use open IO => ':crlf';

##</code><code>##

#!/usr/bin/env perl -l

use strict;
use warnings;
use autodie;
use open IO => ':crlf';

my ($f, $fh); 
my $mf = \$f;
my $test_file = 'pm_1144333_test_file.txt';

open $fh, '>', $mf;
print $fh 'hello';
close $fh;
print_raw_1('mem:  ', $mf);
print_raw_2('mem:  ', $mf);
print_raw_3('mem:  ', $mf);
print_raw_4('mem:  ', $mf);
print_raw_5('mem:  ', $mf);

open $fh, '>', $test_file;
print $fh 'hello';
close $fh;
print_raw_1('file: ', $test_file);
print_raw_2('file: ', $test_file);
print_raw_3('file: ', $test_file);
print_raw_4('file: ', $test_file);
print_raw_5('file: ', $test_file);


sub print_raw_1 {
    my ($prompt, $file) = @_;

    open my $fh, '<:raw', $file;
    print '1. ', $prompt, unpack 'H*' while (<$fh>);
    close $fh;
}

sub print_raw_2 {
    my ($prompt, $file) = @_;

    open my $fh, '<', $file;
    binmode $fh, ':raw';
    print '2. ', $prompt, unpack 'H*' while (<$fh>);
    close $fh;
}

sub print_raw_3 {
    my ($prompt, $file) = @_;

    use open IN => ':raw';
    open my $fh, '<', $file;
    print '3. ', $prompt, unpack 'H*' while (<$fh>);
    close $fh;
}

sub print_raw_4 {
    my ($prompt, $file) = @_;

    use open IO => ':raw';
    open my $fh, '<', $file;
    print '4. ', $prompt, unpack 'H*' while (<$fh>);
    close $fh;
}

sub print_raw_5 {
    my ($prompt, $file) = @_;

    open my $fh, '<', $file;
    print '5. ', $prompt, unpack 'H*' while (<$fh>);
    close $fh;
}

##</code><code>##

1. mem:  68656c6c6f0d0a
2. mem:  68656c6c6f0d0a
3. mem:  68656c6c6f0d0a
4. mem:  68656c6c6f0d0a
5. mem:  68656c6c6f0a
1. file: 68656c6c6f0d0a
2. file: 68656c6c6f0d0a
3. file: 68656c6c6f0d0a
4. file: 68656c6c6f0d0a
5. file: 68656c6c6f0a

##</code><code>##

1. mem:  68656c6c6f0a
2. mem:  68656c6c6f0a
3. mem:  68656c6c6f0a
4. mem:  68656c6c6f0a
5. mem:  68656c6c6f0a
1. file: 68656c6c6f0a
2. file: 68656c6c6f0a
3. file: 68656c6c6f0a
4. file: 68656c6c6f0a
5. file: 68656c6c6f0a