s3cr3t

#!/usr/bin/env perl
use strict;
use warnings;
use Pod::Usage;
use Getopt::Long;
use File::Slurp 'slurp';

my %options;
GetOptions(\%options, "--show", "--help");

run(\%options, @ARGV);

sub run {
    my ($opts, @args) = @_;

    pod2usage(0) if $opts->{help};

    my @files;

    if (@args == 0) {
        @files = (join '', <STDIN>);
    } else {
        for my $arg (@args) {
            push @files, slurp $arg;
        }
    }

    for my $file (@files) {
        if ($opts->{show}) {
            print show($file), "\n";
        } else {
            print hide($file), "\n";
        }
    }
}

sub hide {
    my $text = shift;

    $text = unpack "b*", $text;
    $text =~ tr/01/ \t/;
    $text;
}

sub show {
    my $text = shift;

    $text =~ tr/ \t/01/;
    $text = pack "b*", $text;
    $text;
}

__END__

=head1 NAME

s3cr3t - 'hide' and 'unhide' text files

=head1 SYNOPSIS

    s3cr3t OPTION file1 [file2 ...]
    -s, --show          Show hidden text(reverse hide mode)
    -h, --help          Display the help information

    $ s3cr3t --help
    $ s3cr3t a.txt > a.hidden
    $ s3cr3t a.hidden
    $ cat a.txt | s3cr3t

=head1 DESCRIPTION

No more description.

=head1 LICENSE

same as Perl.

=head1 AUTHOR

Hyungsuk Hong

=cut