print "Basic binary key bit numbers\n";
print "$_\t", dec_to_bin_text($_), "\n" for qw ( 0 1 2 4 8 16 32 64 128 255 );
print "\nSubnet Mask binary\n";
print "$_\t", dec_to_bin_text($_), "\n" for qw ( 255 254 252 248 240 224 192 128 0);

print "\nWhat binary OR does - the | operator\n";
print do_or( 255, $_ ) for qw( 0 1 2 4 8 16 32 64 128 255 );
print do_or( 0, $_ ) for qw( 0 1 2 4 8 16 32 64 128 255 );

print "\nWhat binary AND does - the & operator\n";
print do_and( 255, $_ ) for qw( 0 1 2 4 8 16 32 64 128 255 );
print do_and( 0, $_ ) for qw( 0 1 2 4 8 16 32 64 128 255 );

print "\nWhat binary XOR does - the ^ operator\n";
print do_xor( 255, $_ ) for qw( 0 1 2 4 8 16 32 64 128 255 );
print do_xor( 0, $_ ) for qw( 0 1 2 4 8 16 32 64 128 255 );

print "\nUsing OR to set a bit in a bit mask to true\n";
print do_or( 0, 64 );
print do_or( 128, 64 );
print do_or( 255, 64 );

print "\nUsing XOR and AND to set a bit in a bit mask for false\n";
print "We want to set the 64 bit 0100000 and use the 255 XOR 64\n";
print "Which is 10111111 = 191 as a mask to do this\n";
print do_and( 255, 255^64 );
print do_and( 0, 255^64 );

print "\nUsing AND to get the value of a bit in a bit mask ( res = zero if not set, >0 if set )\n";
print do_and( 0, 64);
print do_and( 255, 64);

print "\nThe interesting property of double XOR against a bit mask - bit fliping\n";
print "This can be the basis or a simple encryption routine as in Active State Perl App\n";
print "\nExample 1\n";
print do_xor( 255, 10 );
print do_xor( 255, 245 );
print "\nExample 2\n";
print do_xor( 123, 10 );
print do_xor( 123, 113 );

print "\n\nThere you go!\n";

sub do_or {
    my ( $b1, $b2 ) = @_;
    my $res = $b1 | $b2;
    $b1_txt = dec_to_bin_text($b1);
    $b2_txt = dec_to_bin_text($b2);
    $res_txt = dec_to_bin_text($res);
  return "
$b1_txt = $b1
$b2_txt = $b2
---OR---
$res_txt = $res
";
}

sub do_xor {
    my ( $b1, $b2 ) = @_;
    my $res = $b1 ^ $b2;
    $b1_txt = dec_to_bin_text($b1);
    $b2_txt = dec_to_bin_text($b2);
    $res_txt = dec_to_bin_text($res);
  return "
$b1_txt = $b1
$b2_txt = $b2
--XOR---
$res_txt = $res
";
}

sub do_and {
    my ( $b1, $b2 ) = @_;
    my $res = $b1 & $b2;
    $b1_txt = dec_to_bin_text($b1);
    $b2_txt = dec_to_bin_text($b2);
    $res_txt = dec_to_bin_text($res);
  return "
$b1_txt = $b1
$b2_txt = $b2
--AND---
$res_txt = $res
";
}


sub dec_to_bin_text {
    my $dec = shift;
    my $bin_str = sprintf "%08b", $dec;
  return $bin_str;
}

__DATA__
Basic binary key bit numbers
0	00000000
1	00000001
2	00000010
4	00000100
8	00001000
16	00010000
32	00100000
64	01000000
128	10000000
255	11111111

Subnet Mask binary
255	11111111
254	11111110
252	11111100
248	11111000
240	11110000
224	11100000
192	11000000
128	10000000
0	00000000

What binary OR does - the | operator

11111111 = 255
00000000 = 0
---OR---
11111111 = 255

11111111 = 255
00000001 = 1
---OR---
11111111 = 255

11111111 = 255
00000010 = 2
---OR---
11111111 = 255

11111111 = 255
00000100 = 4
---OR---
11111111 = 255

11111111 = 255
00001000 = 8
---OR---
11111111 = 255

11111111 = 255
00010000 = 16
---OR---
11111111 = 255

11111111 = 255
00100000 = 32
---OR---
11111111 = 255

11111111 = 255
01000000 = 64
---OR---
11111111 = 255

11111111 = 255
10000000 = 128
---OR---
11111111 = 255

11111111 = 255
11111111 = 255
---OR---
11111111 = 255

00000000 = 0
00000000 = 0
---OR---
00000000 = 0

00000000 = 0
00000001 = 1
---OR---
00000001 = 1

00000000 = 0
00000010 = 2
---OR---
00000010 = 2

00000000 = 0
00000100 = 4
---OR---
00000100 = 4

00000000 = 0
00001000 = 8
---OR---
00001000 = 8

00000000 = 0
00010000 = 16
---OR---
00010000 = 16

00000000 = 0
00100000 = 32
---OR---
00100000 = 32

00000000 = 0
01000000 = 64
---OR---
01000000 = 64

00000000 = 0
10000000 = 128
---OR---
10000000 = 128

00000000 = 0
11111111 = 255
---OR---
11111111 = 255

What binary AND does - the & operator

11111111 = 255
00000000 = 0
--AND---
00000000 = 0

11111111 = 255
00000001 = 1
--AND---
00000001 = 1

11111111 = 255
00000010 = 2
--AND---
00000010 = 2

11111111 = 255
00000100 = 4
--AND---
00000100 = 4

11111111 = 255
00001000 = 8
--AND---
00001000 = 8

11111111 = 255
00010000 = 16
--AND---
00010000 = 16

11111111 = 255
00100000 = 32
--AND---
00100000 = 32

11111111 = 255
01000000 = 64
--AND---
01000000 = 64

11111111 = 255
10000000 = 128
--AND---
10000000 = 128

11111111 = 255
11111111 = 255
--AND---
11111111 = 255

00000000 = 0
00000000 = 0
--AND---
00000000 = 0

00000000 = 0
00000001 = 1
--AND---
00000000 = 0

00000000 = 0
00000010 = 2
--AND---
00000000 = 0

00000000 = 0
00000100 = 4
--AND---
00000000 = 0

00000000 = 0
00001000 = 8
--AND---
00000000 = 0

00000000 = 0
00010000 = 16
--AND---
00000000 = 0

00000000 = 0
00100000 = 32
--AND---
00000000 = 0

00000000 = 0
01000000 = 64
--AND---
00000000 = 0

00000000 = 0
10000000 = 128
--AND---
00000000 = 0

00000000 = 0
11111111 = 255
--AND---
00000000 = 0

What binary XOR does - the ^ operator

11111111 = 255
00000000 = 0
--XOR---
11111111 = 255

11111111 = 255
00000001 = 1
--XOR---
11111110 = 254

11111111 = 255
00000010 = 2
--XOR---
11111101 = 253

11111111 = 255
00000100 = 4
--XOR---
11111011 = 251

11111111 = 255
00001000 = 8
--XOR---
11110111 = 247

11111111 = 255
00010000 = 16
--XOR---
11101111 = 239

11111111 = 255
00100000 = 32
--XOR---
11011111 = 223

11111111 = 255
01000000 = 64
--XOR---
10111111 = 191

11111111 = 255
10000000 = 128
--XOR---
01111111 = 127

11111111 = 255
11111111 = 255
--XOR---
00000000 = 0

00000000 = 0
00000000 = 0
--XOR---
00000000 = 0

00000000 = 0
00000001 = 1
--XOR---
00000001 = 1

00000000 = 0
00000010 = 2
--XOR---
00000010 = 2

00000000 = 0
00000100 = 4
--XOR---
00000100 = 4

00000000 = 0
00001000 = 8
--XOR---
00001000 = 8

00000000 = 0
00010000 = 16
--XOR---
00010000 = 16

00000000 = 0
00100000 = 32
--XOR---
00100000 = 32

00000000 = 0
01000000 = 64
--XOR---
01000000 = 64

00000000 = 0
10000000 = 128
--XOR---
10000000 = 128

00000000 = 0
11111111 = 255
--XOR---
11111111 = 255

Using OR to set a bit in a bit mask to true

00000000 = 0
01000000 = 64
---OR---
01000000 = 64

10000000 = 128
01000000 = 64
---OR---
11000000 = 192

11111111 = 255
01000000 = 64
---OR---
11111111 = 255

Using XOR and AND to set a bit in a bit mask for false
We want to set the 64 bit 0100000 and use the 255 XOR 64
Which is 10111111 = 191 as a mask to do this

11111111 = 255
10111111 = 191
--AND---
10111111 = 191

00000000 = 0
10111111 = 191
--AND---
00000000 = 0

Using AND to get the value of a bit in a bit mask ( res = zero if not set, >0 if set )

00000000 = 0
01000000 = 64
--AND---
00000000 = 0

11111111 = 255
01000000 = 64
--AND---
01000000 = 64

The interesting property of double XOR against a bit mask - bit fliping
This can be the basis or a simple encryption routine as in Active State Perl App

Example 1

11111111 = 255
00001010 = 10
--XOR---
11110101 = 245

11111111 = 255
11110101 = 245
--XOR---
00001010 = 10

Example 2

01111011 = 123
00001010 = 10
--XOR---
01110001 = 113

01111011 = 123
01110001 = 113
--XOR---
00001010 = 10


There you go!