自分の環境はHomebrewを導入しているので、今回はHomebrewを通してrbenvを入れます。

rbenv

インストール

$ brew install rbenv ruby-build

確認

 $ rbenv --version
 rbenv 1.0.0

 $ brew info rbenv
 rbenv: stable 1.0.0 (bottled), HEAD
 Ruby version manager
 https://github.com/rbenv/rbenv#readme
 /usr/local/Cellar/rbenv/1.0.0 (36 files, 61.9K) *
   Poured from bottle on 2016-05-30 at 09:01:46
 From: https://github.com/Homebrew/homebrew-core/blob/master/Formula/rbenv.rb
 ==> Dependencies
 Recommended: ruby-build ✔
 ==> Options
 --without-ruby-build
 	Build without ruby-build support
 --HEAD
 	Install HEAD version
 ==> Caveats
 Rbenv stores data under ~/.rbenv by default. If you absolutely need to
 store everything under Homebrew's prefix, include this in your profile:
   export RBENV_ROOT=/usr/local/var/rbenv
 
 To enable shims and autocompletion, run this and follow the instructions:
   rbenv init

 $ brew info rbenv
 rbenv: stable 1.0.0 (bottled), HEAD
 Ruby version manager
 https://github.com/rbenv/rbenv#readme
 /usr/local/Cellar/rbenv/1.0.0 (36 files, 61.9K) *
   Poured from bottle on 2016-05-30 at 09:01:46
 From: https://github.com/Homebrew/homebrew-core/blob/master/Formula/rbenv.rb
 ==> Dependencies
 Recommended: ruby-build ✔
 ==> Options
 --without-ruby-build
 	Build without ruby-build support
 --HEAD
 	Install HEAD version
 ==> Caveats
 Rbenv stores data under ~/.rbenv by default. If you absolutely need to
 store everything under Homebrew's prefix, include this in your profile:
   export RBENV_ROOT=/usr/local/var/rbenv
 
 To enable shims and autocompletion, run this and follow the instructions:
   rbenv init
 LowSE01MacBookPro:pyenv LowSE01$
 LowSE01MacBookPro:pyenv LowSE01$
 LowSE01MacBookPro:pyenv LowSE01$ brew info ruby-build
 ruby-build: stable 20160426, HEAD
 Install various Ruby versions and implementations
 https://github.com/rbenv/ruby-build
 /usr/local/Cellar/ruby-build/20160426 (215 files, 124.6K) *
   Built from source on 2016-06-02 at 12:57:56
 From: https://github.com/Homebrew/homebrew-core/blob/master/Formula/ruby-build.rb
 ==> Dependencies
 Recommended: autoconf ✔, pkg-config ✔, openssl ✔
 ==> Options
 --without-autoconf
 	Build without autoconf support
 --without-openssl
 	Build without openssl support
 --without-pkg-config
 	Build without pkg-config support
 --HEAD
 	Install HEAD version

パス設定

パスを通します

 $ echo 'export RBENV_ROOT=/usr/local/var/rbenv' >> ~/.bash_profile
 $ echo 'eval "$(rbenv init -)"'          >> ~/.bash_profile
 $ source ~/.bash_profile

ruby

インストール

インストール可能バージョンの確認
```
 $ rbenv install --list
```

インストール実行

 $ rbenv install 2.3.0
 
 Downloading ruby-2.3.0.tar.bz2...
 -> https://cache.ruby-lang.org/pub/ruby/2.3/ruby-2.3.0.tar.bz2
 Installing ruby-2.3.0...
 Installed ruby-2.3.0 to /Users/LowSE01/.rbenv/versions/2.3.0

デフォルトバージョン指定

デフォルトで使用するバージョンを指定する
```
 rbenv global 2.3.0
```

確認

 $ ruby --version
 ruby 2.3.0p0 (2015-12-25 revision 53290) [x86_64-darwin14]

VersionがインストールしたものになっていればOK。

IntelliJ + Ruby

プラグイン

名前そのまま、「Ruby」ってプラグインがあったのでインストール。