#!/bin/bash

for iface in /sys/class/net/*; do
    iface_name=$(basename "$iface")
#echo "${iface_name:0:2}"

    # Skip loopback
    if [[ "$iface_name" == "lo" ]]; then
        continue
    fi

    if [[ "${iface_name:0:2}" == "wl" ]]; then
        continue
    fi

    # Check if carrier file exists (only for physical interfaces)
    if [[ -f "$iface/carrier" ]]; then
        carrier=$(cat "$iface/carrier")

        if [[ "$carrier" == "1" ]]; then
            echo "Bitte LAN Kabel entfernen"
	    read -n 1 -s -r -p "Any key to continue"
            return 0
        fi
    fi
done

echo "LAN cable is NOT connected"
return 1