use strict;
use warnings;
use Fcntl;

my $stream;

# 'or die ...' removed for clarity

sysopen(DUMMY, "dummy.txt", O_RDWR | O_BINARY);
my $bytes_read = read DUMMY, $stream, 128;

for ( my $i=0; $i<= $bytes_read; $i++ ){
  my $char = substr( $stream, $i, 1 );
  print $i, ": ", ord( $char ), " => *", $char, "*\n";
}