步骤：
1、git clone https://github.com/git/git
2、cd git/contrib/completion/
3、cp git-completion.bash ~/.git-completion.bash
4、vi /etc/bashrc
5、在bashrc文件的最后一行加上 source ~/.git-completion.bash
finish
Macbook安装git自动补全
原文：http://bccat.blog.51cto.com/8845284/1981550
