将淘宝客加密链接转换成普通淘宝链接

1，先获取淘宝客链接一枚：
$clickurl="http://s.click.taobao.com/t?e=m%3D2%26s%3D1xJRigdN6vgcQipKwQzePOeEDrYVVa64REOHN%2B0iJT23bLqV5UHdqdSm9rmNrfhQMlIj6E1wLr6Z1upWVE%2FY63jUGTUkifoD6Iu7YpSAkMmDDvvObppylOm%2B2Cp2Y4AZdQRGST%2FOE66WnyaKIIfB45Ka7uvYZB3KIXgUnhszXk7H%2FWo6QkJXpnEKIlIBiOAf%2BiEiH3X0n4yiZ%2BQMlGz6FQ%3D%3D";

2，PHP获取初步跳转后的URL：
$headers = get_headers($clickurl, TRUE);
$tu = $headers['Location'];

得到链接如下：
$tu="http://s.click.taobao.com/t_js?tu=http%3A%2F%2Fs.click.taobao.com%2Ft%3Fe%3Dm%253D2%2526s%253D1xJRigdN6vgcQipKwQzePOeEDrYVVa64REOHN%252B0iJT23bLqV5UHdqdSm9rmNrfhQMlIj6E1wLr6Z1upWVE%252FY63jUGTUkifoD6Iu7YpSAkMmDDvvObppylOm%252B2Cp2Y4AZdQRGST%252FOE66WnyaKIIfB45Ka7uvYZB3KIXgUnhszXk7H%252FWo6QkJXpnEKIlIBiOAf%252BiEiH3X0n4yiZ%252BQMlGz6FQ%253D%253D%26ref%3D%26et%3DU1NBEMyybRSMZqT%252FAdx5AObU6XqsSK9q";

因此链接中带有一个参数tu，后面要用到，所以将此链接取名为tu，继续第三步。


3，取得tu链接中的tu参数，也就是等号后面的内容：
http%3A%2F%2Fs.click.taobao.com%2Ft%3Fe%3Dm%253D2%2526s%253D1xJRigdN6vgcQipKwQzePOeEDrYVVa64REOHN%252B0iJT23bLqV5UHdqdSm9rmNrfhQMlIj6E1wLr6Z1upWVE%252FY63jUGTUkifoD6Iu7YpSAkMmDDvvObppylOm%252B2Cp2Y4AZdQRGST%252FOE66WnyaKIIfB45Ka7uvYZB3KIXgUnhszXk7H%252FWo6QkJXpnEKIlIBiOAf%252BiEiH3X0n4yiZ%252BQMlGz6FQ%253D%253D%26ref%3D%26et%3DU1NBEMyybRSMZqT%252FAdx5AObU6XqsSK9q

对编码熟悉的同学应该看出来了这其实是一条URL地址被escape编码了，我们使用php自定义一个解码函数对其进行处理一下，网上找到的unescape解码函数：

function unescape($str) { 
    $ret = ''; 
    $len = strlen($str); 
    for ($i = 0; $i < $len; $i ++) 
    { 
        if ($str[$i] == '%' && $str[$i + 1] == 'u') 
        { 
            $val = hexdec(substr($str, $i + 2, 4)); 
            if ($val < 0x7f) 
                $ret .= chr($val); 
            else  
                if ($val < 0x800) 
                    $ret .= chr(0xc0 | ($val >> 6)) . 
                     chr(0x80 | ($val & 0x3f)); 
                else 
                    $ret .= chr(0xe0 | ($val >> 12)) . 
                     chr(0x80 | (($val >> 6) & 0x3f)) . 
                     chr(0x80 | ($val & 0x3f)); 
            $i += 5; 
        } else  
            if ($str[$i] == '%') 
            { 
                $ret .= urldecode(substr($str, $i, 3)); 
                $i += 2; 
            } else 
                $ret .= $str[$i]; 
    } 
       return $ret; 
    }

解码后得到的URL地址为：
$ref="http://s.click.taobao.com/t?e=m%3D2%26s%3D1xJRigdN6vgcQipKwQzePOeEDrYVVa64REOHN%2B0iJT23bLqV5UHdqdSm9rmNrfhQMlIj6E1wLr6Z1upWVE%2FY63jUGTUkifoD6Iu7YpSAkMmDDvvObppylOm%2B2Cp2Y4AZdQRGST%2FOE66WnyaKIIfB45Ka7uvYZB3KIXgUnhszXk7H%2FWo6QkJXpnEKIlIBiOAf%2BiEiH3X0n4yiZ%2BQMlGz6FQ%3D%3D&ref=&et=Tu9eFLz3gxx7bGejK8KgtemqA%2BR0RX35";

这地址跟我们获取的淘宝客链接几乎相同，就是后面多了两个参数，一个ref，一个et，这里我们把这个地址命名为ref。


淘宝客链接的跳转其实就是一个封装的js程序，通过JS发起带有header参数的请求从而达到跳转的，这个header参数中最重要的就是referer，下面我就用PHP模拟请求一下这个地址：

请求后的结果输出跳转后的302头部信息，里面已经有我们想要的淘宝商品实际地址了。


以下是完整的提取淘宝URL函数：

function geturl($clickurl){        
                $headers = get_headers($clickurl, TRUE);
                $tu = $headers['Location'];
                $eturl = unescape($tu);
                $u = parse_url($eturl);
               $param = $u['query'];                
                $ref = str_replace('tu=', '', $param);
                $ch = curl_init();  
                curl_setopt($ch, CURLOPT_URL, $ref);                  
                curl_setopt($ch, CURLOPT_REFERER, $tu);   
                curl_setopt($ch, CURLOPT_HEADER, false);  
                curl_setopt($ch, CURLOPT_NOBODY,1);
                curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
                curl_setopt($ch, CURLOPT_FOLLOWLOCATION,true);
                curl_setopt($ch, CURLOPT_MAXREDIRS,2);                
                $out = curl_exec($ch);  
                $dd =  curl_getinfo($ch);
                curl_close($ch);  
                $item_url = $dd['url'];
                return $item_url; 
}

另外说明一下，curl中如果这个CURLOPT_FOLLOWLOCATION参数无效，很有可能是PHP运行模式问题，可以使用其他方法替代。示例：

function geturl($clickurl){        
                $headers = get_headers($clickurl, TRUE);
                $tu = $headers['Location'];
                $eturl = unescape($tu);
                $u = parse_url($eturl);
                $param = $u['query'];                
                $ref = str_replace('tu=', '', $param);
                $ch = curl_init();  
                curl_setopt($ch, CURLOPT_URL, $ref);                  
                curl_setopt($ch, CURLOPT_REFERER, $tu);   
                curl_setopt($ch, CURLOPT_HEADER, false);  
                curl_setopt($ch, CURLOPT_NOBODY,1);
                curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
                curl_setopt($ch, CURLOPT_FOLLOWLOCATION,true);
                curl_setopt($ch, CURLOPT_MAXREDIRS,2);                
                $out = curl_exec($ch);  
                $dd =  curl_getinfo($ch);
                curl_close($ch);  
                if($dd['redirect_url']){
                $item_url= $dd['redirect_url'];        
                }else{
                if($dd['url']){
                $item_url= $dd['url'];        
                }else{
                $chl = curl_init();  
                curl_setopt($chl, CURLOPT_URL, $et);                  
                curl_setopt($chl, CURLOPT_REFERER, $tu);   
                curl_setopt($chl, CURLOPT_HEADER, true);  
                curl_setopt($chl, CURLOPT_NOBODY,1);
                curl_setopt($chl, CURLOPT_RETURNTRANSFER, 1);
                curl_setopt($chl, CURLOPT_FOLLOWLOCATION,true);
                curl_setopt($chl, CURLOPT_MAXREDIRS,2);                
                $out = curl_exec($chl);                  
                curl_close($chl);
                $item_url= get_word($out,'Location: ','&ali_trackid');
                }
           }
          return $item_url; 
}

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