Installing ruby with RVM

please follow the url
http://rvm.beginrescueend.com/rvm/install/

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in Summary
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#!/usr/bin/env bash

# Install git
bash < <( curl http://rvm.beginrescueend.com/install/git )

# Install RVM
bash < <( curl http://rvm.beginrescueend.com/releases/rvm-install-head )

# Install some rubies
source "$HOME/.rvm/scripts/rvm"
rvm install ree,1.9.2-head,jruby