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How can I set the laptop screen brightness from command line?

Asked by [ Editor ] , Edited by Egon Willighagen [ Editor ]

My laptop’s screen brightness does not always recover properly after returning from a suspend, and like to reset the brightness from the command line. Is that possible, and if so, what command should I use?

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1 answer



Depending on your OS/version there are different ways to do it, of course replace VALUE with your desired value:

  • sudo echo -n VALUE > /proc/acpi/video/VGA/LCD/brightness
  • sudo echo -n VALUE > /proc/acpi/video/GLX0/LCD/brightness
Or you simply install xbacklight:

sudo apt-get install xbacklight

and change the brightness without getting root:

xbacklight -set VALUE
NN comments

The latter command gives me this message: “No outputs have backlight property”.


OK, the device to use on my machine was: /proc/acpi/video/GFX0/DD02/brightness But, the sudo command does not work, because it only seems to apply to the echo, but the permission elevation is lost after the ‘>’… so, I created a /usr/local/bin/bright script to do the echo bits without sudo, allowing me to ‘sudo bright’… that works fine for me :) Thanx!

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