解析php 版获取重定向后的地址(代码)

解析php 版获取重定向后的地址(代码)

代码如下:

//取重定向的地址

class RedirectUrl{

//地址

var $url;

//初始化地址

function RedirectUrl($url){

$this->url = $url;

}

/**

* get_redirect_url()

* 取重定向的地址

*

* @param string $url

* @return string

*/

private function get_redirect_url($url){

$redirect_url = null;

$url_parts = @parse_url($url);

if (!$url_parts) return false;

if (!isset($url_parts['host'])) return false; //can't process relative URLs

if (!isset($url_parts['path'])) $url_parts['path'] = '/';

$sock = fsockopen($url_parts['host'], (isset($url_parts['port']) ? (int)$url_parts['port'] : 80), $errno, $errstr, 30);

if (!$sock) return false;

$request = "HEAD " . $url_parts['path'] . (isset($url_parts['query']) ?'?'.$url_parts['query'] : '') . " HTTP/1.1rn";

$request .= 'Host: ' . $url_parts['host'] . "rn";

$request .= "Connection: Closernrn";

fwrite($sock, $request);

$response = '';

while(!feof($sock)) $response .= fread($sock, 8192);

fclose($sock);

if (preg_match('/^Location: (.+?)$/m', $response, $matches)){

return trim($matches[1]);

} else {

return false;

}

}

/**

* get_all_redirects()

* 取所有重定向地址

*

* @param string $url

* @return array

*/

private function get_all_redirects($url){

$redirects = array();

while ($newurl = $this->get_redirect_url($url)){

if (in_array($newurl, $redirects)){

break;

}

$redirects[] = $newurl;

$url = $newurl;

}

return $redirects;

}

/**

* get_final_url()

* 取实际地址

*

* @param string $url

* @return string

*/

function get_final_url(){

$redirects = $this->get_all_redirects($this->url);

if (count($redirects)>0){

return array_pop($redirects);

} else {

return $this->url;

}

}

}

/**

* get_show_pic

* 取最终要显示的图片地址

*

* @param string $url

* @return string

*/

function get_show_pic($url,$noimg ='noimg.gif',$newimg="http://special.ku6img.com/projects/2010/d-color/images/slt-1.jpg"){

$obj = new RedirectUrl($url);

$realurl = $obj->get_final_url();

if(strpos($realurl,$noimg)>0){

return $newimg;

}

return $url;

}

//参考

echo "<img src='".get_show_pic("http://i2.ku6img.com/encode/picpath/2010/12/9/14/1294948410019/5.jpg")."'/>";

?>