> > Oliver Bandel wrote:
> But why didn't worked the code with the two sprintf's?!
> The outer sprintf should have do what I was looking for?!

Printf.sprintf "%0X" converts a number to a capitalised hex *string* (the 0
is pointless without a width specification --- there will never be padding)

Printf.sprintf "%02s" inserts a *string* ensuring that it is at least two
characters long. The '0' is ignored --- the O'Caml manual states that the
'0' and '+' flags are for numerical conversion only
(http://caml.inria.fr/pub/docs/manual-ocaml/libref/Printf.html). I guess you
could argue that "%02s" is not a valid format and so should raise 

This is also the behaviour of ISO C sprintf
(http://www.opengroup.org/onlinepubs/009695399/functions/printf.html) 

> Thanks,
>    Oliver


David