It seems that File Handling in PHP doesn't work with certain characters (e.g. €) encoded UTF-8 if the path is hardcoded and the php-file saved as UTF-8.

Is it possible to make it work with all (or most western characters)? Is there a library which makes it possible maybe? Because I couldn't find any.

For example a folder named äöü&()éèàâêûô@$+ç%&=!£_;{[]}~´¢¬§°#@¦…€` in windows won't work with is_dir().

EDIT: SOLUTION

Ok, I have found a solution. I haven't tested it fully yet, I'm not sure if it's foolproof yet and I don't know if this is the best practise but encoding the string back to ANSI seems to do the trick (at least for the string I posted).

$string = iconv(mb_detect_encoding($string, "auto"), 'Windows-1252', $string);

I guess this should work with the default setting of most western windows computers.

I'd refuse to work with such a folder too! :-)
Jokes apart, you might try to save the file as UTF-16, as this is supposed to be the encoding Windows uses internally.