How to install Ruby with rbenv on Ubuntu 12.04

So you got a clean 12.04 install or you are starting out with Ruby on Ubuntu, either way if you just go ahead and follow the steps on the rbenv site it will fail on Ubuntu because we need to use bashrc instead of bash_profile.

Start by installing a bunch of stuff needed such as zlib and git

$ sudo apt-get install zlib1g-dev openssl libopenssl-ruby1.9.1 libssl-dev libruby1.9.1 libreadline-dev git-core

$ cd
$ git clone git://github.com/sstephenson/rbenv.git .rbenv

Here is where we need to stray from the rbenv site:

$ echo 'export PATH="$HOME/.rbenv/bin:$PATH"' >> ~/.bashrc

Again

$ echo 'eval "$(rbenv init -)"' >> ~/.bashrc

Restart

$ exec $SHELL

Now install ruby_build to easily install Ruby with rbenv

$ mkdir -p ~/.rbenv/plugins
$ cd ~/.rbenv/plugins
$ git clone git://github.com/sstephenson/ruby-build.git

Install Ruby

$ rbenv install 1.9.3-p194

You will have to rehash everytime you install a Ruby version or a gem

$ rbenv rehash

Make a Ruby version default:

rbenv global 1.9.3-p194

Test:

$ irb
irb(main):001:0>