使用RVM更新Ruby 版本

http://rvm.io/rvm/install

Install RVM (development version):
curl -sSL https://get.rvm.io | bash
Without autolibs
curl -sSL https://get.rvm.io | bash -s -- --autolibs=read-fail
Install RVM stable with ruby:
curl -sSL https://get.rvm.io | bash -s stable --ruby
Additionally with rails (poor man's railsinstaller ):
curl -sSL https://get.rvm.io | bash -s stable --rails
Or with jruby, rails and puma:
curl -sSL https://get.rvm.io | bash -s stable --ruby=jruby --gems=rails,puma
To install without rubygems-bundler and rvm gems (and also remove those gems from both global.gems and default.gems):
curl -sSL https://get.rvm.io | bash -s stable --without-gems="rvm rubygems-bundler"
To install with hirb gem (and also add it to global.gems):
curl -sSL https://get.rvm.io | bash -s stable --with-gems="hirb"
To install with rails and haml gems (and also add them to default.gems):
curl -sSL https://get.rvm.io | bash -s stable --with-default-gems="rails haml"
For a progress bar when downloading RVM / Rubies:
echo progress-bar >> ~/.curlrc
Point to be noted is, there is a backslash before curl. This prevents misbehaving if you have aliased it with configuration in your ~/.curlrc file.