source: branches/rsr.v5.1.1/web/punbb/include/utf8/stristr.php @ 10

<?php

/**
* @version $Id: stristr.php,v 1.1 2006/02/25 13:50:17 harryf Exp $
* @package utf8
* @subpackage strings
*/

/**
* UTF-8 aware alternative to stristr
* Find first occurrence of a string using case insensitive comparison
* Note: requires utf8_strtolower
* @param string
* @param string
* @return int
* @see http://www.php.net/strcasecmp
* @see utf8_strtolower
* @package utf8
* @subpackage strings
*/
function utf8_stristr($str, $search)
{
        if (strlen($search) == 0)
                return $str;

        $lstr = utf8_strtolower($str);
        $lsearch = utf8_strtolower($search);
        preg_match('/^(.*)'.preg_quote($lsearch).'/Us', $lstr, $matches);

        if (count($matches) == 2)
                return substr($str, strlen($matches[1]));

        return false;
}