Archive/src/zip/headers/local_file.php - zetacomponents - Git at Google

 <?php
 /**
  * File containing the ezcArchiveLocalFileHeader class.
  *
  * Licensed to the Apache Software Foundation (ASF) under one
  * or more contributor license agreements.  See the NOTICE file
  * distributed with this work for additional information
  * regarding copyright ownership.  The ASF licenses this file
  * to you under the Apache License, Version 2.0 (the
  * "License"); you may not use this file except in compliance
  * with the License.  You may obtain a copy of the License at
  *
  *   http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing,
  * software distributed under the License is distributed on an
  * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
  * KIND, either express or implied.  See the License for the
  * specific language governing permissions and limitations
  * under the License.
  *
  * @package Archive
  * @version //autogentag//
  * @license http://www.apache.org/licenses/LICENSE-2.0 Apache License, Version 2.0
  * @access private
  */

 /**
  * The ezcArchiveLocalFileHeader class represents the Zip local header.
  *
  * ezcArchiveLocalFileHeader can read the header from an ezcArchiveCharacterFile or ezcArchiveEntry.
  *
  * The values from the headers are directly accessible via the class properties, and allows
  * reading and writing to specific header values.
  *
  * The entire header can be appended to an ezcArchiveCharacterFile again or written to an ezcArchiveFileStructure.
  * Information may get lost, though.
  *
  * The overall .ZIP file format[1] :
  *
  * <pre>
  *   [local file header 1]
  *   [file data 1]
  *   [data descriptor 1]
  *   .
  *   .
  *   [local file header n]
  *   [file data n]
  *   [data descriptor n]
  *   [central directory]
  *   [end of central directory record]
  * </pre>
  *
  * The Local File Header has the following structure:
  *
  * <pre>
  * + ---+--------+------------+-------------------+-------------------------------+
  * | ID | Offset | Field size | Property          |  Description                  |
  * +----+--------+------------+-------------------+-------------------------------+
  * |    |  0     | 4          | -                 | Local file header signature   |
  * |    |  4     | 2          | version           | Version needed to extract     |
  * |    |  6     | 2          | bitFlag           | General purpose bit flag      |
  * |    |  8     | 2          | compressionMethod | Compression method            |
  * |    |  10    | 2          | lastModFileTime   | Last modification file time   |
  * |    |  12    | 2          | lastModFileDate   | Last modification file date   |
  * |    |  14    | 4          | crc               | crc-32                        |
  * |    |  18    | 4          | compressedSize    | compressed size               |
  * |    |  22    | 4          | uncompressedSize  | uncompressed size             |
  * | X  |  26    | 2          | fileNameLength    | file name length              |
  * | Y  |  28    | 2          | extraFieldLength  | extra field length            |
  * |    |  30    | X          | fileName          | file name                     |
  * |    |  30+X  | Y          | -                 | extra field                   |
  * +----+--------+------------+-------------------+-------------------------------+
  * </pre>
  *
  * The columns of the table are:
  * - ID gives a label to a specific field or row in the table.
  * - Offset describes the start position of a header field.
  * - Field size describes the size of the field in bytes.
  * - Property is the name of the property that will be set by the header field.
  * - Description explains what this field describes.
  *
  * The local file signature cannot be changed and is set in the constant {@link self::magic}.
  *
  * The extra fields that are implemented are:
  * - Info-Zip Unix field (old).
  * - Info-Zip Unix field (new).
  * - Universal timestamp.
  *
  * Info-Zip Unix field (old):
  * <pre>
  * +--------+------------+------------------------------------+
  * | Offset | Field size |  Description                       |
  * +--------+------------+------------------------------------+
  * |  0     | 2          | Header ID (0x5855)                 |
  * |  2     | 2          | Data size: Full size = 12          |
  * |  4     | 4          | Last Access Time                   |
  * |  8     | 4          | Last Modification Time             |
  * |  12    | 2          | User ID  (Optional if size < 12 )  |
  * |  14    | 2          | Group ID (Optional if size < 12 )  |
  * +--------+------------+------------------------------------+
  * </pre>
  *
  * Info-Zip Unix field (new):
  * <pre>
  * +--------+------------+--------------------+
  * | Offset | Field size |  Description       |
  * +--------+------------+--------------------+
  * |  0     | 2          | Header ID (0x7855) |
  * |  2     | 2          | Data size.         |
  * |  4     | 2          | User ID            |
  * |  6     | 2          | Group ID           |
  * +--------+------------+--------------------+
  * </pre>
  *
  * Universal timestamp:
  * <pre>
  * +--------+------------+-------------------------+
  * | Offset | Field size |  Description            |
  * +--------+------------+-------------------------+
  * |  0     | 2          | Header ID (0x5455)      |
  * |  2     | 2          | Data size.              |
  * |  4     | 1          | Info bits (flags)       |
  * |  5     | 4          | Last Modification Time  |
  * |  9     | 4          | Last Access Time        |
  * |  13    | 4          | Creation Time           |
  * +--------+------------+-------------------------+
  * </pre>
  *
  * Info bits indicate which fields are set:
  * - bit 0, if set then the modification time is present.
  * - bit 1, if set then the access time is present.
  * - bit 2, if set then the creation time is present.
  *
  * These info bits are ONLY valid for the local file header. The
  * central header has the same Universal Timestamp, but reflects
  * the bits from the local file header!
  *
  *
  * See PKWare documentation and InfoZip extra field documentation for more information.
  *
  *
  * [1] PKWARE .ZIP file format specification:
  * <pre>
  * File:    APPNOTE.TXT - .ZIP File Format Specification
  * Version: 4.5
  * Revised: 11/01/2001
  * Copyright (c) 1989 - 2001 PKWARE Inc., All Rights Reserved.
  * </pre>
  *
  * [2] InfoZip distribution contains the file: proginfo/extra.fld
  *
  * @package Archive
  * @version //autogentag//
  * @access private
  */
 class ezcArchiveLocalFileHeader
 {
     /**
      * Defines the signature of this header.
      */
     const magic = 0x04034b50;

     /**
      * Extra field definition.
      *
      * UNIX Extra Field ID ("UX").
      */
     const EF_IZUNIX  = 0x5855;

     /**
      * Extra field definition.
      *
      * Info-ZIP's new Unix( "Ux" ).
      */
     const EF_IZUNIX2 = 0x7855;

     /**
      * Extra field definition.
      *
      * Universal timestamp( "UT" ).
      */
     const EF_TIME    = 0x5455;

     /**
      * Minimal UT field contains Flags byte
      */
     const EB_UT_MINLEN = 1;

     /**
      * Byte offset of Flags field
      */
     const EB_UT_FLAGS  = 0;

     /**
      * Byte offset of 1st time value
      */
     const EB_UT_TIME1  = 1;

     /**
      * mtime present
      */
     const EB_UT_FL_MTIME = 1;

     /**
      * atime present
      */
     const EB_UT_FL_ATIME = 2;

     /**
      * ctime present
      */
     const EB_UT_FL_CTIME = 4;

     /**
      * UT field length.
      */
     const EB_UT_FL_LEN = 4;

     /**
      * Minimal "UX" field contains atime, mtime
      */
     const EB_UX_MINLEN = 8;

     /**
      * Offset of atime in "UX" extra field data
      */
     const EB_UX_ATIME  = 0;

     /**
      * Offset of mtime in "UX" extra field data
      */
     const EB_UX_MTIME  = 4;

     /**
      * Full "UX" field ( atime, mtime, uid, gid )
      */
     const EB_UX_FULLSIZE = 12;

     /**
      * Byte offset of UID in "UX" field data
      */
     const EB_UX_UID = 8;

     /**
      * Byte offset of GID in "UX" field data
      */
     const EB_UX_GID = 10;

     /**
      * Minimal Ux field contains UID/GID
      */
     const EB_UX2_MINLEN = 4;

     /**
      * Byte offset of UID in "Ux" field data
      */
     const EB_UX2_UID = 0;

     /**
      * Byte offset of GID in "Ux" field data
      */
     const EB_UX2_GID = 2;

     /**
      * Byte offset of valid in "Ux" field data
      */
     const EB_UX2_VALID =  256;

     /**
      * Holds the properties of this class.
      *
      * @var array(string=>mixed)
      */
     protected $properties = array();

     /**
      * Holds the user ID and is false if not set.
      *
      * @var int
      */
     protected $userId = false;

     /**
      * Holds the group ID and is false if not set.
      *
      * @var int
      */
     protected $groupId = false;

     /**
      * Holds the modification time as a timestamp and is false if not set.
      *
      * @var int
      */
     protected $mtime = false;

     /**
      * Holds the modification time as a timestamp and is false if not set.
      *
      * @var int
      */
     protected $atime = false;

     /**
      * Holds the creation time as a timestamp and is false if not set.
      *
      * @var int
      */
     protected $ctime = false;

     /**
      * Creates and initializes a new header.
      *
      * If the ezcArchiveCharacterFile $file is null then the header will be empty.
      * When an ezcArchiveCharacterFile is given, the file position should be directly after the
      * signature of the header. This header will be read from the file and initialized in this class.
      *
      * @param ezcArchiveCharacterFile $file
      */
     public function __construct( ezcArchiveCharacterFile $file = null, ezcArchiveCentralDirectoryHeader $centralHeader = null )
     {
         // Offset | Field size |  Description
         // ----------------------------------
         //  0     | 4          | Local file header signature ( 0x04034b50 ).
         //  4     | 2          | Version needed to extract.
         //  6     | 2          | General purpose bit flag.
         //  8     | 2          | Compression method.
         //  10    | 2          | Last mod file time.
         //  12    | 2          | Last mod file date.
         //  14    | 4          | Crc-32.
         //  18    | 4          | Compressed size.
         //  22    | 4          | Uncompressed size.
         //  26    | 2          | File name length.
         //  28    | 2          | Extra field length.

         if ( !is_null( $file ) )
         {
             $this->properties = unpack (
                 "vversion/".
                 "vbitFlag/".
                 "vcompressionMethod/".
                 "vlastModFileTime/".
                 "vlastModFileDate/".
                 "Vcrc/".
                 "VcompressedSize/".
                 "VuncompressedSize/".
                 "vfileNameLength/".
                 "vextraFieldLength",
                 $file->read( 26 ) );

             $this->properties["fileName"] = $file->read( $this->properties["fileNameLength"] );
             $extraField = $file->read( $this->properties["extraFieldLength"] );

             // Append extra field information.
             $this->setExtraFieldData( $extraField );

             // Fix the local file headers from the central header, in case crc,
             // compressed size and original size are not set. This is needed
             // for Open Office documents at least.
             if ( $centralHeader && $this->properties['compressedSize'] === 0 && $this->properties['uncompressedSize'] === 0 )
             {
                 $this->properties['compressedSize'] = $centralHeader->compressedSize;
                 $this->properties['uncompressedSize'] = $centralHeader->uncompressedSize;
                 $this->properties['crc'] = $centralHeader->crc;
             }

             // Skip the file.
             $file->seek( $this->compressedSize, SEEK_CUR );
         }
     }

     /**
      * Serializes this header and appends it to the given ezcArchiveCharacterFile $archiveFile.
      *
      * @param ezcArchiveCharacterFile $archiveFile
      * @return void
      */
     public function writeEncodedHeader( $archiveFile )
     {
         $this->properties["extraFieldLength" ] = 21; // FIXME.

         $enc = pack( "VvvvvvVVVvv",
             self::magic,
             $this->properties["version"],
             $this->properties["bitFlag"],
             $this->properties["compressionMethod"],
             $this->properties["lastModFileTime"],
             $this->properties["lastModFileDate"],
             $this->properties["crc"],
             $this->properties["compressedSize"],
             $this->properties["uncompressedSize"],
             $this->properties["fileNameLength"],
             $this->properties["extraFieldLength"] );

         $time = pack( "vvcVV", self::EF_TIME, 9, 3, $this->mtime, $this->atime ); // set accesss time to modification time.
         $unix2 = pack( "vvvv", self::EF_IZUNIX2, 4, $this->userId, $this->groupId );

         $archiveFile->write( $enc . $this->fileName . $time . $unix2 );
     }

     /**
      * Sets the property $name to $value.
      *
      * @throws ezcBasePropertyNotFoundException if the property does not exist
      * @throws ezcBasePropertyReadOnlyException if the property is read-only
      * @param string $name
      * @param mixed $value
      * @return void
      * @ignore
      */
     public function __set( $name, $value )
     {
         switch ( $name )
         {
              case "version":
              case "bitFlag":
              case "compressionMethod":
              case "crc":
              case "compressedSize":
              case "uncompressedSize":
              case "extraFieldLength":
                 $this->properties[$name] = $value;
                 break;

              case "lastModFileTime":
              case "lastModFileDate":
              case "fileNameLength":
                 throw new ezcBasePropertyReadOnlyException( $name );

              default:
                 throw new ezcBasePropertyNotFoundException( $name );
         }
     }

     /**
      * Returns the value of the property $name.
      *
      * @throws ezcBasePropertyNotFoundException if the property does not exist.
      * @param string $name
      * @return mixed
      * @ignore
      */
     public function __get( $name )
     {
         switch ( $name )
         {
             case "version":
             case "bitFlag":
             case "compressionMethod":
             case "lastModFileTime":
             case "lastModFileDate":
             case "crc":
             case "compressedSize":
             case "uncompressedSize":
             case "extraFieldLength":
             case "fileNameLength":
             case "fileName":
                 return $this->properties[ $name ];

             default:
                 throw new ezcBasePropertyNotFoundException( $name );
         }
     }

     /**
      * Returns the modification timestamp.
      *
      * The timestamp from the extra fields is returned if it is available.
      * If it cannot be found, the ZIP time is converted to a timestamp.
      *
      * @return int
      */
     public function getModificationTime()
     {
         return ( $this->mtime ? $this->mtime : self::dosFormatToTimestamp( array( $this->lastModFileTime, $this->lastModFileDate ) ) );
     }

     /**
      * Sets the modification time to the int $timestamp.
      *
      * The properties lastModFileTime and lastModFileDate properties will be set.
      *
      * @param int $timestamp
      * @return void
      */
     public function setModificationTime( $timestamp )
     {
         $this->mtime = $timestamp;
         list( $this->properties["lastModFileTime"], $this->properties["lastModFileDate"] ) = self::timestampToDosFormat( $timestamp );
     }

     /**
      * Returns an two element array with, respectively, the dos time and dos date, which are converted from
      * the given int $timestamp.
      *
      * The DOS time and date format are described here: {@link http://www.vsft.com/hal/dostime.htm}.
      *
      * @see http://www.vsft.com/hal/dostime.htm
      *
      * @param int $timestamp
      * @return array(int)
      */
     public static function timestampToDosFormat( $timestamp )
     {
         $time = getdate( $timestamp );

         $dosTime = ( $time["hours"]  & 31 ); // Hours. Bit: 11 .. 15
         $dosTime <<= 6;
         $dosTime |= ( $time["minutes"] & 63 ); // Minutes.
         $dosTime <<= 5;
         $dosTime |= ( ( int ) ( $time["seconds"] / 2 ) & 31 );  // seconds.

         $dosDate = ( $time["year"] - 1980 ) & 127;  // Year.
         $dosDate <<= 4;
         $dosDate |= ( $time["mon"] & 15 ); // month.
         $dosDate <<= 5;
         $dosDate |= ( $time["mday"] & 31 ); // day.

         return array( $dosTime, $dosDate );
     }

     /**
      * Returns the timestamp which is converted from an array with, respectively, the dos time and dos date.
      *
      * Expects an array with two elements.
      *
      * The DOS time and date format are described here: {@link http://www.vsft.com/hal/dostime.htm}.
      *
      * @see http://www.vsft.com/hal/dostime.htm
      *
      * @param array(int) $array
      * @return int
      */
     public static function dosFormatToTimestamp( array $array )
     {
         $dosTime = $array[0];

         $seconds = ( ($dosTime ) & 31 ) * 2 ;  // Bit  0 .. 4
         $minutes = ( $dosTime >>  5 ) & 63 ;          // Bit  5 .. 10
         $hours = ( $dosTime >> 11 ) & 31;               // Bit 11 .. 15

         $dosDate = $array[1];
         $day =  ( ( $dosDate ) & 31 );          // Bit  0 .. 4
         $month = ( $dosDate >>  5 ) & 15 ;            // Bit  5 .. 8
         $year = ( ( $dosDate >> 9 ) & 127 ) + 1980;     // Bit  9 .. 15

         return mktime( $hours, $minutes, $seconds, $month, $day, $year );
     }

     /**
      * Sets the filename in the header.
      *
      * The properties fileName and file length are changed.
      *
      * @param string $name
      */
     public function setFileName( $name )
     {
         $this->properties["fileName"] = $name;
         $this->properties["fileNameLength"] = strlen( $name );
     }

     /**
      * Sets the compression.
      *
      * @param int $compressionMethod
      * @param int $compressedSize
      * @return void
      */
     public function setCompression( $compressionMethod, $compressedSize )
     {
         // Fixme, for now only decompressed.
         $this->compressionMethod = $compressionMethod;
         $this->compressedSize = $compressedSize;

     }

     /**
      * Updates the given ezcArchiveFileStructure $struct with the values from this header.
      *
      * If bool $override is false, this method will not overwrite the values from the ezcArchiveFileStructure $struct.
      * The values that can be set in the archiveFileStructure are: path, gid, uid, mtime, and size.
      *
      * @param ezcArchiveFileStructure &$struct
      * @param bool $override
      * @return void
      */
     public function setArchiveFileStructure( ezcArchiveFileStructure &$struct, $override = false )
     {
         if ( !isset( $struct->path ) || $override )
         {
             $struct->path = $this->fileName;
         }

         if ( !isset( $struct->size ) || $override )
         {
             $struct->size = $this->uncompressedSize;
         }

         if ( $this->groupId && ( !isset( $struct->size )  || $override ) )
         {
             $struct->gid   = $this->groupId;
         }

         if ( $this->userId &&  ( !isset( $struct->size )  || $override ) )
         {
             $struct->uid   = $this->userId;
         }

         if ( $this->mtime &&   ( !isset( $struct->mtime ) || $override ) )
         {
             $struct->mtime = $this->mtime;
         }

         if ( $this->atime &&   ( !isset( $struct->atime ) || $override ) )
         {
             $struct->atime = $this->atime;
         }
     }

     /**
      * Sets this header with the values from the ezcArchiveEntry $entry.
      *
      * The values that are possible to set from the ezcArchiveEntry $entry are set in this header.
      *
      * @param ezcArchiveEntry $entry
      * @return void
      */
     public function setHeaderFromArchiveEntry( ezcArchiveEntry $entry )
     {
         $this->version = 10; // FIXME
         $this->bitFlag = 0; // FIXME

         $this->atime = $entry->getAccessTime();

         $this->groupId = $entry->getGroupId();
         $this->userId = $entry->getUserId();

         $this->setModificationTime( $entry->getModificationTime() );

         if ( $entry->isSymLink() )
         {
             $this->uncompressedSize = strlen( $entry->getLink() );
             $this->crc = ezcArchiveChecksums::getCrc32FromString( $entry->getLink() );
         }
         else
         {
             $this->uncompressedSize = $entry->getSize();
             $this->crc = ezcArchiveChecksums::getCrc32FromFile( $entry->getPath() );
         }

         $this->setFileName( $entry->getPath( false ) );
     }

     /**
      * Returns the total size of this header.
      *
      * @return int
      */
     public function getHeaderSize()
     {
         return 30 + $this->properties["fileNameLength"] + $this->properties["extraFieldLength"];
     }

     /**
      * Decodes and sets the extra header properties from the string $data.
      *
      * @param string $data
      * @return void
      */
     protected function setExtraFieldData( $data )
     {
         $raw = array();

         $offset = 0;
         $dataLength = strlen( $data );

         while ( $offset < $dataLength )
         {
             // Read header.
             $dec = unpack( "vid/vlength", substr( $data, $offset, 4 ) );
             $offset += 4;

             switch ( $dec["id"] )
             {
                 case self::EF_IZUNIX2:
                     $raw[ "EF_IZUNIX2" ] = $this->getNewInfoZipExtraField( substr( $data, $offset, $dec["length"] ), $dec["length"] );
                     break;

                 case self::EF_IZUNIX:
                     $raw[ "EF_IZUNIX" ] = $this->getOldInfoZipExtraField( substr( $data, $offset, $dec["length"] ), $dec["length"] );
                     break;

                 case self::EF_TIME:
                     $raw[ "EF_TIME" ] = $this->getUniversalTimestampField( substr( $data, $offset, $dec["length"] ), $dec["length"] );
                     break;
             }

             $offset += $dec["length"];
         }

         $result = array();

         // The order is important.
         if ( isset( $raw["EF_TIME"]["mtime"] ) )
         {
             $this->mtime = $raw["EF_TIME"]["mtime"];
         }

         if ( isset( $raw["EF_TIME"]["atime"] ) )
         {
             $this->atime = $raw["EF_TIME"]["atime"];
         }

         if ( isset( $raw["EF_TIME"]["ctime"] ) )
         {
             $this->ctime = $raw["EF_TIME"]["ctime"];
         }

         if ( isset( $raw["EF_IZUNIX"]["mtime"] ) )
         {
             $this->mtime = $raw["EF_IZUNIX"]["mtime"];
         }

         if ( isset( $raw["EF_IZUNIX"]["atime"] ) )
         {
             $this->atime = $raw["EF_IZUNIX"]["atime"];
         }

         if ( isset( $raw["EF_IZUNIX"]["gid"] ) )
         {
             $this->groupId = $raw["EF_IZUNIX"]["gid"];
         }

         if ( isset( $raw["EF_IZUNIX"]["uid"] ) )
         {
             $this->userId = $raw["EF_IZUNIX"]["uid"];
         }

         if ( isset( $raw["EF_IZUNIX2"]["gid"] ) )
         {
             $this->groupId = $raw["EF_IZUNIX2"]["gid"];
         }

         if ( isset( $raw["EF_IZUNIX2"]["uid"] ) )
         {
             $this->userId = $raw["EF_IZUNIX2"]["uid"];
         }

         return $result;
     }

     /**
      * Returns an array with the decoded 'new Info-Zip' data.
      *
      * @param string $field
      * @param int $length
      * @return array(string)
      */
     protected function getNewInfoZipExtraField( $field, $length )
     {
         $localOffset = 0;

         if ( $length >= self::EB_UX2_MINLEN )
         {
             return unpack( "vuid/vgid", substr( $field, 0, self::EB_UX2_MINLEN ) );
         }

         return array();
     }

     /**
      * Returns an array with the decoded 'old Info-Zip' data.
      *
      * @param string $field
      * @param int $length
      * @return array(string)
      */
     protected function getOldInfoZipExtraField( $field, $length )
     {
         if ( $length >= self::EB_UX_FULLSIZE )
         {
             return unpack( "Vatime/Vmtime/vuid/vgid", substr( $field, 0, self::EB_UX_FULLSIZE ) );
         }
         else if ( $length >= self::EB_UX_MINLEN )
         {
             return unpack( "Vatime/Vmtime", substr( $field, 0, self::EB_UX_MINLEN ) );
         }

         return array();
     }

     /**
      * Returns an array with the decoded 'universal timestamp' data.
      *
      * @param string $field
      * @param int $length
      * @return array(string)
      */
     protected function getUniversalTimestampField( $field, $length )
     {
         $localOffset = 0;
         $result = array();

         if ( $length >= self::EB_UT_MINLEN )
         {
             $f = unpack( "cflags", substr( $field, $localOffset, 1 ) );
             $length--; // Flag takes one byte.

             if ( ( $f["flags"] & self::EB_UT_FL_MTIME ) && $length >= 4 )
             {
                 $result = array_merge( $result, unpack( "Vmtime", substr( $field, $localOffset + self::EB_UT_MINLEN + ( self::EB_UT_FL_LEN * 0 ), self::EB_UT_FL_LEN ) ) );
                 $length -= 4;
             }

             if ( $f["flags"] & self::EB_UT_FL_ATIME  && $length >= 4 )
             {
                 $result = array_merge( $result, unpack( "Vatime", substr( $field, $localOffset + self::EB_UT_MINLEN + ( self::EB_UT_FL_LEN * 1 ), self::EB_UT_FL_LEN ) ) );
                 $length -= 4;
             }

             if ( $f["flags"] & self::EB_UT_FL_CTIME && $length >= 4 )
             {
                 $result = array_merge( $result, unpack( "Vctime", substr( $field, $localOffset + self::EB_UT_MINLEN + ( self::EB_UT_FL_LEN * 2 ), self::EB_UT_FL_LEN ) ) );
                 $length -= 4;
             }
         }

         return $result;
     }

     /**
      * Returns true if the given string $string matches with the current signature.
      *
      * @param string $string
      * @return bool
      */
     public static function isSignature( $string )
     {
         return $string == pack( "V", self::magic );
     }
 }
 ?>
	<?php
	/**
	* File containing the ezcArchiveLocalFileHeader class.
	*
	* Licensed to the Apache Software Foundation (ASF) under one
	* or more contributor license agreements. See the NOTICE file
	* distributed with this work for additional information
	* regarding copyright ownership. The ASF licenses this file
	* to you under the Apache License, Version 2.0 (the
	* "License"); you may not use this file except in compliance
	* with the License. You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing,
	* software distributed under the License is distributed on an
	* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
	* KIND, either express or implied. See the License for the
	* specific language governing permissions and limitations
	* under the License.
	*
	* @package Archive
	* @version //autogentag//
	* @license http://www.apache.org/licenses/LICENSE-2.0 Apache License, Version 2.0
	* @access private
	*/

	/**
	* The ezcArchiveLocalFileHeader class represents the Zip local header.
	*
	* ezcArchiveLocalFileHeader can read the header from an ezcArchiveCharacterFile or ezcArchiveEntry.
	*
	* The values from the headers are directly accessible via the class properties, and allows
	* reading and writing to specific header values.
	*
	* The entire header can be appended to an ezcArchiveCharacterFile again or written to an ezcArchiveFileStructure.
	* Information may get lost, though.
	*
	* The overall .ZIP file format[1] :
	*
	* <pre>
	* [local file header 1]
	* [file data 1]
	* [data descriptor 1]
	* .
	* .
	* [local file header n]
	* [file data n]
	* [data descriptor n]
	* [central directory]
	* [end of central directory record]
	* </pre>
	*
	* The Local File Header has the following structure:
	*
	* <pre>
	* + ---+--------+------------+-------------------+-------------------------------+
	* \| ID \| Offset \| Field size \| Property \| Description \|
	* +----+--------+------------+-------------------+-------------------------------+
	* \| \| 0 \| 4 \| - \| Local file header signature \|
	* \| \| 4 \| 2 \| version \| Version needed to extract \|
	* \| \| 6 \| 2 \| bitFlag \| General purpose bit flag \|
	* \| \| 8 \| 2 \| compressionMethod \| Compression method \|
	* \| \| 10 \| 2 \| lastModFileTime \| Last modification file time \|
	* \| \| 12 \| 2 \| lastModFileDate \| Last modification file date \|
	* \| \| 14 \| 4 \| crc \| crc-32 \|
	* \| \| 18 \| 4 \| compressedSize \| compressed size \|
	* \| \| 22 \| 4 \| uncompressedSize \| uncompressed size \|
	* \| X \| 26 \| 2 \| fileNameLength \| file name length \|
	* \| Y \| 28 \| 2 \| extraFieldLength \| extra field length \|
	* \| \| 30 \| X \| fileName \| file name \|
	* \| \| 30+X \| Y \| - \| extra field \|
	* +----+--------+------------+-------------------+-------------------------------+
	* </pre>
	*
	* The columns of the table are:
	* - ID gives a label to a specific field or row in the table.
	* - Offset describes the start position of a header field.
	* - Field size describes the size of the field in bytes.
	* - Property is the name of the property that will be set by the header field.
	* - Description explains what this field describes.
	*
	* The local file signature cannot be changed and is set in the constant {@link self::magic}.
	*
	* The extra fields that are implemented are:
	* - Info-Zip Unix field (old).
	* - Info-Zip Unix field (new).
	* - Universal timestamp.
	*
	* Info-Zip Unix field (old):
	* <pre>
	* +--------+------------+------------------------------------+
	* \| Offset \| Field size \| Description \|
	* +--------+------------+------------------------------------+
	* \| 0 \| 2 \| Header ID (0x5855) \|
	* \| 2 \| 2 \| Data size: Full size = 12 \|
	* \| 4 \| 4 \| Last Access Time \|
	* \| 8 \| 4 \| Last Modification Time \|
	* \| 12 \| 2 \| User ID (Optional if size < 12 ) \|
	* \| 14 \| 2 \| Group ID (Optional if size < 12 ) \|
	* +--------+------------+------------------------------------+
	* </pre>
	*
	* Info-Zip Unix field (new):
	* <pre>
	* +--------+------------+--------------------+
	* \| Offset \| Field size \| Description \|
	* +--------+------------+--------------------+
	* \| 0 \| 2 \| Header ID (0x7855) \|
	* \| 2 \| 2 \| Data size. \|
	* \| 4 \| 2 \| User ID \|
	* \| 6 \| 2 \| Group ID \|
	* +--------+------------+--------------------+
	* </pre>
	*
	* Universal timestamp:
	* <pre>
	* +--------+------------+-------------------------+
	* \| Offset \| Field size \| Description \|
	* +--------+------------+-------------------------+
	* \| 0 \| 2 \| Header ID (0x5455) \|
	* \| 2 \| 2 \| Data size. \|
	* \| 4 \| 1 \| Info bits (flags) \|
	* \| 5 \| 4 \| Last Modification Time \|
	* \| 9 \| 4 \| Last Access Time \|
	* \| 13 \| 4 \| Creation Time \|
	* +--------+------------+-------------------------+
	* </pre>
	*
	* Info bits indicate which fields are set:
	* - bit 0, if set then the modification time is present.
	* - bit 1, if set then the access time is present.
	* - bit 2, if set then the creation time is present.
	*
	* These info bits are ONLY valid for the local file header. The
	* central header has the same Universal Timestamp, but reflects
	* the bits from the local file header!
	*
	*
	* See PKWare documentation and InfoZip extra field documentation for more information.
	*
	*
	* [1] PKWARE .ZIP file format specification:
	* <pre>
	* File: APPNOTE.TXT - .ZIP File Format Specification
	* Version: 4.5
	* Revised: 11/01/2001
	* Copyright (c) 1989 - 2001 PKWARE Inc., All Rights Reserved.
	* </pre>
	*
	* [2] InfoZip distribution contains the file: proginfo/extra.fld
	*
	* @package Archive
	* @version //autogentag//
	* @access private
	*/
	class ezcArchiveLocalFileHeader
	{
	/**
	* Defines the signature of this header.
	*/
	const magic = 0x04034b50;

	/**
	* Extra field definition.
	*
	* UNIX Extra Field ID ("UX").
	*/
	const EF_IZUNIX = 0x5855;

	/**
	* Extra field definition.
	*
	* Info-ZIP's new Unix( "Ux" ).
	*/
	const EF_IZUNIX2 = 0x7855;

	/**
	* Extra field definition.
	*
	* Universal timestamp( "UT" ).
	*/
	const EF_TIME = 0x5455;

	/**
	* Minimal UT field contains Flags byte
	*/
	const EB_UT_MINLEN = 1;

	/**
	* Byte offset of Flags field
	*/
	const EB_UT_FLAGS = 0;

	/**
	* Byte offset of 1st time value
	*/
	const EB_UT_TIME1 = 1;

	/**
	* mtime present
	*/
	const EB_UT_FL_MTIME = 1;

	/**
	* atime present
	*/
	const EB_UT_FL_ATIME = 2;

	/**
	* ctime present
	*/
	const EB_UT_FL_CTIME = 4;

	/**
	* UT field length.
	*/
	const EB_UT_FL_LEN = 4;

	/**
	* Minimal "UX" field contains atime, mtime
	*/
	const EB_UX_MINLEN = 8;

	/**
	* Offset of atime in "UX" extra field data
	*/
	const EB_UX_ATIME = 0;

	/**
	* Offset of mtime in "UX" extra field data
	*/
	const EB_UX_MTIME = 4;

	/**
	* Full "UX" field ( atime, mtime, uid, gid )
	*/
	const EB_UX_FULLSIZE = 12;

	/**
	* Byte offset of UID in "UX" field data
	*/
	const EB_UX_UID = 8;

	/**
	* Byte offset of GID in "UX" field data
	*/
	const EB_UX_GID = 10;

	/**
	* Minimal Ux field contains UID/GID
	*/
	const EB_UX2_MINLEN = 4;

	/**
	* Byte offset of UID in "Ux" field data
	*/
	const EB_UX2_UID = 0;

	/**
	* Byte offset of GID in "Ux" field data
	*/
	const EB_UX2_GID = 2;

	/**
	* Byte offset of valid in "Ux" field data
	*/
	const EB_UX2_VALID = 256;

	/**
	* Holds the properties of this class.
	*
	* @var array(string=>mixed)
	*/
	protected $properties = array();

	/**
	* Holds the user ID and is false if not set.
	*
	* @var int
	*/
	protected $userId = false;

	/**
	* Holds the group ID and is false if not set.
	*
	* @var int
	*/
	protected $groupId = false;

	/**
	* Holds the modification time as a timestamp and is false if not set.
	*
	* @var int
	*/
	protected $mtime = false;

	/**
	* Holds the modification time as a timestamp and is false if not set.
	*
	* @var int
	*/
	protected $atime = false;

	/**
	* Holds the creation time as a timestamp and is false if not set.
	*
	* @var int
	*/
	protected $ctime = false;

	/**
	* Creates and initializes a new header.
	*
	* If the ezcArchiveCharacterFile $file is null then the header will be empty.
	* When an ezcArchiveCharacterFile is given, the file position should be directly after the
	* signature of the header. This header will be read from the file and initialized in this class.
	*
	* @param ezcArchiveCharacterFile $file
	*/
	public function __construct( ezcArchiveCharacterFile $file = null, ezcArchiveCentralDirectoryHeader $centralHeader = null )
	{
	// Offset \| Field size \| Description
	// ----------------------------------
	// 0 \| 4 \| Local file header signature ( 0x04034b50 ).
	// 4 \| 2 \| Version needed to extract.
	// 6 \| 2 \| General purpose bit flag.
	// 8 \| 2 \| Compression method.
	// 10 \| 2 \| Last mod file time.
	// 12 \| 2 \| Last mod file date.
	// 14 \| 4 \| Crc-32.
	// 18 \| 4 \| Compressed size.
	// 22 \| 4 \| Uncompressed size.
	// 26 \| 2 \| File name length.
	// 28 \| 2 \| Extra field length.

	if ( !is_null( $file ) )
	{
	$this->properties = unpack (
	"vversion/".
	"vbitFlag/".
	"vcompressionMethod/".
	"vlastModFileTime/".
	"vlastModFileDate/".
	"Vcrc/".
	"VcompressedSize/".
	"VuncompressedSize/".
	"vfileNameLength/".
	"vextraFieldLength",
	$file->read( 26 ) );

	$this->properties["fileName"] = $file->read( $this->properties["fileNameLength"] );
	$extraField = $file->read( $this->properties["extraFieldLength"] );

	// Append extra field information.
	$this->setExtraFieldData( $extraField );

	// Fix the local file headers from the central header, in case crc,
	// compressed size and original size are not set. This is needed
	// for Open Office documents at least.
	if ( $centralHeader && $this->properties['compressedSize'] === 0 && $this->properties['uncompressedSize'] === 0 )
	{
	$this->properties['compressedSize'] = $centralHeader->compressedSize;
	$this->properties['uncompressedSize'] = $centralHeader->uncompressedSize;
	$this->properties['crc'] = $centralHeader->crc;
	}

	// Skip the file.
	$file->seek( $this->compressedSize, SEEK_CUR );
	}
	}

	/**
	* Serializes this header and appends it to the given ezcArchiveCharacterFile $archiveFile.
	*
	* @param ezcArchiveCharacterFile $archiveFile
	* @return void
	*/
	public function writeEncodedHeader( $archiveFile )
	{
	$this->properties["extraFieldLength" ] = 21; // FIXME.

	$enc = pack( "VvvvvvVVVvv",
	self::magic,
	$this->properties["version"],
	$this->properties["bitFlag"],
	$this->properties["compressionMethod"],
	$this->properties["lastModFileTime"],
	$this->properties["lastModFileDate"],
	$this->properties["crc"],
	$this->properties["compressedSize"],
	$this->properties["uncompressedSize"],
	$this->properties["fileNameLength"],
	$this->properties["extraFieldLength"] );

	$time = pack( "vvcVV", self::EF_TIME, 9, 3, $this->mtime, $this->atime ); // set accesss time to modification time.
	$unix2 = pack( "vvvv", self::EF_IZUNIX2, 4, $this->userId, $this->groupId );

	$archiveFile->write( $enc . $this->fileName . $time . $unix2 );
	}

	/**
	* Sets the property $name to $value.
	*
	* @throws ezcBasePropertyNotFoundException if the property does not exist
	* @throws ezcBasePropertyReadOnlyException if the property is read-only
	* @param string $name
	* @param mixed $value
	* @return void
	* @ignore
	*/
	public function __set( $name, $value )
	{
	switch ( $name )
	{
	case "version":
	case "bitFlag":
	case "compressionMethod":
	case "crc":
	case "compressedSize":
	case "uncompressedSize":
	case "extraFieldLength":
	$this->properties[$name] = $value;
	break;

	case "lastModFileTime":
	case "lastModFileDate":
	case "fileNameLength":
	throw new ezcBasePropertyReadOnlyException( $name );

	default:
	throw new ezcBasePropertyNotFoundException( $name );
	}
	}

	/**
	* Returns the value of the property $name.
	*
	* @throws ezcBasePropertyNotFoundException if the property does not exist.
	* @param string $name
	* @return mixed
	* @ignore
	*/
	public function __get( $name )
	{
	switch ( $name )
	{
	case "version":
	case "bitFlag":
	case "compressionMethod":
	case "lastModFileTime":
	case "lastModFileDate":
	case "crc":
	case "compressedSize":
	case "uncompressedSize":
	case "extraFieldLength":
	case "fileNameLength":
	case "fileName":
	return $this->properties[ $name ];

	default:
	throw new ezcBasePropertyNotFoundException( $name );
	}
	}

	/**
	* Returns the modification timestamp.
	*
	* The timestamp from the extra fields is returned if it is available.
	* If it cannot be found, the ZIP time is converted to a timestamp.
	*
	* @return int
	*/
	public function getModificationTime()
	{
	return ( $this->mtime ? $this->mtime : self::dosFormatToTimestamp( array( $this->lastModFileTime, $this->lastModFileDate ) ) );
	}

	/**
	* Sets the modification time to the int $timestamp.
	*
	* The properties lastModFileTime and lastModFileDate properties will be set.
	*
	* @param int $timestamp
	* @return void
	*/
	public function setModificationTime( $timestamp )
	{
	$this->mtime = $timestamp;
	list( $this->properties["lastModFileTime"], $this->properties["lastModFileDate"] ) = self::timestampToDosFormat( $timestamp );
	}

	/**
	* Returns an two element array with, respectively, the dos time and dos date, which are converted from
	* the given int $timestamp.
	*
	* The DOS time and date format are described here: {@link http://www.vsft.com/hal/dostime.htm}.
	*
	* @see http://www.vsft.com/hal/dostime.htm
	*
	* @param int $timestamp
	* @return array(int)
	*/
	public static function timestampToDosFormat( $timestamp )
	{
	$time = getdate( $timestamp );

	$dosTime = ( $time["hours"] & 31 ); // Hours. Bit: 11 .. 15
	$dosTime <<= 6;
	$dosTime \|= ( $time["minutes"] & 63 ); // Minutes.
	$dosTime <<= 5;
	$dosTime \|= ( ( int ) ( $time["seconds"] / 2 ) & 31 ); // seconds.

	$dosDate = ( $time["year"] - 1980 ) & 127; // Year.
	$dosDate <<= 4;
	$dosDate \|= ( $time["mon"] & 15 ); // month.
	$dosDate <<= 5;
	$dosDate \|= ( $time["mday"] & 31 ); // day.

	return array( $dosTime, $dosDate );
	}

	/**
	* Returns the timestamp which is converted from an array with, respectively, the dos time and dos date.
	*
	* Expects an array with two elements.
	*
	* The DOS time and date format are described here: {@link http://www.vsft.com/hal/dostime.htm}.
	*
	* @see http://www.vsft.com/hal/dostime.htm
	*
	* @param array(int) $array
	* @return int
	*/
	public static function dosFormatToTimestamp( array $array )
	{
	$dosTime = $array[0];

	$seconds = ( ($dosTime ) & 31 ) * 2 ; // Bit 0 .. 4
	$minutes = ( $dosTime >> 5 ) & 63 ; // Bit 5 .. 10
	$hours = ( $dosTime >> 11 ) & 31; // Bit 11 .. 15

	$dosDate = $array[1];
	$day = ( ( $dosDate ) & 31 ); // Bit 0 .. 4
	$month = ( $dosDate >> 5 ) & 15 ; // Bit 5 .. 8
	$year = ( ( $dosDate >> 9 ) & 127 ) + 1980; // Bit 9 .. 15

	return mktime( $hours, $minutes, $seconds, $month, $day, $year );
	}

	/**
	* Sets the filename in the header.
	*
	* The properties fileName and file length are changed.
	*
	* @param string $name
	*/
	public function setFileName( $name )
	{
	$this->properties["fileName"] = $name;
	$this->properties["fileNameLength"] = strlen( $name );
	}

	/**
	* Sets the compression.
	*
	* @param int $compressionMethod
	* @param int $compressedSize
	* @return void
	*/
	public function setCompression( $compressionMethod, $compressedSize )
	{
	// Fixme, for now only decompressed.
	$this->compressionMethod = $compressionMethod;
	$this->compressedSize = $compressedSize;

	}

	/**
	* Updates the given ezcArchiveFileStructure $struct with the values from this header.
	*
	* If bool $override is false, this method will not overwrite the values from the ezcArchiveFileStructure $struct.
	* The values that can be set in the archiveFileStructure are: path, gid, uid, mtime, and size.
	*
	* @param ezcArchiveFileStructure &$struct
	* @param bool $override
	* @return void
	*/
	public function setArchiveFileStructure( ezcArchiveFileStructure &$struct, $override = false )
	{
	if ( !isset( $struct->path ) \|\| $override )
	{
	$struct->path = $this->fileName;
	}

	if ( !isset( $struct->size ) \|\| $override )
	{
	$struct->size = $this->uncompressedSize;
	}

	if ( $this->groupId && ( !isset( $struct->size ) \|\| $override ) )
	{
	$struct->gid = $this->groupId;
	}

	if ( $this->userId && ( !isset( $struct->size ) \|\| $override ) )
	{
	$struct->uid = $this->userId;
	}

	if ( $this->mtime && ( !isset( $struct->mtime ) \|\| $override ) )
	{
	$struct->mtime = $this->mtime;
	}

	if ( $this->atime && ( !isset( $struct->atime ) \|\| $override ) )
	{
	$struct->atime = $this->atime;
	}
	}

	/**
	* Sets this header with the values from the ezcArchiveEntry $entry.
	*
	* The values that are possible to set from the ezcArchiveEntry $entry are set in this header.
	*
	* @param ezcArchiveEntry $entry
	* @return void
	*/
	public function setHeaderFromArchiveEntry( ezcArchiveEntry $entry )
	{
	$this->version = 10; // FIXME
	$this->bitFlag = 0; // FIXME

	$this->atime = $entry->getAccessTime();

	$this->groupId = $entry->getGroupId();
	$this->userId = $entry->getUserId();

	$this->setModificationTime( $entry->getModificationTime() );

	if ( $entry->isSymLink() )
	{
	$this->uncompressedSize = strlen( $entry->getLink() );
	$this->crc = ezcArchiveChecksums::getCrc32FromString( $entry->getLink() );
	}
	else
	{
	$this->uncompressedSize = $entry->getSize();
	$this->crc = ezcArchiveChecksums::getCrc32FromFile( $entry->getPath() );
	}

	$this->setFileName( $entry->getPath( false ) );
	}

	/**
	* Returns the total size of this header.
	*
	* @return int
	*/
	public function getHeaderSize()
	{
	return 30 + $this->properties["fileNameLength"] + $this->properties["extraFieldLength"];
	}

	/**
	* Decodes and sets the extra header properties from the string $data.
	*
	* @param string $data
	* @return void
	*/
	protected function setExtraFieldData( $data )
	{
	$raw = array();

	$offset = 0;
	$dataLength = strlen( $data );

	while ( $offset < $dataLength )
	{
	// Read header.
	$dec = unpack( "vid/vlength", substr( $data, $offset, 4 ) );
	$offset += 4;

	switch ( $dec["id"] )
	{
	case self::EF_IZUNIX2:
	$raw[ "EF_IZUNIX2" ] = $this->getNewInfoZipExtraField( substr( $data, $offset, $dec["length"] ), $dec["length"] );
	break;

	case self::EF_IZUNIX:
	$raw[ "EF_IZUNIX" ] = $this->getOldInfoZipExtraField( substr( $data, $offset, $dec["length"] ), $dec["length"] );
	break;

	case self::EF_TIME:
	$raw[ "EF_TIME" ] = $this->getUniversalTimestampField( substr( $data, $offset, $dec["length"] ), $dec["length"] );
	break;
	}

	$offset += $dec["length"];
	}

	$result = array();

	// The order is important.
	if ( isset( $raw["EF_TIME"]["mtime"] ) )
	{
	$this->mtime = $raw["EF_TIME"]["mtime"];
	}

	if ( isset( $raw["EF_TIME"]["atime"] ) )
	{
	$this->atime = $raw["EF_TIME"]["atime"];
	}

	if ( isset( $raw["EF_TIME"]["ctime"] ) )
	{
	$this->ctime = $raw["EF_TIME"]["ctime"];
	}

	if ( isset( $raw["EF_IZUNIX"]["mtime"] ) )
	{
	$this->mtime = $raw["EF_IZUNIX"]["mtime"];
	}

	if ( isset( $raw["EF_IZUNIX"]["atime"] ) )
	{
	$this->atime = $raw["EF_IZUNIX"]["atime"];
	}

	if ( isset( $raw["EF_IZUNIX"]["gid"] ) )
	{
	$this->groupId = $raw["EF_IZUNIX"]["gid"];
	}

	if ( isset( $raw["EF_IZUNIX"]["uid"] ) )
	{
	$this->userId = $raw["EF_IZUNIX"]["uid"];
	}

	if ( isset( $raw["EF_IZUNIX2"]["gid"] ) )
	{
	$this->groupId = $raw["EF_IZUNIX2"]["gid"];
	}

	if ( isset( $raw["EF_IZUNIX2"]["uid"] ) )
	{
	$this->userId = $raw["EF_IZUNIX2"]["uid"];
	}

	return $result;
	}

	/**
	* Returns an array with the decoded 'new Info-Zip' data.
	*
	* @param string $field
	* @param int $length
	* @return array(string)
	*/
	protected function getNewInfoZipExtraField( $field, $length )
	{
	$localOffset = 0;

	if ( $length >= self::EB_UX2_MINLEN )
	{
	return unpack( "vuid/vgid", substr( $field, 0, self::EB_UX2_MINLEN ) );
	}

	return array();
	}

	/**
	* Returns an array with the decoded 'old Info-Zip' data.
	*
	* @param string $field
	* @param int $length
	* @return array(string)
	*/
	protected function getOldInfoZipExtraField( $field, $length )
	{
	if ( $length >= self::EB_UX_FULLSIZE )
	{
	return unpack( "Vatime/Vmtime/vuid/vgid", substr( $field, 0, self::EB_UX_FULLSIZE ) );
	}
	else if ( $length >= self::EB_UX_MINLEN )
	{
	return unpack( "Vatime/Vmtime", substr( $field, 0, self::EB_UX_MINLEN ) );
	}

	return array();
	}

	/**
	* Returns an array with the decoded 'universal timestamp' data.
	*
	* @param string $field
	* @param int $length
	* @return array(string)
	*/
	protected function getUniversalTimestampField( $field, $length )
	{
	$localOffset = 0;
	$result = array();

	if ( $length >= self::EB_UT_MINLEN )
	{
	$f = unpack( "cflags", substr( $field, $localOffset, 1 ) );
	$length--; // Flag takes one byte.

	if ( ( $f["flags"] & self::EB_UT_FL_MTIME ) && $length >= 4 )
	{
	$result = array_merge( $result, unpack( "Vmtime", substr( $field, $localOffset + self::EB_UT_MINLEN + ( self::EB_UT_FL_LEN * 0 ), self::EB_UT_FL_LEN ) ) );
	$length -= 4;
	}

	if ( $f["flags"] & self::EB_UT_FL_ATIME && $length >= 4 )
	{
	$result = array_merge( $result, unpack( "Vatime", substr( $field, $localOffset + self::EB_UT_MINLEN + ( self::EB_UT_FL_LEN * 1 ), self::EB_UT_FL_LEN ) ) );
	$length -= 4;
	}

	if ( $f["flags"] & self::EB_UT_FL_CTIME && $length >= 4 )
	{
	$result = array_merge( $result, unpack( "Vctime", substr( $field, $localOffset + self::EB_UT_MINLEN + ( self::EB_UT_FL_LEN * 2 ), self::EB_UT_FL_LEN ) ) );
	$length -= 4;
	}
	}

	return $result;
	}

	/**
	* Returns true if the given string $string matches with the current signature.
	*
	* @param string $string
	* @return bool
	*/
	public static function isSignature( $string )
	{
	return $string == pack( "V", self::magic );
	}
	}
	?>