# check for explicit feed link
page_ext=`echo "$content" | grep -Po '(?<=<link rel="alternate" type="application/rss\+xml" title=").*?(?=" />)' | head -1 | tr '\0' '\n'`
page_ext=${page_ext##*href=\"}

# if explicit feed link not found (article, not author page), truncate post URL to get author URL
if [[ "$page_ext" == "" ]]
then
	# check for invalid link that cannot be shortened
	# I don't think this is necessary, but just in case
	if [[ "${url:0:8}" != "https://" && "${url:0:7}" != "http://" ]] && [[ "${url%%/}" == */* ]] || [[ "${url%%/}" == http*://*/* ]]
	then
		# truncate tailing slash (if applicable)
		rss=${url%%/}
		
		# truncate last item
		rss=${rss%/*}
		
		# add /feed/
		page_ext=${rss}/feed/
	fi
fi