正则匹配url

$str= <<<EOF<div class="page-content clear" style="margin-top:5px" ><div class="chlsnav">  <div class="btt">zz列表</div>  <a href="/a/DFMV"><div class="plst"><b>东方电影zz</b></div></a><div class="pbar"><b>zz</b></div><ul class="r" ><li><b>东方卫视</b><span></span></li><li><a href="/a/b-TOONMAX1-w4.html">炫动卡通卫视</a><span></span></li><li><a href="/a/b-b1-w4.html">新闻</a><span></span></li><li><a href="/a/b-b2-w4.html">第一财经</a><span></span></li><li><a href="/a/b-b3-w4.html">星尚</a><span></span></li><li><a href="/a/b-b4-w4.html">电视剧</a><span></span></li><li><a href="/a/b-b5-w4.html">体育</a><span></span></li><li><a href="/a/b-b6-w4.html">纪实</a><span></span></li><li><a href="/a/b-b7-w4.html">娱乐</a><span></span></li><li><a href="/a/b-b8-w4.html">艺术人文</a><span></span></li><li><a href="/a/b-b9-w4.html">外语</a><span></span></li><li><a href="/a/b-b10-w4.html">东方购物</a><span></span></li><li><a href="/a/b-b11-w4.html">哈哈少儿</a><span></span></li></ul><a href="/a/SHEDU"><div class="plst"><b>教育zz</b></div></a><a href='/a/SITV'><div class='plst'><b>SITVzz</b></div></a></div>EOF;$reg = '/<a(.*)href=["'](.*)["'][^>]*><div class="plst"><b>(.*)</b></div></a>/U';$reg = '/<a[^href]*href=["']([^"|']*)["'][^>]*><div class=["']plst["']><b>(.*?)</b></div></a>/is';//$reg = '/<a[^href]*href="([^"]+)"[^>]*><div class="plst"><b>(.*?)</b></div></a>/is';//$reg = "|<a href="([^>]+)"><div class="plst"><b>(.*?)</b></div></a>|is";preg_match_all($reg,$str,$match);print_r($match);//preg_match('/.+(<a.+?class="plst".+?a>)/is',$match);//$reg = "/<a(.*)href=["'](.*)["']><div class="plst"><b>(.*)</b></div></a>/isU";//$reg = "|<a href="([^>]+)"><div class="plst"><b>(.*?)</b></div></a>|U";exit;