复制仓库

例：使用在GitHub.com上Spoon-Knife项目
1、复制Spoon-Knife仓库
在GitHub.com 仓库点击“Fork”按钮
2、Clone your fork（分支)
复制fork到你本地机器上
git clone https://github.com/username/Spoon-Knife.git #Clones your fork of the repository into the current directory in terminal
3、Configure remotes配置远端
完成仓库复制后，它有一个默认称为origin的远端指向你在GitHub上的分支，而非最原始仓库。为跟踪最原始仓库，你必须添加另一个名为upstream远端
$cd Spoon-Knife
# Changes the active directory in the prompt to the newly cloned
"Spoon-Knife" directory
$git remote add upstream https://github.com/octocat/Spoon-Knife.git # Assigns the original repository to a remote called "upstream"
git fetch upstream
# Pulls in changes not present in your local repository, without modifying your files提取变化不会显示在你本地仓库里，不会改变你的文件

你还可以做更多的事

1、Push commits
$git push origin master
# Pushes commits to your remote repository stored on GitHub
上传文件到远端仓库

2、Pull in upstream changes提取upstream更新
$git fetch upstream
# Fetches any new changes from the original repository
git merge upstream/master
# Merges any changes fetched into your working files

pull和fetch区别：
$git pull upstream master
# Pulls commits from 'upstream' and stores them in the local repository
pull自动完成merge,并保存到你的仓库

$git fetch upstream
# Fetches any new commits from the original repository
$git merge upstream/master
# Merges any fetched commits into your working files

3、创建分支
$git branch mybranch
$git cheakout mybranch切换到分支
$git checkout master切换到主分支
$git merge mybranch 合并分支到主分支
$git branch -d mybranch删除分支

4、pull requests
如果你想对项目有所贡献，你可以发送给原作者pull request