rvm installation under ubuntu

ubuntu_rvm.sh

#!/bin/bash -l

install_path="$HOME/install"

### Verify if the executing user is the root
function is_root {
	if [[ $(/usr/bin/id -u) -ne 0 ]]; then
		echo "The installation process requires to be run as root. Consider using sudo."
		false
	fi
}

function is_rvm_installed {
	[[ "`type rvm | head -n1`"	== "rvm is a function" ]]
}

### to run ruby and native gems with extensions we need those:
function do_install {
	if is_rvm_installed; then
		echo "Rvm is already installed"
		exit 0	
	else
		mkdir -p $install_path
		# cd $install_path
		apt-get install -y libruby1.8 zlib1g-dev libssl-dev libreadline5-dev build-essential \
                                   libxslt-dev libxml2-dev curl git-core
		curl -L http://bit.ly/rvm-install-system-wide > $install_path/rvm-install-system-wide
		bash -l < $install_path/rvm-install-system-wide

		usermod -a -G rvm $USER
	fi
}

### add the rvm script so it is run by all users and run it so it is available in the current session
function install_to_profile {
	cat > $install_path/rvm.sh <<EOF                                                                                              
[[ -s "/usr/local/lib/rvm" ]] && . "/usr/local/lib/rvm" # This loads RVM into a shell session
EOF
	cp $install_path/rvm.sh /etc/profile.d/rvm.sh
	chmod a+x /etc/profile.d/rvm.sh
	source /usr/local/lib/rvm
}

function install_failed {
	echo "Install failed :("
	exit 1
}

is_root &&
do_install &&
install_to_profile &&
is_rvm_installed || install_failed