WordPress at a glance
filter is not described

update_attached_file filter-hook . WP 2.1.0

Filters the path to the attached file to update.

Usage

add_filter( 'update_attached_file', 'filter_function_name_4891', 10, 2 );
function filter_function_name_4891( $file, $attachment_id ){
	// filter...

	return $file;
}
$file(string)
Path to the attached file to update.
$attachment_id(int)
Attachment ID.

Where the hook is called

update_attached_file()
update_attached_file
wp-includes/post.php 432
$file = apply_filters( 'update_attached_file', $file, $attachment_id );

Where the hook is used (in WP core)

Does not used.