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)';