找回丢失的对象

译者注: 原书这里只有两个链接： [Recovering Lost Commits Blog Post](http://programblings.com/2008/06/07/the-illustrated-guide-to-recovering-lost-commits-with-git)，　 [Recovering Corrupted Blobs by Linus](http://www.kernel.org/pub/software/scm/git/docs/howto/recover-corrupted-blob-object.txt) 我根据第一个链接，整理了一篇[博文](http://liuhui998.com/2010/10/22/recover_lost_commits_with_git/)，并把它做为原书补充。 在玩git的过程中，常有失误的时候，有时把需要的东东给删了。 不过没有关系，git给了我们一层安全网，让们能有机会把失去的东东给找回来。 Let's go! ## 准备 我们先创建一个用以实验的仓库，在里面创建了若干个提交和分支。 BTW：你可以直接把下面的命令复制到shell里执行。 ~~~ mkdir recovery;cd recovery git init touch file git add file git commit -m "First commit" echo "Hello World" > file git add . git commit -m "Greetings" git branch cool_branch　 git checkout cool_branch echo "What up world?" > cool_file git add . git commit -m "Now that was cool" git checkout master echo "What does that mean?" >> file ~~~ ## 恢复已删除分支提交 现在repo里有两个branch ~~~ $ git branch cool_branch * master ~~~ 存储当前仓库未提交的改动 ~~~ $ git stash save "temp save" Saved working directory and index state On master: temp save HEAD is now at e3c9b6b Greetings ~~~ 删除一个分支 ~~~ $ git branch -D cool_branch Deleted branch cool_branch (was 2e43cd5). $ git branch * master ~~~ 用`git fsck --lost-found`命令找出刚才删除的分支里面的提交对象。 ~~~ $git fsck --lost-found dangling commit 2e43cd56ee4fb08664cd843cd32836b54fbf594a ~~~ 用git show命令查看一个找到的对象的内容，看是否为我们所找的。 ~~~ git show 2e43cd56ee4fb08664cd843cd32836b54fbf594a commit 2e43cd56ee4fb08664cd843cd32836b54fbf594a Author: liuhui <liuhui998[#]gmail.com> Date: Sat Oct 23 12:53:50 2010 +0800 Now that was cool diff --git a/cool_file b/cool_file new file mode 100644 index 0000000..79c2b89 --- /dev/null +++ b/cool_file @@ -0,0 +1 @@ +What up world? ~~~ 这个提交对象确实是我们在前面删除的分支的内容；下面我们就要考虑一下要如何来恢复它了。 ### 使用git rebase　进行恢复 ~~~ $git rebase 2e43cd56ee4fb08664cd843cd32836b54fbf594a First, rewinding head to replay your work on top of it... Fast-forwarded master to 2e43cd56ee4fb08664cd843cd32836b54fbf594a. ~~~ 现在我们用git log命令看一下，看看它有没有恢复: ~~~ $ git log commit 2e43cd56ee4fb08664cd843cd32836b54fbf594a Author: liuhui <liuhui998[#]gmail.com> Date: Sat Oct 23 12:53:50 2010 +0800 Now that was cool commit e3c9b6b967e6e8c762b500202b146f514af2cb05 Author: liuhui <liuhui998[#]gmail.com> Date: Sat Oct 23 12:53:50 2010 +0800 Greetings commit 5e90516a4a369be01b54323eb8b2660545051764 Author: liuhui <liuhui998[#]gmail.com> Date: Sat Oct 23 12:53:50 2010 +0800 First commit ~~~ 提交是找回来，但是分支没有办法找回来： ~~~ liuhui@liuhui:~/work/test/git/recovery$ git branch * master ~~~ ### 使用git merge　进行恢复 我们把刚才的恢复的提交删除 ~~~ $ git reset --hard HEAD^ HEAD is now at e3c9b6b Greetings ~~~ 再把刚删的提交给找回来： ~~~ git fsck --lost-found dangling commit 2e43cd56ee4fb08664cd843cd32836b54fbf594a ~~~ 不过这回我们用是合并命令进行恢复： ~~~ $ git merge 2e43cd56ee4fb08664cd843cd32836b54fbf594a Updating e3c9b6b..2e43cd5 Fast-forward cool_file | 1 + 1 files changed, 1 insertions(+), 0 deletions(-) create mode 100644 cool_file ~~~ ## git stash的恢复 前面我们用git stash把没有提交的内容进行了存储，如果这个存储不小心删了怎么办呢？ 当前repo里有的存储： ~~~ $ git stash list stash@{0}: On master: temp save ~~~ 把它们清空： ~~~ $git stash clear liuhui@liuhui:~/work/test/git/recovery$ git stash list ~~~ 再用git fsck --lost-found找回来： ~~~ $git fsck --lost-found dangling commit 674c0618ca7d0c251902f0953987ff71860cb067 ~~~ 用git show看一下回来的内容对不对： ~~~ $git show 674c0618ca7d0c251902f0953987ff71860cb067 commit 674c0618ca7d0c251902f0953987ff71860cb067 Merge: e3c9b6b 2b2b41e Author: liuhui <liuhui998[#]gmail.com> Date: Sat Oct 23 13:44:49 2010 +0800 On master: temp save diff --cc file index 557db03,557db03..f2a8bf3 --- a/file +++ b/file @@@ -1,1 -1,1 +1,2 @@@ Hello World ++What does that mean? ~~~ 看起来没有问题，好的，那么我就把它恢复了吧： ~~~ $ git merge 674c0618ca7d0c251902f0953987ff71860cb067 Merge made by recursive. file | 1 + 1 files changed, 1 insertions(+), 0 deletions(-) ~~~ ## 备注 这篇文章主要内容来自这里：[The illustrated guide to recovering lost commits with Git](http://programblings.com/2008/06/07/the-illustrated-guide-to-recovering-lost-commits-with-git/),我做了一些整理的工作。 如果对于文中的一些命令不熟，可以参考[Git Community Book中文版](http://gitbook.liuhui998.com/) 其实这里最重要的一个命令就是：git fsck --lost-found，因为git中把commit删了后，并不是真正的删除，而是变成了悬空对象（dangling commit）。我们只要把把这悬空对象（dangling commit）找出来，用[git rebase](http://gitbook.liuhui998.com/4_2.html)也好，用[git merge](http://gitbook.liuhui998.com/3_3.html)也行就能把它们给恢复。