HTTP 笔记与总结（3 ）socket 编程：发送 GET 请求

<?php
/*
	PHP + socket 编程
	@发送 HTTP GET 请求
*/

//http 请求类的接口
interface Proto{
	//连接 url 
	function conn($url);

	//发送 GET 请求
	function get();

	//发送 POST 请求
	function post();

	//关闭连接
	function close();
}

class Http implements Proto{

	//换行符
	const CRLF = "\r\n";

	//fsocket 的错误号与错误描述
	protected $errno = -1;
	protected $errstr = ‘‘;

	//响应内容
	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‘]);
	}

	//写请求行
	protected function setLine($method){
		$this->line[0] = $method . ‘ ‘ . $this->url[‘path‘] . ‘ ‘ . $this->version;
	}

	//写头信息
	protected function setHeader($headerline){
		$this->header[] = $headerline;
	} 

	//写主体信息
	protected function setBody(){

	}

	//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;
		}
		$this->fh = fsockopen($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‘);
		//发送请求
		$this->request();
		return $this->response;
	}

	//构造 POST 请求的数据
	public function post(){

	}

	//发送请求
	public function request(){
		//把请求行、头信息、主体信息拼接起来
		$req = array_merge($this->line, $this->header, array(‘‘), $this->body, array(‘‘));
		$req = implode(self::CRLF, $req);
		//echo $req;

		fwrite($this->fh, $req);

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

		//关闭连接
		$this->close();
	}

	//关闭连接
	public function close(){

	}
}

$url = ‘http://book.douban.com/subject/26376603/‘;

$http = new Http($url);
echo $http->get();