use strict;
use warnings;
my $template = 'D<';
my $nv = 2.4;
my $p = pack $template, $nv;
# I'm running this script on perl-5.34.0
# with nvtype of 'long double'.
# I want to see the result of perl-5.34.0
# with nvtype of 'double' unpacking $p :
my $perl = "C:/perl-5.34.0/bin/MSWin32-x64-multi-thread/perl.exe";
system $perl, '-wle', 'print unpack("H*", $p)';
####
9a999999999999990040000000000000
##
##
Use of uninitialized value $_ in print at -e line 1.
##
##
system $perl, '-wle', 'print $ARGV[0]', unpack('H*', $p);