# The raw data as you might read it fro the file
$raw = '2010/02/03 10:52:03.123456'; print length $raw;;
26

## First unpack in your main loop
$level1hex = unpack 'H*', $raw; print $level1hex;;
323031302f30322f30332031303a35323a30332e313233343536

## Now re-unpack it two different ways in you print_trailer() sub
$level2text = unpack 'A*', $level1hex; print $level2text;;
323031302f30322f30332031303a35323a30332e313233343536

$level2hex = unpack 'H*', $level1hex; print $level2hex;;
33323330333133303266333033323266333033333230333133303361333533323361333033333265333133323333333433353336