>perl -E"say sprintf '%vX', pack 'd>', $ARGV[0]" 0.1
3F.B9.99.99.99.99.99.9A

##</code><code>##

$ perl -E'say sprintf "%vX", pack "d>", $ARGV[0]', 0.1
3F.B9.99.99.99.99.99.9A