SYNOPSIS
--------
[verse]
-'git checkout' [-q] [-f] [-t | --track | --no-track] [-b <new_branch> [-l]] [-m] [<branch>]
+'git checkout' [-q] [-f] [-m] [<branch>]
+'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' --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.
-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`.
-
-As a convenience, --track will default to creating a branch whose
-name is constructed from the specified branch name by stripping
-the first namespace level.
-
-When <paths> are given, this command 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.
-
-The index may contain unmerged entries after a failed merge. By
-default, if you try to check out such an entry from the index, the
+'git checkout' [<branch>]::
+'git checkout' -b|-B <new_branch> [<start point>]::
+
+ This form switches branches by updating the index, working
+ tree, and HEAD to reflect the specified branch.
++
+If `-b` is given, a new branch is created as if linkgit: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' [--patch] [<tree-ish>] [--] <pathspec>...::
+
+ When <paths> or `--patch` are given, 'git checkout' *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.
++
+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
+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 recreate the original conflicted merge result.
+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.
-b::
Create a new branch named <new_branch> and start it at
- <branch>. The new branch name must pass all checks defined
- by linkgit:git-check-ref-format[1]. Some of these checks
- may restrict the characters allowed in a branch name.
+ <start_point>; see linkgit:git-branch[1] for details.
+
+-B::
+ 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
+ linkgit:git-branch[1] for details.
-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.
+ When creating a new branch, set up "upstream" configuration. See
+ "--track" in linkgit:git-branch[1] for details.
+
If no '-b' option is given, the name of the new branch will be
derived from the remote branch. If "remotes/" or "refs/remotes/"
branch.autosetupmerge configuration variable is true.
-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}".
+ Create the new branch's reflog; see linkgit:git-branch[1] for
+ details.
+
+--orphan::
+ 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.
-m::
--merge::
"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.
+
+<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
+checks out the branch (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
+ linkgit: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.
-<branch>::
- Branch to checkout (when no paths are given); 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'.
-+
-As a special case, the `"@\{-N\}"` syntax for the N-th last branch
-checks out the branch (instead of detaching). You may also specify
-`-` which is synonymous with `"@\{-1\}"`.
Detached HEAD
+
------------
$ git checkout mytopic
-fatal: Entry 'frotz' not uptodate. Cannot merge.
+error: You have local changes to 'frotz'; not switching branches.
------------
+
You can give the `-m` flag to the command, which would try a