求教一个正则匹配，提取html中href的地址

<h3 class="summary"><a stat="lf_aclog=1-13118660943-3-coefp|-0-32.00&lf_acfrom=0&at_alitrackid=&stats_click=user_group%3A--0_0_0_0_0_0----1%3Bscreen_size%3A1%3Bcomment%3A1&rn=e762f6164d91fd1cb720d7bb78817412"   href="http://s.click.taobao.com/t?e=zGU34CA7K%2BPkqB07S4%2FK0CITy7klw8EwSaaCpkdoG9hDKYG%2Fyv27eBF7KZXD9QYriHA81bPtdjTFV04DE8cMiT16A%2F73Y9ZCeL9g3uCDBPJySyXA12d%2B8dRoXUsK30H1PTA54EAkLOrgoItaPrf2AfxarGZQIkSliO9Xf0cWpc9pgr4X&pid=mm_30683801_3323295_10799945&unid=0" target="_blank" class="EventCanSelect" title="外贸原单nihao Kai-lan你好凯兰长袖外套+短袖T恤 女童 春装2012">外贸原单<span class=H>nihao</span> Kai-lan你好凯兰长袖外套+短袖T恤 女童 春装2012 </a></h3

解决方案 »

  1.   

    $s=<<<html
    <h3 class="summary"><a stat="lf_aclog=1-13118660943-3-coefp|-0-32.00&lf_acfrom=0&at_alitrackid=&stats_click=user_group%3A--0_0_0_0_0_0----1%3Bscreen_size%3A1%3Bcomment%3A1&rn=e762f6164d91fd1cb720d7bb78817412" href="http://s.click.taobao.com/t?e=zGU34CA7K%2BPkqB07S4%2FK0CITy7klw8EwSaaCpkdoG9hDKYG%2Fyv27eBF7KZXD9QYriHA81bPtdjTFV04DE8cMiT16A%2F73Y9ZCeL9g3uCDBPJySyXA12d%2B8dRoXUsK30H1PTA54EAkLOrgoItaPrf2AfxarGZQIkSliO9Xf0cWpc9pgr4X&pid=mm_30683801_3323295_10799945&unid=0" target="_blank" class="EventCanSelect" title="外贸原单nihao Kai-lan你好凯兰长袖外套+短袖T恤 女童 春装2012">外贸原单<span class=H>nihao</span> Kai-lan你好凯兰长袖外套+短袖T恤 女童 春装2012 </a></h3>
    html;
    preg_match('/href="(.*?)"/i',$s,$m);
    echo $m[1];