<?php
$s=str_repeat("xD", 100);
function hash_part($start,$length) {
        $ctx = hash_init('md5');
 
	$ch = "";
	$remaining=$length;
	while ($remaining > 0) {
		//$data = fread($fp, $chunkSize);
		$data = $GLOBALS['s'];
		
		$read = hash_update($ctx, $data);
		$ch .= md5($data);
		
		$remaining -= strlen($data);
        }
	return hash_final($ctx) . " : " . md5($ch);
}
for($i=0;$i<100;$i++)
echo hash_part(0,40*1024*1024) . "\n";
?>