1 现对readme.txt作出修改,增加一行内容: Git has a mutable index called stage.
Git is a distributed version control system. Git is free software distributed under the GPL. Git has a mutable index called stage.
2 在工作区新添加一个文件:LICENSE文本文件（内容随便写）
3 通过git status 查看当前的状态
$ 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 # # Untracked files: # (use "git add <file>..." to include in what will be committed) # # LICENSE no changes added to commit (use "git add" and/or "git commit -a")
Git非常清楚地告诉我们，readme.txt被修改了，而LICENSE还从来没有被添加过，所以它的状态是Untracked。
4 git add readme.txt git add LICENSE( 没有执行git commit)
现在，使用两次命令git add，把readme.txt和LICENSE都添加后，用git status再查看一下：
$ git status # On branch master # Changes to be committed: # (use "git reset HEAD <file>..." to unstage) # # new file: LICENSE # modified: readme.txt #
git add 就是将文件修改放到存储区
5 执行git commit
执行git commit就可以一次性把暂存区的所有修改提交到分支。
$ git commit -m "understand how stage works" [master 27c9860] understand how stage works 2 files changed, 675 insertions(+) create mode 100644 LICENSE