source: sourcecode/application/libraries/PHPExcel/Shared/File.php @ 1

<?php
/**
 * PHPExcel
 *
 * Copyright (c) 2006 - 2014 PHPExcel
 *
 * 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
 *
 * @category   PHPExcel
 * @package    PHPExcel_Shared
 * @copyright  Copyright (c) 2006 - 2014 PHPExcel (http://www.codeplex.com/PHPExcel)
 * @license    http://www.gnu.org/licenses/old-licenses/lgpl-2.1.txt    LGPL
 * @version    1.8.0, 2014-03-02
 */


/**
 * PHPExcel_Shared_File
 *
 * @category   PHPExcel
 * @package    PHPExcel_Shared
 * @copyright  Copyright (c) 2006 - 2014 PHPExcel (http://www.codeplex.com/PHPExcel)
 */
class PHPExcel_Shared_File
{
        /*
         * Use Temp or File Upload Temp for temporary files
         *
         * @protected
         * @var boolean
         */
        protected static $_useUploadTempDirectory       = FALSE;


        /**
         * Set the flag indicating whether the File Upload Temp directory should be used for temporary files
         *
         * @param        boolean        $useUploadTempDir               Use File Upload Temporary directory (true or false)
         */
        public static function setUseUploadTempDirectory($useUploadTempDir = FALSE) {
                self::$_useUploadTempDirectory = (boolean) $useUploadTempDir;
        }       //      function setUseUploadTempDirectory()


        /**
         * Get the flag indicating whether the File Upload Temp directory should be used for temporary files
         *
         * @return       boolean        Use File Upload Temporary directory (true or false)
         */
        public static function getUseUploadTempDirectory() {
                return self::$_useUploadTempDirectory;
        }       //      function getUseUploadTempDirectory()


        /**
          * Verify if a file exists
          *
          * @param      string  $pFilename      Filename
          * @return bool
          */
        public static function file_exists($pFilename) {
                // Sick construction, but it seems that
                // file_exists returns strange values when
                // doing the original file_exists on ZIP archives...
                if ( strtolower(substr($pFilename, 0, 3)) == 'zip' ) {
                        // Open ZIP file and verify if the file exists
                        $zipFile                = substr($pFilename, 6, strpos($pFilename, '#') - 6);
                        $archiveFile    = substr($pFilename, strpos($pFilename, '#') + 1);

                        $zip = new ZipArchive();
                        if ($zip->open($zipFile) === true) {
                                $returnValue = ($zip->getFromName($archiveFile) !== false);
                                $zip->close();
                                return $returnValue;
                        } else {
                                return false;
                        }
                } else {
                        // Regular file_exists
                        return file_exists($pFilename);
                }
        }

        /**
         * Returns canonicalized absolute pathname, also for ZIP archives
         *
         * @param string $pFilename
         * @return string
         */
        public static function realpath($pFilename) {
                // Returnvalue
                $returnValue = '';

                // Try using realpath()
                if (file_exists($pFilename)) {
                        $returnValue = realpath($pFilename);
                }

                // Found something?
                if ($returnValue == '' || ($returnValue === NULL)) {
                        $pathArray = explode('/' , $pFilename);
                        while(in_array('..', $pathArray) && $pathArray[0] != '..') {
                                for ($i = 0; $i < count($pathArray); ++$i) {
                                        if ($pathArray[$i] == '..' && $i > 0) {
                                                unset($pathArray[$i]);
                                                unset($pathArray[$i - 1]);
                                                break;
                                        }
                                }
                        }
                        $returnValue = implode('/', $pathArray);
                }

                // Return
                return $returnValue;
        }

        /**
         * Get the systems temporary directory.
         *
         * @return string
         */
        public static function sys_get_temp_dir()
        {
                if (self::$_useUploadTempDirectory) {
                        //  use upload-directory when defined to allow running on environments having very restricted
                        //      open_basedir configs
                        if (ini_get('upload_tmp_dir') !== FALSE) {
                                if ($temp = ini_get('upload_tmp_dir')) {
                                        if (file_exists($temp))
                                                return realpath($temp);
                                }
                        }
                }

                // sys_get_temp_dir is only available since PHP 5.2.1
                // http://php.net/manual/en/function.sys-get-temp-dir.php#94119
                if ( !function_exists('sys_get_temp_dir')) {
                        if ($temp = getenv('TMP') ) {
                                if ((!empty($temp)) && (file_exists($temp))) { return realpath($temp); }
                        }
                        if ($temp = getenv('TEMP') ) {
                                if ((!empty($temp)) && (file_exists($temp))) { return realpath($temp); }
                        }
                        if ($temp = getenv('TMPDIR') ) {
                                if ((!empty($temp)) && (file_exists($temp))) { return realpath($temp); }
                        }

                        // trick for creating a file in system's temporary dir
                        // without knowing the path of the system's temporary dir
                        $temp = tempnam(__FILE__, '');
                        if (file_exists($temp)) {
                                unlink($temp);
                                return realpath(dirname($temp));
                        }

                        return null;
                }

                // use ordinary built-in PHP function
                //      There should be no problem with the 5.2.4 Suhosin realpath() bug, because this line should only
                //              be called if we're running 5.2.1 or earlier
                return realpath(sys_get_temp_dir());
        }

}