<?php
/***************************************************************
*  Copyright notice
*
*  (c) Vincent Blavet <vincent@phpconcept.net>
*  (c) 2005-2006 Karsten Dambekalns <karsten@typo3.org>
*  All rights reserved
*
*  This library is free software; you can redistribute it and/or
*  modify it under the terms of the GNU Lesser General Public
*  License as published by the Free Software Foundation; either
*  version 2.1 of the License, or (at your option) any later version.
*
*  This library is distributed in the hope that it will be useful,
*  but WITHOUT ANY WARRANTY; without even the implied warranty of
*  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
*  Lesser General Public License for more details.
*
*  You should have received a copy of the GNU Lesser General Public
*  License along with this library; if not, write to the Free Software
*  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
*  MA  02110-1301  USA
*
*  This copyright notice MUST APPEAR in all copies of the script!
***************************************************************/
/**
 * Module: Extension manager
 *
 * $Id: class.em_unzip.php 1869 2006-12-12 11:57:52Z k-fish $
 *
 * @author	Vincent Blavet <vincent@phpconcept.net>
 * @author	Karsten Dambekalns <karsten@typo3.org>
 */


// Constants
define( 'ARCHIVE_ZIP_READ_BLOCK_SIZE', 2048 );

// File list separator
define( 'ARCHIVE_ZIP_SEPARATOR', ',' );

define( 'ARCHIVE_ZIP_TEMPORARY_DIR', '' );

// Error codes
define( 'ARCHIVE_ZIP_ERR_NO_ERROR', 0 );
define( 'ARCHIVE_ZIP_ERR_WRITE_OPEN_FAIL', -1 );
define( 'ARCHIVE_ZIP_ERR_READ_OPEN_FAIL', -2 );
define( 'ARCHIVE_ZIP_ERR_INVALID_PARAMETER', -3 );
define( 'ARCHIVE_ZIP_ERR_MISSING_FILE', -4 );
define( 'ARCHIVE_ZIP_ERR_FILENAME_TOO_LONG', -5 );
define( 'ARCHIVE_ZIP_ERR_INVALID_ZIP', -6 );
define( 'ARCHIVE_ZIP_ERR_BAD_EXTRACTED_FILE', -7 );
define( 'ARCHIVE_ZIP_ERR_DIR_CREATE_FAIL', -8 );
define( 'ARCHIVE_ZIP_ERR_BAD_EXTENSION', -9 );
define( 'ARCHIVE_ZIP_ERR_BAD_FORMAT', -10 );
define( 'ARCHIVE_ZIP_ERR_DELETE_FILE_FAIL', -11 );
define( 'ARCHIVE_ZIP_ERR_RENAME_FILE_FAIL', -12 );
define( 'ARCHIVE_ZIP_ERR_BAD_CHECKSUM', -13 );
define( 'ARCHIVE_ZIP_ERR_INVALID_ARCHIVE_ZIP', -14 );
define( 'ARCHIVE_ZIP_ERR_MISSING_OPTION_VALUE', -15 );
define( 'ARCHIVE_ZIP_ERR_INVALID_PARAM_VALUE', -16 );

// Warning codes
define( 'ARCHIVE_ZIP_WARN_NO_WARNING', 0 );
define( 'ARCHIVE_ZIP_WARN_FILE_EXIST', 1 );

// Methods parameters
define( 'ARCHIVE_ZIP_PARAM_PATH', 'path' );
define( 'ARCHIVE_ZIP_PARAM_ADD_PATH', 'add_path' );
define( 'ARCHIVE_ZIP_PARAM_REMOVE_PATH', 'remove_path' );
define( 'ARCHIVE_ZIP_PARAM_REMOVE_ALL_PATH', 'remove_all_path' );
define( 'ARCHIVE_ZIP_PARAM_SET_CHMOD', 'set_chmod' );
define( 'ARCHIVE_ZIP_PARAM_EXTRACT_AS_STRING', 'extract_as_string' );
define( 'ARCHIVE_ZIP_PARAM_NO_COMPRESSION', 'no_compression' );

define( 'ARCHIVE_ZIP_PARAM_PRE_EXTRACT', 'callback_pre_extract' );
define( 'ARCHIVE_ZIP_PARAM_POST_EXTRACT', 'callback_post_extract' );
define( 'ARCHIVE_ZIP_PARAM_PRE_ADD', 'callback_pre_add' );
define( 'ARCHIVE_ZIP_PARAM_POST_ADD', 'callback_post_add' );



/**
* Class for unpacking zip archive files
*
* @author   Vincent Blavet <vincent@blavet.net>
* @author   Karsten Dambekalns <karsten@typo3.org>
*/
class em_unzip {
	/**
    * The filename of the zip archive.
    *
    * @var string Name of the Zip file
    */
	var $_zipname='';

	/**
    * File descriptor of the opened Zip file.
    *
    * @var int Internal zip file descriptor
    */
	var $_zip_fd=0;

	/**
    * @var int last error code
    */
	var $_error_code=1;

	/**
    * @var string Last error description
    */
	var $_error_string='';

	/**
    * em_unzip Class constructor. This flavour of the constructor only
    * declare a new em_unzip object, identifying it by the name of the
    * zip file.
    *
    * @param    string  $p_zipname  The name of the zip archive to create
    * @access public
    */
	function em_unzip($p_zipname) {

		// Check the zlib
		if (!extension_loaded('zlib')) {
			die("The extension 'zlib' couldn't be found.\n".
			"Please make sure your version of PHP was built ".
			"with 'zlib' support.\n");
		}

		// Set the attributes
		$this->_zipname = $p_zipname;
		$this->_zip_fd = 0;

		return;
	}



	/**
    * This method extract the files and folders which are in the zip archive.
    * It can extract all the archive or a part of the archive by using filter
    * feature (extract by name, by index, by ereg, by preg). The extraction
    * can occur in the current path or an other path.
    * All the advanced features are activated by the use of variable
		* parameters.
		* The return value is an array of entry descriptions which gives
		* information on extracted files (See listContent()).
		* The method may return a success value (an array) even if some files
		* are not correctly extracted (see the file status in listContent()).
    * The supported variable parameters for this method are :
    *   'add_path' : Path where the files and directories are to be extracted
    *
    * @access public
    * @param    mixed  $p_params  An array of variable parameters and values.
    * @return mixed An array of file description on success,
	*               0 on an unrecoverable failure, an error code is logged.
    */
	function extract($p_params=0) {
		$this->_errorReset();

		// Check archive
		if (!$this->_checkFormat()) {
			return(0);
		}

		// Set default values
		if ($p_params === 0) {
			$p_params = array();
		}
		if ($this->_check_parameters($p_params,
		array ('extract_as_string' => false,
		'add_path' => '',
		'remove_path' => '',
		'remove_all_path' => false,
		'callback_pre_extract' => '',
		'callback_post_extract' => '',
		'set_chmod' => 0) ) != 1) {
			return 0;
		}

		// Call the extracting fct
		$v_list = array();
		if ($this->_extractByRule($v_list, $p_params) != 1) {
			unset($v_list);
			return(0);
		}

		return $v_list;
	}

	/**
    * Method that gives the lastest error code.
    *
    * @access public
    * @return integer The error code value.
    */
	function errorCode() {
		return($this->_error_code);
	}

	/**
    * This method gives the latest error code name.
    *
    * @access public
    * @param  boolean $p_with_code  If true, gives the name and the int value.
    * @return string The error name.
    */
	function errorName($p_with_code=false) {
		$v_const_list = get_defined_constants();

		// Extract error constants from all const.
		for (reset($v_const_list);
		list($v_key, $v_value) = each($v_const_list);) {
			if (substr($v_key, 0, strlen('ARCHIVE_ZIP_ERR_')) =='ARCHIVE_ZIP_ERR_') {
				$v_error_list[$v_key] = $v_value;
			}
		}

		// Search the name form the code value
		$v_key=array_search($this->_error_code, $v_error_list, true);
		if ($v_key!=false) {
			$v_value = $v_key;
		} else {
			$v_value = 'NoName';
		}

		if ($p_with_code) {
			return($v_value.' ('.$this->_error_code.')');
		} else {
			return($v_value);
		}
	}

	/**
    * This method returns the description associated with the latest error.
    *
    * @access public
    * @param  boolean $p_full If set to true gives the description with the
    *                         error code, the name and the description.
    *                         If set to false gives only the description
    *                         and the error code.
    * @return string The error description.
    */
	function errorInfo($p_full=false) {
		if ($p_full) {
			return($this->errorName(true)." : ".$this->_error_string);
		} else {
			return($this->_error_string." [code ".$this->_error_code."]");
		}
	}


	/**
  * em_unzip::_checkFormat()
  *
  * { Description }
  *
  * @param integer $p_level
  */
	function _checkFormat($p_level=0) {
		$v_result = true;

		// Reset the error handler
		$this->_errorReset();

		// Look if the file exits
		if (!is_file($this->_zipname)) {
			// Error log
			$this->_errorLog(ARCHIVE_ZIP_ERR_MISSING_FILE,
			"Missing archive file '".$this->_zipname."'");
			return(false);
		}

		// Check that the file is readeable
		if (!is_readable($this->_zipname)) {
			// Error log
			$this->_errorLog(ARCHIVE_ZIP_ERR_READ_OPEN_FAIL,
			"Unable to read archive '".$this->_zipname."'");
			return(false);
		}

		// Check the magic code
		// TBC

		// Check the central header
		// TBC

		// Check each file header
		// TBC

		// Return
		return $v_result;
	}


	/**
  * em_unzip::_openFd()
  *
  * { Description }
  *
  */
	function _openFd($p_mode) {
		$v_result=1;

		// Look if already open
		if ($this->_zip_fd != 0) {
			$this->_errorLog(ARCHIVE_ZIP_ERR_READ_OPEN_FAIL,
			'Zip file \''.$this->_zipname.'\' already open');
			return em_unzip::errorCode();
		}

		// Open the zip file
		if (($this->_zip_fd = @fopen($this->_zipname, $p_mode)) == 0) {
			$this->_errorLog(ARCHIVE_ZIP_ERR_READ_OPEN_FAIL,
			'Unable to open archive \''.$this->_zipname
			.'\' in '.$p_mode.' mode');
			return em_unzip::errorCode();
		}

		// Return
		return $v_result;
	}

	/**
  * em_unzip::_closeFd()
  *
  * { Description }
  *
  */
	function _closeFd() {
		$v_result=1;

		if ($this->_zip_fd != 0)
		@fclose($this->_zip_fd);
		$this->_zip_fd = 0;

		// Return
		return $v_result;
	}



	/**
  * em_unzip::_convertHeader2FileInfo()
  *
  * { Description }
  *
  */
	function _convertHeader2FileInfo($p_header, &$p_info) {
		$v_result=1;

		// Get the interesting attributes
		$p_info['filename'] = $p_header['filename'];
		$p_info['stored_filename'] = $p_header['stored_filename'];
		$p_info['size'] = $p_header['size'];
		$p_info['compressed_size'] = $p_header['compressed_size'];
		$p_info['mtime'] = $p_header['mtime'];
		$p_info['comment'] = $p_header['comment'];
		$p_info['folder'] = (($p_header['external']&0x00000010)==0x00000010);
		$p_info['index'] = $p_header['index'];
		$p_info['status'] = $p_header['status'];

		// Return
		return $v_result;
	}


	// Function : _extractByRule()
	// Description :
	//   Extract a file or directory depending of rules (by index, by name, ...)
	// Parameters :
	//   $p_file_list : An array where will be placed the properties of each
	//                  extracted file
	//   $p_path : Path to add while writing the extracted files
	//   $p_remove_path : Path to remove (from the file memorized path) while writing the
	//                    extracted files. If the path does not match the file path,
	//                    the file is extracted with its memorized path.
	//                    $p_remove_path does not apply to 'list' mode.
	//                    $p_path and $p_remove_path are commulative.
	// Return Values :
	//   1 on success,0 or less on error (see error code list)

	/**
  * em_unzip::_extractByRule()
  *
  * { Description }
  *
  */
	function _extractByRule(&$p_file_list, &$p_params)
	{
		$v_result=1;

		$p_path = $p_params['add_path'];
		$p_remove_path = $p_params['remove_path'];
		$p_remove_all_path = $p_params['remove_all_path'];

		// Check the path
		if (($p_path == "")
		|| ((substr($p_path, 0, 1) != "/")
		&& (substr($p_path, 0, 3) != "../") && (substr($p_path,1,2)!=":/")))
		$p_path = "./".$p_path;

		// Reduce the path last (and duplicated) '/'
		if (($p_path != "./") && ($p_path != "/")) {
			// Look for the path end '/'
			while (substr($p_path, -1) == "/") {
				$p_path = substr($p_path, 0, strlen($p_path)-1);
			}
		}

		// Open the zip file
		if (($v_result = $this->_openFd('rb')) != 1)
		{
			return $v_result;
		}

		// Read the central directory informations
		$v_central_dir = array();
		if (($v_result = $this->_readEndCentralDir($v_central_dir)) != 1)
		{
			// Close the zip file
			$this->_closeFd();

			return $v_result;
		}

		// Start at beginning of Central Dir
		$v_pos_entry = $v_central_dir['offset'];

		// Read each entry
		$j_start = 0;
		for ($i=0, $v_nb_extracted=0; $i<$v_central_dir['entries']; $i++) {
			// Read next Central dir entry
			@rewind($this->_zip_fd);
			if (@fseek($this->_zip_fd, $v_pos_entry)) {
				$this->_closeFd();

				$this->_errorLog(ARCHIVE_ZIP_ERR_INVALID_ARCHIVE_ZIP,
				'Invalid archive size');

				return em_unzip::errorCode();
			}

			// Read the file header
			$v_header = array();
			if (($v_result = $this->_readCentralFileHeader($v_header)) != 1) {
				$this->_closeFd();

				return $v_result;
			}

			// Store the index
			$v_header['index'] = $i;

			// Store the file position
			$v_pos_entry = ftell($this->_zip_fd);


			// Go to the file position
			@rewind($this->_zip_fd);
			if (@fseek($this->_zip_fd, $v_header['offset']))
			{
				// Close the zip file
				$this->_closeFd();

				// Error log
				$this->_errorLog(ARCHIVE_ZIP_ERR_INVALID_ARCHIVE_ZIP, 'Invalid archive size');

				// Return
				return em_unzip::errorCode();
			}

			// Extracting the file
			if (($v_result = $this->_extractFile($v_header, $p_path, $p_remove_path, $p_remove_all_path, $p_params)) != 1)
			{
				// Close the zip file
				$this->_closeFd();

				return $v_result;
			}

			// Get the only interesting attributes
			if (($v_result = $this->_convertHeader2FileInfo($v_header, $p_file_list[$v_nb_extracted++])) != 1)
			{
				// Close the zip file
				$this->_closeFd();

				return $v_result;
			}
		}

		// Close the zip file
		$this->_closeFd();

		// Return
		return $v_result;
	}

	/**
  * em_unzip::_extractFile()
  *
  * { Description }
  *
  */
	function _extractFile(&$p_entry, $p_path, $p_remove_path, $p_remove_all_path, &$p_params) {
		$v_result=1;

		// Read the file header
		$v_header = '';
		if (($v_result = $this->_readFileHeader($v_header)) != 1)
		{
			// Return
			return $v_result;
		}


		// Check that the file header is coherent with $p_entry info
		// TBC

		// Look for all path to remove
		if ($p_remove_all_path == true) {
			// Get the basename of the path
			$p_entry['filename'] = basename($p_entry['filename']);
		}

		// Look for path to remove
		else if ($p_remove_path != "")
		{
			//if (strcmp($p_remove_path, $p_entry['filename'])==0)
			if ($this->_tool_PathInclusion($p_remove_path, $p_entry['filename']) == 2)
			{

				// Change the file status
				$p_entry['status'] = "filtered";

				// Return
				return $v_result;
			}

			$p_remove_path_size = strlen($p_remove_path);
			if (substr($p_entry['filename'], 0, $p_remove_path_size) == $p_remove_path)
			{

				// Remove the path
				$p_entry['filename'] = substr($p_entry['filename'], $p_remove_path_size);

			}
		}

		// Add the path
		if ($p_path != '')
		{
			$p_entry['filename'] = $p_path."/".$p_entry['filename'];
		}

		// Look for pre-extract callback
		if (   (isset($p_params[ARCHIVE_ZIP_PARAM_PRE_EXTRACT]))
		&& ($p_params[ARCHIVE_ZIP_PARAM_PRE_EXTRACT] != '')) {

			// Generate a local information
			$v_local_header = array();
			$this->_convertHeader2FileInfo($p_entry, $v_local_header);

			// Call the callback
			// Here I do not use call_user_func() because I need to send a reference to the
			// header.
			eval('$v_result = '.$p_params[ARCHIVE_ZIP_PARAM_PRE_EXTRACT].'(ARCHIVE_ZIP_PARAM_PRE_EXTRACT, $v_local_header);');
			if ($v_result == 0) {
				// Change the file status
				$p_entry['status'] = "skipped";
				$v_result = 1;
			}

			// Update the informations
			// Only some fields can be modified
			$p_entry['filename'] = $v_local_header['filename'];
		}

		// Trace

		// Look if extraction should be done
		if ($p_entry['status'] == 'ok') {

			// Look for specific actions while the file exist
			if (file_exists($p_entry['filename'])) {
				// Look if file is a directory
				if (is_dir($p_entry['filename'])) {
					// Change the file status
					$p_entry['status'] = "already_a_directory";

					// Return
					//return $v_result;
				}
				// Look if file is write protected
				else if (!is_writeable($p_entry['filename'])) {
					// Change the file status
					$p_entry['status'] = "write_protected";

					// Return
					//return $v_result;
				}

				// Look if the extracted file is older
				else if (filemtime($p_entry['filename']) > $p_entry['mtime']) {
					// Change the file status
					$p_entry['status'] = "newer_exist";

					// Return
					//return $v_result;
				}
			}

			// Check the directory availability and create it if necessary
			else {
				if ((($p_entry['external']&0x00000010)==0x00000010) || (substr($p_entry['filename'], -1) == '/'))
				$v_dir_to_check = $p_entry['filename'];
				else if (!strstr($p_entry['filename'], "/"))
				$v_dir_to_check = "";
				else
				$v_dir_to_check = dirname($p_entry['filename']);

				if (($v_result = $this->_dirCheck($v_dir_to_check, (($p_entry['external']&0x00000010)==0x00000010))) != 1) {
					// Change the file status
					$p_entry['status'] = "path_creation_fail";

					// Return
					//return $v_result;
					$v_result = 1;
				}
			}
		}

		// Look if extraction should be done
		if ($p_entry['status'] == 'ok') {
			// Do the extraction (if not a folder)
			if (!(($p_entry['external']&0x00000010)==0x00000010)) {
				// Look for not compressed file
				if ($p_entry['compressed_size'] == $p_entry['size']) {
					// Opening destination file
					if (($v_dest_file = @fopen($p_entry['filename'], 'wb')) == 0) {
						// Change the file status
						$p_entry['status'] = "write_error";

						// Return
						return $v_result;
					}


					// Read the file by ARCHIVE_ZIP_READ_BLOCK_SIZE octets blocks
					$v_size = $p_entry['compressed_size'];
					while ($v_size != 0) {
						$v_read_size = ($v_size < ARCHIVE_ZIP_READ_BLOCK_SIZE ? $v_size : ARCHIVE_ZIP_READ_BLOCK_SIZE);
						$v_buffer = fread($this->_zip_fd, $v_read_size);
						$v_binary_data = pack('a'.$v_read_size, $v_buffer);
						@fwrite($v_dest_file, $v_binary_data, $v_read_size);
						$v_size -= $v_read_size;
					}

					// Closing the destination file
					fclose($v_dest_file);

					// Change the file mtime
					touch($p_entry['filename'], $p_entry['mtime']);
				} else {
					// Trace

					// Opening destination file
					if (($v_dest_file = @fopen($p_entry['filename'], 'wb')) == 0) {

						// Change the file status
						$p_entry['status'] = "write_error";

						return $v_result;
					}


					// Read the compressed file in a buffer (one shot)
					$v_buffer = @fread($this->_zip_fd, $p_entry['compressed_size']);

					// Decompress the file
					$v_file_content = gzinflate($v_buffer);
					unset($v_buffer);

					// Write the uncompressed data
					@fwrite($v_dest_file, $v_file_content, $p_entry['size']);
					unset($v_file_content);

					// Closing the destination file
					@fclose($v_dest_file);

					// Change the file mtime
					@touch($p_entry['filename'], $p_entry['mtime']);
				}

				// Look for chmod option
				if (   (isset($p_params[ARCHIVE_ZIP_PARAM_SET_CHMOD]))
				&& ($p_params[ARCHIVE_ZIP_PARAM_SET_CHMOD] != 0)) {

					// Change the mode of the file
					chmod($p_entry['filename'], $p_params[ARCHIVE_ZIP_PARAM_SET_CHMOD]);
				}

			}
		}

		// Look for post-extract callback
		if (   (isset($p_params[ARCHIVE_ZIP_PARAM_POST_EXTRACT]))
		&& ($p_params[ARCHIVE_ZIP_PARAM_POST_EXTRACT] != '')) {

			// Generate a local information
			$v_local_header = array();
			$this->_convertHeader2FileInfo($p_entry, $v_local_header);

			// Call the callback
			// Here I do not use call_user_func() because I need to send a reference to the
			// header.
			eval('$v_result = '.$p_params[ARCHIVE_ZIP_PARAM_POST_EXTRACT].'(ARCHIVE_ZIP_PARAM_POST_EXTRACT, $v_local_header);');
		}

		// Return
		return $v_result;
	}

	/**
  * em_unzip::_readFileHeader()
  *
  * { Description }
  *
  */
	function _readFileHeader(&$p_header) {
		$v_result=1;

		// Read the 4 bytes signature
		$v_binary_data = @fread($this->_zip_fd, 4);
		$v_data = unpack('Vid', $v_binary_data);

		// Check signature
		if ($v_data['id'] != 0x04034b50) {

			// Error log
			$this->_errorLog(ARCHIVE_ZIP_ERR_BAD_FORMAT, 'Invalid archive structure');

			// Return
			return em_unzip::errorCode();
		}

		// Read the first 42 bytes of the header
		$v_binary_data = fread($this->_zip_fd, 26);

		// Look for invalid block size
		if (strlen($v_binary_data) != 26) {
			$p_header['filename'] = "";
			$p_header['status'] = "invalid_header";

			// Error log
			$this->_errorLog(ARCHIVE_ZIP_ERR_BAD_FORMAT, "Invalid block size : ".strlen($v_binary_data));

			// Return
			return em_unzip::errorCode();
		}

		// Extract the values
		$v_data = unpack('vversion/vflag/vcompression/vmtime/vmdate/Vcrc/Vcompressed_size/Vsize/vfilename_len/vextra_len', $v_binary_data);

		// Get filename
		$p_header['filename'] = fread($this->_zip_fd, $v_data['filename_len']);

		// Get extra_fields
		if ($v_data['extra_len'] != 0) {
			$p_header['extra'] = fread($this->_zip_fd, $v_data['extra_len']);
		}
		else {
			$p_header['extra'] = '';
		}

		// Extract properties
		$p_header['compression'] = $v_data['compression'];
		$p_header['size'] = $v_data['size'];
		$p_header['compressed_size'] = $v_data['compressed_size'];
		$p_header['crc'] = $v_data['crc'];
		$p_header['flag'] = $v_data['flag'];

		// Recuperate date in UNIX format
		$p_header['mdate'] = $v_data['mdate'];
		$p_header['mtime'] = $v_data['mtime'];
		if ($p_header['mdate'] && $p_header['mtime']) {
			// Extract time
			$v_hour = ($p_header['mtime'] & 0xF800) >> 11;
			$v_minute = ($p_header['mtime'] & 0x07E0) >> 5;
			$v_seconde = ($p_header['mtime'] & 0x001F)*2;

			// Extract date
			$v_year = (($p_header['mdate'] & 0xFE00) >> 9) + 1980;
			$v_month = ($p_header['mdate'] & 0x01E0) >> 5;
			$v_day = $p_header['mdate'] & 0x001F;

			// Get UNIX date format
			$p_header['mtime'] = mktime($v_hour, $v_minute, $v_seconde, $v_month, $v_day, $v_year);

		} else {
			$p_header['mtime'] = time();
		}

		// Other informations

		// TBC
		//for(reset($v_data); $key = key($v_data); next($v_data)) {
		//}

		// Set the stored filename
		$p_header['stored_filename'] = $p_header['filename'];

		// Set the status field
		$p_header['status'] = "ok";

		// Return
		return $v_result;
	}

	/**
  * em_unzip::_readCentralFileHeader()
  *
  * { Description }
  *
  */
	function _readCentralFileHeader(&$p_header) {
		$v_result=1;

		// Read the 4 bytes signature
		$v_binary_data = @fread($this->_zip_fd, 4);
		$v_data = unpack('Vid', $v_binary_data);

		// Check signature
		if ($v_data['id'] != 0x02014b50) {

			// Error log
			$this->_errorLog(ARCHIVE_ZIP_ERR_BAD_FORMAT, 'Invalid archive structure');

			// Return
			return em_unzip::errorCode();
		}

		// Read the first 42 bytes of the header
		$v_binary_data = fread($this->_zip_fd, 42);

		// Look for invalid block size
		if (strlen($v_binary_data) != 42) {
			$p_header['filename'] = "";
			$p_header['status'] = "invalid_header";

			// Error log
			$this->_errorLog(ARCHIVE_ZIP_ERR_BAD_FORMAT, "Invalid block size : ".strlen($v_binary_data));

			// Return
			return em_unzip::errorCode();
		}

		// Extract the values
		$p_header = unpack('vversion/vversion_extracted/vflag/vcompression/vmtime/vmdate/Vcrc/Vcompressed_size/Vsize/vfilename_len/vextra_len/vcomment_len/vdisk/vinternal/Vexternal/Voffset', $v_binary_data);

		// Get filename
		if ($p_header['filename_len'] != 0)
		$p_header['filename'] = fread($this->_zip_fd, $p_header['filename_len']);
		else
		$p_header['filename'] = '';

		// Get extra
		if ($p_header['extra_len'] != 0)
		$p_header['extra'] = fread($this->_zip_fd, $p_header['extra_len']);
		else
		$p_header['extra'] = '';

		// Get comment
		if ($p_header['comment_len'] != 0)
		$p_header['comment'] = fread($this->_zip_fd, $p_header['comment_len']);
		else
		$p_header['comment'] = '';

		// Extract properties

		// Recuperate date in UNIX format
		if ($p_header['mdate'] && $p_header['mtime']) {
			// Extract time
			$v_hour = ($p_header['mtime'] & 0xF800) >> 11;
			$v_minute = ($p_header['mtime'] & 0x07E0) >> 5;
			$v_seconde = ($p_header['mtime'] & 0x001F)*2;

			// Extract date
			$v_year = (($p_header['mdate'] & 0xFE00) >> 9) + 1980;
			$v_month = ($p_header['mdate'] & 0x01E0) >> 5;
			$v_day = $p_header['mdate'] & 0x001F;

			// Get UNIX date format
			$p_header['mtime'] = mktime($v_hour, $v_minute, $v_seconde, $v_month, $v_day, $v_year);

		} else {
			$p_header['mtime'] = time();
		}

		// Set the stored filename
		$p_header['stored_filename'] = $p_header['filename'];

		// Set default status to ok
		$p_header['status'] = 'ok';

		// Look if it is a directory
		if (substr($p_header['filename'], -1) == '/') {
			$p_header['external'] = 0x41FF0010;
		}


		// Return
		return $v_result;
	}

	/**
  * em_unzip::_readEndCentralDir()
  *
  * { Description }
  *
  */
	function _readEndCentralDir(&$p_central_dir) {
		$v_result=1;

		// Go to the end of the zip file
		$v_size = filesize($this->_zipname);
		@fseek($this->_zip_fd, $v_size);
		if (@ftell($this->_zip_fd) != $v_size) {
			$this->_errorLog(ARCHIVE_ZIP_ERR_BAD_FORMAT,
			'Unable to go to the end of the archive \''
			.$this->_zipname.'\'');
			return em_unzip::errorCode();
		}

		// First try : look if this is an archive with no commentaries
		// (most of the time)
		// in this case the end of central dir is at 22 bytes of the file end
		$v_found = 0;
		if ($v_size > 26) {
			@fseek($this->_zip_fd, $v_size-22);
			if (($v_pos = @ftell($this->_zip_fd)) != ($v_size-22)) {
				$this->_errorLog(ARCHIVE_ZIP_ERR_BAD_FORMAT,
				'Unable to seek back to the middle of the archive \''
				.$this->_zipname.'\'');
				return em_unzip::errorCode();
			}

			// Read for bytes
			$v_binary_data = @fread($this->_zip_fd, 4);
			$v_data = unpack('Vid', $v_binary_data);

			// Check signature
			if ($v_data['id'] == 0x06054b50) {
				$v_found = 1;
			}

			$v_pos = ftell($this->_zip_fd);
		}

		// Go back to the maximum possible size of the Central Dir End Record
		if (!$v_found) {
			$v_maximum_size = 65557; // 0xFFFF + 22;
			if ($v_maximum_size > $v_size)
			$v_maximum_size = $v_size;
			@fseek($this->_zip_fd, $v_size-$v_maximum_size);
			if (@ftell($this->_zip_fd) != ($v_size-$v_maximum_size)) {
				$this->_errorLog(ARCHIVE_ZIP_ERR_BAD_FORMAT,
				'Unable to seek back to the middle of the archive \''
				.$this->_zipname.'\'');
				return em_unzip::errorCode();
			}

			// Read byte per byte in order to find the signature
			$v_pos = ftell($this->_zip_fd);
			$v_bytes = 0x00000000;
			while ($v_pos < $v_size) {
				// Read a byte
				$v_byte = @fread($this->_zip_fd, 1);

				//  Add the byte
				$v_bytes = ($v_bytes << 8) | Ord($v_byte);

				// Compare the bytes
				if ($v_bytes == 0x504b0506) {
					$v_pos++;
					break;
				}

				$v_pos++;
			}

			// Look if not found end of central dir
			if ($v_pos == $v_size) {
				$this->_errorLog(ARCHIVE_ZIP_ERR_BAD_FORMAT,
				"Unable to find End of Central Dir Record signature");
				return em_unzip::errorCode();
			}
		}

		// Read the first 18 bytes of the header
		$v_binary_data = fread($this->_zip_fd, 18);

		// Look for invalid block size
		if (strlen($v_binary_data) != 18) {
			$this->_errorLog(ARCHIVE_ZIP_ERR_BAD_FORMAT,
			"Invalid End of Central Dir Record size : "
			.strlen($v_binary_data));
			return em_unzip::errorCode();
		}

		// Extract the values
		$v_data = unpack('vdisk/vdisk_start/vdisk_entries/ventries/Vsize/Voffset/vcomment_size', $v_binary_data);

		// Check the global size
		if (($v_pos + $v_data['comment_size'] + 18) != $v_size) {
			$this->_errorLog(ARCHIVE_ZIP_ERR_BAD_FORMAT,
			"Fail to find the right signature");
			return em_unzip::errorCode();
		}

		// Get comment
		if ($v_data['comment_size'] != 0)
		$p_central_dir['comment'] = fread($this->_zip_fd, $v_data['comment_size']);
		else
		$p_central_dir['comment'] = '';

		$p_central_dir['entries'] = $v_data['entries'];
		$p_central_dir['disk_entries'] = $v_data['disk_entries'];
		$p_central_dir['offset'] = $v_data['offset'];
		$p_central_dir['size'] = $v_data['size'];
		$p_central_dir['disk'] = $v_data['disk'];
		$p_central_dir['disk_start'] = $v_data['disk_start'];

		// Return
		return $v_result;
	}

	/**
  * em_unzip::_dirCheck()
  *
  * { Description }
  *
  * @param [type] $p_is_dir
  */
	function _dirCheck($p_dir, $p_is_dir=false) {
		$v_result = 1;

		// Remove the final '/'
		if (($p_is_dir) && (substr($p_dir, -1)=='/')) {
			$p_dir = substr($p_dir, 0, strlen($p_dir)-1);
		}

		// Check the directory availability
		if ((is_dir($p_dir)) || ($p_dir == "")) {
			return 1;
		}

		// Extract parent directory
		$p_parent_dir = dirname($p_dir);

		// Just a check
		if ($p_parent_dir != $p_dir) {
			// Look for parent directory
			if ($p_parent_dir != "") {
				if (($v_result = $this->_dirCheck($p_parent_dir)) != 1) {
					return $v_result;
				}
			}
		}

		// Create the directory
		if (!@mkdir($p_dir, 0777)) {
			$this->_errorLog(ARCHIVE_ZIP_ERR_DIR_CREATE_FAIL,
			"Unable to create directory '$p_dir'");
			return em_unzip::errorCode();
		}

		// Return
		return $v_result;
	}

	/**
  * em_unzip::_check_parameters()
  *
  * { Description }
  *
  * @param integer $p_error_code
  * @param string $p_error_string
  */
	function _check_parameters(&$p_params, $p_default) {

		// Check that param is an array
		if (!is_array($p_params)) {
			$this->_errorLog(ARCHIVE_ZIP_ERR_INVALID_PARAMETER,
			'Unsupported parameter, waiting for an array');
			return em_unzip::errorCode();
		}

		// Check that all the params are valid
		for (reset($p_params); list($v_key, $v_value) = each($p_params); ) {
			if (!isset($p_default[$v_key])) {
				$this->_errorLog(ARCHIVE_ZIP_ERR_INVALID_PARAMETER,
				'Unsupported parameter with key \''.$v_key.'\'');

				return em_unzip::errorCode();
			}
		}

		// Set the default values
		for (reset($p_default); list($v_key, $v_value) = each($p_default); ) {
			if (!isset($p_params[$v_key])) {
				$p_params[$v_key] = $p_default[$v_key];
			}
		}

		// Check specific parameters
		$v_callback_list = array ('callback_pre_add','callback_post_add',
		'callback_pre_extract','callback_post_extract');
		for ($i=0; $i<sizeof($v_callback_list); $i++) {
			$v_key=$v_callback_list[$i];
			if (   (isset($p_params[$v_key])) && ($p_params[$v_key] != '')) {
				if (!function_exists($p_params[$v_key])) {
					$this->_errorLog(ARCHIVE_ZIP_ERR_INVALID_PARAM_VALUE,
					"Callback '".$p_params[$v_key]
					."()' is not an existing function for "
					."parameter '".$v_key."'");
					return em_unzip::errorCode();
				}
			}
		}

		return(1);
	}

	/**
  * em_unzip::_errorLog()
  *
  * { Description }
  *
  * @param integer $p_error_code
  * @param string $p_error_string
  */
	function _errorLog($p_error_code=0, $p_error_string='') {
		$this->_error_code = $p_error_code;
		$this->_error_string = $p_error_string;
	}

	/**
  * em_unzip::_errorReset()
  *
  * { Description }
  *
  */
	function _errorReset() {
		$this->_error_code = 1;
		$this->_error_string = '';
	}

	/**
  * _tool_PathReduction()
  *
  * { Description }
  *
  */
	function _tool_PathReduction($p_dir) {
		$v_result = "";

		// Look for not empty path
		if ($p_dir != "") {
			// Explode path by directory names
			$v_list = explode("/", $p_dir);

			// Study directories from last to first
			for ($i=sizeof($v_list)-1; $i>=0; $i--) {
				// Look for current path
				if ($v_list[$i] == ".") {
					// Ignore this directory
					// Should be the first $i=0, but no check is done
				} else if ($v_list[$i] == "..") {
					// Ignore it and ignore the $i-1
					$i--;
				} else if (($v_list[$i] == "") && ($i!=(sizeof($v_list)-1)) && ($i!=0)) {
					// Ignore only the double '//' in path,
					// but not the first and last '/'
				} else {
					$v_result = $v_list[$i].($i!=(sizeof($v_list)-1)?"/".$v_result:"");
				}
			}
		}

		// Return
		return $v_result;
	}

	/**
  * _tool_PathInclusion()
  *
  * { Description }
  *
  */
	function _tool_PathInclusion($p_dir, $p_path) {
		$v_result = 1;

		// Explode dir and path by directory separator
		$v_list_dir = explode("/", $p_dir);
		$v_list_dir_size = sizeof($v_list_dir);
		$v_list_path = explode("/", $p_path);
		$v_list_path_size = sizeof($v_list_path);

		// Study directories paths
		$i = 0;
		$j = 0;
		while (($i < $v_list_dir_size) && ($j < $v_list_path_size) && ($v_result)) {
			// Look for empty dir (path reduction)
			if ($v_list_dir[$i] == '') {
				$i++;
				continue;
			}
			if ($v_list_path[$j] == '') {
				$j++;
				continue;
			}

			// Compare the items
			if (   ($v_list_dir[$i] != $v_list_path[$j]) && ($v_list_dir[$i] != '') && ( $v_list_path[$j] != ''))  {
				$v_result = 0;
			}

			// Next items
			$i++;
			$j++;
		}

		// Look if everything seems to be the same
		if ($v_result) {
			// Skip all the empty items
			while (($j < $v_list_path_size) && ($v_list_path[$j] == '')) $j++;
			while (($i < $v_list_dir_size) && ($v_list_dir[$i] == '')) $i++;

			if (($i >= $v_list_dir_size) && ($j >= $v_list_path_size)) {
				// There are exactly the same
				$v_result = 2;
			} else if ($i < $v_list_dir_size) {
				// The path is shorter than the dir
				$v_result = 0;
			}
		}

		// Return
		return $v_result;
	}

	/**
  * _tool_CopyBlock()
  *
  * { Description }
  *
  * @param integer $p_mode
  */
	function _tool_CopyBlock($p_src, $p_dest, $p_size, $p_mode=0) {
		$v_result = 1;

		if ($p_mode==0) {
			while ($p_size != 0) {
				$v_read_size = ($p_size < ARCHIVE_ZIP_READ_BLOCK_SIZE
				? $p_size : ARCHIVE_ZIP_READ_BLOCK_SIZE);
				$v_buffer = @fread($p_src, $v_read_size);
				@fwrite($p_dest, $v_buffer, $v_read_size);
				$p_size -= $v_read_size;
			}
		} else if ($p_mode==1) {
			while ($p_size != 0) {
				$v_read_size = ($p_size < ARCHIVE_ZIP_READ_BLOCK_SIZE
				? $p_size : ARCHIVE_ZIP_READ_BLOCK_SIZE);
				$v_buffer = @gzread($p_src, $v_read_size);
				@fwrite($p_dest, $v_buffer, $v_read_size);
				$p_size -= $v_read_size;
			}
		} else if ($p_mode==2) {
			while ($p_size != 0) {
				$v_read_size = ($p_size < ARCHIVE_ZIP_READ_BLOCK_SIZE
				? $p_size : ARCHIVE_ZIP_READ_BLOCK_SIZE);
				$v_buffer = @fread($p_src, $v_read_size);
				@gzwrite($p_dest, $v_buffer, $v_read_size);
				$p_size -= $v_read_size;
			}
		}
		else if ($p_mode==3) {
			while ($p_size != 0) {
				$v_read_size = ($p_size < ARCHIVE_ZIP_READ_BLOCK_SIZE
				? $p_size : ARCHIVE_ZIP_READ_BLOCK_SIZE);
				$v_buffer = @gzread($p_src, $v_read_size);
				@gzwrite($p_dest, $v_buffer, $v_read_size);
				$p_size -= $v_read_size;
			}
		}

		// Return
		return $v_result;
	}

	/**
  * _tool_Rename()
  *
  * { Description }
  *
  */
	function _tool_Rename($p_src, $p_dest) {
		$v_result = 1;

		// Try to rename the files
		if (!@rename($p_src, $p_dest)) {

			// Try to copy & unlink the src
			if (!@copy($p_src, $p_dest)) {
				$v_result = 0;
			} else if (!@unlink($p_src)) {
				$v_result = 0;
			}
		}

		// Return
		return $v_result;
	}

	/**
  * _tool_TranslateWinPath()
  *
  * { Description }
  *
  * @param [type] $p_remove_disk_letter
  */
	function _tool_TranslateWinPath($p_path, $p_remove_disk_letter=true) {
		if (stristr(php_uname(), 'windows')) {
			// Look for potential disk letter
			if (   ($p_remove_disk_letter)
			&& (($v_position = strpos($p_path, ':')) != false)) {
				$p_path = substr($p_path, $v_position+1);
			}
			// Change potential windows directory separator
			if ((strpos($p_path, '\\') > 0) || (substr($p_path, 0,1) == '\\')) {
				$p_path = strtr($p_path, '\\', '/');
			}
		}
		return $p_path;
	}

}

?>