Batocera service to set a udev rule that persists through upgrades, in this case, the Lossless GC adapter

udev_boot

#!/bin/sh

case "$1" in
    start)
        # Ensure the destination directory exists
        mkdir -p /etc/udev/rules.d/

        # Create the udev rule directly in the volatile root filesystem
        cat << 'EOF' > /etc/udev/rules.d/99-gamecube-adapter.rules
ACTION=="add", SUBSYSTEM=="usb", ATTRS{idVendor}=="057e", ATTRS{idProduct}=="0337", DRIVER=="usbhid", RUN+="/bin/sh -c 'echo -n $kernel > /sys/bus/usb/drivers/usbhid/unbind'"
EOF

        # Reload and trigger the rule immediately
        udevadm control --reload-rules
        udevadm trigger
        ;;
    stop)
        # Clean up the rule file when stopping the service
        rm -f /etc/udev/rules.d/99-gamecube-adapter.rules
        udevadm control --reload-rules
        ;;
esac