nextcloud/lib/private/naturalsort_defaultcollator.php

<?php
/**
 * Copyright (c) 2014 Vincent Petry <PVince81@owncloud.com>
 * This file is licensed under the Affero General Public License version 3 or
 * later.
 * See the COPYING-README file.
 *
 */

namespace OC;

class NaturalSort_DefaultCollator {
	public function compare($a, $b) {
		$result = strcasecmp($a, $b); 
    		if ($result === 0) {
      			return 0;
    		}
    		return ($result < 0) ? -1 : 1;
	}
}