Caesar Shift

[TZapper]

In regards to an old post about a caesar shift solution, I have tried my skills to approach this in an efficient way and came up with the following:

#!/usr/bin/perl -w
#
# Caesar shift decrypting script
# Author: Aleksandr Melentiev <[e-mail]>          
# Redistributable under the BSD License

use strict;
use warnings;

print "Enter encrypted string:\n";
chomp(my $cipher = <STDIN>);

my @alphabet = ('A' .. 'Z');
for (@alphabet) {
        my $text = $cipher;
        my $rot = join("", @alphabet);
        eval "\$text =~ tr/a-zA-Z/$rot/, 1" or die $@;
        print "ROT: $text\n";
        push(@alphabet, shift(@alphabet));
}

[tachyon]

You can do it much more simply and without the arrays or the eval. Just rotate by 1 x 26 times and you are back to the start ie:

$_ = "Hello\n";
for my $i(1..26){
    tr/a-zA-Z/b-zaB-ZA/;
    print;
}

[belg4mit]

If I'm not mistaken, you should only need to do 25 rotations to present all possible results, the 26th being identity. This would then also allow the results to fit on a standard terminal without scrolling (assuming a message LTE 80 chars).

[mpeg4codec]

#!/usr/bin/perl -w
use strict;

chomp(my $cypher = <STDIN>);
$cypher = lc($cypher);

$cypher =~ tr/a-z/n-za-m/;

print "ROT: $cypher\n";

Untested.

[Aristotle]

The point of the OP's code is to apply all 26 possible shift widths.