call with rainbow https://github.com/nicoulaj/rainbow , i.e. rainbow --red-before 'ERROR:.*' --green-before 'OK:.*' bash inetest.sh

inetest.sh

#!/usr/bin/env bash

FLIP=0
TS1=`date +%s`
TS2=`date +%s`
while true 
do
	ping 8.8.8.8 -q -c 1 -w 10 &> /dev/null
	STATE=$?
	if [[ $STATE -eq 0 ]] 
	then 
		if [[ $INET -eq 0 ]] 
		then
		       FLIP=1
		       TS1=`date +%s`
		fi
		INET=1
	else
		if [[ $INET -eq 1 ]] 
		then
		       FLIP=1
		       TS1=`date +%s`
		fi
		INET=0
	fi
	

	if [[ $FLIP -eq 1 ]] 
	then
		echo "last state lasts "
		let "S = $TS1 - $TS2"
	        date -u -d @"$S" +%T	
		echo "---------"
		if [[ $INET -eq 1 ]] 
		then
			echo "OK:"
		else
			echo "ERROR:"
		fi
		date
		FLIP=0
		TS2=`date +%s`
	fi
	sleep 1 
done;