PHP 正则表达式查找字符串

<?php
set_time_limit(0);
$url='http://item.taobao.com/auction/item_detail.htm?xid=0db2&item_num_id=4512430274&cm_cat=50000671&pm2=1';
$ch = curl_init();
$timeout = 10;
curl_setopt ($ch, CURLOPT_URL, $url);
curl_setopt ($ch, CURLOPT_RETURNTRANSFER, 1);
curl_setopt ($ch, CURLOPT_CONNECTTIMEOUT, $timeout);
$html = curl_exec($ch);
curl_close($ch);
$reg="|好评率：[\s\S]*<strong>(\d{0,5}[.]\d{0,5})%</strong>|";
preg_match_all ($reg,
$html,
$out, PREG_PATTERN_ORDER);
/*
foreach ($out as $value){
foreach ($value as $value2){
if(strlen($value2)<20)
echo ($value2."<br>");
}
}
*/
echo $out[1][0];

//ikmb
?>