$re = '/.+:(\S+).+/';
$str = 'q:* > event_id:5156 > count
q:* > event_id:5158 > count
q:* > event_id:3006 > count
q:* > event_id:4656 > count
q:* > event_id:4663 > count
q:* > event_id:3008 > count
q:* > event_id:1016 > count
q:* > event_id:4688 > count
q:* > event_id:5154 > count';
preg_match_all($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