命令“ git add <文件>”将所有文件添加到阶段

Question

有很多git命令可以在其中指定文件名。它们似乎不适用于我的项目，因为这些命令仍然适用于所有文件，而不是一个。

示例：

git add <file> # causes adding all files to the stage, not just one
git checkout <file> # discard all changes
git log -- file # works as usual git log command
git blame <file> # this one seems to work right

我做错了什么还是我的git有问题？如何解决它，尤其是git add file问题？

git add <file>的详细示例：

$ git status
On branch master
Changes not staged for commit:
  (use "git add/rm <file>..." to update what will be committed)
  (use "git checkout -- <file>..." to discard changes in working directory)

        modified:   file1
        modified:   file2
        modified:   file3

$ git add file1
$ git status
On branch master
Changes to be committed:
  (use "git reset HEAD <file>..." to unstage)

        modified:   file1
        modified:   file2
        modified:   file3