This just prints the ethernet link status to the console every 1 second

network_status.sh

#! /bin/bash

while :
do
    # Update the interface as needed
    ifconfig en9 | grep media | tr -d '\t'
    # Update the delay as needed (seconds)
    sleep 1
done

# Prints something like: media: autoselect (1000baseT <full-duplex,flow-control>)