I installed RVM using the following command
\curl -L https://get.rvm.io | bash -s stable
Then I restarted the terminal and executed this commands
source ~/.rvm/scripts/rvm
rvm requirements
rvm install ruby
rvm use ruby --default
If I run this commands when I start the terminal I get ruby 2.1.2 as the default ruby version, but if I restart the terminal and I run
ruby -v
I get the following message
The program 'ruby' can be found in the following packages:
* ruby
* ruby1.8
Try: sudo apt-get install <selected package>