1、检查rvm安装环境

rvm -v
不存在的情况下：-bash: rvm: command not found

2、安装rvm

curl -L https://get.rvm.io | bash -s stable

3、载入rvm环境

source ~/.rvm/scripts/rvm

4、验证

rvm -v
rvm 1.29.12 (latest) by Michal Papis, Piotr Kuczynski, Wayne E. Seguin [https://rvm.io]