/.xbindkeysrc

This apparently removes the 'locking' behavior of Caps Lock and assigns that key (key 66) to nothingness. Then it lets xbindkeys assign the behavior we want. (You may need to install xbindkeys, on Debian/Ubuntu that is sudo apt install xbindkeys.)

For that I created the file ~/.xbindkeysrc with these lines:

"xte 'mouseclick 1'"

  c:66

A reboot or running source ~/.bashrc should make it work. If you are tinkering with xbindkeys and need to reload it, try this:

killall xbindkeys

xbindkeys -f ~/.xbindkeysrc