PHP抓取、分析国内视频网站的视频信息工具类(6)

$out = <<<HEADER
GET $path HTTP/1.1
Host: $host
User-Agent: $user_agent
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
Accept-Language: zh-cn,zh;q=0.5
Accept-Charset: GB2312,utf-8;q=0.7,*;q=0.7\r\n\r\n
HEADER;
        $fp = @fsockopen($host, 80, $errno, $errstr, 10);
        if (!$fp)  return false;
        if(!fputs($fp, $out)) return false;
        while ( !feof($fp) ) {
            $html .= fgets($fp, 1024);
        }
        fclose($fp);
        // 判断是否gzip压缩
        if($dehtml = self::_gzdecode($html))
            return $dehtml;
        else
            return $html;
    }

/*
     * 通过 curl 获取内容
     */
    private function _cget($url='', $user_agent=''){
        if(!$url) return;

$user_agent = $user_agent ? $user_agent : self::USER_AGENT;

$ch = curl_init();
        curl_setopt($ch, CURLOPT_URL, $url);
        curl_setopt($ch, CURLOPT_HEADER, 0);
        if(strlen($user_agent)) curl_setopt($ch, CURLOPT_USERAGENT, $user_agent);

ob_start();
        curl_exec($ch);
        $html = ob_get_contents();       
        ob_end_clean();

if(curl_errno($ch)){
            curl_close($ch);
            return false;
        }
        curl_close($ch);
        if(!is_string($html) || !strlen($html)){
            return false;
        }
        return $html;
        // 判断是否gzip压缩
        if($dehtml = self::_gzdecode($html))
            return $dehtml;
        else
            return $html;
    }

    private function _gzdecode($data) {
        $len = strlen ( $data );
        if ($len < 18 || strcmp ( substr ( $data, 0, 2 ), "\x1f\x8b" )) {
            return null; // Not GZIP format (See RFC 1952)
        }
        $method = ord ( substr ( $data, 2, 1 ) ); // Compression method
        $flags = ord ( substr ( $data, 3, 1 ) ); // Flags
        if ($flags & 31 != $flags) {
            // Reserved bits are set -- NOT ALLOWED by RFC 1952
            return null;
        }
        // NOTE: $mtime may be negative (PHP integer limitations)
        $mtime = unpack ( "V", substr ( $data, 4, 4 ) );
        $mtime = $mtime [1];
        $xfl = substr ( $data, 8, 1 );
        $os = substr ( $data, 8, 1 );
        $headerlen = 10;
        $extralen = 0;
        $extra = "";
        if ($flags & 4) {
            // 2-byte length prefixed EXTRA data in header
            if ($len - $headerlen - 2 < 8) {
                return false; // Invalid format
            }
            $extralen = unpack ( "v", substr ( $data, 8, 2 ) );
            $extralen = $extralen [1];
            if ($len - $headerlen - 2 - $extralen < 8) {
                return false; // Invalid format
            }
            $extra = substr ( $data, 10, $extralen );
            $headerlen += 2 + $extralen;
        }

        $filenamelen = 0;
        $filename = "";
        if ($flags & 8) {
            // C-style string file NAME data in header
            if ($len - $headerlen - 1 < 8) {
                return false; // Invalid format
            }
            $filenamelen = strpos ( substr ( $data, 8 + $extralen ), chr ( 0 ) );
            if ($filenamelen === false || $len - $headerlen - $filenamelen - 1 < 8) {
                return false; // Invalid format
            }
            $filename = substr ( $data, $headerlen, $filenamelen );
            $headerlen += $filenamelen + 1;
        }

        $commentlen = 0;
        $comment = "";
        if ($flags & 16) {
            // C-style string COMMENT data in header
            if ($len - $headerlen - 1 < 8) {
                return false; // Invalid format
            }
            $commentlen = strpos ( substr ( $data, 8 + $extralen + $filenamelen ), chr ( 0 ) );
            if ($commentlen === false || $len - $headerlen - $commentlen - 1 < 8) {
                return false; // Invalid header format
            }
            $comment = substr ( $data, $headerlen, $commentlen );
            $headerlen += $commentlen + 1;
        }

        $headercrc = "";
        if ($flags & 1) {
            // 2-bytes (lowest order) of CRC32 on header present
            if ($len - $headerlen - 2 < 8) {
                return false; // Invalid format
            }
            $calccrc = crc32 ( substr ( $data, 0, $headerlen ) ) & 0xffff;
            $headercrc = unpack ( "v", substr ( $data, $headerlen, 2 ) );
            $headercrc = $headercrc [1];
            if ($headercrc != $calccrc) {
                return false; // Bad header CRC
            }
            $headerlen += 2;
        }

        // GZIP FOOTER - These be negative due to PHP's limitations
        $datacrc = unpack ( "V", substr ( $data, - 8, 4 ) );
        $datacrc = $datacrc [1];
        $isize = unpack ( "V", substr ( $data, - 4 ) );
        $isize = $isize [1];

        // Perform the decompression:
        $bodylen = $len - $headerlen - 8;
        if ($bodylen < 1) {
            // This should never happen - IMPLEMENTATION BUG!
            return null;
        }
        $body = substr ( $data, $headerlen, $bodylen );
        $data = "";
        if ($bodylen > 0) {
            switch ($method) {
                case 8 :
                    // Currently the only supported compression method:
                    $data = gzinflate ( $body );
                    break;
                default :
                    // Unknown compression method
                    return false;
            }
        } else {
            //...
        }

        if ($isize != strlen ( $data ) || crc32 ( $data ) != $datacrc) {
            // Bad format!  Length or CRC doesn't match!
            return false;
        }
        return $data;
    }
}