想要从一段html中提取出这样的地址：

http://storage.live.com/items/9A8B8BF501A38A36!1211?filename=%e7%82%b9%e5%87%bb%e7%ac%ac%e5%87%a0%e9%a1%b5.jpg

然后对应的php代码为：

# current support valid pic suffiex: 'bmp', 'gif', 'jpeg', 'jpg', 'jpe', 'png', 'tiff', 'tif'
$picSufChars = "befgijmnptBEFGIJMNPT";
//$pattern = '#<a href="(?P<picUrl>http://storage.live.com/items/.+?filename=.+?\.jpg)"><img.+?src="(?P=picUrl)".+?/></a>#';
$pattern = '#<a href="(?P<picUrl>http://storage.live.com/items/.+?filename=.+?\.['.$picSufChars.']{3,4})"><img.+?src="(?P=picUrl)".+?/></a>#';

if(preg_match($pattern, $content, $matches)){
    $picUrl = $matches["picUrl"];
    //print "found picUrl=".$picUrl;
    if(preg_match('#http://storage\.live\.com/items/.+?filename=(?P<filename>.+)#', $picUrl, $foundFilename)){
        $filename = $foundFilename["filename"];
        $filename = rawurldecode($filename);
    }
    else{
        $filename = "";
    }
     
} else {
    $picUrl = "";
}