install ruby and ruby on rails on ubuntu 12.04

In summary

• update your system
• install git, curl, rvm
• install required packages
• install rails
• done

Step by step

Update system

sudo apt-get update

Install git

sudo apt-get install git

Install curl

sudo apt-get install curl

Install rvm

curl -L get.rvm.io | bash -s stable

Reload to start using rvm

source ~/.rvm/scripts/rvm

or 

source /home//.rvm/scripts/rvm

Check required packages

rvm requirements

and then copy the install command from output, it should look like this

sudo apt-get -y install build-essential openssl libreadline6 libreadline6-dev zlib1g zlib1g-dev libssl-dev libyaml-dev libsqlite3-0 libsqlite3-dev sqlite3 libxml2-dev libxslt-dev autoconf libc6-dev ncurses-dev automake libtool bison subversion

Install Javascript runtime

sudo apt-get install nodejs

Install ruby

rvm install 1.9.3

(1.9.3 is the newest version at the time of this writing)

Set ruby version to default

rvm use 1.9.3 --default

Install rails

gem install rails

Done

start your app and see it works! cheers!

references: http://blog.sudobits.com/2012/05/02/how-to-install-ruby-on-rails-in-ubuntu-12-04-lts/