How to control the brightness of the display from command line?

January 17, 2012 · ctheroux Ubuntu 11.10 Ubuntu 11.04

You can set the brightness of the display by issuing this command within a shell

echo 3 > /sys/class/backlight/acpi_video0/brightness

where 3 is the brightness level. Its value is from 0 up to the value in the file /sys/class/backlight/acpi_video0/max_brightness.