# pkg install git sudo bash

sudoeditで設定する¹⁾

# Add for rbenv
Defaults 
secure_path="/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/local/rbenv/bin:/usr/local/rbenv/shims"
Defaults        env_keep += "RBENV_ROOT"

# cd /usr/local
# git clone git://github.com/sstephenson/rbenv.git
# mkdir /usr/local/rbenv/plugins
# cd /usr/local/rbenv/plugins
# git clone git://github.com/sstephenson/ruby-build.git

~/.profile

# for rbenv
export RBENV_ROOT="/usr/local/rbenv"
export PATH="${RBENV_ROOT}/bin:${PATH}"
eval "$(rbenv init -)"

~/.cshrc

# for rbenv
setenv RBENV_ROOT /usr/local/rbenv
setenv PATH ${RBENV_ROOT}/bin:${PATH}
rbenv init -

$ rbenv install –list
Available versions:
1.8.5-p52
1.8.5-p113
1.8.5-p114
......
2.5.0-dev
2.5.0-preview1
2.5.0-rc1
2.5.0
2.5.1
......

$ sudo rbenv install 2.5.1
$ sudo rbenv rehash

https://github.com/rbenv/rbenv