Php Text İçinde Link

function link_sec($text)
if( strpos($text,"http://") )
{
 $start = strpos($text,"http://");
 $end = strpos(substr($text, strpos($text,"http://"), " ");
 $link = strpos($text, $start, $end-$start);
 return strpos($text,0,$start)."<a href=$link>".$link."</a>".strpos($text,$end);
}
return $text;
}

<?php

$reg_exUrl = "/(http|https|ftp|ftps)\:\/\/[a-zA-Z0-9\-\.]+\.[a-zA-Z]{2,3}(\/\S*)?/";

$text = "The text you want to filter goes here. http://google.com";

if(preg_match($reg_exUrl, $text, $url)) {
       echo preg_replace($reg_exUrl, "<a href="{$url[0]}">{$url[0]}</a> ", $text);

} else 
       echo $text;
?>