I'm trying to create a daemon to monitor my system's CPU temps and adjust the clock-rate if it gets too high, but I've never written a daemon before and I'm not sure I've done any of it right.

I created two files in a folder inside of /usr/local/lib as according to the file-heirarchy, called throttle_daemon inside of which is throttle_daemon and throttle_daemon.service, then I linked throttle_daemon.service to /etc/systemd/system/throttle_daemon.service.

This is the throttle_daemon

# !/bin/bash

CPU_TEMP=$(sensors -f | grep -Po "Tdie:\s*\+\d+" | grep -Po "\d+")

function change_frequency {
    for cpu in "/sys/devices/system/cpu/cpu*/"; do
        cpu=${cpu%*/}  # Remove the trailing "/"
        echo "$1" | sudo tee "$cpu/cpufreq/scaling_max_freq"
    done
}

notify-send "CPU Throttle Daemon" "CPU Temp is $CPU_TEMP"

if [[ $CPU_TEMP -ge 122 ]]; then
    notify-send "CPU Throttle Daemon" "Throttling CPU"
    touch /var/tmp/throttle.flag
    change_frequency 2200000
elif [[ $CPU_TEMP -le 113 ]]; then
    if [[ -f /var/tmp/throttle.flag ]]; then
        notify-send "CPU Throttle Daemon" "Un-Throttling CPU"
        change_frequency 3600000
        rm /var/tmp/throttle.flag
    fi
fi

And my throttle_daemon.service

[Unit]
Description="CPU Throttle Service"

[Service]
NotifyAccess=all
Restart=always
RestartSec=1s
ExecStart=/usr/local/lib/throttle_daemon/throttle_daemon

[Install]
WantedBy=multi-user.target

When I run the script from the command line it works as expected, but not when I set up the service. When I call sudo systemctl start throttle_daemon.service nothing errors out, but it also doesn't do anything.

I expected notify-send to ping me every second with the current temperature that my cpu is at, why isn't it?