rbenv install and system wide install on Ubuntu to /opt/rbenv

nodenv-system-wide-install

# Install nodenv
 git clone https://github.com/nodenv/nodenv.git /opt/nodenv

# Add nodenv to the path:
echo '# nodenv setup' > /etc/profile.d/nodenv.sh
echo 'export NODENV_ROOT=/opt/nodenv' >> /etc/profile.d/nodenv.sh
echo 'export PATH="$NODENV_ROOT/bin:$PATH"' >> /etc/profile.d/nodenv.sh
echo 'eval "$(nodenv init -)"' >> /etc/profile.d/nodenv.sh

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

# Install nodenv-build:
mkdir -p "$(nodenv root)"/plugins
git clone https://github.com/nodenv/node-build.git "$(nodenv root)"/plugins/node-build

# Install Node:
nodenv install x.x.x
nodenv global x.x.x

# Rehash:
nodenv rehash

rbenv-install-system-wide.sh

# 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
apt-get -y install zlib1g-dev
apt-get -y install libssl-dev
apt-get -y install libreadline-dev
apt-get -y install libcurl4-openssl-dev

# Install rbenv
git clone https://github.com/sstephenson/rbenv.git /opt/rbenv

# Add rbenv to the path:
echo '# rbenv setup' > /etc/profile.d/rbenv.sh
echo 'export RBENV_ROOT=/opt/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

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

# Install ruby-build:
pushd /tmp
  git clone https://github.com/sstephenson/ruby-build.git
  cd ruby-build
  ./install.sh
popd

# Install Ruby 1.9.2-p290:
rbenv install 1.9.2-p290
rbenv global 1.9.2-p290

# Rehash:
rbenv rehash