Preg_replace whole word only

[cesarcesar]

Im trying to make a naughty word filter. It removes bad words fine, but instances where there is a bad word found in the text like "assist" and "asses" get caught in the filter as well. Strangely though if the sentence is: My asses to assist me." the clean version will read: My asses to ***ist me." It seems to clear the first use of the word in another word, but then blocks the rest. Any ideas? My script is below. Thanks.

 

function cleanWords($value) {

/*   strip naughty words   */
$bad_word_file = 'standards/badwords.txt';
$strtofile = fopen($bad_word_file, "r");
$badwords = explode("\n", fread($strtofile, filesize($bad_word_file)));
fclose($strtofile);

for ($i = 0; $i < count($badwords); $i++) {
	$wordlist .= str_replace(chr(13),'',$badwords[$i]).'|';
}
$wordlist = substr($wordlist,0,-1);

$value = preg_replace("/\b($wordlist)\b/ie", 'preg_replace("/./","*","\\1")', $value);	
return $value;

}