下载配置文件并重命名

curl  https://raw.githubusercontent.com/git/git/master/contrib/completion/git-completion.bash -o ~/.git-completion.bash

添加到 .bash_profile

vim ~/.bash_profile 

添加内容

if [ -f ~/.git-completion.bash ]; then
  . ~/.git-completion.bash
fi

保存后刷新

source ~/.bash_profile