use Data::Dumper qw( Dumper );

sub hexdump { 
   (my $dump = uc unpack 'H*', $_[0]) =~ s/(..)/$1 /g;
   return $dump;
}

sub txtdump {
   local $Data::Dumper::Useqq  = 1;
   local $Data::Dumper::Terse  = 1;
   local $Data::Dumper::Indent = 0;
   return Dumper($_[0]);
}

{
   open(my $fh, '>:raw:encoding(UTF-16le):crlf:utf8', 'test') or die;
   my $data = "foo\nbar\n";
   print("Orig: ", txtdump($data), "\n");
   print $fh $data;
}
 
{
   open(my $fh, '<:raw', 'test') or die;
   local $/;
   my $data = <$fh>;
   print("File: ", hexdump($data), "\n");
}
 
{
   open(my $fh, '<:raw:encoding(UTF-16le):crlf:utf8', 'test') or die;
   local $/;
   my $data = <$fh>;
   print("Read: ", txtdump($data), "\n");
}