#!/bin/bash
link='<https://a...content-available-to-author-only...e.com/v1/monitor/zzsomeLongIdzz?access_token=xxSomeLongTokenxx==>; rel="monitor",<https://a...content-available-to-author-only...e.com/v1/services/xx/something-more/accounts/2345?access_token=xxSomeLongTokenxx==>; rel="parent"'
re=",<([^>]+)>"
my_url="test"
if [[ $link =~ $re ]]; then my_url=${BASH_REMATCH[1]}; fi
echo $my_url