How to change the screen brightness of notebooks in linux

A classic problem with linux notebooks is screen brightness. Always starts at 100%. While it can be corrected with a key or key combination (fn + some key) is annoying to do it every time you boot the system as the changes do not stay for the next session.

The reality is that it's very easy to solve but sometimes newcomers do not realize how. Almost all distros come with a energy manager ,Is that a battery icon that always appears on the taskbar. If they right click on it and give "preferences" and there somewhere will have options to modify the brightness ,Depending on the energy manager to use will have more or less options such as the brightness is different when using the notebook with the battery or when connected to the mains.

But ... some do not use programs as 'complex' and prefer things 'simple'. No graphics applications, it is best command in the console

The first thing to do is type in the console:

xrandr

They will return data on monitors that are connected, but we only want the name.

The following command will be:

xrandr –output LVDS1 –set BACKLIGHT 5

Changing the name to your monitor and adjusting the value 5 for a number of 1 to 10 representing the brightness level. I really like 2

Then just a matter of executing that command at the beginning of each session. In gnome you can find it in the menu that says "Applications to start", I use OpenBox and I have to put in the file .config/openbox/autostart.sh

I hope you learn