<?
class httpdown
{
	var $m_url = "";
	var $m_urlpath = "";
	var $m_scheme = "http";
	var $m_host = "";
	var $m_port = "80";
	var $m_user = "";
	var $m_pass = "";
	var $m_path = "/";
	var $m_query = "";
	var $m_fp = "";
	var $m_error = "";
	var $m_httphead = "" ;
	var $m_html = "";
	var $m_puthead = "";
	var $BaseUrlPath = "";
	var $HomeUrl = "";
	var $JumpCount = 0;//防止多重重定向陷入死循环
	//
	//初始化系统
	//
	function PrivateInit($url)
	{
		if($url=="") return ;
		$urls = "";
		$urls = @parse_url($url);
		$this->m_url = $url;
		if(is_array($urls))
		{
			$this->m_host = $urls["host"];
			if(!empty($urls["scheme"])) $this->m_scheme = $urls["scheme"];

			if(!empty($urls["user"])){
				$this->m_user = $urls["user"];
			}

			if(!empty($urls["pass"])){
				$this->m_pass = $urls["pass"];
			}

			if(!empty($urls["port"])){
				$this->m_port = $urls["port"];
			}

			if(!empty($urls["path"])) $this->m_path = $urls["path"];
			$this->m_urlpath = $this->m_path;

			if(!empty($urls["query"])){
				$this->m_query = $urls["query"];
				$this->m_urlpath .= "?".$this->m_query;
			}
			$this->HomeUrl = $urls["host"];
			$this->BaseUrlPath = $this->HomeUrl.$urls["path"];
			$this->BaseUrlPath = ereg_replace("/([^/]*).(.*)$","/",$this->BaseUrlPath); // ??
			$this->BaseUrlPath = ereg_replace("/$","",$this->BaseUrlPath);
		}
	}
	//
	//打开指定网址
	//
	function OpenUrl($url)
	{
		//重设各参数
		$this->m_url = "";
		$this->m_urlpath = "";
		$this->m_scheme = "http";
		$this->m_host = "";
		$this->m_port = "80";
		$this->m_user = "";
		$this->m_pass = "";
		$this->m_path = "/";
		$this->m_query = "";
		$this->m_error = "";
		$this->JumpCount = 0;
		$this->m_httphead = Array() ;
		//$this->m_puthead = "";
		$this->m_html = "";
		$this->Close();
		//初始化系统
		$this->PrivateInit($url);
		$this->PrivateStartSession();
	}
	//
	//打开303重定向网址
	//
	function JumpOpenUrl($url)
	{
		//重设各参数
		$this->m_url = "";
		$this->m_urlpath = "";
		$this->m_scheme = "http";
		$this->m_host = "";
		$this->m_port = "80";
		$this->m_user = "";
		$this->m_pass = "";
		$this->m_path = "/";
		$this->m_query = "";
		$this->m_error = "";
		$this->JumpCount++;
		$this->m_httphead = Array() ;
		$this->m_html = "";
		$this->Close();
		//初始化系统
		$this->PrivateInit($url);
		$this->PrivateStartSession();
	}
	//
	//获得某操作错误的原因
	//
	function printError()
	{
		echo "错误信息：".$this->m_error;
		echo "具体返回头：<br>";
		foreach($this->m_httphead as $k=>$v)
		{ echo "$k => $v <br>rn"; }
	}
	//
	//判别用Get方法发送的头的应答结果是否正确
	//
	function IsGetOK()
	{
		if( ereg("^2",$this->GetHead("http-state")) )
		{        return true; }
		else
		{
			$this->m_error .= $this->GetHead("http-state")." - ".$this->GetHead("http-describe")."<br>";
			return false;
		}
	}
	//
	//看看返回的网页是否是text类型
	//
	function IsText()
	{
		if(ereg("^2",$this->GetHead("http-state"))
		&& eregi("^text",$this->GetHead("content-type")))
		{        return true; }
		else
		{
			$this->m_error .= "内容为非文本类型或网址重定向<br>";
			return false;
		}
	}
	//
	//判断返回的网页是否是特定的类型
	//
	function IsContentType($ctype)
	{
		if(ereg("^2",$this->GetHead("http-state"))
		&& $this->GetHead("content-type")==strtolower($ctype))
		{        return true; }
		else
		{
			$this->m_error .= "类型不对 ".$this->GetHead("content-type")."<br>";
			return false;
		}
	}
	//
	//用Http协议下载文件
	//
	function SaveToBin($savefilename)
	{
		if(!$this->IsGetOK()) return false;
		if(@feof($this->m_fp)) { $this->m_error = "连接已经关闭！"; return false; }
		if($fp = fopen($savefilename,"w")){
			$raw=&GetRaw();
			fwrite($fp,$raw,strlen($raw));
			fclose($this->m_fp);
			fclose($fp);
			return true;
		}else{
			//can not open the file
		}
	}

	function &GetRaw(){
		$rBin="";
		while(!feof($this->m_fp)){
			$rBin.=fread($this->m_fp,1024);
		}
		return $rBin;
	}
	//
	//保存网页内容为Text文件
	//
	function SaveToText($savefilename)
	{
		if($this->IsText()) $this->SaveBinFile($savefilename);
		else return "";
	}
	//
	//用Http协议获得一个网页的内容
	//
	function GetHtml()
	{
		if(!$this->IsText()) return "";
		if($this->m_html!="") return $this->m_html;
		if(!$this->m_fp||@feof($this->m_fp)) return "";
		while(!feof($this->m_fp)){
			$this->m_html .= fgets($this->m_fp,256);
		}
		@fclose($this->m_fp);
		return $this->m_html;
	}
	//
	//开始HTTP会话
	//
	function PrivateStartSession()
	{

		if(!$this->PrivateOpenHost()){
			$this->m_error .= "打开远程主机出错!";
			return false;
		}

		if($this->GetHead("http-edition")=="HTTP/1.1") $httpv = "HTTP/1.1";
		else $httpv = "HTTP/1.0";

		//发送固定的起始请求头GET、Host信息
		fputs($this->m_fp,"GET ".$this->m_urlpath." $httpv\r\n");
		$this->m_puthead["Host"] = $this->m_host;

		//发送用户自定义的请求头
		if(!isset($this->m_puthead["Accept"])) { $this->m_puthead["Accept"] = "*/*"; }
		if(!isset($this->m_puthead["User-Agent"])) { $this->m_puthead["User-Agent"] = "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.2)"; }
		if(!isset($this->m_puthead["Refer"])) { $this->m_puthead["Refer"] = "http://".$this->m_puthead["Host"]; }
		foreach($this->m_puthead as $k=>$v){
			$k = trim($k);
			$v = trim($v);
			if($k!=""&&$v!=""){
				fputs($this->m_fp,"$k: $v\r\n");
			}
		}

	    fputs($this->m_fp,"Connection: Close\r\n\r\n");

		$httpstas = explode(" ",fgets($this->m_fp,256));
		$this->m_httphead["http-edition"] = trim($httpstas[0]);
		$this->m_httphead["http-state"] = trim($httpstas[1]);
		$this->m_httphead["http-describe"] = "";
		for($i=2;$i<count($httpstas);$i++){
			$this->m_httphead["http-describe"] .= " ".trim($httpstas[$i]);
		}
		//获取详细应答头
		while(!feof($this->m_fp)){
			$line = trim(fgets($this->m_fp,256));
			if($line == "") break;
			$hkey = "";
			$hvalue = "";
			$v = 0;
			for($i=0;$i<strlen($line);$i++){
				if($v==1) $hvalue .= $line[$i];
				if($line[$i]==":") $v = 1;
				if($v==0) $hkey .= $line[$i];
			}
			$hkey = trim($hkey);
			if($hkey!="") $this->m_httphead[strtolower($hkey)] = trim($hvalue);
		}
		//判断是否是3xx开头的应答
		if(ereg("^3",$this->m_httphead["http-state"]))
		{
			if($this->JumpCount > 3) return;
			if(isset($this->m_httphead["location"])){
				$newurl = $this->m_httphead["location"];
				if(eregi("^http",$newurl)){
					$this->JumpOpenUrl($newurl);
				}else{
					$newurl = $this->FillUrl($newurl);
					$this->JumpOpenUrl($newurl);
				}
			}else{
				$this->m_error = "无法识别的转移应答！";
				return false;
			}
		}
	}
	//
	//获得一个Http头的值
	//
	function GetHead($headname)
	{
		$headname = strtolower($headname);
		if(isset($this->m_httphead[$headname]))
		return $this->m_httphead[$headname];
		else
		return "";
	}
	//
	//设置Http头的值
	//
	function SetHead($skey,$svalue)
	{
		$this->m_puthead[$skey] = $svalue;
	}
	//
	//打开连接
	//
	function PrivateOpenHost()
	{
		if($this->m_host=="") return false;
		$this->m_fp = @fsockopen($this->m_host, $this->m_port, $errno, $errstr,10);
		if(!$this->m_fp){
			$this->m_error = $errstr;
			return false;
		}
		else{
			return true;
		}
	}
	//
	//关闭连接
	//
	function Close(){
		@fclose($this->m_fp);
	}
	//
	//补全相对网址
	//
	function FillUrl($surl)
	{
		$i = 0;
		$dstr = "";
		$pstr = "";
		$okurl = "";
		$pathStep = 0;
		$surl = trim($surl);
		if($surl=="") return "";
		$pos = strpos($surl,"#");
		if($pos>0) $surl = substr($surl,0,$pos);
		if($surl[0]=="/"){
			$okurl = "http://".$this->HomeUrl.$surl;
		}else if($surl[0]=="."){
			if(strlen($surl)<=2) return "";
			else if($surl[0]=="/")
			{
				$okurl = "http://".$this->BaseUrlPath."/".substr($surl,2,strlen($surl)-2);
			}
			else{
				$urls = explode("/",$surl);
				foreach($urls as $u){
					if($u=="..") $pathStep++;
					else if($i<count($urls)-1) $dstr .= $urls[$i]."/";
					else $dstr .= $urls[$i];
					$i++;
				}
				$urls = explode("/",$this->BaseUrlPath);
				if(count($urls) <= $pathStep)
				return "";
				else{
					$pstr = "http://";
					for($i=0;$i<count($urls)-$pathStep;$i++)
					{ $pstr .= $urls[$i]."/"; }
					$okurl = $pstr.$dstr;
				}
			}
		}

		else
		{
			if(strtolower(substr($surl,0,7))=="http://")
			$okurl = $surl;
			else
			$okurl = "http://".$this->BaseUrlPath."/".$surl;
		}
		$okurl = eregi_replace("^(http://)","",$okurl);
		$okurl = eregi_replace("/{1,}","/",$okurl);
		return "http://".$okurl;
	}
}
?>
