Install rbenv on Ubuntu 12.04

install-rbenv.sh

# pre-reqs
sudo apt-get install git-core build-essential libssl-dev libreadline-dev zlib1g-dev libxml2-dev libxslt-dev

# rbenv
cd
git clone https://github.com/sstephenson/rbenv.git .rbenv
echo 'export PATH="$HOME/.rbenv/bin:$PATH"' >> ~/.bashrc
echo 'eval "$(rbenv init -)"' >> ~/.bashrc
exec $SHELL

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

# install some rubies
cd
rbenv install 1.9.2-p290
rbenv install 1.9.2-p320
rbenv install 1.9.3-p194
rbenv rehash

# set a global ruby
rbenv global 1.9.2-p290