Question

I need some easy (without mb_* and things like that) to go around this issue.
I’ve tried something like
preg_match_all('#[a-ząśćłóżźń]{3,}#', $text, $matches);
but it doesn’t work.

Answer 1

Try…

preg_match_all('#[a-z\x{0105}\x{015B}\x{0107}\x{0142}\x{00F3}\x{017C}\x{017A}\x{0144}]{3,}#uis', $text, $matches);