Scroll Lock Monitor Service

A systemd service that monitors the brightness of the Scroll Lock LED and ensures it remains turned on by setting the value inside the file /sys/class/leds/inputX::scrolllock/brightness to 1 whenever it changes back to 0. This is designed to work with any inputX::scrolllock device.

This is made mainly to turn on the RGB backlight of cheap keyboards that use the ScrollLock key to turn the RGB leds on(note: this is for Wayland, if you are using x11 you can just use xset led on/off to control leds). On many Linux distributions, the Scroll Lock is disabled by default, and since there is no xset led alternative for Wayland, I use this script. While you could manually edit the file, it resets to 0 whenever you press NumLock or Caps Lock.

Files Included

• install.sh: Installs the scrolllock-monitor service.
• uninstall.sh: Uninstalls the scrolllock-monitor service.

Requirements

• Linux-based system with systemd and running under wayland
• Sudo privileges to create files and manage system services

Installation

1. Clone the repository and Run install.sh with sudo privileges:

git clone https://github.com/zero-stacks/ScrollLock_Monitor_Service.git
cd ScrollLock_Monitor_Service
sudo sh install.sh

This script performs the following actions:

• Creates a monitoring script (/usr/local/bin/scrolllock_monitor.sh) to keep the Scroll Lock LED brightness set to 1.
• Creates a systemd service (/etc/systemd/system/scrolllock-monitor.service) to run the script at startup.
• Enables and starts the service.

Uninstallation

1. Run uninstall.sh with sudo privileges:

sudo sh uninstall.sh

This script will:

• Stop and disable the scrolllock-monitor service.
• Remove the service file (/etc/systemd/system/scrolllock-monitor.service).
• Remove the script file (/usr/local/bin/scrolllock_monitor.sh).
  
  

Manual Installation (in case you don't trust the install script)

To install the scrolllock-monitor service:

1. Create the Monitoring Script:

sudo nano /usr/local/bin/scrolllock_monitor.sh

2. copy and past this inside the script:

#!/bin/bash

# Function to monitor brightness and set it to 1 if it changes to 0
monitor_brightness() {
    while true; do
        for brightness_file in /sys/class/leds/input*::scrolllock/brightness; do
            # If the brightness is 0, set it to 1
            if [[ $(cat "$brightness_file") -eq 0 ]]; then
                echo 1 | sudo tee "$brightness_file" > /dev/null
            fi
        done
        sleep 2  # Adjust the sleep time to reduce CPU usage
    done
}

# Start monitoring
monitor_brightness

3. Make the Script Executable:

sudo chmod +x /usr/local/bin/scrolllock_monitor.sh

4. Create the systemd Service:

sudo nano /etc/systemd/system/scrolllock-monitor.service

5. Copy and paste this inside the service file:

[Unit]
Description=Scroll Lock Monitor Service
After=multi-user.target

[Service]
ExecStart=/usr/local/bin/scrolllock_monitor.sh
Restart=always
User=root

[Install]
WantedBy=multi-user.target

6. Enable and Start the Service:

sudo systemctl daemon-reload
sudo systemctl enable scrolllock-monitor.service
sudo systemctl start scrolllock-monitor.service

Manual Uninstallation

To uninstall the service manually:

1. Stop and Disable the Service:

sudo systemctl stop scrolllock-monitor.service
sudo systemctl disable scrolllock-monitor.service

2. Remove the Script and Service Files:

sudo rm -f /usr/local/bin/scrolllock_monitor.sh
sudo rm -f /etc/systemd/system/scrolllock-monitor.service

3. Reload systemd:

sudo systemctl daemon-reload

Notes

• Adjusting the Script: The script monitors all /sys/class/leds/inputX::scrolllock/brightness files and sets them to 1 if they change to 0. Adjustments to monitoring frequency can be made by changing the sleep interval in the script.