--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/includes/file.inc	Tue Dec 23 14:28:28 2008 +0100
@@ -0,0 +1,984 @@
+<?php
+// $Id: file.inc,v 1.121.2.1 2008/02/07 18:20:37 goba Exp $
+
+/**
+ * @file
+ * API for handling file uploads and server file management.
+ */
+
+/**
+ * @defgroup file File interface
+ * @{
+ * Common file handling functions.
+ */
+
+define('FILE_DOWNLOADS_PUBLIC', 1);
+define('FILE_DOWNLOADS_PRIVATE', 2);
+define('FILE_CREATE_DIRECTORY', 1);
+define('FILE_MODIFY_PERMISSIONS', 2);
+define('FILE_EXISTS_RENAME', 0);
+define('FILE_EXISTS_REPLACE', 1);
+define('FILE_EXISTS_ERROR', 2);
+
+/**
+ * A files status can be one of two values: temporary or permanent. The status
+ * for each file Drupal manages is stored in the {files} tables. If the status
+ * is temporary Drupal's file garbage collection will delete the file and
+ * remove it from the files table after a set period of time.
+ *
+ * If you wish to add custom statuses for use by contrib modules please expand as
+ * binary flags and consider the first 8 bits reserved. (0,1,2,4,8,16,32,64,128)
+ */
+define('FILE_STATUS_TEMPORARY', 0);
+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 $dest A string containing the path to verify. If this value is
+ *   omitted, Drupal's 'files' directory will be used.
+ * @return A string containing the path to file, with file system directory
+ *   appended if necessary, or FALSE if the path is invalid (i.e. outside the
+ *   configured 'files' or temp directories).
+ */
+function file_create_path($dest = 0) {
+  $file_path = file_directory_path();
+  if (!$dest) {
+    return $file_path;
+  }
+  // file_check_location() checks whether the destination is inside the Drupal files directory.
+  if (file_check_location($dest, $file_path)) {
+    return $dest;
+  }
+  // check if the destination is instead inside the Drupal temporary files directory.
+  else if (file_check_location($dest, file_directory_temp())) {
+    return $dest;
+  }
+  // Not found, try again with prefixed directory path.
+  else if (file_check_location($file_path .'/'. $dest, $file_path)) {
+    return $file_path .'/'. $dest;
+  }
+  // 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 Boolean value to indicate if the directory should be created
+ *   if it does not exist or made writable if it is read-only.
+ * @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)) {
+      drupal_set_message(t('The directory %directory has been created.', array('%directory' => $directory)));
+      @chmod($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' => $directory)));
+      }
+      return FALSE;
+    }
+  }
+
+  // Check to see if the directory is writable.
+  if (!is_writable($directory)) {
+    if (($mode & FILE_MODIFY_PERMISSIONS) && @chmod($directory, 0775)) {
+      drupal_set_message(t('The permissions of directory %directory have been changed to make it writable.', array('%directory' => $directory)));
+    }
+    else {
+      form_set_error($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 dir/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. Should be used to make
+ * sure a file specified is really located within the directory to prevent
+ * exploits.
+ *
+ * @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 $directory A string where the file should be located.
+ * @return 0 for invalid path or the real path of the source.
+ */
+function file_check_location($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 0;
+  }
+  return $source;
+}
+
+/**
+ * Copies a file to a new location. This is a powerful function that in many ways
+ * performs like an advanced version of copy().
+ * - Checks if $source and $dest are valid and readable/writable.
+ * - Performs a file copy if $source is not equal to $dest.
+ * - If file already exists in $dest 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.
+ *   This parameter will contain the resulting destination filename in case of
+ *   success.
+ * @param $dest A string containing the directory $source should be copied to.
+ *   If this value is omitted, Drupal's 'files' directory will be used.
+ * @param $replace Replace behavior when the destination file already exists.
+ *   - FILE_EXISTS_REPLACE - Replace the existing file
+ *   - FILE_EXISTS_RENAME - Append _{incrementing number} until the filename is unique
+ *   - FILE_EXISTS_ERROR - Do nothing and return FALSE.
+ * @return True for success, FALSE for failure.
+ */
+function file_copy(&$source, $dest = 0, $replace = FILE_EXISTS_RENAME) {
+  $dest = file_create_path($dest);
+
+  $directory = $dest;
+  $basename = file_check_path($directory);
+
+  // Make sure we at least have a valid directory.
+  if ($basename === FALSE) {
+    $source = is_object($source) ? $source->filepath : $source;
+    drupal_set_message(t('The selected file %file could not be uploaded, because the destination %directory is not properly configured.', array('%file' => $source, '%directory' => $dest)), 'error');
+    watchdog('file system', 'The selected file %file could not be uploaded, because the destination %directory could not be found, or because its permissions do not allow the file to be written.', array('%file' => $source, '%directory' => $dest), WATCHDOG_ERROR);
+    return 0;
+  }
+
+  // Process a file upload object.
+  if (is_object($source)) {
+    $file = $source;
+    $source = $file->filepath;
+    if (!$basename) {
+      $basename = $file->filename;
+    }
+  }
+
+  $source = realpath($source);
+  if (!file_exists($source)) {
+    drupal_set_message(t('The selected 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 0;
+  }
+
+  // If the destination file is not specified then use the filename of the source file.
+  $basename = $basename ? $basename : basename($source);
+  $dest = $directory .'/'. $basename;
+
+  // Make sure source and destination filenames are not the same, makes no sense
+  // to copy it if they are. In fact copying the file will most likely result in
+  // a 0 byte file. Which is bad. Real bad.
+  if ($source != realpath($dest)) {
+    if (!$dest = file_destination($dest, $replace)) {
+      drupal_set_message(t('The selected file %file could not be copied, because a file by that name already exists in the destination.', array('%file' => $source)), 'error');
+      return FALSE;
+    }
+
+    if (!@copy($source, $dest)) {
+      drupal_set_message(t('The selected file %file could not be copied.', array('%file' => $source)), 'error');
+      return 0;
+    }
+
+    // Give everyone read access so that FTP'd users or
+    // non-webserver users can see/read these files,
+    // and give group write permissions so group members
+    // can alter files uploaded by the webserver.
+    @chmod($dest, 0664);
+  }
+
+  if (isset($file) && is_object($file)) {
+    $file->filename = $basename;
+    $file->filepath = $dest;
+    $source = $file;
+  }
+  else {
+    $source = $dest;
+  }
+
+  return 1; // Everything went ok.
+}
+
+/**
+ * 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_RENAME:
+        $basename = basename($destination);
+        $directory = dirname($destination);
+        $destination = file_create_filename($basename, $directory);
+        break;
+
+      case FILE_EXISTS_ERROR:
+        drupal_set_message(t('The selected 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;
+}
+
+/**
+ * Moves a file to a new location.
+ * - Checks if $source and $dest are valid and readable/writable.
+ * - Performs a file move if $source is not equal to $dest.
+ * - If file already exists in $dest 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.
+ *   This parameter will contain the resulting destination filename in case of
+ *   success.
+ * @param $dest A string containing the directory $source should be copied to.
+ *   If this value is omitted, Drupal's 'files' directory will be used.
+ * @param $replace Replace behavior when the destination file already exists.
+ *   - FILE_EXISTS_REPLACE - Replace the existing file
+ *   - FILE_EXISTS_RENAME - Append _{incrementing number} until the filename is unique
+ *   - FILE_EXISTS_ERROR - Do nothing and return FALSE.
+ * @return True for success, FALSE for failure.
+ */
+function file_move(&$source, $dest = 0, $replace = FILE_EXISTS_RENAME) {
+  $path_original = is_object($source) ? $source->filepath : $source;
+
+  if (file_copy($source, $dest, $replace)) {
+    $path_current = is_object($source) ? $source->filepath : $source;
+
+    if ($path_original == $path_current || file_delete($path_original)) {
+      return 1;
+    }
+    drupal_set_message(t('The removal of the original file %file has failed.', array('%file' => $path_original)), 'error');
+  }
+  return 0;
+}
+
+/**
+ * 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 $filename string filename
+ * @return string
+ */
+function file_unmunge_filename($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 $directory string directory
+ * @return
+ */
+function file_create_filename($basename, $directory) {
+  $dest = $directory .'/'. $basename;
+
+  if (file_exists($dest)) {
+    // Destination file already exists, generate an alternative.
+    if ($pos = strrpos($basename, '.')) {
+      $name = substr($basename, 0, $pos);
+      $ext = substr($basename, $pos);
+    }
+    else {
+      $name = $basename;
+    }
+
+    $counter = 0;
+    do {
+      $dest = $directory .'/'. $name .'_'. $counter++ . $ext;
+    } while (file_exists($dest));
+  }
+
+  return $dest;
+}
+
+/**
+ * Delete a file.
+ *
+ * @param $path A string containing a file path.
+ * @return TRUE for success, FALSE for failure.
+ */
+function file_delete($path) {
+  if (is_file($path)) {
+    return unlink($path);
+  }
+}
+
+/**
+ * Determine total disk space used by a single user or the whole filesystem.
+ *
+ * @param $uid
+ *   An optional user id. A NULL value returns the total space used
+ *   by all files.
+ */
+function file_space_used($uid = NULL) {
+  if (isset($uid)) {
+    return (int) db_result(db_query('SELECT SUM(filesize) FROM {files} WHERE uid = %d', $uid));
+  }
+  return (int) db_result(db_query('SELECT SUM(filesize) FROM {files}'));
+}
+
+/**
+ * Saves a file upload to a new location. The source file is validated as a
+ * proper upload and handled as such.
+ *
+ * The file will be added to the files table as a temporary file. Temporary files
+ * are periodically cleaned. To make the file permanent file call
+ * file_set_status() to change its status.
+ *
+ * @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. 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.
+ * @param $dest
+ *   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 $replace
+ *   A boolean indicating whether an existing file of the same name in the
+ *   destination directory should overwritten. A false value will generate a
+ *   new, unique filename in the destination directory.
+ * @return
+ *   An object containing the file information, or 0 in the event of an error.
+ */
+function file_save_upload($source, $validators = array(), $dest = FALSE, $replace = FILE_EXISTS_RENAME) {
+  global $user;
+  static $upload_cache;
+
+  // Add in our check of the the file name length.
+  $validators['file_validate_name_length'] = array();
+
+  // Return cached objects without processing since the file will have
+  // already been processed and the paths in _FILES will be invalid.
+  if (isset($upload_cache[$source])) {
+    return $upload_cache[$source];
+  }
+
+  // If a file was uploaded, process it.
+  if (isset($_FILES['files']) && $_FILES['files']['name'][$source] && is_uploaded_file($_FILES['files']['tmp_name'][$source])) {
+    // Check for file upload errors and return FALSE if a
+    // lower level system error occurred.
+    switch ($_FILES['files']['error'][$source]) {
+      // @see http://php.net/manual/en/features.file-upload.errors.php
+      case UPLOAD_ERR_OK:
+        break;
+
+      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' => $source, '%maxsize' => format_size(file_upload_max_size()))), 'error');
+        return 0;
+
+      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' => $source)), 'error');
+        return 0;
+
+        // Unknown error
+      default:
+        drupal_set_message(t('The file %file could not be saved. An unknown error has occurred.', array('%file' => $source)), 'error');
+        return 0;
+    }
+
+    // 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();
+    $file->filename = file_munge_filename(trim(basename($_FILES['files']['name'][$source]), '.'), $extensions);
+    $file->filepath = $_FILES['files']['tmp_name'][$source];
+    $file->filemime = $_FILES['files']['type'][$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';
+      $file->filename .= '.txt';
+    }
+
+    // If the destination is not provided, or is not writable, then use the
+    // temporary directory.
+    if (empty($dest) || file_check_path($dest) === FALSE) {
+      $dest = file_directory_temp();
+    }
+
+    $file->source = $source;
+    $file->destination = file_destination(file_create_path($dest .'/'. $file->filename), $replace);
+    $file->filesize = $_FILES['files']['size'][$source];
+
+    // Call the validation functions.
+    $errors = array();
+    foreach ($validators as $function => $args) {
+      array_unshift($args, $file);
+      $errors = array_merge($errors, call_user_func_array($function, $args));
+    }
+
+    // Check for validation errors.
+    if (!empty($errors)) {
+      $message = t('The selected file %name could not be uploaded.', array('%name' => $file->filename));
+      if (count($errors) > 1) {
+        $message .= '<ul><li>'. implode('</li><li>', $errors) .'</li></ul>';
+      }
+      else {
+        $message .= ' '. array_pop($errors);
+      }
+      form_set_error($source, $message);
+      return 0;
+    }
+
+    // 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 0;
+    }
+
+    // If we made it this far it's safe to record this file in the database.
+    $file->uid = $user->uid;
+    $file->status = FILE_STATUS_TEMPORARY;
+    $file->timestamp = time();
+    drupal_write_record('files', $file);
+
+    // Add file to the cache.
+    $upload_cache[$source] = $file;
+    return $file;
+  }
+  return 0;
+}
+
+/**
+ * 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) {
+  $errors = array();
+
+  if (strlen($file->filename) > 255) {
+    $errors[] = t('Its name exceeds the 255 characters limit. Please rename the file and try again.');
+  }
+  return $errors;
+}
+
+/**
+ * Check that the filename ends with an allowed extension. This check is not
+ * enforced for the user #1.
+ *
+ * @param $file
+ *   A Drupal file object.
+ * @param $extensions
+ *   A string with a space separated
+ * @return
+ *   An array. If the file extension is not allowed, it will contain an error message.
+ */
+function file_validate_extensions($file, $extensions) {
+  global $user;
+
+  $errors = array();
+
+  // Bypass validation for uid  = 1.
+  if ($user->uid != 1) {
+    $regex = '/\.('. ereg_replace(' +', '|', preg_quote($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.
+ */
+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)));
+    }
+
+    $total_size = file_space_used($user->uid) + $file->filesize;
+    if ($user_limit && $total_size > $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.
+ */
+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.
+ *
+ * @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.
+ */
+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.
+ *
+ * @param $data A string containing the contents of the file.
+ * @param $dest A string containing the destination location.
+ * @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 containing the resulting filename or 0 on error
+ */
+function file_save_data($data, $dest, $replace = FILE_EXISTS_RENAME) {
+  $temp = file_directory_temp();
+  // On Windows, tempnam() requires an absolute path, so we use realpath().
+  $file = tempnam(realpath($temp), 'file');
+  if (!$fp = fopen($file, 'wb')) {
+    drupal_set_message(t('The file could not be created.'), 'error');
+    return 0;
+  }
+  fwrite($fp, $data);
+  fclose($fp);
+
+  if (!file_move($file, $dest, $replace)) {
+    return 0;
+  }
+
+  return $file;
+}
+
+/**
+ * Set the status of a file.
+ *
+ * @param file A Drupal file object
+ * @param status A status value to set the file to.
+ * @return FALSE on failure, TRUE on success and $file->status will contain the
+ *     status.
+ */
+function file_set_status(&$file, $status) {
+  if (db_query('UPDATE {files} SET status = %d WHERE fid = %d', $status, $file->fid)) {
+    $file->status = $status;
+    return TRUE;
+  }
+  return FALSE;
+}
+
+/**
+ * Transfer file using http to client. Pipes a file through Drupal to the
+ * client.
+ *
+ * @param $source File to transfer.
+ * @param $headers An array of http headers to send along with file.
+ */
+function file_transfer($source, $headers) {
+  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();
+}
+
+/**
+ * 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.
+ */
+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))) {
+    $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 regular expression of the files to find.
+ * @param $nomask
+ *   An array of files/directories 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 = array('.', '..', '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 ($file = readdir($handle)) {
+      if (!in_array($file, $nomask) && $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 && ereg($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';
+      $path_delimiter = '\\';
+    }
+    else {
+      $directories[] = '/tmp';
+      $path_delimiter = '/';
+    }
+
+    foreach ($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' or 'files\\tmp';
+    $temporary_directory = $temporary_directory ? $temporary_directory : file_directory_path() . $path_delimiter .'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;
+}
+
+/**
+ * @} End of "defgroup file".
+ */