1.安装curl

sudo yum install curl

2. 安装RVM

curl -L get.rvm.io | bash -s stable 

一: 错误 ： 

$ curl -sSL https://get.rvm.io | bash -s stable 
Downloading  https://github.com/rvm/rvm/archive/1.26.11.tar.gz… 
Downloading  https://github.com/rvm/rvm/releases/download/1.26.11/1.26.11.tar.gz.asc… 
gpg: failed to create temporary file `/home/cky/.gnupg/.#lk0x2518060.cky-pc.29930’: 权限不够 
gpg: 密钥块资源‘/home/cky/.gnupg/pubring.gpg’：常规错误 
gpg: 于 2015年03月31日 星期二 05时52分13秒 CST 创建的签名，使用 RSA，钥匙号 BF04FF17 
gpg: 无法检查签名：找不到公钥 
二 ：解决方法 ： 
**$ curl -sSL  https://rvm.io/mpapis.asc | gpg –import - 
$ gpg –keyserver hkp://http://keys.gnupg.net –recv-keys 409B6B1796C275462A1703113804BB82D39DC0E3 
接下来再次执行： 
$ curl -sSL https://get.rvm.io | bash -s stable 
% Total % Received % Xferd Average Speed Time Time Time Current 
Dload Upload Total Spent Left Speed 
100 184 100 184 0 0 229 0 –:–:– –:–:– –:–:– 229 
100 22721 100 22721 0 0 21250 0 0:00:01 0:00:01 –:–:– 6802k 
Downloading  https://github.com/rvm/rvm/archive/1.26.11.tar.gz 
Downloading  https://github.com/rvm/rvm/releases/download/1.26.11/1.26.11.tar.gz.asc 
gpg: Signature made Tue 31 Mar 2015 05:52:13 CST using RSA key ID BF04FF17 
gpg: Good signature from “Michal Papis (RVM signing)  mpapis@gmail.com” 
gpg: WARNING: This key is not certified with a trusted signature! 
gpg: There is no indication that the signature belongs to the owner. 
Primary key fingerprint: 409B 6B17 96C2 7546 2A17 0311 3804 BB82 D39D C0E3 
Subkey fingerprint: 62C9 E5F4 DA30 0D94 AC36 166B E206 C29F BF04 FF17 
GPG verified ‘/home/charles/.rvm/archives/rvm-1.26.11.tgz’

Installing RVM to /home/charles/.rvm/ 
Adding rvm PATH line to /home/charles/.profile /home/charles/.mkshrc /home/charles/.bashrc /home/charles/.zshrc. 
Adding rvm loading line to /home/charles/.profile /home/charles/.bash_profile /home/charles/.zlogin. 
Installation of RVM in /home/charles/.rvm/ is almost complete:

*To start using RVM you need to run source /home/charles/.rvm/scripts/rvm 
in all your open shell windows, in rare cases you need to reopen all shell windows. 
# Thank you for using RVM! 
# We sincerely hope that RVM helps to make your life easier and more enjoyable!!! 
# 
~Wayne, Michal & team. 

这时我们以安装好了RVM,接下来就可以使用RVM安装ruby了：

3. 

source /usr/local/rvm/scripts/rvm

4. 查看rvm库中已知的ruby版本

rvm list known

5. 安装一个ruby版本

rvm install 2.3.3

6. 使用一个ruby版本

rvm use 2.3.3

7. 设置默认版本

rvm remove 2.0.0

8. 卸载一个已知版本

ruby --version

9. 再安装redis就可以了

gem install redis