-- version
```
1.$ sudo gem update --system// 先更新gem，国内需要切换源
2.$ gem sources --removehttps://rubygems.org/
3.$ gem sources -ahttps://ruby.taobao.org
4./$ gem sources -l
\*\*\* CURRENT SOURCES \*\*\*https://ruby.taobao.org/
5.$ sudo gem install cocoapods// 安装cocoapods
6.$ pod setup
在cocoapods 执行
sudo gem install cocoapods
的时候出现 While executing gem ... (Gem::FilePermissionError)
You don't have write permissions for the /usr/bin directory.
改为 sudo gem install -n /usr/local/bin cocoapods 即可
