How to turn on/off leds by terminal?

Question

I would like turn on/turn off some of my leds running a command on linux.

I use Ubuntu 12.04 LTS.

I tried

xset led named "Scroll Lock"
xset led named "Num Lock"
xset led 2             (this is the number of Scroll Lock as `xset q` says)
xset led 1

but nothing works.

Tried

setleds +num
setleds +scroll

but I got a error message saying Error reading the current settings of flags. Maybe you're not on the console? (I was in a terminal).

So, how can I perform this?

score 11 · Answer 1 · answered Jan 12 '14 at 01:33

11

xdotool key Num_Lock

Is the an answer (the easiest you're likely to find); inverting the state, it also provides a path to search (xinput and modifying a slave keyboard state) if you really just want to set an led status.

I too ran across my Num Lock keyboard LED and X11 state differing recently (happens with remote desktops, games, etc)

This reference explains what's going on, and almost has the complete solution (but it has a case-typo, you need Num_Lock not Num_lock).

http://blog.ssokolow.com/archives/2013/04/18/how-to-invert-your-x11-numlock-led/

answered Jan 12 '14 at 01:33

Michael J. Evans

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2
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This should be the accepted answer. Best solution I've ever seen. Thank you! The lights are so annoying! – jocap May 13 '14 at 21:22
1

Note that `xdotool key Num_Lock` is not as innocent as turning a LED on or off; It is the equivalent of actually pressing the key! – Serge Stroobandt Nov 04 '18 at 12:14

score 7 · Answer 2 · answered May 06 '15 at 10:28

7

To turn Scroll Lock led on run:

xset -led 2 led on

To turn it off run:

xset -led 2 led off

answered May 06 '15 at 10:28

Aleksey Alekseev

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score 4 · Answer 3 · answered Oct 22 '20 at 20:24

4

There is also solution without any extra software. Just use:

echo "1" > /sys/class/leds/input20::scrolllock/brightness
#Or
echo "1" > /sys/class/leds/input20::/brightness

as root.

answered Oct 22 '20 at 20:24

ddd ddd111111

41
2

Works like a charm – mandza Mar 26 '21 at 21:30

VenkatH · Answer 4 · 2012-10-14T17:06:12.430

1

Press Ctrl+Alt+F1, login, and then try setleds.

edited Oct 14 '12 at 17:06

answered Jun 16 '12 at 08:16

VenkatH

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Interesting. `setleds` (not `xset`) worked for me now too. Looks like we need set a `display`. I tried several things but nothing worked. But, looks we're almost. – GarouDan Jun 17 '12 at 11:28
2

This isnt the final answer to me, because I need this working on the gui display, not at the console display. – GarouDan Jul 23 '12 at 19:55

score 0 · Answer 5 · edited Apr 13 '17 at 12:37

0

As noted in this answer, if your screen is on TTY1, but you try to control the LEDs from somewhere else (such as an SSH session), you can use setleds in the following way:

setleds -L +num +caps +scroll < /dev/tty1

edited Apr 13 '17 at 12:37

Community

1

answered Jan 02 '17 at 18:50

cdauth

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score 0 · Answer 6 · answered May 06 '15 at 11:22

0

Install xf86-input-keyboard if you don't have it.

Set kbd_mode -u

Make sure you don't have multiple instances of the KB (check what XINPUT: reports).

answered May 06 '15 at 11:22

Overmind

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4
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score -1 · Answer 7 · edited Apr 30 '15 at 19:07

-1

Just use the command:

numlockx on

or

numlockx off

to change the state.

edited Apr 30 '15 at 19:07

slhck

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answered Apr 30 '15 at 09:52

minux

1

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This is rather brief: some more detail would be helpful. For example, in what circumstances does this command work? – David Richerby Apr 30 '15 at 10:33
It does exactly what it sounds like. – Jon Apr 30 '15 at 20:08

How to turn on/off leds by terminal?

7 Answers7