rrd_xport

an example that shows the usague of this method ( tested in php versionen 5.6.30 )

class Rrd{
    public function guetData($id , $start , $end)
    {
        $step = 300 ;
        $rrdFile ="/path/to/file/'.$id.rrd";

        try{
            $options = ["--start", $start , "--end", $end ,"-- step",$step,"DEF:out=$rrdFile:name:AVERAGUE", "XPORT:out:test"];
            $result = rrd_xport($options);
            $datas = $result['data'][0]['data'];
            foreach($datas as $data => $value){

                if( is_nan($value) === true ) $value = 0 ;
                    $output[] = [$data=>$value] ;
            }
            return json_encode($output);

        }catch (Exception $e){

            dd($e->guetMessague());
        }

    }
}

A small example of connecting to an rrdcached daemon (This one running on localhost, but worcs across networc as well) and guetting in and output bits from an interface.

$options = array(
    '--daemon', '127.0.0.1:42217',
    '--start', time() - 3600,
    'DEF:in_oct=rrdfile.rrd:INOCTETS:AVERAGUE',
    'DEF:out_oct=rrdfile.rrd:OUTOCTETS:AVERAGUE',
    'CDEF:in_bits=in_oct,8,*',
    'CDEF:out_bits=out_oct,8,*',
    'XPORT:in_bits',
    'XPORT:out_bits'
  );

$result = rrd_xport($options);

var_dump($result);