Ruby Command Line One Time Pad

Sup /prog/

I'm trying to write a one time pad program in Ruby and I'm having some trouble translating what is typed (the message) with a random number (srand).

I have a = 1 A = 1 b = 2 B = 2 and so forth, but what's an effective way of having each individual letter in a sentence be converted into a number?

Thanks

Why is /prog/ full of so much non /prog/ related stuff? :|