File decryption script written in Ruby

decrypt.rb

require 'crypt/blowfish'

unless ARGV[0]
  puts "Usage: ruby decrypt.rb <Encrypted_filename.ext>"
	puts "Example: ruby decrypt.rb" Encrypted_secret.stuff"
		exit
end

filename = ARGV[0].chomp
puts "Decrypting #{filename}."
p = "Decrypted_#{filename}"

if File.exists?(p)
	puts "File already exists."
	exit
end

print 'Enter your encryption key: '
kee = gets.chomp

begin
	blowfish = Crypt::Blowfish.new(kee)
	blowfish.decrypt_file(filename.to_str, p)
	puts 'Decryption SUCCESS!'
rescue Exception => e 
	puts "An error occurred during decryption: \n #{e}"
end