git开始篇-Git撤销和回退

Git撤销和回退

如果你的文本里面有一个readme.txt文件在里面增加了一行test txt

test readme.txt
test txt

如果你想恢复到之前的版本，你可以将最后一行删除了，如果你不知道修改了哪些内容，或者修改的内容太多了，你可以用git status查看有一下。git会告诉你用 git checkout -- <file> 放弃工作区的内容

$ git status
On branch master
Your branch is ahead of 'origin/master' by 1 commit.
  (use "git push" to publish your local commits)

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

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

命令 git checkout -- readme.txt 意思就是，把readme.txt文件在工作区的修改全部撤销，有2种情况
1、readme.txt自修改后还没有被放到暂存区，现在要修改就回到和版本库一模一样的状态
2、readme.txt已经添加到暂存区后，又作了修改，现在，撤销修改就回到添加到暂存区后的状态
总之，就是让这个文件回到最近一次 git commit或 git add时的状态

$ cat readme.txt
test readme.txt
test txt

$ git checkout -- readme.txt

$ cat readme.txt
test readme.txt

如果现在不仅仅修改工作区里面的文件，并且git add了

$ cat readme.txt
test readme.txt
test txt

$ git add readme.txt

如果在commit之前，用 git status查看一下，修改只是添加到了暂存区，还没有提交

$ git status
On branch master
Your branch is ahead of 'origin/master' by 1 commit.
  (use "git push" to publish your local commits)

Changes to be committed:
  (use "git reset HEAD <file>..." to unstage)

        modified:   readme.txt

git 告诉我们，用命令 git reset HEAD <file> 可以把暂存区的修改撤销掉，将版本库里面的内容撤销到暂存区里面

$ git reset HEAD readme.txt
Unstaged changes after reset:
M       readme.txt

这个时候在用git status 查看 一下，现在暂存区是干净的，工作区有修改

$ git status
On branch master
Your branch is ahead of 'origin/master' by 1 commit.
  (use "git push" to publish your local commits)

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

这个时候有用git checkout -- readme.txt

$ git checkout -- readme.txt

$ git status
On branch master
Your branch is ahead of 'origin/master' by 1 commit.
  (use "git push" to publish your local commits)

nothing to commit, working tree clean