#!/usr/bin/perl

use strict; # https://perlmonks.org/?node_id=11166492
use warnings;
use Path::Tiny;
use feature 'signatures';

my $file = path('../tmp.tmp'); # FIXME for testing
system "hexdump -C $file; echo";
print hexdump( $file->slurp );

sub hexdump($data) {
   $data =~ s/\G(?|
       ( \0{16} )+ (?{ '*' })
     | ( .{1,16} ) (?{
            sprintf '%08X  %-50s|%s|', $-[1],
              "@{[unpack '(H2)8a0(H2)8', $1]}",
              $1 =~ y{ -~}{.}cr
       })
   )/$^R\n/xsgr . sprintf "%08x\n", length $data;
   }