#!/bin/bash
# http://stackoverflow.com/questions/30284930/single-pcre-regex-to-swap-0-for-1-and-1-for-0-at-a-specific-location-in/30285133#30285133
perl -pe 's/([01])/ 0+!$1 /ge' <<':'
hello111000goodbye
01010101
11110000
goodbye
:
IyEvYmluL2Jhc2gKIyBodHRwOi8vc3RhY2tvdmVyZmxvdy5jb20vcXVlc3Rpb25zLzMwMjg0OTMwL3NpbmdsZS1wY3JlLXJlZ2V4LXRvLXN3YXAtMC1mb3ItMS1hbmQtMS1mb3ItMC1hdC1hLXNwZWNpZmljLWxvY2F0aW9uLWluLzMwMjg1MTMzIzMwMjg1MTMzCgpwZXJsIC1wZSAgJ3MvKFswMV0pLyAwKyEkMSAvZ2UnIDw8JzonCmhlbGxvMTExMDAwZ29vZGJ5ZQowMTAxMDEwMQoxMTExMDAwMApnb29kYnllCjoK