$re = '/(http|https|)\:\/\/[a-zA-Z0-9\-\.]+\.[a-zA-Z]{2,3}(\/\S*)?\/[a-zA-Z0-9\-\.]+\.xml/m';
$str = 'https://regex101.com/a.xml
https://wwww.regex101.com/a.xml
https://wwww.regex101.com/www/1/4a.xml
http://wwww.regex101.com/www/1/4a.xml
https://regex101.com/www/1/4a.xml
https://wwww.regex101.co/www/1/4a.xml
http://regex101.co/www/1/4a.xml
http://regex101.co/1/4a.xml
http://regex101.co/1/4aasfw/a.xml';
preg_match_all($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