#!/bin/bash

send_headers() {
	local timestamp do_exit header thisdate expiredate
	read timestamp < <(stat -c %Y $0 settings "$rrdfile" lib/* |sort -r)
	thisdate=$(LC_ALL=C TZ=GMT date +'%a, %d %b %Y %X %Z' -d @$timestamp)
	expiredate=$(LC_ALL=C TZ=GMT date +'%a, %d %b %Y %X %Z' -d '+1 minute')
	if [[ $thisdate == $HTTP_IF_MODIFIED_SINCE ]]
	then
		echo "Status: 304 Not Modified"
		do_exit=1
	fi
	echo "Last-Modified: $thisdate"
	echo "Expires: $expiredate"
	echo "Cache-Control: must-revalidate, max-age=60"
	while read header
	do
		echo "$header"
	done
	echo
	(( do_exit )) && exit
}