$re = '/.*?1920x1200.*$(*SKIP)(*F)|(?:\d+[a-z]|[a-z]+\d)[a-z\d]*/im';
$str = 'group1:
2aa
a2
2aaaaaa
aaaa2
aaa2aaaa
2222a2222-2222-aaaa
sdfzugsdufz-aaaaa7-7aaaa
sdfz/////...ugsd33ufz_//__-aaaaa7__///-7aaaa
group-two:
aaaaaa
22222
aaa-222-aaa-aaa
aaaaa222aaa1920x1200bbbbb1234556789
aaa1920x1200-
aaaaf344t---1920x1200aaa------
aaaaaaaaaaaaaaaaa-1920x1200
aa456456a-1920x1200-dfgfdg656dfg';
preg_match_all($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