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);