#!/bin/bash

readold() {
	local	when=$1		\
		line		\
		dataindex	\
		empty		\
		id		\
		LANG=C
	{
		read line
		dataindex=( $line )
		read empty
		read first['time'] $(
				for id in ${dataindex[@]}
				do
					echo "first['"$id"']"
				done
			)
	} < <(
		rrdtool fetch -s "$when" "$rrdfile" AVERAGE | sed '/: nan/d'
	)
}