YubiKey lock screen when unplugged

21-yubikey.rules

## /etc/udev/rules.d/21-yubikey.rules
ACTION=="remove", SUBSYSTEM=="input", ATTRS{idVendor}=="1050", ATTRS{idProduct}=="0407", RUN+="/usr/local/bin/lockscreen.sh"

lockscreen.sh

#!/bin/bash
## /usr/local/bin/lockscreen.sh

SESSIONS="$(loginctl list-sessions --no-legend)"

# if '/tmp/.noyubilock' file exists, disable autolock at usb unplug
if [ -f /tmp/.noyubilock ]; then
    exit 0
fi

while read -r line; do
        read sess_id _ _ _ tty <<< "$line"
        if [ -z "${tty}" ]; then
                # if X11 session: just lock it
                loginctl lock-session "$sess_id"
        else
                # if TTY session: terminate it (logout)
                loginctl terminate-session "$sess_id"
        fi
done <<< "$SESSIONS"