#!/usr/bin/perl

   use strict;

   if (@ARGV < 1) {
      print STDERR "\nUsage: $0 filename [bytes]\n\n";
      exit;
   }

   my ($File, $Bytes) = @ARGV;
   my ($numread, $totread, $lines);
   my ($ch, $input, $hex, $text);

   if (!open(IN, $File)) {
      print STDERR "\nError opening file: $File\n\n"; exit;
   }

   while ($numread = read(IN, $input, 16)) {

      $totread += $numread;

      $hex = $text = '';

      for $ch (unpack("C16", $input)) {

         $hex .= sprintf("%2.2x ", $ch);

         if ($ch >= 0x20 && $ch < 0x7f) { $text .= chr($ch); }
         else                           { $text .= '.'; }
      }

      substr($hex, 24, 0, ' ');

      printf(STDOUT "%8.8x  %-48.48s  %-16.16s\n",
         $lines * 16, $hex, $text);

      if (++$lines % 8 == 0) { print "\n"; }
      if ($Bytes && $totread >= $Bytes) { last; }
   }