Binary, decimal, and hex in Perl 5

bin-dec-hex.pl

use strict;
use warnings;
use Test::More;

# See `perldoc -f pack` for documentation.

subtest 'Test unsigned char (8-bit)' => sub {

    my $packed = pack('B8', '0001'.'1111');

    is unpack('C', $packed),   31; # C: unsigned char
    is unpack('H2', $packed), '1f';

    # From: 0001 1111
    # To  : 1110 0000
    my $complement = pack('C', ~31);

    is unpack('B8', $complement), '11100000';
};

subtest 'Test unsigned short (16-bit)' => sub {

    my $packed = pack('B16', '0000'.'0000'.'0001'.'1111');

    is unpack('n', $packed),  31; # n: unsigned short (16-bit)
    is unpack('H4', $packed), '001f';

    # From: 0000 0000 0001 1111
    # To  : 1111 1111 1110 0000
    my $complement = pack('n', ~31);

    is unpack('B16', $complement), '1111111111100000';
};

subtest 'Test unsigned long (32-bit)' => sub {

    my $packed = pack('B32', ('0000' x 6) . '0001'.'1111');

    is unpack('N', $packed),   31; # N: unsigned long (32-bit)
    is unpack('H8', $packed), '0000001f';

    # From: 0000 0000 0000 0000 0000 0000 0001 1111
    # To  : 1111 1111 1111 1111 1111 1111 1110 0000
    my $complement = pack('N', ~31);

    is unpack('B32', $complement), '11111111111111111111111111100000';
};

done_testing;