git pull origin master

/Users/***/dance/dance.txt

$cd /Users/***/dance

$pwd

$git status

$git init

$clear

$git status

$git add dance.txt 

$git status

$git commit -m "adding a new dance"

$git status

On branch master

nothing to commit, working directory clean

$git remote -v

github网站上建立repository，名称dance

$git remote add origin https://github.com/huafeng2018/dance.git

$git remote 

$git remote -v

$git push origin master

github网站上,修改dance.txt

$git pull origin master

本地机器的dance.txt就获得了最新的版本

/Users/***/dance/dance.txt