php 设置URL访问指定IP的服务器

<?php
/*
 * 在代码里面设定url访问对应ip的服务器
 * 适用于lvs等集群服务器的管理
 * 根据需要，可自行添加返回值
 */

url_bind_ip('http://www.xxx.com/index.php?aa=123','192.168.10.23'); // 这是示例

function url_bind_ip($url, $ip = null) {  

    $url = parse_url($url);  

    if (!isset($url['port'])) {  
        if ($url['scheme'] == 'http'){  
            $url['port'] = 80;   
        } else if ($url['scheme'] == 'https'){  
            $url['port'] = 443;  
        }  
    }  

    $url['query'] = isset($url['query'])?$url['query']:'';  
    $url['protocol'] = $url['scheme'].'://';  
    $eol="\\r\\n";  

    $headers = 'GET '.$url['protocol'].$url['host'].$url['path'].'?'.$url['query'].' HTTP/1.1'.$eol.   
               'Host: '.$url['host'].$eol.   
               'Content-Length: '.strlen($url['query']).$eol.  
               $eol.$url['query'];  
    $fp = fsockopen($ip ? $ip : $url['host'], $url['port'], $errno, $errstr, 5);   

    if ($fp) {  
        fwrite($fp, $headers);
    } 

} 

?>
//该片段来自于http://outofmemory.cn