I do like to skip ri and RDoc documentation while installing gems on my development machine, because it takes more time to generate ri and RDoc then actual installation of gem.

We can skip rdoc and ri documentation while installing a gem by:

gem install rails --no-ri --no-rdoc

I am sure that you would not like to give –no-ri and –no-rdoc every time you install a gem. To avoid this situation, you can create/update $HOME/.gemrc file with following option:

gem: --no-ri --no-rdoc

Now every time you install a gem, it will skip installation of ri and RDoc for the gem.

My .gemrc file looks like:

---
:update_sources: true
:sources:
- http://gems.rubyforge.org/
- http://gems.github.com
:benchmark: false
:bulk_threshold: 1000
:backtrace: false
:verbose: true
gem: --no-ri --no-rdoc