This program allows you to control the brightness of your primary monitor on a software level from the command line. It uses the xrandr command to adjust the brightness and stores the current brightness level in a file for future reference.

xrandr allows you to set a brightness level with xrandr --output <outputname> --brightness <value> but doesn't allow you to simply increase or decrease it by a value. This script simply stores the brightness level so it can access it and increase/decrease it by whatever desired.

The program also supports the following options:

• --detectmonitor or -d: This option detects the primary monitor and saves its name. Use this option if you change your monitor and want to update the program with the new monitor name.
• --help or -h: Displays the program's usage information.

The program stores the brightness level and monitor name in a file located in the user's home directory. The default file name is .brightness. You can change the file name by modifying the FILENAME constant in the program.

To use the program, run the following command:

./brightness <value>

Replace <value> with the desired brightness level. The program accepts both positive and negative values. Positive values increase the brightness, while negative values decrease it. The program caps the brightness level at 0 and 10, ensuring that it doesn't go beyond the minimum or maximum limits.

On the first time you run it, it runs xrandr | grep "connected primary" | cut -f1 -d " " to get the name of your primary monitor and saves it in "$HOME/.brightness" along with the current brightness (represented as an int from 0 to 10). The program will now fetch the name of the monitor as well as the current brightness from "$HOME/.brightness" to save time in the next executions.

The script sets the brightness by running xrandr --output <outputname> --brightness <value>.

• Since I have switched to Wayland, I no longer use the script and will not be updating it.

This project is licensed under the GNU General Public License. Feel free to modify and use it according to your needs.