Provided by:
git-core_1.5.6.3-1.1ubuntu2_i386 
NAME
git-checkout - Checkout a branch or paths to the working tree
SYNOPSIS
git-checkout [-q] [-f] [[--track | --no-track] -b <new_branch> [-l]] [-m] [<branch>]
git-checkout [<tree-ish>] <paths>...
DESCRIPTION
When <paths> are not given, this command switches branches by updating
the index and working tree to reflect the specified branch, <branch>,
and updating HEAD to be <branch> or, if specified, <new_branch>. Using
-b will cause <new_branch> to be created; in this case you can use the
--track or --no-track options, which will be passed to git branch.
When <paths> are given, this command does not switch branches. It
updates the named paths in the working tree from the index file (i.e.
it runs git-checkout-index -f -u), or from a named commit. In this
case, the -f and -b options are meaningless and giving either of them
results in an error. <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.
OPTIONS
-q
Quiet, suppress feedback messages.
-f
Proceed even if the index or the working tree differs from HEAD.
This is used to throw away local changes.
-b
Create a new branch named <new_branch> and start it at <branch>.
The new branch name must pass all checks defined by git-check-ref-
format(1). Some of these checks may restrict the characters allowed
in a branch name.
-t, --track
When creating a new branch, set up configuration so that git-pull
will automatically retrieve data from the start point, which must
be a branch. Use this if you always pull from the same upstream
branch into the new branch, and if you don´t want to use "git pull
<repository> <refspec>" explicitly. This behavior is the default
when the start point is a remote 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 branch.
--no-track
Ignore the branch.autosetupmerge configuration variable.
-l
Create the new 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}".
-m
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).
<new_branch>
Name for the new branch.
<branch>
Branch to checkout; may be any object ID that resolves to a commit.
Defaults to HEAD.
When this parameter names a non-branch (but still a valid commit
object), your HEAD becomes detached.
DETACHED HEAD
It is sometimes useful to be able to checkout a commit that is not at
the tip of one of your branches. The most obvious example is to check
out the commit at a tagged official release point, like this:
$ git checkout v2.6.18
Earlier versions of git did not allow this and asked you to create a
temporary branch using -b option, but starting from version 1.5.0, the
above command detaches your HEAD from the current branch and directly
point at the commit named by the tag (v2.6.18 in the above example).
You can use usual git commands while in this state. You can use
git-reset --hard $othercommit to further move around, for example. You
can make changes and create a new commit on top of a detached HEAD. You
can even create a merge by using git merge $othercommit.
The state you are in while your HEAD is detached is not recorded by any
branch (which is natural --- you are not on any branch). What this
means is that you can discard your temporary commits and merges by
switching back to an existing branch (e.g. git checkout master), and a
later git prune or git gc would garbage-collect them. If you did this
by mistake, you can ask the reflog for HEAD where you were, e.g.
$ 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 âfB(1)âfR
$ git checkout master~2 Makefile âfB(2)âfR
$ rm -f hello.c
$ git checkout hello.c âfB(3)âfR
â
âfB1. âfRswitch branch â
âfB2. âfRtake out a file out of other commit â
âfB3. âfRrestore hello.c from HEAD of current branch
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
â
.RE
2. After working in a 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 locally modified, in which case,
the above checkout would fail like this:
$ git checkout mytopic
fatal: Entry ´frotz´ not uptodate. Cannot merge.
You can give the -m flag to the command, which would try a
three-way merge:
$ git checkout -m mytopic
Auto-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 mytopic
Auto-merging frotz
merge: warning: conflicts during merge
ERROR: Merge conflict in frotz
fatal: 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
AUTHOR
Written by Linus Torvalds <torvalds@osdl.org>
DOCUMENTATION
Documentation by Junio C Hamano and the git-list <git@vger.kernel.org>.
GIT
Part of the git(1) suite