rbenv install and system wide install on Ubuntu 10.04 LTS.

rbenv-install-system-wide.sh

#!/bin/bash

# Update, upgrade and install development tools:
# apt-get update
# apt-get -y upgrade
# apt-get -y install build-essential
# apt-get -y install git-core

# Install rbenv
git clone git://github.com/sstephenson/rbenv.git /usr/local/rbenv

# Add rbenv to the path:
echo '# rbenv setup' > /etc/profile.d/rbenv.sh
echo 'export RBENV_ROOT=/usr/local/rbenv' >> /etc/profile.d/rbenv.sh
echo 'export PATH="$RBENV_ROOT/bin:$PATH"' >> /etc/profile.d/rbenv.sh
echo 'eval "$(rbenv init -)"' >> /etc/profile.d/rbenv.sh

# ... and for zsh too
echo '# rbenv setup' >> /etc/zsh/zprofile
echo 'export RBENV_ROOT=/usr/local/rbenv' >> /etc/zsh/zprofile
echo 'export PATH="$RBENV_ROOT/bin:$PATH"' >> /etc/zsh/zprofile
echo 'eval "$(rbenv init -)"' >> /etc/zsh/zprofile

chmod +x /etc/profile.d/rbenv.sh
source /etc/profile.d/rbenv.sh

# Install ruby-build:
git clone https://github.com/rbenv/ruby-build.git /usr/local/rbenv/plugins/ruby-build

# Install Ruby 2.4.1:
rbenv install 2.4.1
rbenv global 2.4.1

# Rehash:
rbenv rehash

gem install bundler