Does anyone have any documentation for shell.rb?  It seems quite useful, 
but I can't seem to find any documentation on it.  It's in the standard 
library but there are no docs on it in ruby-doc.org or in the new 
pickaxe II.  Is there any coverage on it elsewhere?  I think there is 
some in the ruby way, but I was curious about any publicly available docs?

Charles Comstock