I've searched a method to change the brightness of my laptop display. I saw one article on this forum and followed the instruction like below (under the line) written by Serge (user name).
I ran command line
sudo nano brightness and when editor popped up I typed 100 and hit the new. However, the brightness didn't get changed even though I restarted the laptop. So I gave up changing setting.
Then, I want to delete the setting, file or folder that I created(?) using nano which I typed 100 in it. How can I do this?
Now we can edit brightness file to actually change screen brightness. We will need some text editor command. I prefer using command line text editor nano. So I would do
sudo nano brightness
It will ask you for your password. Enter it, and you will see another screen. Look at where your cursoris, right after the number. That's what I mean when I said "don't hit enter".
This file has to have only that one line, no other. You can use left / right keys to move cursor, and backspace or del keys to delete old number, and then type new. Remember, that you can only go from whatever number was in max_brightness file to 0.
When you wrote new number, press Ctrl+X, it will ask if you want to "Save modified buffer". Press Y. Then it will asks what name of the file to write. Just press enter, we do not want to change name of this file. Done. At this point your brightness should change.