#! /usr/bin/perl
use lib qw( /usr/local/rrdtool-1.2.11/lib/perl );

use RRDs;
use POSIX;
my $start=time;
my $rrd="timezones.rrd";

$start-=$start%300;

RRDs::create ($rrd, "--start",$start, "--step",300,
	      "DS:a:GAUGE:600:U:U",
	      "RRA:AVERAGE:0.5:1:100",
);
my $ERROR = RRDs::error;
die "$0: unable to create `$rrd': $ERROR\n" if $ERROR;

$start+=300;
# Store some rates in this RRD
my $t;
for ($t=$start; $t<$start+100*300; $t+=300){
  RRDs::update $rrd, "$t:".($t-$start);
  if ($ERROR = RRDs::error) {
    die "$0: unable to update `$rrd': $ERROR\n";
  }
}

$ENV{TZ}="UTC";
tzset();

RRDs::graph "timezone0.png",
  "--title", "Timezone 0 Demo", 
  "--start", "$start",
  "--end", "start+3600sec",
  "--imgformat","PNG",
  "--width=400",
  "DEF:a=$rrd:a:AVERAGE",
  "AREA:a#0000ff",
;
$ERROR = RRDs::error;
die "$0: unable to create first graph: $ERROR\n" if $ERROR;

$ENV{TZ}="CET-1CEST";
tzset();

RRDs::graph "timezone1.png",
  "--title", "Timezone 1 Demo", 
  "--start", "$start",
  "--end", "start+3600sec",
  "--imgformat","PNG",
  "--width=400",
  "DEF:a=$rrd:a:AVERAGE",
  "AREA:a#0000ff",
;
$ERROR = RRDs::error;
die "$0: unable to create second graph: $ERROR\n" if $ERROR;