A guide for astronauts (now, programmers using Git) about what to do when things go wrong.
> *Flight Rules* are the hard-earned body of knowledge recorded in manuals that list, step-by-step, what to do if X occurs, and why. Essentially, they are extremely detailed, scenario-specific standard operating procedures. [...]
> NASA has been capturing our missteps, disasters and solutions since the early 1960s, when Mercury-era ground teams first started gathering "lessons learned" into a compendium that now lists thousands of problematic situations, from engine failure to busted hatch handles to computer glitches, and their solutions.
— Chris Hadfield, *An Astronaut's Guide to Life*.
#### Conventions for this document
For clarity's sake all examples in this document use a customized bash prompt in order to indicate the current branch and whether or not there are staged changes. The branch is enclosed in parentheses, and a `*` next to the branch name indicates staged changes.
All commands should work for at least git version 2.13.0. See the [git website](https://www.git-scm.com/) to update your local git version.
[](https://gitter.im/k88hudson/git-flight-rules?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)
<!-- START doctoc generated TOC please keep comment here to allow auto update -->
<!-- DON'T EDIT THIS SECTION, INSTEAD RE-RUN doctoc TO UPDATE -->
**Table of Contents** *generated with [DocToc](https://github.com/thlorenz/doctoc)*
- [Repositories](#repositories)
- [I want to start a local repository](#i-want-to-start-a-local-repository)
- [I want to clone a remote repository](#i-want-to-clone-a-remote-repository)
- [I set the wrong remote repository](#i-set-the-wrong-remote-repository)
- [I want to add code to someone else's repository](#i-want-to-add-code-to-someone-elses-repository)
- [Suggesting code via pull requests](#suggesting-code-via-pull-requests)
- [I need to update my fork with latest updates from the original repository](#i-need-to-update-my-fork-with-latest-updates-from-the-original-repository)
- [Editing Commits](#editing-commits)
- [What did I just commit?](#what-did-i-just-commit)
- [I wrote the wrong thing in a commit message](#i-wrote-the-wrong-thing-in-a-commit-message)
- [I committed with the wrong name and email configured](#i-committed-with-the-wrong-name-and-email-configured)
- [I want to remove a file from the previous commit](#i-want-to-remove-a-file-from-the-previous-commit)
- [I want to delete or remove my last commit](#i-want-to-delete-or-remove-my-last-commit)
- [I tried to push my amended commit to a remote, but I got an error message](#i-tried-to-push-my-amended-commit-to-a-remote-but-i-got-an-error-message)
- [I accidentally did a hard reset, and I want my changes back](#i-accidentally-did-a-hard-reset-and-i-want-my-changes-back)
- [I accidentally committed and pushed a merge](#i-accidentally-committed-and-pushed-a-merge)
- [I accidentally committed and pushed files containing sensitive data](#i-accidentally-committed-and-pushed-files-containing-sensitive-data)
- [I want to remove a large file from ever existing in repo history](#i-want-to-remove-a-large-file-from-ever-existing-in-repo-history)
- [Recommended Technique: Use third-party bfg](#recommended-technique-use-third-party-bfg)
- [Built-in Technique: Use git-filter-branch](#built-in-technique-use-git-filter-branch)
- [Final Step: Pushing your changed repo history](#final-step-pushing-your-changed-repo-history)
- [I need to change the content of a commit which is not my last](#i-need-to-change-the-content-of-a-commit-which-is-not-my-last)
- [Staging](#staging)
- [I want to stage all tracked files and leave untracked files](#i-want-to-stage-all-tracked-files-and-leave-untracked-files)
- [To stage part of tracked files](#to-stage-part-of-tracked-files)
- [I need to add staged changes to the previous commit](#i-need-to-add-staged-changes-to-the-previous-commit)
- [I want to stage part of a new file, but not the whole file](#i-want-to-stage-part-of-a-new-file-but-not-the-whole-file)
- [I want to add changes in one file to two different commits](#i-want-to-add-changes-in-one-file-to-two-different-commits)
- [I staged too many edits, and I want to break them out into a separate commit](#i-staged-too-many-edits-and-i-want-to-break-them-out-into-a-separate-commit)
- [I want to stage my unstaged edits, and unstage my staged edits](#i-want-to-stage-my-unstaged-edits-and-unstage-my-staged-edits)
- [Unstaged Edits](#unstaged-edits)
- [I want to move my unstaged edits to a new branch](#i-want-to-move-my-unstaged-edits-to-a-new-branch)
- [I want to move my unstaged edits to a different, existing branch](#i-want-to-move-my-unstaged-edits-to-a-different-existing-branch)
- [I want to discard my local uncommitted changes (staged and unstaged)](#i-want-to-discard-my-local-uncommitted-changes-staged-and-unstaged)
- [I want to discard specific unstaged changes](#i-want-to-discard-specific-unstaged-changes)
- [I want to discard specific unstaged files](#i-want-to-discard-specific-unstaged-files)
- [I want to discard only my unstaged local changes](#i-want-to-discard-only-my-unstaged-local-changes)
- [I want to discard all of my untracked files](#i-want-to-discard-all-of-my-untracked-files)
- [I want to unstage a specific staged file](#i-want-to-unstage-a-specific-staged-file)
- [Branches](#branches)
- [I want to list all branches](#i-want-to-list-all-branches)
- [Create a branch from a commit](#create-a-branch-from-a-commit)
- [I pulled from/into the wrong branch](#i-pulled-frominto-the-wrong-branch)
- [I want to discard local commits so my branch is the same as one on the server](#i-want-to-discard-local-commits-so-my-branch-is-the-same-as-one-on-the-server)
- [I committed to master instead of a new branch](#i-committed-to-master-instead-of-a-new-branch)
- [I want to keep the whole file from another ref-ish](#i-want-to-keep-the-whole-file-from-another-ref-ish)
- [I made several commits on a single branch that should be on different branches](#i-made-several-commits-on-a-single-branch-that-should-be-on-different-branches)
- [I want to delete local branches that were deleted upstream](#i-want-to-delete-local-branches-that-were-deleted-upstream)
- [I accidentally deleted my branch](#i-accidentally-deleted-my-branch)
- [I want to delete a branch](#i-want-to-delete-a-branch)
- [I want to delete multiple branches](#i-want-to-delete-multiple-branches)
- [I want to rename a branch](#i-want-to-rename-a-branch)
- [I want to checkout to a remote branch that someone else is working on](#i-want-to-checkout-to-a-remote-branch-that-someone-else-is-working-on)
- [I want to create a new remote branch from current local one](#i-want-to-create-a-new-remote-branch-from-current-local-one)
- [I want to set a remote branch as the upstream for a local branch](#i-want-to-set-a-remote-branch-as-the-upstream-for-a-local-branch)
- [I want to set my HEAD to track the default remote branch](#i-want-to-set-my-head-to-track-the-default-remote-branch)
- [I made changes on the wrong branch](#i-made-changes-on-the-wrong-branch)
- [Rebasing and Merging](#rebasing-and-merging)
- [I want to undo rebase/merge](#i-want-to-undo-rebasemerge)
- [I rebased, but I don't want to force push](#i-rebased-but-i-dont-want-to-force-push)
- [I need to combine commits](#i-need-to-combine-commits)
- [Safe merging strategy](#safe-merging-strategy)
- [I need to merge a branch into a single commit](#i-need-to-merge-a-branch-into-a-single-commit)
- [I want to combine only unpushed commits](#i-want-to-combine-only-unpushed-commits)
- [I need to abort the merge](#i-need-to-abort-the-merge)
- [I need to update the parent commit of my branch](#i-need-to-update-the-parent-commit-of-my-branch)
- [Check if all commits on a branch are merged](#check-if-all-commits-on-a-branch-are-merged)
- [Possible issues with interactive rebases](#possible-issues-with-interactive-rebases)
- [The rebase editing screen says 'noop'](#the-rebase-editing-screen-says-noop)
- [There were conflicts](#there-were-conflicts)
- [Stash](#stash)
- [Stash all edits](#stash-all-edits)
- [Stash specific files](#stash-specific-files)
- [Stash with message](#stash-with-message)
- [Apply a specific stash from list](#apply-a-specific-stash-from-list)
- [Stash while keeping unstaged edits](#stash-while-keeping-unstaged-edits)
- [Finding](#finding)
- [I want to find a string in any commit](#i-want-to-find-a-string-in-any-commit)
- [I want to find by author/committer](#i-want-to-find-by-authorcommitter)
- [I want to list commits containing specific files](#i-want-to-list-commits-containing-specific-files)
- [I want to view the commit history for a specific function](#i-want-to-view-the-commit-history-for-a-specific-function)
- [Find a tag where a commit is referenced](#find-a-tag-where-a-commit-is-referenced)
- [Submodules](#submodules)
- [Clone all submodules](#clone-all-submodules)
- [Remove a submodule](#remove-a-submodule)
- [Miscellaneous Objects](#miscellaneous-objects)
- [Copy a folder or file from one branch to another](#copy-a-folder-or-file-from-one-branch-to-another)
- [Restore a deleted file](#restore-a-deleted-file)
- [Delete tag](#delete-tag)
- [Recover a deleted tag](#recover-a-deleted-tag)
- [Deleted Patch](#deleted-patch)
- [Exporting a repository as a Zip file](#exporting-a-repository-as-a-zip-file)
- [Push a branch and a tag that have the same name](#push-a-branch-and-a-tag-that-have-the-same-name)
- [Tracking Files](#tracking-files)
- [I want to change a file name's capitalization, without changing the contents of the file](#i-want-to-change-a-file-names-capitalization-without-changing-the-contents-of-the-file)
- [I want to overwrite local files when doing a git pull](#i-want-to-overwrite-local-files-when-doing-a-git-pull)
- [I want to remove a file from Git but keep the file](#i-want-to-remove-a-file-from-git-but-keep-the-file)
- [I want to revert a file to a specific revision](#i-want-to-revert-a-file-to-a-specific-revision)
- [I want to list changes of a specific file between commits or branches](#i-want-to-list-changes-of-a-specific-file-between-commits-or-branches)
- [I want Git to ignore changes to a specific file](#i-want-git-to-ignore-changes-to-a-specific-file)
- [Debugging with Git](#debugging-with-git)
- [Configuration](#configuration)
- [I want to add aliases for some Git commands](#i-want-to-add-aliases-for-some-git-commands)
- [I want to add an empty directory to my repository](#i-want-to-add-an-empty-directory-to-my-repository)
- [I want to cache a username and password for a repository](#i-want-to-cache-a-username-and-password-for-a-repository)
- [I want to make Git ignore permissions and filemode changes](#i-want-to-make-git-ignore-permissions-and-filemode-changes)
- [I want to set a global user](#i-want-to-set-a-global-user)
- [I want to add command line coloring for Git](#i-want-to-add-command-line-coloring-for-git)
- [I've no idea what I did wrong](#ive-no-idea-what-i-did-wrong)
- [Git Shortcuts](#git-shortcuts)
- [Git Bash](#git-bash)
- [PowerShell on Windows](#powershell-on-windows)
- [Other Resources](#other-resources)
- [Books](#books)
- [Tutorials](#tutorials)
- [Scripts and Tools](#scripts-and-tools)
- [GUI Clients](#gui-clients)
<!-- END doctoc generated TOC please keep comment here to allow auto update -->
Even if you delete a large or unwanted file in a recent commit, it still exists in git history, in your repo's `.git` folder, and will make `git clone` download unneeded files.
The actions in this part of the guide will require a force push, and rewrite large sections of repo history, so if you are working with remote collaborators, check first that any local work of theirs is pushed.
<!--There are two options for rewriting history, the built-in `git-filter-branch` or [`bfg-repo-cleaner`](https://rtyley.github.io/bfg-repo-cleaner/). `bfg` is significantly cleaner and more performant, but it is a third-party download and requires java. We will describe both alternatives. The final step is to force push your changes, which requires special consideration on top of a regular force push, given that a great deal of repo history will have been permanently changed.-->
<!--Using bfg-repo-cleaner requires java. Download the bfg jar from the link [here](https://rtyley.github.io/bfg-repo-cleaner/). Our examples will use `bfg.jar`, but your download may have a version number, e.g. `bfg-1.13.0.jar`.-->
<!--Consider you created some (e.g. three) commits and later realize you missed doing something that belongs contextually into the first of those commits.
This bothers you, because if you'd create a new commit containing those changes, you'd have a clean code base, but your commits weren't atomic (i.e. changes that belonged to each other weren't in the same commit). In such a situation you may want to change the commit where these changes belong to, include them and have the following commits unaltered. In such a case, `git rebase` might save you.-->
<!--This tells rebase that you want to edit your third last commit and keep the other two unaltered. Then you'll save (and close) the editor. Git will then start to rebase. It stops on the commit you want to alter, giving you the chance to edit that commit. Now you can apply the changes which you missed applying when you initially committed that commit. You do so by editing and staging them. Afterwards you'll run-->
Git は危険な操作の前に HEAD が指すものを変数 `ORIG_HEAD` に保存しているので、ブランチをリベースないしマージの前の状態に差し戻すのは簡単です。
<!--You may have merged or rebased your current branch with a wrong branch, or you can't figure it out or finish the rebase/merge process. Git saves the original HEAD pointer in a variable called ORIG_HEAD before doing dangerous operations, so it is simple to recover your branch at the state before the rebase/merge.-->
<!--Unfortunately, you have to force push, if you want those changes to be reflected on the remote branch. This is because you have changed the history. The remote branch won't accept changes unless you force push. This is one of the main reasons many people use a merge workflow, instead of a rebasing workflow - large teams can get into trouble with developers force pushing. Use this with caution. A safer way to use rebase is not to reflect your changes on the remote branch at all, and instead to do the following:-->
<!--Let's suppose you are working in a branch that is/will become a pull-request against `master`. In the simplest case when all you want to do is to combine*all* commits into a single one and you don't care about commit timestamps, you can reset and recommit. Make sure the master branch is up to date and all your changes committed, then:-->
<!--If you aren't working against another branch you'll have to rebase relative to your `HEAD`. If you want to squash the last 2 commits, for example, you'll have to rebase against `HEAD~2`. For the last 3, `HEAD~3`, etc.-->
<!--For example, if you want to**leave the oldest (first) commit alone and combine all the following commits with the second oldest**, you should edit the letter next to each commit except the first and the second to say `f`:-->
<!--If you want to combine these commits**and rename the commit**, you should additionally add an `r` next to the second commit or simply use `s` instead of `f`:-->
`--no-commit` performs the merge but pretends the merge failed and does not autocommit, giving the user a chance to inspect and further tweak the merge result before committing. `no-ff` maintains evidence that a feature branch once existed, keeping project history consistent.
<!--Sometimes you have several work in progress commits that you want to combine before you push them upstream. You don't want to accidentally combine any commits that have already been pushed upstream because someone else may have already made commits that reference them.-->
<!--This will do an interactive rebase that lists only the commits that you haven't already pushed, so it will be safe to reorder/fix/squash anything in the list.-->
<!--Sometimes the merge can produce problems in certain files, in those cases we can use the option `abort` to abort the current conflict resolution process, and try to reconstruct the pre-merge state.-->
今 feature-1 ブランチにコミットしたとすると、feature-2 ブランチの親コミットはもはや正確ではありません(feature-1 から分岐したので、親コミットは feature-1 ブランチの head であるべきです。)
こういうときは `git rebase --onto` で修正できます。
<!--Say I have a master branch, a feature-1 branch branched from master, and a feature-2 branch branched off of feature-1. If I make a commit to feature-1, then the parent commit of feature-2 is no longer accurate (it should be the head of feature-1, since we branched off of it). We can fix this with `git rebase --onto`.-->
<!--This helps in sticky scenarios where you might have a feature built on another feature that hasn't been merged yet, and a bugfix on the feature-1 branch needs to be reflected in your feature-2 branch.-->
<!--This will tell you if any commits are in one but not the other, and will give you a list of any nonshared between the branches. Another option is to do this:-->
<!--You will need to resolve the differences between the code that was added in your new commit (in the example, everything from the middle line to `new-commit`) and your `HEAD`.-->
コンフリクトを全て解消し、コードのテストが済んだら、`git add ` で編集内容をステージし、`git rebase --continue` でリベースを再開します。
<!--After you have resolved all conflicts and tested your code, `git add` the files you have changed, and then continue the rebase with `git rebase --continue`-->
コンフリクトを解消した結果、ワーキングツリーがコミット前と全く同じ状態になった場合は、代わりに `git rebase --skip` を実行します。
<!--If after resolving all the conflicts you end up with an identical tree to what it was before the commit, you need to `git rebase --skip` instead.-->
Using `git reset` it is then possible to change master back to the commit it was before. This provides a safety net in case history was accidentally changed.
Once you're comfortable with what the above commands are doing, you might want to create some shortcuts for Git Bash. This allows you to work a lot faster by doing complex tasks in really short commands.
```sh
alias sq=squash
function squash() {
git rebase -i HEAD~$1
}
```
Copy those commands to your .bashrc or .bash_profile.
### PowerShell on Windows
If you are using PowerShell on Windows, you can also set up aliases and functions. Add these commands to your profile, whose path is defined in the `$profile` variable. Learn more at the [About Profiles](https://docs.microsoft.com/en-us/powershell/module/microsoft.powershell.core/about/about_profiles) page on the Microsoft documentation site.
```powershell
Set-Alias sq Squash-Commits
function Squash-Commits {
git rebase -i HEAD~$1
}
```
# Other Resources
## Books
* [Learn Enough Git to Be Dangerous](https://www.learnenough.com/git-tutorial) - A book by Michael Hartl covering Git from basics
* [Pro Git](https://git-scm.com/book/en/v2) - Scott Chacon and Ben Straub's excellent book about Git
* [Git Internals](https://github.com/pluralsight/git-internals-pdf) - Scott Chacon's other excellent book about Git
* [19 Git Tips For Everyday Use](https://www.alexkras.com/19-git-tips-for-everyday-use) - A list of useful Git one liners
* [Atlassian's Git tutorial](https://www.atlassian.com/git/tutorials) Get Git right with tutorials from beginner to advanced.
* [Learn Git branching](https://learngitbranching.js.org/) An interactive web based branching/merging/rebasing tutorial
* [Getting solid at Git rebase vs. merge](https://medium.com/@porteneuve/getting-solid-at-git-rebase-vs-merge-4fa1a48c53aa)
* [Git Commands and Best Practices Cheat Sheet](https://zeroturnaround.com/rebellabs/git-commands-and-best-practices-cheat-sheet) - A Git cheat sheet in a blog post with more explanations
* [Git from the inside out](https://codewords.recurse.com/issues/two/git-from-the-inside-out) - A tutorial that dives into Git's internals
* [git-workflow](https://github.com/asmeurer/git-workflow) - [Aaron Meurer](https://github.com/asmeurer)'s howto on using Git to contribute to open source repositories
* [GitHub as a workflow](https://hugogiraudel.com/2015/08/13/github-as-a-workflow/) - An interesting take on using GitHub as a workflow, particularly with empty PRs
* [Githug](https://github.com/Gazler/githug) - A game to learn more common Git workflows
* [learnGitBranching](https://github.com/pcottle/learnGitBranching) - An interactive git visualization to challenge and educate!
## Scripts and Tools
* [firstaidgit.io](http://firstaidgit.io/) A searchable selection of the most frequently asked Git questions
* [git-extra-commands](https://github.com/unixorn/git-extra-commands) - a collection of useful extra Git scripts
* [git-extras](https://github.com/tj/git-extras) - GIT utilities -- repo summary, repl, changelog population, author commit percentages and more
* [git-fire](https://github.com/qw3rtman/git-fire) - git-fire is a Git plugin that helps in the event of an emergency by adding all current files, committing, and pushing to a new branch (to prevent merge conflicts).
* [git-tips](https://github.com/git-tips/tips) - Small Git tips
* [GitKraken](https://www.gitkraken.com/) - The downright luxurious Git client,for Windows, Mac & Linux
* [git-cola](https://git-cola.github.io/) - another Git client for Windows and OS X
* [GitUp](https://github.com/git-up/GitUp) - A newish GUI that has some very opinionated ways of dealing with Git's complications
* [gitx-dev](https://rowanj.github.io/gitx/) - another graphical Git client for OS X
* [Sourcetree](https://www.sourcetreeapp.com/) - Simplicity meets power in a beautiful and free Git GUI. For Windows and Mac.
* [Tower](https://www.git-tower.com/) - graphical Git client for OS X (paid)
* [tig](https://jonas.github.io/tig/) - terminal text-mode interface for Git
* [Magit](https://magit.vc/) - Interface to Git implemented as an Emacs package.
* [GitExtensions](https://github.com/gitextensions/gitextensions) - a shell extension, a Visual Studio 2010-2015 plugin and a standalone Git repository tool.
* [Fork](https://git-fork.com/) - a fast and friendly Git client for Mac (beta)
* [gmaster](https://gmaster.io/) - a Git client for Windows that has 3-way merge, analyze refactors, semantic diff and merge (beta)
* [gitk](https://git-scm.com/docs/gitk) - a Git client for linux to allow simple view of repo state.
* [SublimeMerge](https://www.sublimemerge.com/) - Blazing fast, extensible client that provides 3-way merges, powerful search and syntax highlighting, in active development.