"Nothing known about..." message when trying to view documentation

Question

I'm quite new to ruby and I'm trying to view Ruby documentation through command prompt (I'm on Windows 7, Ruby version 2.0.0p195). However, no matter which command I try, for example ri String#upcase, I always get the message "Nothing known about..."

I have read several posts here but nothing seems to fix the problem.

Answer 1

With RVM in order to get the system documentation, you can issue the command

rvm docs generate-all

If you only want the ri documentation, this is what I do:

rvm docs generate-ri