use strict;
use warnings;

use File::Slurp qw( read_file );

my $f = 'testdata';

{
   open(my $fh, '>', $f) or die $!;
   print $fh ("line1\n");
   print $fh ("line2\n");
   print $fh ("line3\n");
}

{
   print("Disk size:            ");
   print((stat($f))[7], "\n");

   print("\n");

   print("Inlined, binmode:     ");
   print(length(do { local $/;
                     open(my $fh, '<', $f) or die $!;
                     binmode($fh);
                     <$fh>                            }), "\n");

   print("Slurp,   binmode:     ");
   print(length(read_file($f, binmode => 1)), "\n");

   print("\n");

   print("Inlined, not binmode: ");
   print(length(do { local $/;
                     open(my $fh, '<', $f) or die $!;
                     <$fh>                            }), "\n");

   print("Slurp,   not binmode: ");
   print(length(read_file($f, binmode => 0)), "\n");

   print("\n");

   print("Slurp:                ");
   print(length(read_file($f)), "\n");
}

print("\n");
print("\n");

{
   my $inline = do { local $/;
                     open(my $fh, '<', $f) or die $!;
                     <$fh>                            };

   my $slurp = read_file($f);

   if ($inline eq $slurp) {
      print("Slurp is indentical to inlined version.\n");
   } else {
      print("Slurp is different from inlined version.\n");
   }
}

##</code><code>##

Disk size:            21

Inlined, binmode:     21
Slurp,   binmode:     21

Inlined, not binmode: 18
Slurp,   not binmode: 18

Slurp:                18


Slurp is indentical to inlined version.

##</code><code>##

>perl -MFile::Slurp -le "print $File::Slurp::VERSION"
9999.09

>perl -v

This is perl, v5.6.1 built for MSWin32-x86-multi-thread
(with 1 registered patch, see perl -V for more detail)

...