Question

My ruby script doesn’t seem to wait for my input. I’m trying to follow a script that encrypts your file from the first chapter of the book: wicked cool ruby, but it doesn’t wait for my input after I run the file in command prompt.

Code snippet that is causing trouble:

require 'crypt/blowfish'

unless ARGV[0]
   puts "Usage: ruby encrypt.rb <filename.ext>"
   puts "Example: ruby encrypt.rb secret.stuff"
   exit
end

#take in the file name to encrypt as an argument
filename = ARGV[0].chomp
puts filename

c = "Encrypted_#{filename}"

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

print 'Enter your encryption key (1-56 bytes): '
kee = gets.chomp

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

What I see in cmd after I try to run the file:

C:\Users\me\>ruby new4.rb fileToEnrypt.txt
Enter your encryption key (1-56 bytes): An error occurred during encryption:
 can't convert String into Integer
C:\Users\me\>

Answer 1

You have two problems here:

Concerning the fact that you don’t get the user prompt, replace your code with:

kee = $stdin.gets.chomp

Concerning the error message, it’s because:

The key is anywhere between 64 and 448 bits (8 and 56 bytes), and
should be passed as a packed string