$re = '/Game\.of\.Thrones\.S08\.(1080p|720p).*/i';
$str = 'Game.of.Thrones.S06.720p.BluRay.x264-DEMAND
Game.of.Thrones.S06.1080p.BluRay.x264-DEMAND
Game.of.Thrones.S08.720p.BluRay.x264-DEMAND
Game.of.Thrones.S08.1080p.BluRay.x264-DEMAND
Game.of.Thrones.S08.MiX.XviD-VARGRP';
preg_match($re, $str, $matches, PREG_OFFSET_CAPTURE, 0);
// Print the entire match result
var_dump($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