ＰＨＰ正则表达式的使用技巧

function dangdang ($keywords)
{
//$keywords="java";//搜索关键词
$urls='http://search.dangdang.com/?key='.$keywords.'&category_path=01.00.00.00.00.00&type=01.00.00.00.00.00/';
//echo $urls;
$st=curl_init();
curl_setopt($st, CURLOPT_URL, $urls);
curl_setopt($st, CURLOPT_RETURNTRANSFER,1);//返回内容为字符串
curl_setopt($st,CURLOPT_FOLLOWLOCATION,TRUE);
curl_setopt($st,CURLOPT_MAXREDIRS,2);//设置重定向最大两次
curl_setopt($st,CURLOPT_TIMEOUT,100);//等待时间不超过五秒
$dl_page=curl_exec($st);
$info_arr=curl_getinfo($st);
//var_dump($info_arr);
preg_match_all("/<a title=.*/",$dl_page,$matches_all);
//var_dump($matches_all);
$num= count($matches_all[0]);
for($count=0;$count<$num;$count++)
{
echo $count.'<br>';
preg_match_all("/title="([^"]*)"s*class/",$matches_all[0][$count],$matches_title);
echo($matches_title[1][0]);
echo '<br>';
preg_match_all("/http://img.*jpg/",$matches_all[0][$count],$matches_img);
echo ('@@##@@');
echo '<br>';
preg_match_all("/http([^A]*)A/",$matches_all[0][$count],$matches_url);
echo($matches_url[0][0]);
echo '<br>';
preg_match_all("/http://comm([^"]*)/",$matches_all[0][$count],$matches_plurl);
//preg_match_all("/<as*href="([^"]*)"/",$matches_all[0][$count],$matches_plurl);
//var_dump($matches_plurl);//评论url
echo($matches_plurl[0][0]);
echo '<br>';
preg_match_all("/detail"s*>([^<]*)</",$matches_all[0][$count],$matches_jianjie);
echo($matches_jianjie[1][0]);
echo '<br>';
preg_match_all("/&yen;d+.dd/",$matches_all[0][$count],$matches_price);
preg_match_all("/d+.dd/",$matches_price[0][0],$matches_price);
echo($matches_price[0][0]);
//echo($matches_price[0][0]);
echo '<br>';
preg_match_all("/num">d*/",$matches_all[0][$count],$matches_pinglun);
preg_match_all("/d+/",$matches_pinglun[0][0],$matches_pinglun);
echo($matches_pinglun[0][0]);
echo '<br>';
preg_match_all("/title='([^']*)'/",$matches_all[0][$count],$matches_price);
echo($matches_price[1][0]);
echo '<br>';
}
}

preg_match_all("/<lis+id="result_[0-9]*.*([.
]*)\n.*\n.*\n[\s| ]*.*/",$dl_page,$matches_all);