#!/bin/sh
awk '
{
    i=0
    split($0,a,"")
    split(L,b,"")
    for (c in a)
        if (a[c]==b[c]) i++
        else break
    #print substr($0,1,i) "\033[7m" substr($0,i+1) "\033[0m"
    print "\033[31m" substr($0,1,i) "\033[0m" substr($0,i+1)
    L=$0
}'