git的使用(三)

$ vim readme.txt                                        #修改readme.txt 增加一行Git tracks changes.
Git is a distributed  version control system.
Git is free software distributed under the GPL.
Git has a mutable index called stage.
Git tracks changes.


$ git add readme.txt                                    #提交到暂存区


$ git status                                            #查看工作区所有文件的状态
On branch master
Changes to be committed:
  (use "git reset HEAD <file>..." to unstage)

        modified:   readme.txt

$ vim readme.txt
Git is a distributed  version control system.
Git is free software distributed under the GPL.
Git has a mutable index called stage.
Git tracks changes of files.

$ git commit -m "git tracks changes"
[master 4f2760d] git tracks changes
 1 file changed, 1 insertion(+)

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

        modified:   readme.txt                                                    #第二次的修改没有被提交到仓库，因为未被add提交到暂存区，无法commit到仓库

no changes added to commit (use "git add" and/or "git commit -a")