$re = '/(?<date>\d{4}-\d{2}-\d{2}) (?<time>\d{2}_\d{2}_\d{2})(-| - )(?<window>.*?)(?<extension>\.(png|jpg|jpeg))/';
$str = '2017-08-31 18_57_42-HandBrake.png
2017-08-31 18_57_43-HandBrake.png
2017-08-31 18_57_42-HandBrake - Kopie.png
2017-08-31 18_57_42-HandBrake2.png
2019-03-09 11_11_09 - musicBee - 000003.png
should fail.png\'';
preg_match_all($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