#!/bin/bash

readlast() {
	local			\
		index		\
		indices		\
		lastupdatelines	\
		time		\
		values		\

	readarray -t lastupdatelines < <(
		rrdtool lastupdate $rrdfile
	)
	indices=( ${lastupdatelines[0]} )
	time=${lastupdatelines[2]%:*}
	last["time"]=${time:-0}
	values=( ${lastupdatelines[2]#*:} )
	for index in ${!indices[@]}
	do
		last["${indices[index]}"]=${values[index]}
	done
}