source: branches/rsr.v5.1.1/web/punbb/include/utf8/str_ireplace.php @ 6

<?php

/**
* @version $Id: str_ireplace.php,v 1.2 2007/08/12 01:20:46 harryf Exp $
* @package utf8
* @subpackage strings
*/

/**
* UTF-8 aware alternative to str_ireplace
* Case-insensitive version of str_replace
* Note: requires utf8_strtolower
* Note: it's not fast and gets slower if $search / $replace is array
* Notes: it's based on the assumption that the lower and uppercase
* versions of a UTF-8 character will have the same length in bytes
* which is currently true given the hash table to strtolower
* @param string
* @return string
* @see http://www.php.net/str_ireplace
* @see utf8_strtolower
* @package utf8
* @subpackage strings
*/
function utf8_ireplace($search, $replace, $str, $count=null)
{
        if (!is_array($search))
        {
                $slen = strlen($search);

                if ($slen == 0)
                        return $str;

                $lendif = strlen($replace) - strlen($search);
                $search = utf8_strtolower($search);

                $search = preg_quote($search);
                $lstr = utf8_strtolower($str);
                $i = 0;
                $matched = 0;

                while (preg_match('/(.*)'.$search.'/Us', $lstr, $matches))
                {
                        if ($i === $count)
                                break;

                        $mlen = strlen($matches[0]);
                        $lstr = substr($lstr, $mlen);
                        $str = substr_replace($str, $replace, $matched+strlen($matches[1]), $slen);
                        $matched += $mlen + $lendif;
                        $i++;
                }

                return $str;
        }
        else
        {
                foreach (array_keys($search) as $k)
                {
                        if (is_array($replace))
                        {
                                if (array_key_exists($k, $replace))
                                        $str = utf8_ireplace($search[$k], $replace[$k], $str, $count);
                                else
                                        $str = utf8_ireplace($search[$k], '', $str, $count);
                        }
                        else
                                $str = utf8_ireplace($search[$k], $replace, $str, $count);
                }

                return $str;
        }
}