Auto Link HTML In PHP

// linkify URLs in a block of text.


function make_clickable($text)
{
    $ret = ' ' . $text;
    $ret = preg_replace("#(^|[\n ])([\w]+?://[\w]+[^ \"\n\r\t<]*)#ise", "'\\1\\2'", $ret);
    $ret = preg_replace("#(^|[\n ])((www|ftp)\.[^ \"\t\n\r<]*)#ise", "'\\1\\2'", $ret);
    $ret = preg_replace("#(^|[\n ])([a-z0-9&\-_\.]+?)@([\w\-]+\.([\w\-\.]+\.)*[\w]+)#i", "\\1\\2@\\3", $ret);
    $ret = substr($ret, 1);
    return($ret);
}