git - git HEAD 和当前项目状态的区别？

Question

我引用一个git教程:

git diff shows the diff between HEAD and the current project state

我想知道这是什么意思。 HEAD 不是当前事件的项目吗？

谢谢

Answer 1

来自“Specifying revisions”

HEAD names the commit on which you based the changes in the working tree.

还有其他头(FETCH_HEAD、ORIG_HEAD 和MERGE_HEAD)。参见 Jefromi's answer了解更多。

问题是，默认情况下 git diff 实际上显示了“项目的当前状态”(即工作树上的文件)和索引 之间的差异(不是 HEAD)。
换句话说，差异是您可以告诉 git 进一步添加到索引但您仍然没有。

如果您执行 git diff --cached，然后它会将索引与 HEAD 进行比较。

参见 git book for more (archive link) :

A common use is to simply run

$ git diff

which will show you changes in the working directory that are not yet staged for the next commit. If you want to see what is staged for the next commit, you can run

$ git diff --cached

which will show you the difference between the index and your last commit; what you would be committing if you run "git commit" without the "-a" option. (In Git versions 1.6.1 and later, you can also use git diff --staged which may be easier to remember.) Lastly, you can run

$ git diff HEAD

which shows changes in the working directory since your last commit; what you would be committing if you run "git commit -a".

另见 365git: Getting a diff between the working tree and other commits :