为什么没有'hadoop fs -head'shell命令？(Why is there no 'hadoop fs -head' shell command?)

 
 
 如果我们把所有这些都移到GitHub上，每个用户是否必须下载250MB，或者他们是否必须下载1GB或更多才能获得存储库的完整历史记录？ 
 
 
 当第一次克隆时，每个用户都必须检索整个存储库。 但是，git服务器端实现会将存储库的“压缩”版本作为packfile发送 。 因此传输的数据的重量远小于1Gb。 
 
 每个连续的提取/拉取操作只会检索服务器知道的并且尚未在客户端的本地存储库中的新git对象（提交，树和Blob）。 那些也将作为packfile通过线路发送。 
 
 
 尽管@akonsu在说明您可以克隆存储库的浅版本时是正确的（即没有整个历史记录），但这会阻止用户与GitHub托管的主上游存储库进一步交互。 
 
 实际上， git clone文档指出： “一个浅的存储库有许多限制（你不能克隆或获取它，也不能从中推送或推入它）” 

 
 
If we moved all this over to GitHub, would each user have to download the 250MBs or would they have to download 1GB or more to get the full history of the repository?
 
 
Each of the users, when cloning for the first time, would have to retrieve the whole repository. However, git server side implementation would send a "compressed" version of the repository as a packfile. So the transmitted data would weight much less than 1Gb.
 
Each successive fetch/pull operation would only retrieve the new git objects (Commits, Trees and Blobs) that the server knows about and that are not already on the client's local repository. Those would also be sent over the wire as a packfile.
 
 
Although @akonsu is correct when stating you can clone a shallow version of your repository (ie. without the whole history), that would prevent the user from further interacting with a GitHub hosted main upstream repository. 
 
Indeed the git clone documentation states: "A shallow repository has a number of limitations (you cannot clone or fetch from it, nor push from nor into it)"