request-line>
 headers>
 blank line>
 [request-body>]

status-line>
headers>
blank line>

[response-body>]

?php 

interface Proto {
  // 连接url
  function conn($url);

  //发送get查询
  function get();

  // 发送post查询
  function post();

  // 关闭连接
  function close();
}



class Http implements Proto {

  const CRLF = "\r\n";

  protected $errno = -1;
  protected $errstr = '';
  protected $response = '';

  protected $url = null;
  protected $version = 'HTTP/1.1';
  protected $fh = null;
  
  protected $line = array();
  protected $header = array();
  protected $body = array();

  
  public function __construct($url) {
    $this->conn($url);
    $this->setHeader('Host: ' . $this->url['host']);
  }

  // 此方法负责写请求行
  protected function setLine($method) {
    $this->line[0] = $method . ' ' . $this->url['path'] . '?' .$this->url['query'] . ' '. $this->version;
  }

  // 此方法负责写头信息
  public function setHeader($headerline) {
    $this->header[] = $headerline; 
  }

  // 此方法负责写主体信息
  protected function setBody($body) {
     $this->body[] = http_build_query($body);
  }


  // 连接url
  public function conn($url) {
    $this->url = parse_url($url);
    //　判断端口
    if(!isset($this->url['port'])) {
      $this->url['port'] = 80;
    }

    //　判断query
    if(!isset($this->url['query'])) {
      $this->url['query'] = '';
    }

    $this->fh = fsockopen($this->url['host'],$this->url['port'],$this->errno,$this->errstr,3);
  }

  //构造get请求的数据
  public function get() {
    $this->setLine('GET');
    $this->request();
    return $this->response;
  }

  // 构造post查询的数据
  public function post($body = array()) {   
    $this->setLine('POST');

    // 设计content-type
    $this->setHeader('Content-type: application/x-www-form-urlencoded');
    
    // 设计主体信息,比GET不一样的地方
    $this->setBody($body);


    // 计算content-length
    $this->setHeader('Content-length: ' . strlen($this->body[0]));

    $this->request();

    return $this->response;
  }

  // 真正请求
  public function request() {
    // 把请求行，头信息，实体信息　放在一个数组里，便于拼接
    $req = array_merge($this->line,$this->header,array(''),$this->body,array(''));
    //print_r($req);

    $req = implode(self::CRLF,$req); 
    //echo $req; exit;

    fwrite($this->fh,$req);
    
    while(!feof($this->fh)) {
      $this->response .= fread($this->fh,1024);
    }

    $this->close(); //　关闭连接
  }


  // 关闭连接
  public function close() {
    fclose($this->fh);
  }

}

?php//记得引用Http类
$url="http://home.cnblogs.com/u/DeanChopper/";
$http=new Http($url);


$response=$http->get();

print_r($response);