CapsLockLed

A little program to control the CapsLock LED on my laptop (DELL XPS 15 9560) keyboard.

I like to have CapsLock mapped to Escape, since I use Escape way more than I ever use CapsLock. This is especially useful in vim to exit from INSERT mode.

What I don't like is useless technical stuff. What I like is giving useless technical stuff new purpose.

So I thought, the integrated CapsLock LED on my keyboard would make a good visual indicator for INSERT mode.

This program must be owned by root and have SUID bit set.

$ sudo chown root capslockled
$ sudo chmod u+s capslockled

The program can be called with capslockled 1 to turn LED on. Basically any other argument turns the LED off, but it would of course make sense to call it with capslockled 0

On success the program returns 0 on failure 1.

Building this program

It has a simple Makefile to compile the program, set permissions and copy it to a specific folder.

Only build program, you have to change ownership and set SUID bit yourself.

make

Or just let the Makefile handle it. Default is to copy the compiled program to ~/bin. This is the folder where I keep my own compiled programs. You will have to adapt it to your likings.

make install

Add hook to vimrc

" call a helper program to set CapsLock LED when in INSERT mode
au InsertEnter * :silent ! capslockled 1
au InsertLeave * :silent ! capslockled 0