Permanently adjust screen brightness in Ubuntu / Linux Mint

· 1 min read

This is a fix to reset the screen brightness in Ubuntu / Linux Mint on each boot.

This only works if you have a file named brightness in /sys/class/backlight/acpi_video0, and is relevant for Ubuntu (version < 12.04), which had a bug where the brightness would be too high on each restart.

To check your system’s current brightness level:

cat /sys/class/backlight/acpi_video0/brightness

Change brightness by changing the value:

echo 0 > /sys/class/backlight/acpi_video0/brightness

To permanently set the brightness, edit the rc.local script, which runs on each reboot:

sudo gedit /etc/rc.local

Add the following line above exit 0 at the bottom of the file:

echo 0 > /sys/class/backlight/acpi_video0/brightness

Restart your system after saving the file.

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