Manual pages for Ruby functions from command line

Is there a way 开发者_StackOverflow中文版to get at the manuals of Ruby functions from the command line?

Like the ?func man pages in R.

The ri tool might help here.

ri Array  
ri Array.sort  
ri Hash#each  
ri Math::sqrt  

I have the following shell script that I use because it does color formatting in the terminal:

wesbailey@feynman:~/insiderpages> cat `which rim`
ri -Tf ansi -w 150 $1
wesbailey@feynman:~/insiderpages> rim Array

...