How to automate keyboard backlight ON at boot

Question

Right now I am running a cooler Master keyboard on Kubuntu 16.04. At present I have to run

xset led 3

in Konsole in order to turn the keyboard on, which is a PITA.

How can I instruct the system to light the keyboard at boot, particularly before and after the login screen?

I would put the command in `/etc/rc.local` but you can also use a `cron` job with `@reboot`. See: https://askubuntu.com/questions/228304/how-do-i-run-a-script-at-start-up — WinEunuuchs2Unix, Jan 07 '18 at 19:31
Can I enter the command as is, or should I enter a pathway for an *.sh file? — Timbot2000, Jan 07 '18 at 20:12
You can enter the command as is. A `*.sh` (script) file is typically only used for multi-line commands. When using `cron` you must find out the directory name to prefix the command. ie use `which xset` returns: `/usr/bin/xset` which is the exact command format you need to use. The simpler method is just to put the command in `/etc/rc.local` rather than using `cron`. — WinEunuuchs2Unix, Jan 07 '18 at 20:23
Sorry WinEunuuchs2Unix, entering it in the rc.local file failed to enact the command at startup. What do we try next? — Timbot2000, Jan 08 '18 at 02:49
Sorry the rc.local didn't work out. I've posted an answer which I hope does work. — WinEunuuchs2Unix, Jan 08 '18 at 03:42
[This](https://unix.stackexchange.com/a/625650/143980) is a more generic approach that lets you either set keyboard backlight to be **continuously** `on` since boot time or to be `on` since boot time **only during an specific time interval** (e.g. 6 PM till 8 AM). — Yuri Sucupira, Jun 24 '22 at 05:38

score 3 · Answer 1 · edited Jun 12 '20 at 14:37

Using "Startup Applications" instead of `/etc/rc.local`

Select the first option on your Launcher called Dash. Then type "startup" and a screen similar to this will appear:
Select the option "Startup Applications" and a screen similar to this will appear:
Select Add and this screen will appear:
Make sure you enter the command as: /usr/bin/xset led 3
I entered the comment as: Ubuntu 16.04 regular crash, Compiz segfault, error 4 in i965_dri.so, Fresh install but you don't need to.

I can't test this on my system because the Laptop's built-in keyboard and wireless keyboard both light up automatically.

You can't put xrandr commands in /etc/rc.local because it runs before a user logs in. xrandr commands can only be used after the user logs on.

I can confirm, this actually works on Linux Mint 19.1 – falconR Dec 27 '18 at 23:37 — falconR, Dec 27 '18 at 23:37