union: git command

# switch one tag
# warning: if do that, can't commit  any change
git clone $project_path
git checkout $tag_name

# switch one tag, but can change the files on this tag
git checkout -b $branch_name $tag_name

2018-01-12 17:47:33
# if you have the project in local disk, how to link to the remote project
# @
git init

# @
git remote add origin $ssh_url