Documentation / git-checkout.txton commit apply --whitespace=warn/error: diagnose blank at EOF (77b15bb)
   1git-checkout(1)
   2===============
   3
   4NAME
   5----
   6git-checkout - Checkout a branch or paths to the working tree
   7
   8SYNOPSIS
   9--------
  10[verse]
  11'git checkout' [-q] [-f] [[--track | --no-track] -b <new_branch> [-l]] [-m] [<branch>]
  12'git checkout' [<tree-ish>] [--] <paths>...
  13
  14DESCRIPTION
  15-----------
  16
  17When <paths> are not given, this command switches branches by
  18updating the index and working tree to reflect the specified
  19branch, <branch>, and updating HEAD to be <branch> or, if
  20specified, <new_branch>.  Using -b will cause <new_branch> to
  21be created; in this case you can use the --track or --no-track
  22options, which will be passed to `git branch`.
  23
  24When <paths> are given, this command does *not* switch
  25branches.  It updates the named paths in the working tree from
  26the index file (i.e. it runs `git checkout-index -f -u`), or
  27from a named commit.  In
  28this case, the `-f` and `-b` options are meaningless and giving
  29either of them results in an error.  <tree-ish> argument can be
  30used to specify a specific tree-ish (i.e. commit, tag or tree)
  31to update the index for the given paths before updating the
  32working tree.
  33
  34
  35OPTIONS
  36-------
  37-q::
  38        Quiet, suppress feedback messages.
  39
  40-f::
  41        Proceed even if the index or the working tree differs
  42        from HEAD.  This is used to throw away local changes.
  43
  44-b::
  45        Create a new branch named <new_branch> and start it at
  46        <branch>.  The new branch name must pass all checks defined
  47        by linkgit:git-check-ref-format[1].  Some of these checks
  48        may restrict the characters allowed in a branch name.
  49
  50-t::
  51--track::
  52        When creating a new branch, set up configuration so that 'git-pull'
  53        will automatically retrieve data from the start point, which must be
  54        a branch. Use this if you always pull from the same upstream branch
  55        into the new branch, and if you don't want to use "git pull
  56        <repository> <refspec>" explicitly. This behavior is the default
  57        when the start point is a remote branch. Set the
  58        branch.autosetupmerge configuration variable to `false` if you want
  59        'git-checkout' and 'git-branch' to always behave as if '--no-track' were
  60        given. Set it to `always` if you want this behavior when the
  61        start-point is either a local or remote branch.
  62
  63--no-track::
  64        Ignore the branch.autosetupmerge configuration variable.
  65
  66-l::
  67        Create the new branch's reflog.  This activates recording of
  68        all changes made to the branch ref, enabling use of date
  69        based sha1 expressions such as "<branchname>@\{yesterday}".
  70
  71-m::
  72        If you have local modifications to one or more files that
  73        are different between the current branch and the branch to
  74        which you are switching, the command refuses to switch
  75        branches in order to preserve your modifications in context.
  76        However, with this option, a three-way merge between the current
  77        branch, your working tree contents, and the new branch
  78        is done, and you will be on the new branch.
  79+
  80When a merge conflict happens, the index entries for conflicting
  81paths are left unmerged, and you need to resolve the conflicts
  82and mark the resolved paths with `git add` (or `git rm` if the merge
  83should result in deletion of the path).
  84
  85<new_branch>::
  86        Name for the new branch.
  87
  88<tree-ish>::
  89        Tree to checkout from (when paths are given). If not specified,
  90        the index will be used.
  91
  92<branch>::
  93        Branch to checkout (when no paths are given); may be any object
  94        ID that resolves to a commit.  Defaults to HEAD.
  95+
  96When this parameter names a non-branch (but still a valid commit object),
  97your HEAD becomes 'detached'.
  98
  99
 100Detached HEAD
 101-------------
 102
 103It is sometimes useful to be able to 'checkout' a commit that is
 104not at the tip of one of your branches.  The most obvious
 105example is to check out the commit at a tagged official release
 106point, like this:
 107
 108------------
 109$ git checkout v2.6.18
 110------------
 111
 112Earlier versions of git did not allow this and asked you to
 113create a temporary branch using `-b` option, but starting from
 114version 1.5.0, the above command 'detaches' your HEAD from the
 115current branch and directly point at the commit named by the tag
 116(`v2.6.18` in the above example).
 117
 118You can use usual git commands while in this state.  You can use
 119`git reset --hard $othercommit` to further move around, for
 120example.  You can make changes and create a new commit on top of
 121a detached HEAD.  You can even create a merge by using `git
 122merge $othercommit`.
 123
 124The state you are in while your HEAD is detached is not recorded
 125by any branch (which is natural --- you are not on any branch).
 126What this means is that you can discard your temporary commits
 127and merges by switching back to an existing branch (e.g. `git
 128checkout master`), and a later `git prune` or `git gc` would
 129garbage-collect them.  If you did this by mistake, you can ask
 130the reflog for HEAD where you were, e.g.
 131
 132------------
 133$ git log -g -2 HEAD
 134------------
 135
 136
 137EXAMPLES
 138--------
 139
 140. The following sequence checks out the `master` branch, reverts
 141the `Makefile` to two revisions back, deletes hello.c by
 142mistake, and gets it back from the index.
 143+
 144------------
 145$ git checkout master             <1>
 146$ git checkout master~2 Makefile  <2>
 147$ rm -f hello.c
 148$ git checkout hello.c            <3>
 149------------
 150+
 151<1> switch branch
 152<2> take a file out of another commit
 153<3> restore hello.c from the index
 154+
 155If you have an unfortunate branch that is named `hello.c`, this
 156step would be confused as an instruction to switch to that branch.
 157You should instead write:
 158+
 159------------
 160$ git checkout -- hello.c
 161------------
 162
 163. After working in a wrong branch, switching to the correct
 164branch would be done using:
 165+
 166------------
 167$ git checkout mytopic
 168------------
 169+
 170However, your "wrong" branch and correct "mytopic" branch may
 171differ in files that you have locally modified, in which case,
 172the above checkout would fail like this:
 173+
 174------------
 175$ git checkout mytopic
 176fatal: Entry 'frotz' not uptodate. Cannot merge.
 177------------
 178+
 179You can give the `-m` flag to the command, which would try a
 180three-way merge:
 181+
 182------------
 183$ git checkout -m mytopic
 184Auto-merging frotz
 185------------
 186+
 187After this three-way merge, the local modifications are _not_
 188registered in your index file, so `git diff` would show you what
 189changes you made since the tip of the new branch.
 190
 191. When a merge conflict happens during switching branches with
 192the `-m` option, you would see something like this:
 193+
 194------------
 195$ git checkout -m mytopic
 196Auto-merging frotz
 197merge: warning: conflicts during merge
 198ERROR: Merge conflict in frotz
 199fatal: merge program failed
 200------------
 201+
 202At this point, `git diff` shows the changes cleanly merged as in
 203the previous example, as well as the changes in the conflicted
 204files.  Edit and resolve the conflict and mark it resolved with
 205`git add` as usual:
 206+
 207------------
 208$ edit frotz
 209$ git add frotz
 210------------
 211
 212
 213Author
 214------
 215Written by Linus Torvalds <torvalds@osdl.org>
 216
 217Documentation
 218--------------
 219Documentation by Junio C Hamano and the git-list <git@vger.kernel.org>.
 220
 221GIT
 222---
 223Part of the linkgit:git[1] suite