Linux terminal - Screen brightness changer

When working with multiple monitors, it’s often hard to keep both brightness synced, which is annoying and probably bad for the eyes health (need to check this later).

Some projects that aim to solve the same problem:

• https://github.com/WinEunuuchs2Unix/eyesome
• https://github.com/LordAmit/Brightness

With this in mind, I decided to start exploring how to control the screen brightness through terminal on Linux. This repository holds what I found most effective to my case.

Script

#!/bin/bash
set -euo pipefail

# must be a float within 0.0 - 1.0 range
BRIGHTNESS_LEVEL="${1:-1.0}"

function main {
    echo "Using BRIGHTNESS_LEVEL: ${BRIGHTNESS_LEVEL}..."
    
    xrandr --listmonitors |\
        grep -E -o '\s\w+(-1)' |\
        xargs -I '{}' xrandr --output '{}' --brightness "${BRIGHTNESS_LEVEL}"
}

main