- var_dump: documentation ( source)
- preg_match: documentation ( source)
<?php
$m = array();
$x = "asdfadsf 'http://valami.lofasz?egy=ketto&harom=negy'blablabla";
preg_match("#\'(https?://[^\']+)\'#", $x, $m);
$d = url_encode($m[1]);
var_dump($d);