Display backlight control

MNT Reform
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The backlight is controllable via /sys/class/backlight/backlight/brightness with valid values being 0 (off) to 6 (fully on).

You can either write to the file directly or use tools like brightnessctl to set the brightness.

Turn off screen:

$ brightnessctl s 0
Updated device 'backlight':
Device 'backlight' of class 'backlight':
	Current brightness: 0 (0%)
	Max brightness: 6

Or:

echo 0 > /sys/class/backlight/backlight/brightness

To turn it back on, write a value between 1 and 6 instead.

If you can execute commands as root, you can also use bl_power:

# echo 4 > /sys/class/backlight/backlight/bl_power # Turn off
# echo 0 > /sys/class/backlight/backlight/bl_power # Turn back on

See Backlight support — The Linux Kernel documentation for more details.

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