git diff 是否比较索引和工作副本或上次提交和工作副本？

在git中参考，据说

一个简单的 git diff 将以统一的 diff 格式（补丁）显示自上次提交以来您在项目中更改的代码或内容尚未为下一个提交快照暂存。

我所做的是提交一个包含文本的文件A.然后我将该文件中的文本从A to B并上演它（没有提交）。最后，我将文件的内容更改为C。现在当我跑步时git diff它向我展示了之间的区别B and C。但我想看看两者之间的区别A and C。我该怎么做？

如果您想检查其他事物之间的差异，请查看下面的示例：

你可以运行

git diff HEAD^       #check against parent of last commit
git diff HEAD^^      #check against grandparent of last commit
git diff HEAD~5      #check against 5 commits ago, 5 can be replaced with any number
git diff HEAD^..HEAD #check second most recent commit against most recent
git diff SHA1 SHA2   #check difference between two pre-defined commits
git diff --staged    #check staged vs current index (HEAD)

您也可以根据时间变化来执行此操作，但这更高级一些。