Backlight
xbacklight
xbacklight
uses X to change the light settings. This can be inconvenient in some situations, e.g. for use with the services.actkbd
service, which doesn't know about the X session. It, though, has an history of being more compatible with different hardware, especially newer hardware[citation needed]
light
light
does not use X to change the light settings. This can be used in situations where the X service isn't available.
Using /proc/
...