Re^3: why doesnt my regex doesnt matches certain character?

[thundergnat]

Those are control characters of some type. That particular one is "Delete" - character \x7F. Assuming they are all the same, you can match against that. It might be better to match against a character class though, in case they vary.

Try:

$text =~ /\p{Control}/;

to match, or

$text =~ s/\p{Control}//g;

to remove.