Well, it's a relatively simple regex
, so there isn't much to verifying it. You've got the
right expression for hex code 0. I'm not sure you need the brackets
at this point (indicating a character class), but it's easier to
start with them so that you don't need to remember them once you
find other characters to exclude.
As near as I can tell, it should be what you want. You may
end up wanting a more complicated regex if you find other invalid
characters you want to remove (like byte order marks), but that
could be done in a separate statement.