2020-11-22

<lejonet> it was a while since I had to dig around that on my laptop (I also use i3) but I have a vague recollection of it being /sys/class/backlight that the brightness control is in

2020-07-07

<confus> just for the record, I ended up with: services.udev.extraRules = '' ACTION=="add", SUBSYSTEM=="backlight", KERNEL=="acpi_video0", RUN+="${pkgs.coreutils}/bin/chmod g+w /sys/class/backlight/%k/brightness" '';
<growpotkin> ACTION=="add", SUBSYSTEM=="backlight", KERNEL=="acpi_video0", RUN+="/bin/chmod g+w /sys/class/backlight/%k/brightness"
<growpotkin> ACTION=="add", SUBSYSTEM=="backlight", KERNEL=="acpi_video0", RUN+="/bin/chgrp video /sys/class/backlight/%k/brightness"
<confus> sudo chmod a+w /sys/class/backlight/*/brightness, it's just a file gchristensen
<confus> hi, I'd like to modify the permissions of /sys/class/backlight/*/brightness in my nixos config, so that all users can write to it. How do I go about that?

2019-10-30

<fresheyeball> It looks like I need to symlink /sys/class/backlight

2019-08-03

<niso> Edes: what's your output of "cat /sys/class/backlight/*/brightness" ?

2019-07-29

<niso> mbrgm: what does the following command return: cat /sys/class/backlight/*/brightness

2019-07-25

<gwen> As far as I can tell, all entries of /sys/class/backlight belong to root/root

2019-05-16

<tilpner> ~ > ls -lah /sys/class/backlight/*/brightness
<tilpner> Paste the output of: ls -lah /sys/class/backlight/*/brightness
<tilpner> ACTION=="add", SUBSYSTEM=="backlight", RUN+="${pkgs.coreutils}/bin/chmod g+w /sys/class/backlight/%k/brightness"

2019-04-26

<__monty__> Also if it doesn't then what's my graphics card's brand doing in the /sys/class/backlight... path?

2019-04-16

<jomik> I only have `ACTION=="add", SUBSYSTEM=="backlight", RUN+="${pkgs.coreutils}/bin/chmod ugo=rw /sys/class/backlight/%k/brightness"`

2019-01-20

<disasm> I was initially running sudo bash -c "echo 2500 > /sys/class/backlight..." and then figured there had to be a better way. light looks nice :)

2018-12-12

<Slabity90> CodeKiwi: Can you see what's in /sys/class/backlight?

2018-11-09

<wpcarro> Any users of `xbacklight` know how to point it to the correct sysfs driver? I have two options when I `ls /sys/class/backlight` and I know which one works. When I run `xbacklight -inc 10` nothing happens though. Any troubleshooting help is appreciated. It hasn't been working for about a month and I'm trying to fix it now

2018-11-04

<tilpner> valwal - You can always script you way around /sys/class/backlight

2018-08-20

<adamantium> Hey, i'm trying to add a a services.udev.extraRules . It nixos-rebuild errs on the line RUN+="/bin/chgrp video /sys/class/backlight/%k/brightness", \ ...

2017-11-27

<MichaelRaskin> petersjt014: what is in /sys/class/backlight ?

2017-08-31

<sphalerite> Delta_VII: Alright… What does `ls /sys/class/backlight` say?

2017-07-21

<srhb> cwre: Right, so something like cat /sys/class/backlight/*/brightness
<srhb> cwre: cwre Do you have anything in /sys/class/backlight ?

2017-05-02

<sphalerite> phorse`: does xbacklight work for you? I had to mess with the X config a bit because X wasn't using the right device — there's both intel_backlight and gmux_backlight in /sys/class/backlight and X was preferring intel_backlight even though gmux_backlight was the right one

2017-04-26

<sphalerite> also, if you're running it from systemd it might make sense not to tie it to X, and use the sysfs interface to control the backlight instead (write to /sys/class/backlight/<id>/brightness)