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encryptor.rb
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encryptor.rb
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class Encryptor
def supported_characters
(' '..'z').to_a
end
def crack(message)
supported_characters.count.times.collect do |attempt|
decrypt(message,attempt)
end
end
def cipher(rotation)
characters = (' '..'z').to_a
rotated_characters = characters.rotate(rotation)
Hash[characters.zip(rotated_characters)]
end
def encrypt_letter(letter, rotation)
cipher_for_rotation = cipher(rotation)
cipher_for_rotation[letter]
end
def encrypt(string, rotation)
# 1. Cut the input string into letters
letters = string.split("")
# 2. Encrypt those letters one at a time, gathering the results
# 3. Join the results back together in one string
encrypted_letters = letters.collect do |letter|
encrypt_letter(letter, rotation)
end.join
end
def decrypt_letter(letter, rotation)
cipher_for_rotation = cipher(rotation-(rotation*2))
cipher_for_rotation[letter]
end
def decrypt(string, rotation)
letters = string.split("")
decrypted_letters = letters.collect do |letter|
decrypt_letter(letter, rotation)
end.join
end
def encrypt_file(filename, rotation)
#1 Create the file handle to the input file
input = File.open(filename, "r")
#2 Read the text of the input file
input_text = input.read
#3 Encrypt the text
secret_text = encrypt(input_text, rotation)
#4 Create a name for the output file
output_filename = filename + ".encrypted"
#5 Create an output file handle
output = File.open(output_filename, "w")
#6 Write out the text
output.write(secret_text)
#7 Close the file
output.close
end
def decrypt_file(filename, rotation)
#1 Create the file handle to the encrypted file
input = File.open(filename, "r")
#2 Read the encrypted text
input_text = input.read
#3 Decrypt the text by passing in the text and rotation
unsecret_text = decrypt(input_text, rotation)
#4 Create a name for the decrypted file
output_filename = filename.gsub("encrypted", "decrypted")
#5 Create an output file handle
output = File.open(output_filename, "w")
#6 Write out the text
output.write(unsecret_text)
#7 Close the file
output.close
end
end