file_managed_file_save_upload($element, FormStateInterface $form_state) Saves any files that have been uploaded

file_validate(FileInterface $file, $validators = array()) Checks that a file meets the criteria specified by

public FileSystem::rmdir($uri, $context = NULL) Removes

public File::setOwner(UserInterface $account) Sets

public FileInterface::getCreatedTime() Returns

public FileSystemInterface::validScheme($scheme)

Default mode for new files. See self::chmod(). File core/lib/Drupal/Core/File/FileSystem.php, line 22

file_theme() Implements

public FileInterface::setPermanent() Sets

public FileSystemInterface::chmod($uri, $mode = NULL)