Every sign only once.

[Lumio]

Hello!

I have some signs here:

ygabodfe

And I want to check a string, if it has at least 5 of this chars and every char has to be there only once.

Is that possible with Regex?

[ddrudik]

function checkval($letters,$val){
  return preg_match('/(?=^['.preg_quote($letters,'/').']{5,}$)(?!.*(.).*\1)/',$val) ? "pass" : "fail";
}
echo checkval('ygabodfe','yodeag');
echo '<br>'.checkval('ygabodfe','yadea');
echo '<br>'.checkval('ygabodfe','yodeq');