<?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();