Μετατροπή των domain σε ενεργά link μέσα σε ένα string

Χρησιμοποιούμε το παρακάτω function ως echo makeLinks($metavlitikeimenou);

function makeLinks($str) {
	$reg_exUrl = "/(www)?[a-zA-Z0-9\-\.]+\.[a-zA-Z]{2,3}(\/\S*)?/";
	$urls = array();
	$urlsToReplace = array();
	if(preg_match_all($reg_exUrl, $str, $urls)) {
		$numOfMatches = count($urls[0]);
		$numOfUrlsToReplace = 0;
		for($i=0; $i<$numOfMatches; $i++) {
			$alreadyAdded = false;
			$numOfUrlsToReplace = count($urlsToReplace);
			for($j=0; $j<$numOfUrlsToReplace; $j++) {
				if($urlsToReplace[$j] == $urls[0][$i]) {
					$alreadyAdded = true;
				}
			}
			if(!$alreadyAdded) {
				array_push($urlsToReplace, $urls[0][$i]);
			}
		}
		$numOfUrlsToReplace = count($urlsToReplace);
		for($i=0; $i<$numOfUrlsToReplace; $i++) {
			$str = str_replace($urlsToReplace[$i], "<a target='blank' href=\"http://".$urlsToReplace[$i]."\">".$urlsToReplace[$i]."</a> ", $str);
		}
		return $str;
	} else {
		return $str;
	}
}