$re = '/(?:ht|f)tps?:\/\/[-a-zA-Z0-9.]+\.[a-zA-Z]{2,3}(?:\/(?:[^"<=]|=)*)?/';
$str = 'href="http://vacante2016.eu/tr/17599/51743713/c4f5eadf38eb475d39e3cde=ca9201538"
"http://vacante2016.eu/clk/17599/5=\\r\\n1743713/150132/bf7639dd7e7aa48c9197a52a8c61e168"><img';
preg_match_all($re, $str, $matches, PREG_SET_ORDER, 0);
// Print the entire match result
var_dump($matches);
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php