Git Reference---Branching and Merging

NAME

git-branch - List, create, or delete branches

SYNOPSIS

git branch [--color[=<when>] | --no-color] [-r | -a][--list] [-v [--abbrev=<length> | --no-abbrev]][--column[=<options>] | --no-column][(--merged | --no-merged | --contains) [<commit>]] [<pattern>…​]git branch [--set-upstream | --track | --no-track] [-l] [-f] <branchname> [<start-point>]git branch (--set-upstream-to=<upstream> | -u <upstream>) [<branchname>]git branch --unset-upstream [<branchname>]git branch (-m | -M) [<oldbranch>] <newbranch>git branch (-d | -D) [-r] <branchname>…​git branch --edit-description [<branchname>]

DESCRIPTION

If --list is given, or if there are no non-option arguments, existing branches are listed; the current branch will be highlighted with an asterisk. Option -r causes the remote-tracking branches to be listed, and option -a shows both local and remote branches. If a <pattern> is given, it is used as a shell wildcard to restrict the output to matching branches. If multiple patterns are given, a branch is shown if it matches any of the patterns. Note that when providing a<pattern>, you must use --list; otherwise the command is interpreted as branch creation.

With --contains, shows only the branches that contain the named commit (in other words, the branches whose tip commits are descendants of the named commit). With --merged, only branches merged into the named commit (i.e. the branches whose tip commits are reachable from the named commit) will be listed. With --no-merged only branches not merged into the named commit will be listed. If the <commit> argument is missing it defaults to HEAD (i.e. the tip of the current branch).

The command’s second form creates a new branch head named <branchname> which points to the current HEAD, or <start-point> if given.

Note that this will create the new branch, but it will not switch the working tree to it; use "git checkout <newbranch>" to switch to the new branch.

When a local branch is started off a remote-tracking branch, Git sets up the branch (specifically thebranch.<name>.remote and branch.<name>.merge configuration entries) so that git pull will appropriately merge from the remote-tracking branch. This behavior may be changed via the globalbranch.autoSetupMerge configuration flag. That setting can be overridden by using the --track and --no-track options, and changed later using git branch --set-upstream-to.

With a -m or -M option, <oldbranch> will be renamed to <newbranch>. If <oldbranch> had a corresponding reflog, it is renamed to match <newbranch>, and a reflog entry is created to remember the branch renaming. If <newbranch> exists, -M must be used to force the rename to happen.

With a -d or -D option, <branchname> will be deleted. You may specify more than one branch for deletion. If the branch currently has a reflog then the reflog will also be deleted.

Use -r together with -d to delete remote-tracking branches. Note, that it only makes sense to delete remote-tracking branches if they no longer exist in the remote repository or if git fetch was configured not to fetch them again. See also the prune subcommand of git-remote[1] for a way to clean up all obsolete remote-tracking branches.

OPTIONS

-d

--delete

Delete a branch. The branch must be fully merged in its upstream branch, or in HEAD if no upstream was set with --track or --set-upstream.

-D

Shortcut for --delete --force.

-l

--create-reflog

Create the branch’s reflog. This activates recording of all changes made to the branch ref, enabling use of date based sha1 expressions such as "<branchname>@{yesterday}". Note that in non-bare repositories, reflogs are usually enabled by default by the core.logallrefupdates config option.

-f

--force

Reset <branchname> to <startpoint> if <branchname> exists already. Without -f git branchrefuses to change an existing branch. In combination with -d (or --delete), allow deleting the branch irrespective of its merged status. In combination with -m (or --move), allow renaming the branch even if the new branch name already exists.

-m

--move

Move/rename a branch and the corresponding reflog.

-M

Shortcut for --move --force.

--color[=<when>]

Color branches to highlight current, local, and remote-tracking branches. The value must be always (the default), never, or auto.

--no-color

Turn off branch colors, even when the configuration file gives the default to color output. Same as--color=never.

--column[=<options>]

--no-column

Display branch listing in columns. See configuration variable column.branch for option syntax.--column and --no-column without options are equivalent to always and never respectively.

This option is only applicable in non-verbose mode.

-r

--remotes

List or delete (if used with -d) the remote-tracking branches.

-a

--all

List both remote-tracking branches and local branches.

--list

Activate the list mode. git branch <pattern> would try to create a branch, use git branch --list <pattern> to list matching branches.

-v

-vv

--verbose

When in list mode, show sha1 and commit subject line for each head, along with relationship to upstream branch (if any). If given twice, print the name of the upstream branch, as well (see alsogit remote show <remote>).

-q

--quiet

Be more quiet when creating or deleting a branch, suppressing non-error messages.

--abbrev=<length>

Alter the sha1’s minimum display length in the output listing. The default value is 7 and can be overridden by the core.abbrev config option.

--no-abbrev

Display the full sha1s in the output listing rather than abbreviating them.

-t

--track

When creating a new branch, set up branch.<name>.remote and branch.<name>.mergeconfiguration entries to mark the start-point branch as "upstream" from the new branch. This configuration will tell git to show the relationship between the two branches in git status andgit branch -v. Furthermore, it directs git pull without arguments to pull from the upstream when the new branch is checked out.

This behavior is the default when the start point is a remote-tracking branch. Set the branch.autoSetupMerge configuration variable to false if you want git checkout and git branch to always behave as if --no-track were given. Set it to always if you want this behavior when the start-point is either a local or remote-tracking branch.

--no-track

Do not set up "upstream" configuration, even if the branch.autoSetupMerge configuration variable is true.

--set-upstream

If specified branch does not exist yet or if --force has been given, acts exactly like --track. Otherwise sets up configuration like --track would when creating the branch, except that where branch points to is not changed.

-u <upstream>

--set-upstream-to=<upstream>

Set up <branchname>'s tracking information so <upstream> is considered <branchname>'s upstream branch. If no <branchname> is specified, then it defaults to the current branch.

--unset-upstream

Remove the upstream information for <branchname>. If no branch is specified it defaults to the current branch.

--edit-description

Open an editor and edit the text to explain what the branch is for, to be used by various other commands (e.g. format-patch, request-pull, and merge (if enabled)). Multi-line explanations may be used.

--contains [<commit>]

Only list branches which contain the specified commit (HEAD if not specified). Implies --list.

--merged [<commit>]

Only list branches whose tips are reachable from the specified commit (HEAD if not specified). Implies --list.

--no-merged [<commit>]

Only list branches whose tips are not reachable from the specified commit (HEAD if not specified). Implies --list.

<branchname>

The name of the branch to create or delete. The new branch name must pass all checks defined bygit-check-ref-format[1]. Some of these checks may restrict the characters allowed in a branch name.

<start-point>

The new branch head will point to this commit. It may be given as a branch name, a commit-id, or a tag. If this option is omitted, the current HEAD will be used instead.

<oldbranch>

The name of an existing branch to rename.

<newbranch>

The new name for an existing branch. The same restrictions as for <branchname> apply.

Examples

Start development from a known tag

$ git clone git://git.kernel.org/pub/scm/.../linux-2.6 my2.6$ cd my2.6$ git branch my2.6.14 v2.6.14   (1)$ git checkout my2.6.14

1. This step and the next one could be combined into a single step with "checkout -b my2.6.14 v2.6.14".

Delete an unneeded branch

$ git clone git://git.kernel.org/.../git.git my.git$ cd my.git$ git branch -d -r origin/todo origin/html origin/man   (1)$ git branch -D test                                    (2)

1. Delete the remote-tracking branches "todo", "html" and "man". The next fetch or pull will create them again unless you configure them not to. See git-fetch[1].

2. Delete the "test" branch even if the "master" branch (or whichever branch is currently checked out) does not have all commits from the test branch.

Notes

If you are creating a branch that you want to checkout immediately, it is easier to use the git checkout command with its -b option to create a branch and check it out with a single command.

The options --contains, --merged and --no-merged serve three related but different purposes:

• --contains <commit> is used to find all branches which will need special attention if <commit> were to be rebased or amended, since those branches contain the specified <commit>.

• --merged is used to find all branches which can be safely deleted, since those branches are fully contained by HEAD.

• --no-merged is used to find branches which are candidates for merging into HEAD, since those branches are not fully contained by HEAD.

SEE ALSO

git-check-ref-format[1], git-fetch[1], git-remote[1], “Understanding history: What is a branch?” in the Git User’s Manual.

GIT

Part of the git[1] suite

NAME

git-checkout - Switch branches or restore working tree files

SYNOPSIS

git checkout [-q] [-f] [-m] [<branch>]git checkout [-q] [-f] [-m] --detach [<branch>]git checkout [-q] [-f] [-m] [--detach] <commit>git checkout [-q] [-f] [-m] [[-b|-B|--orphan] <new_branch>] [<start_point>]git checkout [-f|--ours|--theirs|-m|--conflict=<style>] [<tree-ish>] [--] <paths>…​git checkout [-p|--patch] [<tree-ish>] [--] [<paths>…​]

DESCRIPTION

Updates files in the working tree to match the version in the index or the specified tree. If no paths are given, git checkout will also update HEAD to set the specified branch as the current branch.

git checkout <branch>

To prepare for working on <branch>, switch to it by updating the index and the files in the working tree, and by pointing HEAD at the branch. Local modifications to the files in the working tree are kept, so that they can be committed to the <branch>.

If <branch> is not found but there does exist a tracking branch in exactly one remote (call it <remote>) with a matching name, treat as equivalent to

$ git checkout -b <branch> --track <remote>/<branch>

You could omit <branch>, in which case the command degenerates to "check out the current branch", which is a glorified no-op with a rather expensive side-effects to show only the tracking information, if exists, for the current branch.

git checkout -b|-B <new_branch> [<start point>]

Specifying -b causes a new branch to be created as if git-branch[1] were called and then checked out. In this case you can use the --track or --no-track options, which will be passed to git branch. As a convenience, --track without -b implies branch creation; see the description of--track below.

If -B is given, <new_branch> is created if it doesn’t exist; otherwise, it is reset. This is the transactional equivalent of

$ git branch -f <branch> [<start point>]$ git checkout <branch>

that is to say, the branch is not reset/created unless "git checkout" is successful.

git checkout --detach [<branch>]

git checkout [--detach] <commit>

Prepare to work on top of <commit>, by detaching HEAD at it (see "DETACHED HEAD" section), and updating the index and the files in the working tree. Local modifications to the files in the working tree are kept, so that the resulting working tree will be the state recorded in the commit plus the local modifications.

When the <commit> argument is a branch name, the --detach option can be used to detach HEAD at the tip of the branch (git checkout <branch> would check out that branch without detaching HEAD).

Omitting <branch> detaches HEAD at the tip of the current branch.

git checkout [-p|--patch] [<tree-ish>] [--] <pathspec>…​

When <paths> or --patch are given, git checkout does not switch branches. It updates the named paths in the working tree from the index file or from a named <tree-ish> (most often a commit). In this case, the -b and --track options are meaningless and giving either of them results in an error. The <tree-ish> argument can be used to specify a specific tree-ish (i.e. commit, tag or tree) to update the index for the given paths before updating the working tree.

git checkout with <paths> or --patch is used to restore modified or deleted paths to their original contents from the index or replace paths with the contents from a named <tree-ish> (most often a commit-ish).

The index may contain unmerged entries because of a previous failed merge. By default, if you try to check out such an entry from the index, the checkout operation will fail and nothing will be checked out. Using -f will ignore these unmerged entries. The contents from a specific side of the merge can be checked out of the index by using --ours or --theirs. With -m, changes made to the working tree file can be discarded to re-create the original conflicted merge result.

OPTIONS

-q

--quiet

Quiet, suppress feedback messages.

-f

--force

When switching branches, proceed even if the index or the working tree differs from HEAD. This is used to throw away local changes.

When checking out paths from the index, do not fail upon unmerged entries; instead, unmerged entries are ignored.

--ours

--theirs

When checking out paths from the index, check out stage #2 (ours) or #3 (theirs) for unmerged paths.

Note that during git rebase and git pull --rebase, ours and theirs may appear swapped;--ours gives the version from the branch the changes are rebased onto, while --theirs gives the version from the branch that holds your work that is being rebased.

This is because rebase is used in a workflow that treats the history at the remote as the shared canonical one, and treats the work done on the branch you are rebasing as the third-party work to be integrated, and you are temporarily assuming the role of the keeper of the canonical history during the rebase. As the keeper of the canonical history, you need to view the history from the remote as ours (i.e. "our shared canonical history"), while what you did on your side branch astheirs (i.e. "one contributor’s work on top of it").

-b <new_branch>

Create a new branch named <new_branch> and start it at <start_point>; see git-branch[1] for details.

-B <new_branch>

Creates the branch <new_branch> and start it at <start_point>; if it already exists, then reset it to <start_point>. This is equivalent to running "git branch" with "-f"; see git-branch[1] for details.

-t

--track

When creating a new branch, set up "upstream" configuration. See "--track" in git-branch[1] for details.

If no -b option is given, the name of the new branch will be derived from the remote-tracking branch, by looking at the local part of the refspec configured for the corresponding remote, and then stripping the initial part up to the "*". This would tell us to use "hack" as the local branch when branching off of "origin/hack" (or "remotes/origin/hack", or even "refs/remotes/origin/hack"). If the given name has no slash, or the above guessing results in an empty name, the guessing is aborted. You can explicitly give a name with -b in such a case.

--no-track

Do not set up "upstream" configuration, even if the branch.autoSetupMerge configuration variable is true.

-l

Create the new branch’s reflog; see git-branch[1] for details.

--detach

Rather than checking out a branch to work on it, check out a commit for inspection and discardable experiments. This is the default behavior of "git checkout <commit>" when <commit> is not a branch name. See the "DETACHED HEAD" section below for details.

--orphan <new_branch>

Create a new orphan branch, named <new_branch>, started from <start_point> and switch to it. The first commit made on this new branch will have no parents and it will be the root of a new history totally disconnected from all the other branches and commits.

The index and the working tree are adjusted as if you had previously run "git checkout <start_point>". This allows you to start a new history that records a set of paths similar to <start_point> by easily running "git commit -a" to make the root commit.

This can be useful when you want to publish the tree from a commit without exposing its full history. You might want to do this to publish an open source branch of a project whose current tree is "clean", but whose full history contains proprietary or otherwise encumbered bits of code.

If you want to start a disconnected history that records a set of paths that is totally different from the one of <start_point>, then you should clear the index and the working tree right after creating the orphan branch by running "git rm -rf ." from the top level of the working tree. Afterwards you will be ready to prepare your new files, repopulating the working tree, by copying them from elsewhere, extracting a tarball, etc.

--ignore-skip-worktree-bits

In sparse checkout mode, git checkout -- <paths> would update only entries matched by <paths> and sparse patterns in $GIT_DIR/info/sparse-checkout. This option ignores the sparse patterns and adds back any files in <paths>.

-m

--merge

When switching branches, if you have local modifications to one or more files that are different between the current branch and the branch to which you are switching, the command refuses to switch branches in order to preserve your modifications in context. However, with this option, a three-way merge between the current branch, your working tree contents, and the new branch is done, and you will be on the new branch.

When a merge conflict happens, the index entries for conflicting paths are left unmerged, and you need to resolve the conflicts and mark the resolved paths with git add (or git rm if the merge should result in deletion of the path).

When checking out paths from the index, this option lets you recreate the conflicted merge in the specified paths.

--conflict=<style>

The same as --merge option above, but changes the way the conflicting hunks are presented, overriding the merge.conflictStyle configuration variable. Possible values are "merge" (default) and "diff3" (in addition to what is shown by "merge" style, shows the original contents).

-p

--patch

Interactively select hunks in the difference between the <tree-ish> (or the index, if unspecified) and the working tree. The chosen hunks are then applied in reverse to the working tree (and if a <tree-ish> was specified, the index).

This means that you can use git checkout -p to selectively discard edits from your current working tree. See the “Interactive Mode” section of git-add[1] to learn how to operate the --patchmode.

--ignore-other-worktrees

git checkout refuses when the wanted ref is already checked out by another worktree. This option makes it check the ref out anyway. In other words, the ref can be held by more than one worktree.

<branch>

Branch to checkout; if it refers to a branch (i.e., a name that, when prepended with "refs/heads/", is a valid ref), then that branch is checked out. Otherwise, if it refers to a valid commit, your HEAD becomes "detached" and you are no longer on any branch (see below for details).

As a special case, the "@{-N}" syntax for the N-th last branch/commit checks out branches (instead of detaching). You may also specify - which is synonymous with "@{-1}".

As a further special case, you may use "A...B" as a shortcut for the merge base of A and B if there is exactly one merge base. You can leave out at most one of A and B, in which case it defaults to HEAD.

<new_branch>

Name for the new branch.

<start_point>

The name of a commit at which to start the new branch; see git-branch[1] for details. Defaults to HEAD.

<tree-ish>

Tree to checkout from (when paths are given). If not specified, the index will be used.

DETACHED HEAD

HEAD normally refers to a named branch (e.g. master). Meanwhile, each branch refers to a specific commit. Let’s look at a repo with three commits, one of them tagged, and with branch masterchecked out:

   HEAD (refers to branch 'master')    |    va---b---c  branch 'master' (refers to commit 'c')    ^    |  tag 'v2.0' (refers to commit 'b')

When a commit is created in this state, the branch is updated to refer to the new commit. Specifically, git commit creates a new commit d, whose parent is commit c, and then updates branchmaster to refer to new commit d. HEAD still refers to branch master and so indirectly now refers to commit d:

$ edit; git add; git commit       HEAD (refers to branch 'master')|va---b---c---d  branch 'master' (refers to commit 'd')    ^    |  tag 'v2.0' (refers to commit 'b')

It is sometimes useful to be able to checkout a commit that is not at the tip of any named branch, or even to create a new commit that is not referenced by a named branch. Let’s look at what happens when we checkout commit b (here we show two ways this may be done):

$ git checkout v2.0  # or$ git checkout master^^   HEAD (refers to commit 'b')    |    va---b---c---d  branch 'master' (refers to commit 'd')    ^    |  tag 'v2.0' (refers to commit 'b')

Notice that regardless of which checkout command we use, HEAD now refers directly to commit b. This is known as being in detached HEAD state. It means simply that HEAD refers to a specific commit, as opposed to referring to a named branch. Let’s see what happens when we create a commit:

$ edit; git add; git commit     HEAD (refers to commit 'e')      |      v      e     /a---b---c---d  branch 'master' (refers to commit 'd')    ^    |  tag 'v2.0' (refers to commit 'b')

There is now a new commit e, but it is referenced only by HEAD. We can of course add yet another commit in this state:

$ edit; git add; git commit HEAD (refers to commit 'f')  |  v      e---f     /a---b---c---d  branch 'master' (refers to commit 'd')    ^    |  tag 'v2.0' (refers to commit 'b')

In fact, we can perform all the normal Git operations. But, let’s look at what happens when we then checkout master:

$ git checkout master       HEAD (refers to branch 'master')      e---f     |     /          va---b---c---d  branch 'master' (refers to commit 'd')    ^    |  tag 'v2.0' (refers to commit 'b')

It is important to realize that at this point nothing refers to commit f. Eventually commit f (and by extension commit e) will be deleted by the routine Git garbage collection process, unless we create a reference before that happens. If we have not yet moved away from commit f, any of these will create a reference to it:

$ git checkout -b foo   (1)$ git branch foo        (2)$ git tag foo           (3)

1. creates a new branch foo, which refers to commit f, and then updates HEAD to refer to branchfoo. In other words, we’ll no longer be in detached HEAD state after this command.

2. similarly creates a new branch foo, which refers to commit f, but leaves HEAD detached.

3. creates a new tag foo, which refers to commit f, leaving HEAD detached.

If we have moved away from commit f, then we must first recover its object name (typically by using git reflog), and then we can create a reference to it. For example, to see the last two commits to which HEAD referred, we can use either of these commands:

$ git reflog -2 HEAD # or$ git log -g -2 HEAD

EXAMPLES

1. The following sequence checks out the master branch, reverts the Makefile to two revisions back, deletes hello.c by mistake, and gets it back from the index.

   $ git checkout master             (1)$ git checkout master~2 Makefile  (2)$ rm -f hello.c$ git checkout hello.c            (3)

   1. switch branch

   2. take a file out of another commit

   3. restore hello.c from the index

   If you want to check out all C source files out of the index, you can say

   $ git checkout -- '*.c'

   Note the quotes around *.c. The file hello.c will also be checked out, even though it is no longer in the working tree, because the file globbing is used to match entries in the index (not in the working tree by the shell).

   If you have an unfortunate branch that is named hello.c, this step would be confused as an instruction to switch to that branch. You should instead write:

   $ git checkout -- hello.c

2. After working in the wrong branch, switching to the correct branch would be done using:

   $ git checkout mytopic

   However, your "wrong" branch and correct "mytopic" branch may differ in files that you have modified locally, in which case the above checkout would fail like this:

   $ git checkout mytopicerror: You have local changes to 'frotz'; not switching branches.

   You can give the -m flag to the command, which would try a three-way merge:

   $ git checkout -m mytopicAuto-merging frotz

   After this three-way merge, the local modifications are not registered in your index file, so git diff would show you what changes you made since the tip of the new branch.

3. When a merge conflict happens during switching branches with the -m option, you would see something like this:

   $ git checkout -m mytopicAuto-merging frotzERROR: Merge conflict in frotzfatal: merge program failed

   At this point, git diff shows the changes cleanly merged as in the previous example, as well as the changes in the conflicted files. Edit and resolve the conflict and mark it resolved with git add as usual:

   $ edit frotz$ git add frotz

GIT

Part of the git[1] suite