`git reset --hard master` 和 `git reset --hard origin/master` 有什么区别？

What's the difference between `git reset --hard master` and `git reset --hard origin/master`?

提问by vashishatashu

I tried a lot of links on Stackoverflow/elsewhere to properly understand behaviour of

我在 Stackoverflow/elsewhere 上尝试了很多链接以正确理解

git reset --hard option

git reset --hard option

I know that:

我知道：

• If it is omitted or if it is origin, reset is done on most recent commit on origin
• If a SHA1 hash is provided, reset is done on the corresponding commit.

• 如果省略或省略origin，则在最近一次提交时完成重置origin
• 如果提供了 SHA1 哈希，则在相应的提交上完成重置。

What I don't understand are the following values:

我不明白的是以下值：

1. origin
2. HEAD
3. origin/master
4. origin/branch

1. origin
2. HEAD
3. origin/master
4. origin/branch

All seem to have same behavior i.e. they a point to latest commit on master.

所有似乎都具有相同的行为，即它们指向master.

Please explain what is the significance of all 4 value option provided above.

请解释上面提供的所有 4 个值选项的意义是什么。

I would also like to know if I am on a specific branch how can I reset to the last commit on that very branch? If for example I am on v1.2, origin/v1.2still takes me to latest commit on master.

我还想知道我是否在特定分支上，如何重置到该分支上的最后一次提交？例如v1.2，如果我在，origin/v1.2仍然带我到最新的提交master。

回答by Mohammad AbuShady

First of all you need to understand that branch and tag names are just pointers to hash values, which represent a single commit, if you say that there's 4 options that have the same behaviour, then the first logical answer is because they all point to the same commit

首先，您需要了解分支和标签名称只是指向哈希值的指针，它们代表一次提交，如果您说有 4 个选项具有相同的行为，那么第一个合乎逻辑的答案是因为它们都指向相同的提交

• originI'm not sure about this but i think originby it self will resolve to origin/HEADwhich i think will be dependent on your github settings, in github you set a 'default branch', origin/headwill resolve to origin/[default_branch], in your case im assuming it's master, so this is why it has the same effect as origin/master.

• HEADalways points to the current commit, the one you are standing on, so a git reset --hard HEADwill permenantly remove all changes in tracked files and staged files changes, but not change the commit hash.

• origin/masteris last commit in the remote master branch since your last fetch/pull, each time you commit to master, your local masteris updated and your origin/masteris updated too, if someone else pushes to masteryour repo will have no idea that there is an update, unless you do a git fetchthen your origin/masterwill move ahead of your master, or maybe even diverge.
  running a git reset --hard origin/masterwill have the same effect if you are currently are on the masterbranch and the masteris in sync with origin/master

• origin/branchI'm not sure what this represents, because there's no origin/branchby default, so I'm guessing you created a branch called branchand happens to be in the same commit as your master, to confirm you can try doing a git branchto see all your branches, i'm guessing you'll find one called branch

• origin我不确定这一点，但我认为origin它自己会解决origin/HEAD，我认为这取决于你的 github 设置，在 github 中你设置了一个“默认分支”，origin/head将解决origin/[default_branch]，在你的情况下，我假设它是主人，所以这就是为什么它具有与origin/master.

• HEAD始终指向当前提交，即您所在的提交，因此 agit reset --hard HEAD将永久删除跟踪文件和暂存文件中的所有更改，但不会更改提交哈希。

• origin/master是自上次获取/拉取以来远程主分支中的最后一次提交，每次提交时master，您的本地master都会更新，您的本地也会更新origin/master，如果其他人推送到master您的存储库将不知道有更新，除非您做一个git fetch然后你的origin/master意志走在你的前面master，甚至可能会发散。
  运行git reset --hard origin/master将具有相同的效果，如果您当前是在master分支和master处于同步与origin/master

• origin/branch我不确定这代表什么，因为origin/branch默认情况下没有，所以我猜你创建了一个名为的分支，branch并且恰好与你的主人在同一个提交中，以确认你可以尝试git branch查看你的所有分支，我猜你会发现一个叫branch

To see all this in a visual way, you could try running git log --graph --decorate --allor I prefer a visual tool like gitk, if you have the binary installed you would run gitk --allto see all branches relative to each other

要看到一个可视化的方式这一切，你可以尝试运行git log --graph --decorate --all或者我喜欢的可视化工具一样gitk，如果你有二进制安装你可以运行gitk --all看相互所有分支

回答by Tobia Tesan

master, HEAD, origin/somethingand maybe some tag, why not, mayall point to the same commit, but they are most definitely not the same thing.

master, HEAD,origin/something也许还有一些标签，为什么不，可能都指向同一个提交，但它们绝对不是同一件事。

originis usually the name of a remoterepository.

origin通常是远程存储库的名称。

You can see your remotes and configure new ones with git remote -v.

您可以查看您的遥控器并使用git remote -v.

Try it (with -v) and it will probably make sense.

尝试一下（使用-v），它可能会有意义。

remote/somebranchpoints to the head of some branch on a remote repository.

remote/somebranch指向远程存储库上某个分支的头部。

origin/masterpoints to the head of masteron origin.

origin/master指向的头部master上origin。

Is it the same as master?

是一样的master吗？

Yes and no. If you pull your master branch, do some work and in the meantime somebody else commits on masterand pushes to origin, they will differ.

是和否。如果你拉你的主分支，做一些工作，同时其他人提交master并推送到origin，他们会有所不同。

When you do a git fetch origin, then, origin/masterwill have additional commits (will be ahead).

当您执行 agit fetch origin时，origin/master将有额外的提交（将领先）。

HEADis simply "the current commit". Think of it as ..

HEAD只是“当前提交”。把它想象成..

See this question

看到这个问题

Again, this couldbe the same as master, but if you check out another branch or commit or are in the middle of a rebase, well, it's not.

同样，这可能与 相同master，但如果您检查另一个分支或提交，或者处于 rebase 的中间，那么，事实并非如此。

So try this on a fresh repository on which nobody else is working:

所以在一个没有其他人工作的新存储库上试试这个：

$ git checkout master
$ git log -1 --format="%H" HEAD
123abc
$ git log -1 --format="%H" origin/master
123abc

They are the same!

他们是一样的！

$ git diff origin/master

Of course their content is the same.

当然它们的内容是一样的。

$ echo "foo" > foo
$ git add foo
$ git commit -m "Foo the thingy"
$ git log -1 --format="%H" HEAD
321bca
$ git log -1 --format="%H" origin/master
123abc

Ah, look, now they're different commits!

啊，看，现在它们是不同的提交！

$ git push origin master
$ git log -1 --format="%H" HEAD
321bca
$ git log -1 --format="%H" origin/master
321bca

And now they aren't! we have pushed our latest commit and they both point to the same.

而现在他们不是！我们已经推送了我们最新的提交，它们都指向相同的内容。

$ git checkout -b newbranch
$ echo "baz" > baz
$ git add baz
$ git commit -m "Baz the thingy with the stuff"
$ git branch -a
  master
* new_branch
  origin/master
$ git log -1 --format="%H"
789def
$ git log -1 --format="%H" master
321bca
git log -1 --format="%H" origin/master
321bca
git log -1 --format="%H" origin/new_branch
unknown revision or path not in the working tree.

Of course not. We haven't pushed new_branchto origin, it is only on our local machine

当然不是。我们还没有推new_branch送到origin，它只是在我们的本地机器上

git checkout 123abc

We have just checked out 123abc, the old head of master. It is not the head of any branch, now, but we can check it out just the same.

我们刚退房123abc，老团长了master。现在它不是任何分支的负责人，但我们可以同样地检查它。

Note: checking out 123abc. You are in 'detached HEAD' state, etc
$ git checkout -b old_master
$ git branch -a
  master
* new_branch
  origin/master
  old_master

Now guess what their SHA1 will respectively be?

现在猜猜他们的 SHA1 分别是多少？