Adjust display brightness in Linux

I suddenly wanted to install Linux, but it was really unpleasant.

I started to think about hard disk installation, but I couldn't install it from the mobile hard disk in any way.

Then download red Linux 9 and find that my driver does not exist, so I have to give up.

Install Ubuntu and find that the disk engraving speed is too fast,

Finally, we had to re-burn federa. The installation is complete,

Found:

Just installed the latest Linux era Linux,
However, the brightness of the notebook is very dark, and the eyes are quite uncomfortable.
I just got started. How can I adjust the brightness of my notebook.

I started to prepare to install red Linux 9 and asked to install the driver. I didn't want to, and it took a lot of effort,
This is installed, but it is too dark to be used.

 

 

Through continuous efforts, we finally solved the problem.

Thank you. I have solved the problem.
CodeAs follows:
Sudo sh-c "echo-N 100>/proc/ACPI/Video/VGA/LCDD/brightness"

Note that it is case sensitive.

Run in root.

Su

Enter the password.

 

 

Corrected,It must be run in the "/" directory.