I asked before for a simple solution to my problem (using sphinx search service) but I got nowhere...

someone has kindly provided me with this code

<?php
/**
 * $Project: GeoGraph $
 * $Id$
 * 
 * GeoGraph geographic photo archive project
 * This file copyright (C) 2005  Barry Hunter ([email protected])
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 * 
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 */



/**
* Provides the methods for updating the worknet tables
*
* @package Geograph
* @author Barry Hunter <[email protected]>
* @version $Revision$
*/

function addTwoLetterPhrase($phrase) {
    global $w2;
    $w2[$phrase] = (isset($w2[$phrase]))?($w2[$phrase]+1):1; 
}

function addThreeLetterPhrase($phrase) {
    global $w3;
    $w3[$phrase] = (isset($w3[$phrase]))?($w3[$phrase]+1):1; 
}

function updateWordnet(&$db,$text,$field,$id) {
    global $w1,$w2,$w3;

    $alltext = strtolower(preg_replace('/\W+/',' ',str_replace("'",'',$text)));


    if (strlen($text)< 1)
        return;


    $words = preg_split('/ /',$alltext);

    $w1 = array();
    $w2 = array();
    $w3 = array();

    //build a list of one word phrases
    foreach ($words as $word) {
        $w1[$word] = (isset($w1[$word]))?($w1[$word]+1):1; 
    }

    //build a list of two word phrases
        $text = $alltext;
    $text = preg_replace('/(\w+) (\w+)/e','addTwoLetterPhrase("$1 $2")',$text); 
        $text = $alltext;
        $text = preg_replace('/(\w+)/','',$text,1);
    $text = preg_replace('/(\w+) (\w+)/e','addTwoLetterPhrase("$1 $2")',$text);

    //build a list of three word phrases
        $text = $alltext;
    $text = preg_replace('/(\w+) (\w+) (\w+)/e','addThreeLetterPhrase("$1 $2 $3")',$text);  
        $text = $alltext;
        $text = preg_replace('/(\w+)/','',$text,1);
    $text = preg_replace('/(\w+) (\w+) (\w+)/e','addThreeLetterPhrase("$1 $2 $3")',$text);  
        $text = $alltext;
        $text = preg_replace('/(\w+) (\w+)/','',$text,1);
    $text = preg_replace('/(\w+) (\w+) (\w+)/e','addThreeLetterPhrase("$1 $2 $3")',$text);



    foreach ($w1 as $word=>$count) {
        $db->Execute("insert into wordnet1 set gid = $id,words = '$word',$field = $count");// ON DUPLICATE KEY UPDATE $field=$field+$count");
    }
    foreach ($w2 as $word=>$count) {
        $db->Execute("insert into wordnet2 set gid = $id,words = '$word',$field = $count");
    }   
    foreach ($w3 as $word=>$count) {
        $db->Execute("insert into wordnet3 set gid = $id,words = '$word',$field = $count");
    }   
}


?>

It works fine and does almost exactly what I need....... except.... it is not utf8 friendly... I mean... it splits whole words into parts (on special chars) where it shouldn't!

so my guess is I should use multibyte functions instead of regular preg_replace...

I tried to replace preg_replace with mb_ereg_replace but it is not working as it should... at least not for 2 and 3 words phrases

any ideas?