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structure.inc

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    file.inc 66.11 KiB
    <?php
    // $Id$
    
    /**
     * @file
     * API for handling file uploads and server file management.
     */
    
    /**
     * @defgroup file File interface
     * @{
     * Common file handling functions.
     *
     * Fields on the file object:
     * - fid - File ID
     * - uid - The {users}.uid of the user who is associated with the file.
     * - filename - Name of the file with no path components. This may differ from
     *   the basename of the filepath if the file is renamed to avoid overwriting
     *   an existing file.
     * - filepath - Path of the file relative to Drupal root.
     * - filemime - The file's MIME type.
     * - filesize - The size of the file in bytes.
     * - status - A bitmapped field indicating the status of the file. The first 8
     *   bits are reserved for Drupal core. The least sigifigant bit indicates
     *   temporary (0) or permanent (1). Temporary files older than
     *   DRUPAL_MAXIMUM_TEMP_FILE_AGE will be removed during cron runs.
     * - timestamp - UNIX timestamp for the date the file was added to the database.
     */
    
    /**
     * Flag to indicate that the 'public' file download method is enabled.
     *
     * When using this method, files are available from a regular HTTP request,
     * which provides no additional access restrictions.
     */
    define('FILE_DOWNLOADS_PUBLIC', 1);
    
    /**
     * Flag to indicate that the 'private' file download method is enabled.
     *
     * When using this method, all file requests are served by Drupal, during which
     * access-control checking can be performed.
     */
    define('FILE_DOWNLOADS_PRIVATE', 2);
    
    /**
     * Flag used by file_check_directory() -- create directory if not present.
     */
    define('FILE_CREATE_DIRECTORY', 1);
    
    /**
     * Flag used by file_check_directory() -- file permissions may be changed.
     */
    define('FILE_MODIFY_PERMISSIONS', 2);
    
    /**
     * Flag for dealing with existing files: Appends number until name is unique.
     */
    define('FILE_EXISTS_RENAME', 0);
    
    /**
     * Flag for dealing with existing files: Replace the existing file.
     */
    define('FILE_EXISTS_REPLACE', 1);
    
    /**
     * Flag for dealing with existing files: Do nothing and return FALSE.
     */
    define('FILE_EXISTS_ERROR', 2);
    
    /**
     * File status -- This bit in the status indicates that the file is permanent
     * and should not be deleted during file garbage collection process. Temporary
     * files older than DRUPAL_MAXIMUM_TEMP_FILE_AGE will be removed during cron
     * runs.
     */
    define('FILE_STATUS_PERMANENT', 1);
    
    /**
     * Create the download path to a file.
     *
     * @param $path A string containing the path of the file to generate URL for.
     * @return A string containing a URL that can be used to download the file.
     */
    function file_create_url($path) {
      // Strip file_directory_path from $path. We only include relative paths in
      // URLs.
      if (strpos($path, file_directory_path() . '/') === 0) {
        $path = trim(substr($path, strlen(file_directory_path())), '\\/');
      }
      switch (variable_get('file_downloads', FILE_DOWNLOADS_PUBLIC)) {
        case FILE_DOWNLOADS_PUBLIC:
          return $GLOBALS['base_url'] . '/' . file_directory_path() . '/' . str_replace('\\', '/', $path);
        case FILE_DOWNLOADS_PRIVATE:
          return url('system/files/' . $path, array('absolute' => TRUE));
      }
    }
    
    /**
     * Make sure the destination is a complete path and resides in the file system
     * directory, if it is not prepend the file system directory.
     *
     * @param $destination
     *   A string containing the path to verify. If this value is omitted, Drupal's
     *   'files' directory will be used.
     * @return
     *   A string containing the path to file, with file system directory appended
     *   if necessary, or FALSE if the path is invalid (i.e. outside the configured
     *   'files' or temp directories).
     */
    function file_create_path($destination = NULL) {
      $file_path = file_directory_path();
      if (is_null($destination)) {
        return $file_path;
      }
      // file_check_location() checks whether the destination is inside the Drupal
      // files directory.
      if (file_check_location($destination, $file_path)) {
        return $destination;
      }
      // Check if the destination is instead inside the Drupal temporary files
      // directory.
      elseif (file_check_location($destination, file_directory_temp())) {
        return $destination;
      }
      // Not found, try again with prefixed directory path.
      elseif (file_check_location($file_path . '/' . $destination, $file_path)) {
        return $file_path . '/' . $destination;
      }
      // File not found.
      return FALSE;
    }
    
    /**
     * Check that the directory exists and is writable.
     *
     * Directories need to have execute permissions to be considered a directory by
     * FTP servers, etc.
     *
     * @param $directory
     *   A string containing the name of a directory path.
     * @param $mode
     *   A bitmask to indicate if the directory should be created if it does
     *   not exist (FILE_CREATE_DIRECTORY) or made writable if it is read-only
     *   (FILE_MODIFY_PERMISSIONS).
     * @param $form_item
     *   An optional string containing the name of a form item that any errors will
     *   be attached to. This is useful for settings forms that require the user to
     *   specify a writable directory. If it can't be made to work, a form error
     *   will be set preventing them from saving the settings.
     * @return
     *   FALSE when directory not found, or TRUE when directory exists.
     */
    function file_check_directory(&$directory, $mode = 0, $form_item = NULL) {
      $directory = rtrim($directory, '/\\');
    
      // Check if directory exists.
      if (!is_dir($directory)) {
        if (($mode & FILE_CREATE_DIRECTORY) && @mkdir($directory)) {
          @chmod($directory, 0775); // Necessary for non-webserver users.
        }
        else {
          if ($form_item) {
            form_set_error($form_item, t('The directory %directory does not exist.', array('%directory' => $directory)));
            watchdog('file system', 'The directory %directory does not exist.', array('%directory' => $directory), WATCHDOG_ERROR);
          }
          return FALSE;
        }
      }
    
      // Check to see if the directory is writable.
      if (!is_writable($directory)) {
        // If not able to modify permissions, or if able to, but chmod
        // fails, return false.
        if (!$mode || (($mode & FILE_MODIFY_PERMISSIONS) && !@chmod($directory, 0775))) {
          if ($form_item) {
            form_set_error($form_item, t('The directory %directory is not writable', array('%directory' => $directory)));
            watchdog('file system', 'The directory %directory is not writable, because it does not have the correct permissions set.', array('%directory' => $directory), WATCHDOG_ERROR);
          }
          return FALSE;
        }
      }
    
      if ((file_directory_path() == $directory || file_directory_temp() == $directory) && !is_file("$directory/.htaccess")) {
        $htaccess_lines = "SetHandler Drupal_Security_Do_Not_Remove_See_SA_2006_006\nOptions None\nOptions +FollowSymLinks";
        if (($fp = fopen("$directory/.htaccess", 'w')) && fputs($fp, $htaccess_lines)) {
          fclose($fp);
          chmod($directory . '/.htaccess', 0664);
        }
        else {
          $variables = array('%directory' => $directory, '!htaccess' => '<br />' . nl2br(check_plain($htaccess_lines)));
          form_set_error($form_item, t("Security warning: Couldn't write .htaccess file. Please create a .htaccess file in your %directory directory which contains the following lines: <code>!htaccess</code>", $variables));
          watchdog('security', "Security warning: Couldn't write .htaccess file. Please create a .htaccess file in your %directory directory which contains the following lines: <code>!htaccess</code>", $variables, WATCHDOG_ERROR);
        }
      }
    
      return TRUE;
    }
    
    /**
     * Checks path to see if it is a directory, or a directory/file.
     *
     * @param $path
     *   A string containing a file path. This will be set to the directory's path.
     * @return
     *   If the directory is not in a Drupal writable directory, FALSE is returned.
     *   Otherwise, the base name of the path is returned.
     */
    function file_check_path(&$path) {
      // Check if path is a directory.
      if (file_check_directory($path)) {
        return '';
      }
    
      // Check if path is a possible dir/file.
      $filename = basename($path);
      $path = dirname($path);
      if (file_check_directory($path)) {
        return $filename;
      }
    
      return FALSE;
    }
    
    /**
     * Check if a file is really located inside $directory.
     *
     * This should be used to make sure a file specified is really located within
     * the directory to prevent exploits. Note that the file or path being checked
     * does not actually need to exist yet.
     *
     * @code
     *   // Returns FALSE:
     *   file_check_location('/www/example.com/files/../../../etc/passwd', '/www/example.com/files');
     * @endcode
     *
     * @param $source
     *   A string set to the file to check.
     * @param $directory
     *   A string where the file should be located.
     * @return
     *   FALSE if the path does not exist in the directory; otherwise, the real
     *   path of the source.
     */
    function file_check_location($source, $directory = '') {
      $check = realpath($source);
      if ($check) {
        $source = $check;
      }
      else {
        // This file does not yet exist.
        $source = realpath(dirname($source)) . '/' . basename($source);
      }
      $directory = realpath($directory);
      if ($directory && strpos($source, $directory) !== 0) {
        return FALSE;
      }
      return $source;
    }
    
    /**
     * Load file objects from the database.
     *
     * @param $fids
     *   An array of file IDs.
     * @param $conditions
     *   An array of conditions to match against the {files} table. These
     *   should be supplied in the form array('field_name' => 'field_value').
     * @return
     *  An array of file objects, indexed by fid.
     *
     * @see hook_file_load()
     * @see file_load()
     */
    function file_load_multiple($fids = array(), $conditions = array()) {
      $query = db_select('files', 'f')->fields('f');
    
      // If the $fids array is populated, add those to the query.
      if ($fids) {
        $query->condition('f.fid', $fids, 'IN');
      }
    
      // If the conditions array is populated, add those to the query.
      if ($conditions) {
        foreach ($conditions as $field => $value) {
          $query->condition('f.' . $field, $value);
        }
      }
      $files = $query->execute()->fetchAllAssoc('fid');
    
      // Invoke hook_file_load() on the terms loaded from the database
      // and add them to the static cache.
      if (!empty($files)) {
        foreach (module_implements('file_load') as $module) {
          $function = $module . '_file_load';
          $function($files);
        }
      }
      return $files;
    }
    
    /**
     * Load a file object from the database.
     *
     * @param $fid
     *  A file ID.
     * @return
     *   A file object.
     *
     * @see hook_file_load()
     * @see file_load_multiple()
     */
    function file_load($fid) {
      $files = file_load_multiple(array($fid), array());
      return reset($files);
    }
    
    /**
     * Save a file object to the database.
     *
     * If the $file->fid is not set a new record will be added. Re-saving an
     * existing file will not change its status.
     *
     * @param $file
     *   A file object returned by file_load().
     * @return
     *   The updated file object.
     *
     * @see hook_file_insert()
     * @see hook_file_update()
     */
    function file_save($file) {
      $file = (object)$file;
      $file->timestamp = REQUEST_TIME;
      $file->filesize = filesize($file->filepath);
    
      if (empty($file->fid)) {
        drupal_write_record('files', $file);
        // Inform modules about the newly added file.
        module_invoke_all('file_insert', $file);
      }
      else {
        drupal_write_record('files', $file, 'fid');
        // Inform modules that the file has been updated.
        module_invoke_all('file_update', $file);
      }
    
      return $file;
    }
    
    /**
     * Copy a file to a new location and adds a file record to the database.
     *
     * This function should be used when manipulating files that have records
     * stored in the database. This is a powerful function that in many ways
     * performs like an advanced version of copy().
     * - Checks if $source and $destination are valid and readable/writable.
     * - Checks that $source is not equal to $destination; if they are an error
     *   is reported.
     * - If file already exists in $destination either the call will error out,
     *   replace the file or rename the file based on the $replace parameter.
     * - Adds the new file to the files database. If the source file is a
     *   temporary file, the resulting file will also be a temporary file.
     *   @see file_save_upload() for details on temporary files.
     *
     * @param $source
     *   A file object.
     * @param $destination
     *   A string containing the destination that $source should be copied to. This
     *   can be a complete file path, a directory path or, if this value is omitted,
     *   Drupal's 'files' directory will be used.
     * @param $replace
     *   Replace behavior when the destination file already exists:
     *   - FILE_EXISTS_REPLACE - Replace the existing file. If a managed file with
     *       the destination name exists then its database entry will be updated. If
     *       no database entry is found then a new one will be created.
     *   - FILE_EXISTS_RENAME - Append _{incrementing number} until the filename is
     *       unique.
     *   - FILE_EXISTS_ERROR - Do nothing and return FALSE.
     * @return
     *   File object if the copy is successful, or FALSE in the event of an error.
     *
     * @see file_unmanaged_copy()
     * @see hook_file_copy()
     */
    function file_copy($source, $destination = NULL, $replace = FILE_EXISTS_RENAME) {
      $source = (object)$source;
    
      if ($filepath = file_unmanaged_copy($source->filepath, $destination, $replace)) {
        $file = clone $source;
        $file->fid = NULL;
        $file->filepath = $filepath;
        $file->filename = basename($filepath);
        // If we are replacing an existing file re-use its database record.
        if ($replace == FILE_EXISTS_REPLACE) {
          $existing_files = file_load_multiple(array(), array('filepath' => $filepath));
          if (count($existing_files)) {
            $existing = reset($existing_files);
            $file->fid = $existing->fid;
            $file->filename = $existing->filename;
          }
        }
        // If we are renaming around an existing file (rather than a directory),
        // use its basename for the filename.
        else if ($replace == FILE_EXISTS_RENAME && is_file(file_create_path($destination))) {
          $file->filename = basename($destination);
        }
    
        $file = file_save($file);
    
        // Inform modules that the file has been copied.
        module_invoke_all('file_copy', $file, $source);
    
        return $file;
      }
      return FALSE;
    }
    
    /**
     * Copy a file to a new location without calling any hooks or making any
     * changes to the database.
     *
     * This is a powerful function that in many ways performs like an advanced
     * version of copy().
     * - Checks if $source and $destination are valid and readable/writable.
     * - Checks that $source is not equal to $destination; if they are an error
     *   is reported.
     * - If file already exists in $destination either the call will error out,
     *   replace the file or rename the file based on the $replace parameter.
     *
     * @param $source
     *   A string specifying the file location of the original file.
     * @param $destination
     *   A string containing the destination that $source should be copied to. This
     *   can be a complete file path, a directory path or, if this value is omitted,
     *   Drupal's 'files' directory will be used.
     * @param $replace
     *   Replace behavior when the destination file already exists:
     *   - FILE_EXISTS_REPLACE - Replace the existing file.
     *   - FILE_EXISTS_RENAME - Append _{incrementing number} until the filename is
     *       unique.
     *   - FILE_EXISTS_ERROR - Do nothing and return FALSE.
     * @return
     *   The path to the new file, or FALSE in the event of an error.
     *
     * @see file_copy()
     */
    function file_unmanaged_copy($source, $destination = NULL, $replace = FILE_EXISTS_RENAME) {
      $source = realpath($source);
      if (!file_exists($source)) {
        drupal_set_message(t('The specified file %file could not be copied, because no file by that name exists. Please check that you supplied the correct filename.', array('%file' => $source)), 'error');
        return FALSE;
      }
    
      $destination = file_create_path($destination);
      $directory = $destination;
      $basename = file_check_path($directory);
    
      // Make sure we at least have a valid directory.
      if ($basename === FALSE) {
        drupal_set_message(t('The specified file %file could not be copied, because the destination %directory is not properly configured.', array('%file' => $source, '%directory' => $destination)), 'error');
        return FALSE;
      }
    
      // If the destination file is not specified then use the filename of the
      // source file.
      $basename = $basename ? $basename : basename($source);
      $destination = file_destination($directory . '/' . $basename, $replace);
    
      if ($destination === FALSE) {
        drupal_set_message(t('The specified file %file could not be copied because a file by that name already exists in the destination.', array('%file' => $source)), 'error');
        return FALSE;
      }
      // Make sure source and destination filenames are not the same, makes no
      // sense to copy it if they are. In fact copying the file will most likely
      // result in a 0 byte file. Which is bad. Real bad.
      if ($source == realpath($destination)) {
        drupal_set_message(t('The specified file %file was not copied because it would overwrite itself.', array('%file' => $source)), 'error');
        return FALSE;
      }
      if (!@copy($source, $destination)) {
        drupal_set_message(t('The specified file %file could not be copied.', array('%file' => $source)), 'error');
        return FALSE;
      }
    
      // Give everyone read access so that FTP'd users or
      // non-webserver users can see/read these files,
      // and give group write permissions so group members
      // can alter files uploaded by the webserver.
      @chmod($destination, 0664);
    
      return $destination;
    }
    
    /**
     * Determines the destination path for a file depending on how replacement of
     * existing files should be handled.
     *
     * @param $destination
     *   A string specifying the desired path.
     * @param $replace
     *   Replace behavior when the destination file already exists.
     *   - FILE_EXISTS_REPLACE - Replace the existing file.
     *   - FILE_EXISTS_RENAME - Append _{incrementing number} until the filename is
     *       unique.
     *   - FILE_EXISTS_ERROR - Do nothing and return FALSE.
     * @return
     *   The destination file path or FALSE if the file already exists and
     *   FILE_EXISTS_ERROR was specified.
     */
    function file_destination($destination, $replace) {
      if (file_exists($destination)) {
        switch ($replace) {
          case FILE_EXISTS_REPLACE:
            // Do nothing here, we want to overwrite the existing file.
            break;
    
          case FILE_EXISTS_RENAME:
            $basename = basename($destination);
            $directory = dirname($destination);
            $destination = file_create_filename($basename, $directory);
            break;
    
          case FILE_EXISTS_ERROR:
            drupal_set_message(t('The specified file %file could not be copied, because a file by that name already exists in the destination.', array('%file' => $destination)), 'error');
            return FALSE;
        }
      }
      return $destination;
    }
    
    /**
     * Move a file to a new location and update the file's database entry.
     *
     * Moving a file is performed by copying the file to the new location and then
     * deleting the original.
     * - Checks if $source and $destination are valid and readable/writable.
     * - Performs a file move if $source is not equal to $destination.
     * - If file already exists in $destination either the call will error out,
     *   replace the file or rename the file based on the $replace parameter.
     * - Adds the new file to the files database.
     *
     * @param $source
     *   A file object.
     * @param $destination
     *   A string containing the destination that $source should be moved to. This
     *   can be a complete file path, a directory path or, if this value is omitted,
     *   Drupal's 'files' directory will be used.
     * @param $replace
     *   Replace behavior when the destination file already exists:
     *   - FILE_EXISTS_REPLACE - Replace the existing file. If a managed file with
     *       the destination name exists then its database entry will be updated and
     *       file_delete() called on the source file after hook_file_move is called.
     *       If no database entry is found then the source files record will be
     *       updated.
     *   - FILE_EXISTS_RENAME - Append _{incrementing number} until the filename is
     *       unique.
     *   - FILE_EXISTS_ERROR - Do nothing and return FALSE.
     * @return
     *   Resulting file object for success, or FALSE in the event of an error.
     *
     * @see file_unmanaged_move()
     * @see hook_file_move()
     */
    function file_move($source, $destination = NULL, $replace = FILE_EXISTS_RENAME) {
      $source = (object)$source;
    
      if ($filepath = file_unmanaged_move($source->filepath, $destination, $replace)) {
        $delete_source = FALSE;
    
        $file = clone $source;
        $file->filepath = $filepath;
        // If we are replacing an existing file re-use its database record.
        if ($replace == FILE_EXISTS_REPLACE) {
          $existing_files = file_load_multiple(array(), array('filepath' => $filepath));
          if (count($existing_files)) {
            $existing = reset($existing_files);
            $delete_source = TRUE;
            $file->fid = $existing->fid;
          }
        }
        // If we are renaming around an existing file (rather than a directory),
        // use its basename for the filename.
        else if ($replace == FILE_EXISTS_RENAME && is_file(file_create_path($destination))) {
          $file->filename = basename($destination);
        }
    
        $file = file_save($file);
    
        // Inform modules that the file has been moved.
        module_invoke_all('file_move', $file, $source);
    
        if ($delete_source) {
          // Try a soft delete to remove original if it's not in use elsewhere.
          file_delete($source);
        }
    
        return $file;
      }
      return FALSE;
    }
    
    /**
     * Move a file to a new location without calling any hooks or making any
     * changes to the database.
     *
     * @param $source
     *   A string specifying the file location of the original file.
     * @param $destination
     *   A string containing the destination that $source should be moved to. This
     *   can be a complete file path, a directory name or, if this value is omitted,
     *   Drupal's 'files' directory will be used.
     * @param $replace
     *   Replace behavior when the destination file already exists:
     *   - FILE_EXISTS_REPLACE - Replace the existing file.
     *   - FILE_EXISTS_RENAME - Append _{incrementing number} until the filename is
     *       unique.
     *   - FILE_EXISTS_ERROR - Do nothing and return FALSE.
     * @return
     *   The filepath of the moved file, or FALSE in the event of an error.
     *
     * @see file_move()
     */
    function file_unmanaged_move($source, $destination = NULL, $replace = FILE_EXISTS_RENAME) {
      $filepath = file_unmanaged_copy($source, $destination, $replace);
      if ($filepath == FALSE || file_unmanaged_delete($source) == FALSE) {
        return FALSE;
      }
      return $filepath;
    }
    
    /**
     * Munge the filename as needed for security purposes.
     *
     * For instance the file name "exploit.php.pps" would become "exploit.php_.pps".
     *
     * @param $filename
     *   The name of a file to modify.
     * @param $extensions
     *   A space separated list of extensions that should not be altered.
     * @param $alerts
     *   Whether alerts (watchdog, drupal_set_message()) should be displayed.
     * @return
     *   $filename The potentially modified $filename.
     */
    function file_munge_filename($filename, $extensions, $alerts = TRUE) {
      $original = $filename;
    
      // Allow potentially insecure uploads for very savvy users and admin
      if (!variable_get('allow_insecure_uploads', 0)) {
        $whitelist = array_unique(explode(' ', trim($extensions)));
    
        // Split the filename up by periods. The first part becomes the basename
        // the last part the final extension.
        $filename_parts = explode('.', $filename);
        $new_filename = array_shift($filename_parts); // Remove file basename.
        $final_extension = array_pop($filename_parts); // Remove final extension.
    
        // Loop through the middle parts of the name and add an underscore to the
        // end of each section that could be a file extension but isn't in the list
        // of allowed extensions.
        foreach ($filename_parts as $filename_part) {
          $new_filename .= '.' . $filename_part;
          if (!in_array($filename_part, $whitelist) && preg_match("/^[a-zA-Z]{2,5}\d?$/", $filename_part)) {
            $new_filename .= '_';
          }
        }
        $filename = $new_filename . '.' . $final_extension;
    
        if ($alerts && $original != $filename) {
          drupal_set_message(t('For security reasons, your upload has been renamed to %filename.', array('%filename' => $filename)));
        }
      }
    
      return $filename;
    }
    
    /**
     * Undo the effect of upload_munge_filename().
     *
     * @param $filename
     *   String with the filename to be unmunged.
     * @return
     *   An unmunged filename string.
     */
    function file_unmunge_filename($filename) {
      return str_replace('_.', '.', $filename);
    }
    
    /**
     * Create a full file path from a directory and filename.
     *
     * If a file with the specified name already exists, an alternative will be
     * used.
     *
     * @param $basename
     *   String filename
     * @param $directory
     *   String directory
     * @return
     *   File path consisting of $directory and a unique filename based off
     *   of $basename.
     */
    function file_create_filename($basename, $directory) {
      $destination = $directory . '/' . $basename;
    
      if (file_exists($destination)) {
        // Destination file already exists, generate an alternative.
        $pos = strrpos($basename, '.');
        if ($pos !== FALSE) {
          $name = substr($basename, 0, $pos);
          $ext = substr($basename, $pos);
        }
        else {
          $name = $basename;
          $ext = '';
        }
    
        $counter = 0;
        do {
          $destination = $directory . '/' . $name . '_' . $counter++ . $ext;
        } while (file_exists($destination));
      }
    
      return $destination;
    }
    
    /**
     * Delete a file and its database record.
     *
     * If the $force parameter is not TRUE hook_file_references() will be called
     * to determine if the file is being used by any modules. If the file is being
     * used is the delete will be canceled.
     *
     * @param $file
     *   A file object.
     * @param $force
     *   Boolean indicating that the file should be deleted even if
     *   hook_file_references() reports that the file is in use.
     * @return mixed
     *   TRUE for success, FALSE in the event of an error, or an array if the file
     *   is being used by another module. The array keys are the module's name and
     *   the values are the number of references.
     *
     * @see file_unmanaged_delete()
     * @see hook_file_references()
     * @see hook_file_delete()
     */
    function file_delete($file, $force = FALSE) {
      $file = (object)$file;
    
      // If any module returns a value from the reference hook, the file will not
      // be deleted from Drupal, but file_delete will return a populated array that
      // tests as TRUE.
      if (!$force && ($references = module_invoke_all('file_references', $file))) {
        return $references;
      }
    
      // Let other modules clean up any references to the deleted file.
      module_invoke_all('file_delete', $file);
    
      // Make sure the file is deleted before removing its row from the
      // database, so UIs can still find the file in the database.
      if (file_unmanaged_delete($file->filepath)) {
        db_delete('files')->condition('fid', $file->fid)->execute();
        return TRUE;
      }
      return FALSE;
    }
    
    /**
     * Delete a file without calling any hooks or making any changes to the
     * database.
     *
     * This function should be used when the file to be deleted does not have an
     * entry recorded in the files table.
     *
     * @param $path
     *   A string containing a file path.
     * @return
     *   TRUE for success or path does not exist, or FALSE in the event of an
     *   error.
     *
     * @see file_delete()
     */
    function file_unmanaged_delete($path) {
      if (is_dir($path)) {
        watchdog('file', '%path is a directory and cannot be removed using file_unmanaged_delete().', array('%path' => $path), WATCHDOG_ERROR);
        return FALSE;
      }
      if (is_file($path)) {
        return unlink($path);
      }
      // Return TRUE for non-existent file, but log that nothing was actually
      // deleted, as the current state is the indended result.
      if (!file_exists($path)) {
        watchdog('file', 'The file %path was not deleted, because it does not exist.', array('%path' => $path), WATCHDOG_NOTICE);
        return TRUE;
      }
      // Catch all for everything else: sockets, symbolic links, etc.
      return FALSE;
    }
    
    /**
     * Determine total disk space used by a single user or the whole filesystem.
     *
     * @param $uid
     *   Optional. A user id, specifying NULL returns the total space used by all
     *   non-temporary files.
     * @param $status
     *   Optional. File Status to return. Combine with a bitwise OR(|) to return
     *   multiple statuses. The default status is FILE_STATUS_PERMANENT.
     * @return
     *   An integer containing the number of bytes used.
     */
    function file_space_used($uid = NULL, $status = FILE_STATUS_PERMANENT) {
      $query = db_select('files', 'f');
      // Use separate placeholders for the status to avoid a bug in some versions
      // of PHP. @see http://drupal.org/node/352956
      $query->where('f.status & :status1 = :status2', array(':status1' => $status, ':status2' => $status));
      $query->addExpression('SUM(f.filesize)', 'filesize');
      if (!is_null($uid)) {
        $query->condition('f.uid', $uid);
      }
      return $query->execute()->fetchField();
    }
    
    /**
     * Saves a file upload to a new location.
     *
     * The file will be added to the files table as a temporary file. Temporary
     * files are periodically cleaned. To make the file a permanent file call
     * assign the status and use file_save() to save it.
     *
     * @param $source
     *   A string specifying the name of the upload field to save.
     * @param $validators
     *   An optional, associative array of callback functions used to validate the
     *   file. See @file_validate for a full discussion of the array format.
     * @param $destination
     *   A string containing the directory $source should be copied to. If this is
     *   not provided or is not writable, the temporary directory will be used.
     * @param $replace
     *   A boolean indicating whether an existing file of the same name in the
     *   destination directory should overwritten. A false value will generate a
     *   new, unique filename in the destination directory.
     * @return
     *   An object containing the file information if the upload succeeded, FALSE
     *   in the event of an error, or NULL if no file was uploaded.
     */
    function file_save_upload($source, $validators = array(), $destination = FALSE, $replace = FILE_EXISTS_RENAME) {
      global $user;
      static $upload_cache;
    
      // Return cached objects without processing since the file will have
      // already been processed and the paths in _FILES will be invalid.
      if (isset($upload_cache[$source])) {
        return $upload_cache[$source];
      }
    
      // Make sure there's an upload to process.
      if (empty($_FILES['files']['name'][$source])) {
        return NULL;
      }
    
      // Check for file upload errors and return FALSE if a lower level system
      // error occurred. For a complete list of errors:
      // @see http://php.net/manual/en/features.file-upload.errors.php
      switch ($_FILES['files']['error'][$source]) {
        case UPLOAD_ERR_INI_SIZE:
        case UPLOAD_ERR_FORM_SIZE:
          drupal_set_message(t('The file %file could not be saved, because it exceeds %maxsize, the maximum allowed size for uploads.', array('%file' => $_FILES['files']['name'][$source], '%maxsize' => format_size(file_upload_max_size()))), 'error');
          return FALSE;
    
        case UPLOAD_ERR_PARTIAL:
        case UPLOAD_ERR_NO_FILE:
          drupal_set_message(t('The file %file could not be saved, because the upload did not complete.', array('%file' => $_FILES['files']['name'][$source])), 'error');
          return FALSE;
    
        case UPLOAD_ERR_OK:
          // Final check that this is a valid upload, if it isn't, use the
          // default error handler.
          if (is_uploaded_file($_FILES['files']['tmp_name'][$source])) {
             break;
          }
    
        // Unknown error
        default:
          drupal_set_message(t('The file %file could not be saved. An unknown error has occurred.', array('%file' => $_FILES['files']['name'][$source])), 'error');
          return FALSE;
      }
    
      // Build the list of non-munged extensions.
      // @todo: this should not be here. we need to figure out the right place.
      $extensions = '';
      foreach ($user->roles as $rid => $name) {
        $extensions .= ' ' . variable_get("upload_extensions_$rid",
        variable_get('upload_extensions_default', 'jpg jpeg gif png txt html doc xls pdf ppt pps odt ods odp'));
      }
    
      // Begin building file object.
      $file = new stdClass();
      $file->uid      = $user->uid;
      $file->status   = 0;
      $file->filename = file_munge_filename(trim(basename($_FILES['files']['name'][$source]), '.'), $extensions);
      $file->filepath = $_FILES['files']['tmp_name'][$source];
      $file->filemime = file_get_mimetype($file->filename);
      $file->filesize = $_FILES['files']['size'][$source];
    
      // Rename potentially executable files, to help prevent exploits.
      if (preg_match('/\.(php|pl|py|cgi|asp|js)$/i', $file->filename) && (substr($file->filename, -4) != '.txt')) {
        $file->filemime = 'text/plain';
        $file->filepath .= '.txt';
        $file->filename .= '.txt';
      }
    
      // If the destination is not provided, or is not writable, then use the
      // temporary directory.
      if (empty($destination) || file_check_path($destination) === FALSE) {
        $destination = file_directory_temp();
      }
    
      $file->source = $source;
      $file->destination = file_destination(file_create_path($destination . '/' . $file->filename), $replace);
      // If file_destination() returns FALSE then $replace == FILE_EXISTS_ERROR and
      // there's an existing file so we need to bail.
      if ($file->destination === FALSE) {
        return FALSE;
      }
    
      // Add in our check of the the file name length.
      $validators['file_validate_name_length'] = array();
    
      // Call the validation functions specified by this function's caller.
      $errors = file_validate($file, $validators);
    
      // Check for errors.
      if (!empty($errors)) {
        $message = t('The specified file %name could not be uploaded.', array('%name' => $file->filename));
        if (count($errors) > 1) {
          $message .= theme('item_list', $errors);
        }
        else {
          $message .= ' ' . array_pop($errors);
        }
        form_set_error($source, $message);
        return FALSE;
      }
    
      // Move uploaded files from PHP's upload_tmp_dir to Drupal's temporary
      // directory. This overcomes open_basedir restrictions for future file
      // operations.
      $file->filepath = $file->destination;
      if (!move_uploaded_file($_FILES['files']['tmp_name'][$source], $file->filepath)) {
        form_set_error($source, t('File upload error. Could not move uploaded file.'));
        watchdog('file', 'Upload error. Could not move uploaded file %file to destination %destination.', array('%file' => $file->filename, '%destination' => $file->filepath));
        return FALSE;
      }
    
      // If we are replacing an existing file re-use its database record.
      if ($replace == FILE_EXISTS_REPLACE) {
        $existing_files = file_load_multiple(array(), array('filepath' => $file->filepath));
        if (count($existing_files)) {
          $existing = reset($existing_files);
          $file->fid = $existing->fid;
        }
      }
    
      // If we made it this far it's safe to record this file in the database.
      if ($file = file_save($file)) {
        // Add file to the cache.
        $upload_cache[$source] = $file;
        return $file;
      }
      return FALSE;
    }
    
    
    /**
     * Check that a file meets the criteria specified by the validators.
     *
     * After executing the validator callbacks specified hook_file_validate() will
     * also be called to allow other modules to report errors about the file.
     *
     * @param $file
     *   A Drupal file object.
     * @param $validators
     *   An optional, associative array of callback functions used to validate the
     *   file. The keys are function names and the values arrays of callback
     *   parameters which will be passed in after the user and file objects. The
     *   functions should return an array of error messages, an empty array
     *   indicates that the file passed validation. The functions will be called in
     *   the order specified.
     * @return
     *   An array contaning validation error messages.
     *
     * @see hook_file_validate()
     */
    function file_validate(&$file, $validators = array()) {
      // Call the validation functions specified by this function's caller.
      $errors = array();
      foreach ($validators as $function => $args) {
        array_unshift($args, $file);
        $errors = array_merge($errors, call_user_func_array($function, $args));
      }
    
      // Let other modules perform validation on the new file.
      return array_merge($errors, module_invoke_all('file_validate', $file));
    }
    
    /**
     * Check for files with names longer than we can store in the database.
     *
     * @param $file
     *   A Drupal file object.
     * @return
     *   An array. If the file name is too long, it will contain an error message.
     */
    function file_validate_name_length($file) {
      $errors = array();
    
      if (empty($file->filename)) {
        $errors[] = t("The file's name is empty. Please give a name to the file.");
      }
      if (strlen($file->filename) > 255) {
        $errors[] = t("The file's name exceeds the 255 characters limit. Please rename the file and try again.");
      }
      return $errors;
    }
    
    /**
     * Check that the filename ends with an allowed extension.
     *
     * @param $file
     *   A Drupal file object.
     * @param $extensions
     *   A string with a space separated
     * @return
     *   An array. If the file extension is not allowed, it will contain an error
     *   message.
     *
     * @see hook_file_validate()
     */
    function file_validate_extensions($file, $extensions) {
      global $user;
    
      $errors = array();
    
      $regex = '/\.(' . preg_replace('/ +/', '|', preg_quote($extensions)) . ')$/i';
      if (!preg_match($regex, $file->filename)) {
        $errors[] = t('Only files with the following extensions are allowed: %files-allowed.', array('%files-allowed' => $extensions));
      }
      return $errors;
    }
    
    /**
     * Check that the file's size is below certain limits.
     *
     * This check is not enforced for the user #1.
     *
     * @param $file
     *   A Drupal file object.
     * @param $file_limit
     *   An integer specifying the maximum file size in bytes. Zero indicates that
     *   no limit should be enforced.
     * @param $user_limit
     *   An integer specifying the maximum number of bytes the user is allowed.
     *   Zero indicates that no limit should be enforced.
     * @return
     *   An array. If the file size exceeds limits, it will contain an error
     *   message.
     *
     * @see hook_file_validate()
     */
    function file_validate_size($file, $file_limit = 0, $user_limit = 0) {
      global $user;
    
      $errors = array();
    
      // Bypass validation for uid  = 1.
      if ($user->uid != 1) {
        if ($file_limit && $file->filesize > $file_limit) {
          $errors[] = t('The file is %filesize exceeding the maximum file size of %maxsize.', array('%filesize' => format_size($file->filesize), '%maxsize' => format_size($file_limit)));
        }
    
        if ($user_limit && (file_space_used($user->uid) + $file->filesize) > $user_limit) {
          $errors[] = t('The file is %filesize which would exceed your disk quota of %quota.', array('%filesize' => format_size($file->filesize), '%quota' => format_size($user_limit)));
        }
      }
      return $errors;
    }
    
    /**
     * Check that the file is recognized by image_get_info() as an image.
     *
     * @param $file
     *   A Drupal file object.
     * @return
     *   An array. If the file is not an image, it will contain an error message.
     *
     * @see hook_file_validate()
     */
    function file_validate_is_image($file) {
      $errors = array();
    
      $info = image_get_info($file->filepath);
      if (!$info || empty($info['extension'])) {
        $errors[] = t('Only JPEG, PNG and GIF images are allowed.');
      }
    
      return $errors;
    }
    
    /**
     * If the file is an image verify that its dimensions are within the specified
     * maximum and minimum dimensions.
     *
     * Non-image files will be ignored. If a image toolkit is available the image
     * will be scalled to fit within the desired maximum dimensions.
     *
     * @param $file
     *   A Drupal file object. This function may resize the file affecting its
     *   size.
     * @param $maximum_dimensions
     *   An optional string in the form WIDTHxHEIGHT e.g. '640x480' or '85x85'. If
     *   an image toolkit is installed the image will be resized down to these
     *   dimensions. A value of 0 indicates no restriction on size, so resizing
     *   will be attempted.
     * @param $minimum_dimensions
     *   An optional string in the form WIDTHxHEIGHT. This will check that the
     *   image meets a minimum size. A value of 0 indicates no restriction.
     * @return
     *   An array. If the file is an image and did not meet the requirements, it
     *   will contain an error message.
     *
     * @see hook_file_validate()
     */
    function file_validate_image_resolution($file, $maximum_dimensions = 0, $minimum_dimensions = 0) {
      $errors = array();
    
      // Check first that the file is an image.
      if ($info = image_get_info($file->filepath)) {
        if ($maximum_dimensions) {
          // Check that it is smaller than the given dimensions.
          list($width, $height) = explode('x', $maximum_dimensions);
          if ($info['width'] > $width || $info['height'] > $height) {
            // Try to resize the image to fit the dimensions.
            if (image_get_toolkit() && image_scale($file->filepath, $file->filepath, $width, $height)) {
              drupal_set_message(t('The image was resized to fit within the maximum allowed dimensions of %dimensions pixels.', array('%dimensions' => $maximum_dimensions)));
    
              // Clear the cached filesize and refresh the image information.
              clearstatcache();
              $info = image_get_info($file->filepath);
              $file->filesize = $info['file_size'];
            }
            else {
              $errors[] = t('The image is too large; the maximum dimensions are %dimensions pixels.', array('%dimensions' => $maximum_dimensions));
            }
          }
        }
    
        if ($minimum_dimensions) {
          // Check that it is larger than the given dimensions.
          list($width, $height) = explode('x', $minimum_dimensions);
          if ($info['width'] < $width || $info['height'] < $height) {
            $errors[] = t('The image is too small; the minimum dimensions are %dimensions pixels.', array('%dimensions' => $minimum_dimensions));
          }
        }
      }
    
      return $errors;
    }
    
    /**
     * Save a string to the specified destination and create a database file entry.
     *
     * @param $data
     *   A string containing the contents of the file.
     * @param $destination
     *   A string containing the destination location. If no value is provided
     *   then a randomly name will be generated and the file saved in Drupal's
     *   files directory.
     * @param $replace
     *   Replace behavior when the destination file already exists:
     *   - FILE_EXISTS_REPLACE - Replace the existing file. If a managed file with
     *       the destination name exists then its database entry will be updated. If
     *       no database entry is found then a new one will be created.
     *   - FILE_EXISTS_RENAME - Append _{incrementing number} until the filename is
     *       unique.
     *   - FILE_EXISTS_ERROR - Do nothing and return FALSE.
     * @return
     *   A file object, or FALSE on error.
     *
     * @see file_unmanaged_save_data()
     */
    function file_save_data($data, $destination = NULL, $replace = FILE_EXISTS_RENAME) {
      global $user;
    
      if ($filepath = file_unmanaged_save_data($data, $destination, $replace)) {
        // Create a file object.
        $file = new stdClass();
        $file->fid = NULL;
        $file->filepath = $filepath;
        $file->filename = basename($filepath);
        $file->filemime = file_get_mimetype($file->filepath);
        $file->uid      = $user->uid;
        $file->status  |= FILE_STATUS_PERMANENT;
        // If we are replacing an existing file re-use its database record.
        if ($replace == FILE_EXISTS_REPLACE) {
          $existing_files = file_load_multiple(array(), array('filepath' => $filepath));
          if (count($existing_files)) {
            $existing = reset($existing_files);
            $file->fid = $existing->fid;
            $file->filename = $existing->filename;
          }
        }
        // If we are renaming around an existing file (rather than a directory),
        // use its basename for the filename.
        else if ($replace == FILE_EXISTS_RENAME && is_file(file_create_path($destination))) {
          $file->filename = basename($destination);
        }
    
        return file_save($file);
      }
      return FALSE;
    }
    
    /**
     * Save a string to the specified destination without calling any hooks or
     * making any changes to the database.
     *
     * This function is identical to file_save_data() except the file will not be
     * saved to the files table and none of the file_* hooks will be called.
     *
     * @param $data
     *   A string containing the contents of the file.
     * @param $destination
     *   A string containing the destination location. If no value is provided
     *   then a randomly name will be generated and the file saved in Drupal's
     *   files directory.
     * @param $replace
     *   Replace behavior when the destination file already exists:
     *   - FILE_EXISTS_REPLACE - Replace the existing file.
     *   - FILE_EXISTS_RENAME - Append _{incrementing number} until the filename is
     *                          unique.
     *   - FILE_EXISTS_ERROR - Do nothing and return FALSE.
     * @return
     *   A string with the path of the resulting file, or FALSE on error.
     *
     * @see file_save_data()
     */
    function file_unmanaged_save_data($data, $destination = NULL, $replace = FILE_EXISTS_RENAME) {
      // Write the data to a temporary file.
      $temp_name = tempnam(file_directory_temp(), 'file');
      if (file_put_contents($temp_name, $data) === FALSE) {
        drupal_set_message(t('The file could not be created.'), 'error');
        return FALSE;
      }
    
      // Move the file to its final destination.
      return file_unmanaged_move($temp_name, $destination, $replace);
    }
    
    /**
     * Transfer file using HTTP to client. Pipes a file through Drupal to the
     * client.
     *
     * @param $source
     *   String specifying the file path to transfer.
     * @param $headers
     *   An array of HTTP headers to send along with file.
     */
    function file_transfer($source, $headers) {
      if (ob_get_level()) {
        ob_end_clean();
      }
    
      foreach ($headers as $header) {
        // To prevent HTTP header injection, we delete new lines that are
        // not followed by a space or a tab.
        // See http://www.w3.org/Protocols/rfc2616/rfc2616-sec4.html#sec4.2
        $header = preg_replace('/\r?\n(?!\t| )/', '', $header);
        drupal_set_header($header);
      }
    
      $source = file_create_path($source);
    
      // Transfer file in 1024 byte chunks to save memory usage.
      if ($fd = fopen($source, 'rb')) {
        while (!feof($fd)) {
          print fread($fd, 1024);
        }
        fclose($fd);
      }
      else {
        drupal_not_found();
      }
      exit();
    }
    
    /**
     * Menu handler for private file transfers.
     *
     * Call modules that implement hook_file_download() to find out if a file is
     * accessible and what headers it should be transferred with. If a module
     * returns -1 drupal_access_denied() will be returned. If one or more modules
     * returned headers the download will start with the returned headers. If no
     * modules respond drupal_not_found() will be returned.
     *
     * @see hook_file_download()
     */
    function file_download() {
      // Merge remainder of arguments from GET['q'], into relative file path.
      $args = func_get_args();
      $filepath = implode('/', $args);
    
      // Maintain compatibility with old ?file=paths saved in node bodies.
      if (isset($_GET['file'])) {
        $filepath =  $_GET['file'];
      }
    
      if (file_exists(file_create_path($filepath))) {
        // Let other modules provide headers and controls access to the file.
        $headers = module_invoke_all('file_download', $filepath);
        if (in_array(-1, $headers)) {
          return drupal_access_denied();
        }
        if (count($headers)) {
          file_transfer($filepath, $headers);
        }
      }
      return drupal_not_found();
    }
    
    
    /**
     * Finds all files that match a given mask in a given directory.
     *
     * Directories and files beginning with a period are excluded; this
     * prevents hidden files and directories (such as SVN working directories)
     * from being scanned.
     *
     * @param $dir
     *   The base directory for the scan, without trailing slash.
     * @param $mask
     *   The preg_match() regular expression of the files to find.
     * @param $nomask
     *   The preg_match() regular expression of the files to ignore.
     * @param $callback
     *   The callback function to call for each match.
     * @param $recurse
     *   When TRUE, the directory scan will recurse the entire tree
     *   starting at the provided directory.
     * @param $key
     *   The key to be used for the returned array of files. Possible
     *   values are "filename", for the path starting with $dir,
     *   "basename", for the basename of the file, and "name" for the name
     *   of the file without an extension.
     * @param $min_depth
     *   Minimum depth of directories to return files from.
     * @param $depth
     *   Current depth of recursion. This parameter is only used internally and
     *   should not be passed.
     * @return
     *   An associative array (keyed on the provided key) of objects with
     *   "path", "basename", and "name" members corresponding to the
     *   matching files.
     */
    function file_scan_directory($dir, $mask, $nomask = '/(\.\.?|CVS)$/', $callback = 0, $recurse = TRUE, $key = 'filename', $min_depth = 0, $depth = 0) {
      $key = (in_array($key, array('filename', 'basename', 'name')) ? $key : 'filename');
      $files = array();
    
      if (is_dir($dir) && $handle = opendir($dir)) {
        while (FALSE !== ($file = readdir($handle))) {
          if (!preg_match($nomask, $file) && $file[0] != '.') {
            if (is_dir("$dir/$file") && $recurse) {
              // Give priority to files in this folder by merging them in after any subdirectory files.
              $files = array_merge(file_scan_directory("$dir/$file", $mask, $nomask, $callback, $recurse, $key, $min_depth, $depth + 1), $files);
            }
            elseif ($depth >= $min_depth && preg_match($mask, $file)) {
              // Always use this match over anything already set in $files with the
              // same $$key.
              $filename = "$dir/$file";
              $basename = basename($file);
              $name = substr($basename, 0, strrpos($basename, '.'));
              $files[$$key] = new stdClass();
              $files[$$key]->filename = $filename;
              $files[$$key]->basename = $basename;
              $files[$$key]->name = $name;
              if ($callback) {
                $callback($filename);
              }
            }
          }
        }
    
        closedir($handle);
      }
    
      return $files;
    }
    
    /**
     * Determine the default temporary directory.
     *
     * @return
     *   A string containing a temp directory.
     */
    function file_directory_temp() {
      $temporary_directory = variable_get('file_directory_temp', NULL);
    
      if (is_null($temporary_directory)) {
        $directories = array();
    
        // Has PHP been set with an upload_tmp_dir?
        if (ini_get('upload_tmp_dir')) {
          $directories[] = ini_get('upload_tmp_dir');
        }
    
        // Operating system specific dirs.
        if (substr(PHP_OS, 0, 3) == 'WIN') {
          $directories[] = 'c:/windows/temp';
          $directories[] = 'c:/winnt/temp';
        }
        else {
          $directories[] = '/tmp';
        }
    
        foreach ($directories as $directory) {
          if (!$temporary_directory && is_dir($directory)) {
            $temporary_directory = $directory;
          }
        }
    
        // if a directory has been found, use it, otherwise default to 'files/tmp'
        $temporary_directory = $temporary_directory ? $temporary_directory : file_directory_path() . '/tmp';
        variable_set('file_directory_temp', $temporary_directory);
      }
    
      return $temporary_directory;
    }
    
    /**
     * Determine the default 'files' directory.
     *
     * @return
     *   A string containing the path to Drupal's 'files' directory.
     */
    function file_directory_path() {
      return variable_get('file_directory_path', conf_path() . '/files');
    }
    
    /**
     * Determine the maximum file upload size by querying the PHP settings.
     *
     * @return
     *   A file size limit in bytes based on the PHP upload_max_filesize and
     *   post_max_size
     */
    function file_upload_max_size() {
      static $max_size = -1;
    
      if ($max_size < 0) {
        $upload_max = parse_size(ini_get('upload_max_filesize'));
        $post_max = parse_size(ini_get('post_max_size'));
        $max_size = ($upload_max < $post_max) ? $upload_max : $post_max;
      }
      return $max_size;
    }
    
    /**
     * Determine an Internet Media Type, or MIME type from a filename.
     *
     * @param $filename
     *   Name of the file, including extension.
     * @param $mapping
     *   An optional array of extension to media type mappings in the form
     *   'extension1|extension2|...' => 'type'.
     *
     * @return
     *   The internet media type registered for the extension or application/octet-stream for unknown extensions.
     */
    function file_get_mimetype($filename, $mapping = NULL) {
      if (!is_array($mapping)) {
        $mapping = variable_get('mime_extension_mapping', array(
          'ez' => 'application/andrew-inset',
          'atom' => 'application/atom',
          'atomcat' => 'application/atomcat+xml',
          'atomsrv' => 'application/atomserv+xml',
          'cap|pcap' => 'application/cap',
          'cu' => 'application/cu-seeme',
          'tsp' => 'application/dsptype',
          'spl' => 'application/x-futuresplash',
          'hta' => 'application/hta',
          'jar' => 'application/java-archive',
          'ser' => 'application/java-serialized-object',
          'class' => 'application/java-vm',
          'hqx' => 'application/mac-binhex40',
          'cpt' => 'image/x-corelphotopaint',
          'nb' => 'application/mathematica',
          'mdb' => 'application/msaccess',
          'doc|dot' => 'application/msword',
          'bin' => 'application/octet-stream',
          'oda' => 'application/oda',
          'ogg|ogx' => 'application/ogg',
          'pdf' => 'application/pdf',
          'key' => 'application/pgp-keys',
          'pgp' => 'application/pgp-signature',
          'prf' => 'application/pics-rules',
          'ps|ai|eps' => 'application/postscript',
          'rar' => 'application/rar',
          'rdf' => 'application/rdf+xml',
          'rss' => 'application/rss+xml',
          'rtf' => 'application/rtf',
          'smi|smil' => 'application/smil',
          'wpd' => 'application/wordperfect',
          'wp5' => 'application/wordperfect5.1',
          'xhtml|xht' => 'application/xhtml+xml',
          'xml|xsl' => 'application/xml',
          'zip' => 'application/zip',
          'cdy' => 'application/vnd.cinderella',
          'kml' => 'application/vnd.google-earth.kml+xml',
          'kmz' => 'application/vnd.google-earth.kmz',
          'xul' => 'application/vnd.mozilla.xul+xml',
          'xls|xlb|xlt' => 'application/vnd.ms-excel',
          'cat' => 'application/vnd.ms-pki.seccat',
          'stl' => 'application/vnd.ms-pki.stl',
          'ppt|pps' => 'application/vnd.ms-powerpoint',
          'odc' => 'application/vnd.oasis.opendocument.chart',
          'odb' => 'application/vnd.oasis.opendocument.database',
          'odf' => 'application/vnd.oasis.opendocument.formula',
          'odg' => 'application/vnd.oasis.opendocument.graphics',
          'otg' => 'application/vnd.oasis.opendocument.graphics-template',
          'odi' => 'application/vnd.oasis.opendocument.image',
          'odp' => 'application/vnd.oasis.opendocument.presentation',
          'otp' => 'application/vnd.oasis.opendocument.presentation-template',
          'ods' => 'application/vnd.oasis.opendocument.spreadsheet',
          'ots' => 'application/vnd.oasis.opendocument.spreadsheet-template',
          'odt' => 'application/vnd.oasis.opendocument.text',
          'odm' => 'application/vnd.oasis.opendocument.text-master',
          'ott' => 'application/vnd.oasis.opendocument.text-template',
          'oth' => 'application/vnd.oasis.opendocument.text-web',
          'docm' => 'application/vnd.ms-word.document.macroEnabled.12',
          'docx' => 'application/vnd.openxmlformats-officedocument.wordprocessingml.document',
          'dotm' => 'application/vnd.ms-word.template.macroEnabled.12',
          'dotx' => 'application/vnd.openxmlformats-officedocument.wordprocessingml.template',
          'potm' => 'application/vnd.ms-powerpoint.template.macroEnabled.12',
          'potx' => 'application/vnd.openxmlformats-officedocument.presentationml.template',
          'ppam' => 'application/vnd.ms-powerpoint.addin.macroEnabled.12',
          'ppsm' => 'application/vnd.ms-powerpoint.slideshow.macroEnabled.12',
          'ppsx' => 'application/vnd.openxmlformats-officedocument.presentationml.slideshow',
          'pptm' => 'application/vnd.ms-powerpoint.presentation.macroEnabled.12',
          'pptx' => 'application/vnd.openxmlformats-officedocument.presentationml.presentation',
          'xlam' => 'application/vnd.ms-excel.addin.macroEnabled.12',
          'xlsb' => 'application/vnd.ms-excel.sheet.binary.macroEnabled.12',
          'xlsm' => 'application/vnd.ms-excel.sheet.macroEnabled.12',
          'xlsx' => 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet',
          'xltm' => 'application/vnd.ms-excel.template.macroEnabled.12',
          'xltx' => 'application/vnd.openxmlformats-officedocument.spreadsheetml.template',
          'cod' => 'application/vnd.rim.cod',
          'mmf' => 'application/vnd.smaf',
          'sdc' => 'application/vnd.stardivision.calc',
          'sds' => 'application/vnd.stardivision.chart',
          'sda' => 'application/vnd.stardivision.draw',
          'sdd' => 'application/vnd.stardivision.impress',
          'sdf' => 'application/vnd.stardivision.math',
          'sdw' => 'application/vnd.stardivision.writer',
          'sgl' => 'application/vnd.stardivision.writer-global',
          'sxc' => 'application/vnd.sun.xml.calc',
          'stc' => 'application/vnd.sun.xml.calc.template',
          'sxd' => 'application/vnd.sun.xml.draw',
          'std' => 'application/vnd.sun.xml.draw.template',
          'sxi' => 'application/vnd.sun.xml.impress',
          'sti' => 'application/vnd.sun.xml.impress.template',
          'sxm' => 'application/vnd.sun.xml.math',
          'sxw' => 'application/vnd.sun.xml.writer',
          'sxg' => 'application/vnd.sun.xml.writer.global',
          'stw' => 'application/vnd.sun.xml.writer.template',
          'sis' => 'application/vnd.symbian.install',
          'vsd' => 'application/vnd.visio',
          'wbxml' => 'application/vnd.wap.wbxml',
          'wmlc' => 'application/vnd.wap.wmlc',
          'wmlsc' => 'application/vnd.wap.wmlscriptc',
          'wk' => 'application/x-123',
          '7z' => 'application/x-7z-compressed',
          'abw' => 'application/x-abiword',
          'dmg' => 'application/x-apple-diskimage',
          'bcpio' => 'application/x-bcpio',
          'torrent' => 'application/x-bittorrent',
          'cab' => 'application/x-cab',
          'cbr' => 'application/x-cbr',
          'cbz' => 'application/x-cbz',
          'cdf' => 'application/x-cdf',
          'vcd' => 'application/x-cdlink',
          'pgn' => 'application/x-chess-pgn',
          'cpio' => 'application/x-cpio',
          'csh' => 'text/x-csh',
          'deb|udeb' => 'application/x-debian-package',
          'dcr|dir|dxr' => 'application/x-director',
          'dms' => 'application/x-dms',
          'wad' => 'application/x-doom',
          'dvi' => 'application/x-dvi',
          'rhtml' => 'application/x-httpd-eruby',
          'flac' => 'application/x-flac',
          'pfa|pfb|gsf|pcf|pcf.Z' => 'application/x-font',
          'mm' => 'application/x-freemind',
          'gnumeric' => 'application/x-gnumeric',
          'sgf' => 'application/x-go-sgf',
          'gcf' => 'application/x-graphing-calculator',
          'gtar|tgz|taz' => 'application/x-gtar',
          'hdf' => 'application/x-hdf',
          'phtml|pht|php' => 'application/x-httpd-php',
          'phps' => 'application/x-httpd-php-source',
          'php3' => 'application/x-httpd-php3',
          'php3p' => 'application/x-httpd-php3-preprocessed',
          'php4' => 'application/x-httpd-php4',
          'ica' => 'application/x-ica',
          'ins|isp' => 'application/x-internet-signup',
          'iii' => 'application/x-iphone',
          'iso' => 'application/x-iso9660-image',
          'jnlp' => 'application/x-java-jnlp-file',
          'js' => 'application/x-javascript',
          'jmz' => 'application/x-jmol',
          'chrt' => 'application/x-kchart',
          'kil' => 'application/x-killustrator',
          'skp|skd|skt|skm' => 'application/x-koan',
          'kpr|kpt' => 'application/x-kpresenter',
          'ksp' => 'application/x-kspread',
          'kwd|kwt' => 'application/x-kword',
          'latex' => 'application/x-latex',
          'lha' => 'application/x-lha',
          'lyx' => 'application/x-lyx',
          'lzh' => 'application/x-lzh',
          'lzx' => 'application/x-lzx',
          'frm|maker|frame|fm|fb|book|fbdoc' => 'application/x-maker',
          'mif' => 'application/x-mif',
          'wmd' => 'application/x-ms-wmd',
          'wmz' => 'application/x-ms-wmz',
          'com|exe|bat|dll' => 'application/x-msdos-program',
          'msi' => 'application/x-msi',
          'nc' => 'application/x-netcdf',
          'pac' => 'application/x-ns-proxy-autoconfig',
          'nwc' => 'application/x-nwc',
          'o' => 'application/x-object',
          'oza' => 'application/x-oz-application',
          'p7r' => 'application/x-pkcs7-certreqresp',
          'crl' => 'application/x-pkcs7-crl',
          'pyc|pyo' => 'application/x-python-code',
          'qtl' => 'application/x-quicktimeplayer',
          'rpm' => 'application/x-redhat-package-manager',
          'sh' => 'text/x-sh',
          'shar' => 'application/x-shar',
          'swf|swfl' => 'application/x-shockwave-flash',
          'sit|sitx' => 'application/x-stuffit',
          'sv4cpio' => 'application/x-sv4cpio',
          'sv4crc' => 'application/x-sv4crc',
          'tar' => 'application/x-tar',
          'tcl' => 'application/x-tcl',
          'gf' => 'application/x-tex-gf',
          'pk' => 'application/x-tex-pk',
          'texinfo|texi' => 'application/x-texinfo',
          '~|%|bak|old|sik' => 'application/x-trash',
          't|tr|roff' => 'application/x-troff',
          'man' => 'application/x-troff-man',
          'me' => 'application/x-troff-me',
          'ms' => 'application/x-troff-ms',
          'ustar' => 'application/x-ustar',
          'src' => 'application/x-wais-source',
          'wz' => 'application/x-wingz',
          'crt' => 'application/x-x509-ca-cert',
          'xcf' => 'application/x-xcf',
          'fig' => 'application/x-xfig',
          'xpi' => 'application/x-xpinstall',
          'au|snd' => 'audio/basic',
          'mid|midi|kar' => 'audio/midi',
          'mpga|mpega|mp2|mp3|m4a' => 'audio/mpeg',
          'm3u' => 'audio/x-mpegurl',
          'oga|spx' => 'audio/ogg',
          'sid' => 'audio/prs.sid',
          'aif|aiff|aifc' => 'audio/x-aiff',
          'gsm' => 'audio/x-gsm',
          'wma' => 'audio/x-ms-wma',
          'wax' => 'audio/x-ms-wax',
          'ra|rm|ram' => 'audio/x-pn-realaudio',
          'ra' => 'audio/x-realaudio',
          'pls' => 'audio/x-scpls',
          'sd2' => 'audio/x-sd2',
          'wav' => 'audio/x-wav',
          'alc' => 'chemical/x-alchemy',
          'cac|cache' => 'chemical/x-cache',
          'csf' => 'chemical/x-cache-csf',
          'cbin|cascii|ctab' => 'chemical/x-cactvs-binary',
          'cdx' => 'chemical/x-cdx',
          'cer' => 'chemical/x-cerius',
          'c3d' => 'chemical/x-chem3d',
          'chm' => 'chemical/x-chemdraw',
          'cif' => 'chemical/x-cif',
          'cmdf' => 'chemical/x-cmdf',
          'cml' => 'chemical/x-cml',
          'cpa' => 'chemical/x-compass',
          'bsd' => 'chemical/x-crossfire',
          'csml|csm' => 'chemical/x-csml',
          'ctx' => 'chemical/x-ctx',
          'cxf|cef' => 'chemical/x-cxf',
          'emb|embl' => 'chemical/x-embl-dl-nucleotide',
          'spc' => 'chemical/x-galactic-spc',
          'inp|gam|gamin' => 'chemical/x-gamess-input',
          'fch|fchk' => 'chemical/x-gaussian-checkpoint',
          'cub' => 'chemical/x-gaussian-cube',
          'gau|gjc|gjf' => 'chemical/x-gaussian-input',
          'gal' => 'chemical/x-gaussian-log',
          'gcg' => 'chemical/x-gcg8-sequence',
          'gen' => 'chemical/x-genbank',
          'hin' => 'chemical/x-hin',
          'istr|ist' => 'chemical/x-isostar',
          'jdx|dx' => 'chemical/x-jcamp-dx',
          'kin' => 'chemical/x-kinemage',
          'mcm' => 'chemical/x-macmolecule',
          'mmd|mmod' => 'chemical/x-macromodel-input',
          'mol' => 'chemical/x-mdl-molfile',
          'rd' => 'chemical/x-mdl-rdfile',
          'rxn' => 'chemical/x-mdl-rxnfile',
          'sd|sdf' => 'chemical/x-mdl-sdfile',
          'tgf' => 'chemical/x-mdl-tgf',
          'mcif' => 'chemical/x-mmcif',
          'mol2' => 'chemical/x-mol2',
          'b' => 'chemical/x-molconn-Z',
          'gpt' => 'chemical/x-mopac-graph',
          'mop|mopcrt|mpc|dat|zmt' => 'chemical/x-mopac-input',
          'moo' => 'chemical/x-mopac-out',
          'mvb' => 'chemical/x-mopac-vib',
          'asn' => 'chemical/x-ncbi-asn1-spec',
          'prt|ent' => 'chemical/x-ncbi-asn1-ascii',
          'val|aso' => 'chemical/x-ncbi-asn1-binary',
          'pdb|ent' => 'chemical/x-pdb',
          'ros' => 'chemical/x-rosdal',
          'sw' => 'chemical/x-swissprot',
          'vms' => 'chemical/x-vamas-iso14976',
          'vmd' => 'chemical/x-vmd',
          'xtel' => 'chemical/x-xtel',
          'xyz' => 'chemical/x-xyz',
          'gif' => 'image/gif',
          'ief' => 'image/ief',
          'jpeg|jpg|jpe' => 'image/jpeg',
          'pcx' => 'image/pcx',
          'png' => 'image/png',
          'svg|svgz' => 'image/svg+xml',
          'tiff|tif' => 'image/tiff',
          'djvu|djv' => 'image/vnd.djvu',
          'wbmp' => 'image/vnd.wap.wbmp',
          'ras' => 'image/x-cmu-raster',
          'cdr' => 'image/x-coreldraw',
          'pat' => 'image/x-coreldrawpattern',
          'cdt' => 'image/x-coreldrawtemplate',
          'ico' => 'image/x-icon',
          'art' => 'image/x-jg',
          'jng' => 'image/x-jng',
          'bmp' => 'image/x-ms-bmp',
          'psd' => 'image/x-photoshop',
          'pnm' => 'image/x-portable-anymap',
          'pbm' => 'image/x-portable-bitmap',
          'pgm' => 'image/x-portable-graymap',
          'ppm' => 'image/x-portable-pixmap',
          'rgb' => 'image/x-rgb',
          'xbm' => 'image/x-xbitmap',
          'xpm' => 'image/x-xpixmap',
          'xwd' => 'image/x-xwindowdump',
          'eml' => 'message/rfc822',
          'igs|iges' => 'model/iges',
          'msh|mesh|silo' => 'model/mesh',
          'wrl|vrml' => 'model/vrml',
          'ics|icz' => 'text/calendar',
          'css' => 'text/css',
          'csv' => 'text/csv',
          '323' => 'text/h323',
          'html|htm|shtml' => 'text/html',
          'uls' => 'text/iuls',
          'mml' => 'text/mathml',
          'asc|txt|text|pot' => 'text/plain',
          'rtx' => 'text/richtext',
          'sct|wsc' => 'text/scriptlet',
          'tm|ts' => 'text/texmacs',
          'tsv' => 'text/tab-separated-values',
          'jad' => 'text/vnd.sun.j2me.app-descriptor',
          'wml' => 'text/vnd.wap.wml',
          'wmls' => 'text/vnd.wap.wmlscript',
          'bib' => 'text/x-bibtex',
          'boo' => 'text/x-boo',
          'h++|hpp|hxx|hh' => 'text/x-c++hdr',
          'c++|cpp|cxx|cc' => 'text/x-c++src',
          'h' => 'text/x-chdr',
          'htc' => 'text/x-component',
          'c' => 'text/x-csrc',
          'd' => 'text/x-dsrc',
          'diff|patch' => 'text/x-diff',
          'hs' => 'text/x-haskell',
          'java' => 'text/x-java',
          'lhs' => 'text/x-literate-haskell',
          'moc' => 'text/x-moc',
          'p|pas' => 'text/x-pascal',
          'gcd' => 'text/x-pcs-gcd',
          'pl|pm' => 'text/x-perl',
          'py' => 'text/x-python',
          'etx' => 'text/x-setext',
          'tcl|tk' => 'text/x-tcl',
          'tex|ltx|sty|cls' => 'text/x-tex',
          'vcs' => 'text/x-vcalendar',
          'vcf' => 'text/x-vcard',
          '3gp' => 'video/3gpp',
          'dl' => 'video/dl',
          'dif|dv' => 'video/dv',
          'fli' => 'video/fli',
          'gl' => 'video/gl',
          'mpeg|mpg|mpe' => 'video/mpeg',
          'mp4' => 'video/mp4',
          'ogv' => 'video/ogg',
          'qt|mov' => 'video/quicktime',
          'mxu' => 'video/vnd.mpegurl',
          'lsf|lsx' => 'video/x-la-asf',
          'mng' => 'video/x-mng',
          'asf|asx' => 'video/x-ms-asf',
          'wm' => 'video/x-ms-wm',
          'wmv' => 'video/x-ms-wmv',
          'wmx' => 'video/x-ms-wmx',
          'wvx' => 'video/x-ms-wvx',
          'avi' => 'video/x-msvideo',
          'movie' => 'video/x-sgi-movie',
          'ice' => 'x-conference/x-cooltalk',
          'sisx' => 'x-epoc/x-sisx-app',
          'vrm|vrml|wrl' => 'x-world/x-vrml',
          'xps' => 'application/vnd.ms-xpsdocument',
        ));
      }
      foreach ($mapping as $ext_preg => $mime_match) {
        if (preg_match('!\.('. $ext_preg .')$!i', $filename)) {
          return $mime_match;
        }
      }
    
      return 'application/octet-stream';
    }
    /**
     * @} End of "defgroup file".
     */