PclZip::privReadEndCentralDir( $p_central_dir )

4553  function privReadEndCentralDir(&$p_central_dir)4554  {4555    $v_result=1;4556 4557    // ----- Go to the end of the zip file4558    $v_size = filesize($this->zipname);4559    @fseek($this->zip_fd, $v_size);4560    if (@ftell($this->zip_fd) != $v_size)4561    {4562      // ----- Error log4563      PclZip::privErrorLog(PCLZIP_ERR_BAD_FORMAT, 'Unable to go to the end of the archive \''.$this->zipname.'\'');4564 4565      // ----- Return4566      return PclZip::errorCode();4567    }4568 4569    // ----- First try : look if this is an archive with no commentaries (most of the time)4570    // in this case the end of central dir is at 22 bytes of the file end4571    $v_found = 0;4572    if ($v_size > 26) {4573      @fseek($this->zip_fd, $v_size-22);4574      if (($v_pos = @ftell($this->zip_fd)) != ($v_size-22))4575      {4576        // ----- Error log4577        PclZip::privErrorLog(PCLZIP_ERR_BAD_FORMAT, 'Unable to seek back to the middle of the archive \''.$this->zipname.'\'');4578 4579        // ----- Return4580        return PclZip::errorCode();4581      }4582 4583      // ----- Read for bytes4584      $v_binary_data = @fread($this->zip_fd, 4);4585      $v_data = @unpack('Vid', $v_binary_data);4586 4587      // ----- Check signature4588      if ($v_data['id'] == 0x06054b50) {4589        $v_found = 1;4590      }4591 4592      $v_pos = ftell($this->zip_fd);4593    }4594 4595    // ----- Go back to the maximum possible size of the Central Dir End Record4596    if (!$v_found) {4597      $v_maximum_size = 65557; // 0xFFFF + 22;4598      if ($v_maximum_size > $v_size)4599        $v_maximum_size = $v_size;4600      @fseek($this->zip_fd, $v_size-$v_maximum_size);4601      if (@ftell($this->zip_fd) != ($v_size-$v_maximum_size))4602      {4603        // ----- Error log4604        PclZip::privErrorLog(PCLZIP_ERR_BAD_FORMAT, 'Unable to seek back to the middle of the archive \''.$this->zipname.'\'');4605 4606        // ----- Return4607        return PclZip::errorCode();4608      }4609 4610      // ----- Read byte per byte in order to find the signature4611      $v_pos = ftell($this->zip_fd);4612      $v_bytes = 0x00000000;4613      while ($v_pos < $v_size)4614      {4615        // ----- Read a byte4616        $v_byte = @fread($this->zip_fd, 1);4617 4618        // -----  Add the byte4619        //$v_bytes = ($v_bytes << 8) | ord($v_byte);4620        // Note we mask the old value down such that once shifted we can never end up with more than a 32bit number4621        // Otherwise on systems where we have 64bit integers the check below for the magic number will fail.4622        $v_bytes = ( ($v_bytes & 0xFFFFFF) << 8) | ord($v_byte);4623 4624        // ----- Compare the bytes4625        if ($v_bytes == 0x504b0506)4626        {4627          $v_pos++;4628          break;4629        }4630 4631        $v_pos++;4632      }