dfopen模拟html请求

function dfopen($url, $limit = 0, $post = '', $cookie = '', $bysocket = FALSE, $ip = '', $timeout = 15, $block = TRUE)
{
	$return = '';
	$uri = parse_url($url);
	$host = $uri['host'];
	$path = $uri['path'] ? $uri['path'].($uri['query'] ? '?'.$uri['query'] : '') : '/';
	$port = !empty($uri['port']) ? $uri['port'] : 80;

	if($post) {
		$out = "POST $path HTTP/1.0\r\n";
		$out .= "Accept: */*\r\n";
		//$out .= "Referer: $boardurl\r\n";
		$out .= "Accept-Language: zh-cn\r\n";
		$out .= "Content-Type: application/x-www-form-urlencoded\r\n";
		$out .= "User-Agent: $_SERVER[HTTP_USER_AGENT]\r\n";
		$out .= "Host: $host\r\n";
		$out .= 'Content-Length: '.strlen($post)."\r\n";
		$out .= "Connection: Close\r\n";
		$out .= "Cache-Control: no-cache\r\n";
		$out .= "Cookie: $cookie\r\n\r\n";
		$out .= $post;
	} else {
		$out = "GET $path HTTP/1.0\r\n";
		$out .= "Accept: */*\r\n";
		//$out .= "Referer: $boardurl\r\n";
		$out .= "Accept-Language: zh-cn\r\n";
		$out .= "User-Agent: $_SERVER[HTTP_USER_AGENT]\r\n";
		$out .= "Host: $host\r\n";
		$out .= "Connection: Close\r\n";
		$out .= "Cookie: $cookie\r\n\r\n";
	}
	$fp = @fsockopen(($ip ? $ip : $host), $port, $errno, $errstr, $timeout);
	if(!$fp) {
		return '';//note $errstr : $errno \r\n
	} else {
		//集阻塞/非阻塞模式流,$block==true则应用流模式
		stream_set_blocking($fp, $block);
		//设置流的超时时间
		stream_set_timeout($fp, $timeout);
		@fwrite($fp, $out);
		//从封装协议文件指针中取得报头／元数据
		$status = stream_get_meta_data($fp);
		//timed_out如果在上次调用 fread() 或者 fgets() 中等待数据时流超时了则为 TRUE,下面判断为流没有超时的情况
		if(!$status['timed_out'])
		{
			while (!feof($fp)) {
				if(($header = @fgets($fp)) && ($header == "\r\n" ||  $header == "\n")) {
					break;
				}
			}

			$stop = false;

			//如果没有读到文件尾
			while(!feof($fp) && !$stop) {
				//看连接时限是否=0或者大于8192  =》8192  else =》limit  所读字节数
				$data = fread($fp, ($limit == 0 || $limit > 8192 ? 8192 : $limit));
				$return .= $data;
				if($limit) {
					$limit -= strlen($data);
					$stop = $limit <= 0;
				}
			}
		}
		@fclose($fp);
		return $return;
	}
}