HTTP 笔记与总结（6）referer 头与防盗链

  1 <?php
  2 /*
  3     PHP + socket 编程
  4     @发送 HTTP 请求
  5     @模拟下载
  6     @实现注册、登录、批量发帖
  7 */
  8 
  9 //http 请求类的接口
 10 interface Proto{
 11     //连接 url 
 12     function conn($url);
 13 
 14     //发送 GET 请求
 15     function get();
 16 
 17     //发送 POST 请求
 18     function post();
 19 
 20     //关闭连接
 21     function close();
 22 }
 23 
 24 class Http implements Proto{
 25 
 26     //换行符
 27     const CRLF = "\r\n";
 28 
 29     //fsocket 的错误号与错误描述
 30     protected $errno = -1;
 31     protected $errstr = ‘‘;
 32 
 33     //响应内容
 34     protected $response = ‘‘;
 35 
 36     protected $url = null;
 37     protected $version = ‘HTTP/1.1‘;
 38     protected $fh = null;
 39 
 40     protected $line = array();
 41     protected $header = array();
 42     protected $body = array();
 43 
 44     public function __construct($url){
 45         $this->conn($url);
 46         $this->setHeader(‘Host:‘ . $this->url[‘host‘]);
 47     }
 48 
 49     //写请求行
 50     protected function setLine($method){
 51         $this->line[0] = $method . ‘ ‘ . $this->url[‘path‘] . ‘?‘ . $this->url[‘query‘] . ‘  ‘ . $this->version;
 52     }
 53 
 54     //写头信息
 55     public function setHeader($headerline){
 56         $this->header[] = $headerline;
 57     } 
 58 
 59     //写主体信息
 60     protected function setBody($body){
 61         //构造 body 的字符串
 62         $this->body[] = http_build_query($body);
 63     }
 64 
 65     //连接 url 
 66     public function conn($url){
 67         $this->url = parse_url($url);
 68         //判断端口
 69         if(!isset($this->url[‘port‘])){
 70             $this->url[‘port‘] = 80;
 71         }
 72         //判断 query
 73         if(!isset($this->url[‘query‘])){
 74             $this->url[‘query‘] = ‘‘;
 75         }        
 76         $this->fh = fsockopen($this->url[‘host‘], $this->url[‘port‘], $this->errno, $this->errstr, 3);
 77     }
 78 
 79     //构造 GET 请求的数据
 80     public function get(){
 81         $this->setLine(‘GET‘);
 82         //发送请求
 83         $this->request();
 84         return $this->response;
 85     }
 86 
 87     //构造 POST 请求的数据
 88     public function post($body = array()){
 89         //构造请求行
 90         $this->setLine(‘POST‘);
 91 
 92         //设置 Content-type 和 Content-length
 93         $this->setHeader(‘Content-type: application/x-www-form-urlencoded‘);
 94         
 95         //构造主体信息, 和 GET 请求不一样的地方
 96         $this->setBody($body);
 97         
 98         $this->setHeader(‘Content-length: ‘ . strlen($this->body[0]));
 99 
100         //发送请求
101         $this->request();
102         return $this->response;        
103     }
104 
105     //发送请求
106     public function request(){
107         //把请求行、头信息、主体信息拼接起来
108         $req = array_merge($this->line, $this->header, array(‘‘), $this->body, array(‘‘));
109         $req = implode(self::CRLF, $req);
110         //echo $req;exit;
111 
112         fwrite($this->fh, $req);
113 
114         while(!feof($this->fh)){
115             $this->response .= fread($this->fh, 1024);
116         }
117 
118         //关闭连接
119         $this->close();
120     }
121 
122     //关闭连接
123     public function close(){
124         fclose($this->fh);
125     }
126 }