#!/usr/bin/ruby


# name:     shift-cipher
# author:   ap0calypse ( ap0calypse@agitatio.org )
# version:  0.1 ( 2008-02-22 )
# license:  public domain
# purpose:  reads a sentence from STDIN an returns all
#           possible ciphered sentences. currently, all
#           input will be converted to lowercase letters. maybe
#           future versions will include support for uppercase
#           letters too. this is the ruby-version.

input = $stdin.gets.downcase.chop!  # all input lowercase / without newline

# the function that does the real dirty work

def cipher_sentence(sentence, cipher_value)

    hi_limit, lo_limit = 122, 96
    letters = sentence.split(//)
    sentence_ciphered = []

    letters.each { |letter|
        if letter[0] != 32
            letter[0] += cipher_value
            if letter[0] > hi_limit
                shiftval = letter[0] - hi_limit
                letter[0] = lo_limit + shiftval
            end
            sentence_ciphered.push(letter)
        else
            sentence_ciphered.push(" ")
        end
    }
    sentence_ciphered.push("\n")
end

# returning all possibilities
for i in 1 .. 25 
    print "shift by #{i}:\t"
    print cipher_sentence(input, i)
end