Merge branch 'nd/checkout-m-doc-update'
[git/git.git] / Documentation / git-checkout.txt
1 git-checkout(1)
2 ===============
3
4 NAME
5 ----
6 git-checkout - Switch branches or restore working tree files
7
8 SYNOPSIS
9 --------
10 [verse]
11 'git checkout' [-q] [-f] [-m] [<branch>]
12 'git checkout' [-q] [-f] [-m] --detach [<branch>]
13 'git checkout' [-q] [-f] [-m] [--detach] <commit>
14 'git checkout' [-q] [-f] [-m] [[-b|-B|--orphan] <new_branch>] [<start_point>]
15 'git checkout' [-f|--ours|--theirs|-m|--conflict=<style>] [<tree-ish>] [--] <paths>...
16 'git checkout' [<tree-ish>] [--] <pathspec>...
17 'git checkout' (-p|--patch) [<tree-ish>] [--] [<paths>...]
18
19 DESCRIPTION
20 -----------
21 Updates files in the working tree to match the version in the index
22 or the specified tree. If no paths are given, 'git checkout' will
23 also update `HEAD` to set the specified branch as the current
24 branch.
25
26 'git checkout' <branch>::
27 To prepare for working on <branch>, switch to it by updating
28 the index and the files in the working tree, and by pointing
29 HEAD at the branch. Local modifications to the files in the
30 working tree are kept, so that they can be committed to the
31 <branch>.
32 +
33 If <branch> is not found but there does exist a tracking branch in
34 exactly one remote (call it <remote>) with a matching name, treat as
35 equivalent to
36 +
37 ------------
38 $ git checkout -b <branch> --track <remote>/<branch>
39 ------------
40 +
41 If the branch exists in multiple remotes and one of them is named by
42 the `checkout.defaultRemote` configuration variable, we'll use that
43 one for the purposes of disambiguation, even if the `<branch>` isn't
44 unique across all remotes. Set it to
45 e.g. `checkout.defaultRemote=origin` to always checkout remote
46 branches from there if `<branch>` is ambiguous but exists on the
47 'origin' remote. See also `checkout.defaultRemote` in
48 linkgit:git-config[1].
49 +
50 You could omit <branch>, in which case the command degenerates to
51 "check out the current branch", which is a glorified no-op with
52 rather expensive side-effects to show only the tracking information,
53 if exists, for the current branch.
54
55 'git checkout' -b|-B <new_branch> [<start point>]::
56
57 Specifying `-b` causes a new branch to be created as if
58 linkgit:git-branch[1] were called and then checked out. In
59 this case you can use the `--track` or `--no-track` options,
60 which will be passed to 'git branch'. As a convenience,
61 `--track` without `-b` implies branch creation; see the
62 description of `--track` below.
63 +
64 If `-B` is given, <new_branch> is created if it doesn't exist; otherwise, it
65 is reset. This is the transactional equivalent of
66 +
67 ------------
68 $ git branch -f <branch> [<start point>]
69 $ git checkout <branch>
70 ------------
71 +
72 that is to say, the branch is not reset/created unless "git checkout" is
73 successful.
74
75 'git checkout' --detach [<branch>]::
76 'git checkout' [--detach] <commit>::
77
78 Prepare to work on top of <commit>, by detaching HEAD at it
79 (see "DETACHED HEAD" section), and updating the index and the
80 files in the working tree. Local modifications to the files
81 in the working tree are kept, so that the resulting working
82 tree will be the state recorded in the commit plus the local
83 modifications.
84 +
85 When the <commit> argument is a branch name, the `--detach` option can
86 be used to detach HEAD at the tip of the branch (`git checkout
87 <branch>` would check out that branch without detaching HEAD).
88 +
89 Omitting <branch> detaches HEAD at the tip of the current branch.
90
91 'git checkout' [<tree-ish>] [--] <pathspec>...::
92
93 Overwrite paths in the working tree by replacing with the
94 contents in the index or in the <tree-ish> (most often a
95 commit). When a <tree-ish> is given, the paths that
96 match the <pathspec> are updated both in the index and in
97 the working tree.
98 +
99 The index may contain unmerged entries because of a previous failed merge.
100 By default, if you try to check out such an entry from the index, the
101 checkout operation will fail and nothing will be checked out.
102 Using `-f` will ignore these unmerged entries. The contents from a
103 specific side of the merge can be checked out of the index by
104 using `--ours` or `--theirs`. With `-m`, changes made to the working tree
105 file can be discarded to re-create the original conflicted merge result.
106
107 'git checkout' (-p|--patch) [<tree-ish>] [--] [<pathspec>...]::
108 This is similar to the "check out paths to the working tree
109 from either the index or from a tree-ish" mode described
110 above, but lets you use the interactive interface to show
111 the "diff" output and choose which hunks to use in the
112 result. See below for the description of `--patch` option.
113
114
115 OPTIONS
116 -------
117 -q::
118 --quiet::
119 Quiet, suppress feedback messages.
120
121 --[no-]progress::
122 Progress status is reported on the standard error stream
123 by default when it is attached to a terminal, unless `--quiet`
124 is specified. This flag enables progress reporting even if not
125 attached to a terminal, regardless of `--quiet`.
126
127 -f::
128 --force::
129 When switching branches, proceed even if the index or the
130 working tree differs from HEAD. This is used to throw away
131 local changes.
132 +
133 When checking out paths from the index, do not fail upon unmerged
134 entries; instead, unmerged entries are ignored.
135
136 --ours::
137 --theirs::
138 When checking out paths from the index, check out stage #2
139 ('ours') or #3 ('theirs') for unmerged paths.
140 +
141 Note that during `git rebase` and `git pull --rebase`, 'ours' and
142 'theirs' may appear swapped; `--ours` gives the version from the
143 branch the changes are rebased onto, while `--theirs` gives the
144 version from the branch that holds your work that is being rebased.
145 +
146 This is because `rebase` is used in a workflow that treats the
147 history at the remote as the shared canonical one, and treats the
148 work done on the branch you are rebasing as the third-party work to
149 be integrated, and you are temporarily assuming the role of the
150 keeper of the canonical history during the rebase. As the keeper of
151 the canonical history, you need to view the history from the remote
152 as `ours` (i.e. "our shared canonical history"), while what you did
153 on your side branch as `theirs` (i.e. "one contributor's work on top
154 of it").
155
156 -b <new_branch>::
157 Create a new branch named <new_branch> and start it at
158 <start_point>; see linkgit:git-branch[1] for details.
159
160 -B <new_branch>::
161 Creates the branch <new_branch> and start it at <start_point>;
162 if it already exists, then reset it to <start_point>. This is
163 equivalent to running "git branch" with "-f"; see
164 linkgit:git-branch[1] for details.
165
166 -t::
167 --track::
168 When creating a new branch, set up "upstream" configuration. See
169 "--track" in linkgit:git-branch[1] for details.
170 +
171 If no `-b` option is given, the name of the new branch will be
172 derived from the remote-tracking branch, by looking at the local part of
173 the refspec configured for the corresponding remote, and then stripping
174 the initial part up to the "*".
175 This would tell us to use "hack" as the local branch when branching
176 off of "origin/hack" (or "remotes/origin/hack", or even
177 "refs/remotes/origin/hack"). If the given name has no slash, or the above
178 guessing results in an empty name, the guessing is aborted. You can
179 explicitly give a name with `-b` in such a case.
180
181 --no-track::
182 Do not set up "upstream" configuration, even if the
183 branch.autoSetupMerge configuration variable is true.
184
185 -l::
186 Create the new branch's reflog; see linkgit:git-branch[1] for
187 details.
188
189 --detach::
190 Rather than checking out a branch to work on it, check out a
191 commit for inspection and discardable experiments.
192 This is the default behavior of "git checkout <commit>" when
193 <commit> is not a branch name. See the "DETACHED HEAD" section
194 below for details.
195
196 --orphan <new_branch>::
197 Create a new 'orphan' branch, named <new_branch>, started from
198 <start_point> and switch to it. The first commit made on this
199 new branch will have no parents and it will be the root of a new
200 history totally disconnected from all the other branches and
201 commits.
202 +
203 The index and the working tree are adjusted as if you had previously run
204 "git checkout <start_point>". This allows you to start a new history
205 that records a set of paths similar to <start_point> by easily running
206 "git commit -a" to make the root commit.
207 +
208 This can be useful when you want to publish the tree from a commit
209 without exposing its full history. You might want to do this to publish
210 an open source branch of a project whose current tree is "clean", but
211 whose full history contains proprietary or otherwise encumbered bits of
212 code.
213 +
214 If you want to start a disconnected history that records a set of paths
215 that is totally different from the one of <start_point>, then you should
216 clear the index and the working tree right after creating the orphan
217 branch by running "git rm -rf ." from the top level of the working tree.
218 Afterwards you will be ready to prepare your new files, repopulating the
219 working tree, by copying them from elsewhere, extracting a tarball, etc.
220
221 --ignore-skip-worktree-bits::
222 In sparse checkout mode, `git checkout -- <paths>` would
223 update only entries matched by <paths> and sparse patterns
224 in $GIT_DIR/info/sparse-checkout. This option ignores
225 the sparse patterns and adds back any files in <paths>.
226
227 -m::
228 --merge::
229 When switching branches,
230 if you have local modifications to one or more files that
231 are different between the current branch and the branch to
232 which you are switching, the command refuses to switch
233 branches in order to preserve your modifications in context.
234 However, with this option, a three-way merge between the current
235 branch, your working tree contents, and the new branch
236 is done, and you will be on the new branch.
237 +
238 When a merge conflict happens, the index entries for conflicting
239 paths are left unmerged, and you need to resolve the conflicts
240 and mark the resolved paths with `git add` (or `git rm` if the merge
241 should result in deletion of the path).
242 +
243 When checking out paths from the index, this option lets you recreate
244 the conflicted merge in the specified paths.
245 +
246 When switching branches with `--merge`, staged changes may be lost.
247
248 --conflict=<style>::
249 The same as --merge option above, but changes the way the
250 conflicting hunks are presented, overriding the
251 merge.conflictStyle configuration variable. Possible values are
252 "merge" (default) and "diff3" (in addition to what is shown by
253 "merge" style, shows the original contents).
254
255 -p::
256 --patch::
257 Interactively select hunks in the difference between the
258 <tree-ish> (or the index, if unspecified) and the working
259 tree. The chosen hunks are then applied in reverse to the
260 working tree (and if a <tree-ish> was specified, the index).
261 +
262 This means that you can use `git checkout -p` to selectively discard
263 edits from your current working tree. See the ``Interactive Mode''
264 section of linkgit:git-add[1] to learn how to operate the `--patch` mode.
265 +
266 Note that this option uses the no overlay mode by default (see also
267 `--[no-]overlay`), and currently doesn't support overlay mode.
268
269 --ignore-other-worktrees::
270 `git checkout` refuses when the wanted ref is already checked
271 out by another worktree. This option makes it check the ref
272 out anyway. In other words, the ref can be held by more than one
273 worktree.
274
275 --[no-]recurse-submodules::
276 Using --recurse-submodules will update the content of all initialized
277 submodules according to the commit recorded in the superproject. If
278 local modifications in a submodule would be overwritten the checkout
279 will fail unless `-f` is used. If nothing (or --no-recurse-submodules)
280 is used, the work trees of submodules will not be updated.
281 Just like linkgit:git-submodule[1], this will detach the
282 submodules HEAD.
283
284 --no-guess::
285 Do not attempt to create a branch if a remote tracking branch
286 of the same name exists.
287
288 --[no-]overlay::
289 In the default overlay mode, `git checkout` never
290 removes files from the index or the working tree. When
291 specifying `--no-overlay`, files that appear in the index and
292 working tree, but not in <tree-ish> are removed, to make them
293 match <tree-ish> exactly.
294
295 <branch>::
296 Branch to checkout; if it refers to a branch (i.e., a name that,
297 when prepended with "refs/heads/", is a valid ref), then that
298 branch is checked out. Otherwise, if it refers to a valid
299 commit, your HEAD becomes "detached" and you are no longer on
300 any branch (see below for details).
301 +
302 You can use the `"@{-N}"` syntax to refer to the N-th last
303 branch/commit checked out using "git checkout" operation. You may
304 also specify `-` which is synonymous to `"@{-1}"`.
305 +
306 As a special case, you may use `"A...B"` as a shortcut for the
307 merge base of `A` and `B` if there is exactly one merge base. You can
308 leave out at most one of `A` and `B`, in which case it defaults to `HEAD`.
309
310 <new_branch>::
311 Name for the new branch.
312
313 <start_point>::
314 The name of a commit at which to start the new branch; see
315 linkgit:git-branch[1] for details. Defaults to HEAD.
316
317 <tree-ish>::
318 Tree to checkout from (when paths are given). If not specified,
319 the index will be used.
320
321
322
323 DETACHED HEAD
324 -------------
325 HEAD normally refers to a named branch (e.g. 'master'). Meanwhile, each
326 branch refers to a specific commit. Let's look at a repo with three
327 commits, one of them tagged, and with branch 'master' checked out:
328
329 ------------
330 HEAD (refers to branch 'master')
331 |
332 v
333 a---b---c branch 'master' (refers to commit 'c')
334 ^
335 |
336 tag 'v2.0' (refers to commit 'b')
337 ------------
338
339 When a commit is created in this state, the branch is updated to refer to
340 the new commit. Specifically, 'git commit' creates a new commit 'd', whose
341 parent is commit 'c', and then updates branch 'master' to refer to new
342 commit 'd'. HEAD still refers to branch 'master' and so indirectly now refers
343 to commit 'd':
344
345 ------------
346 $ edit; git add; git commit
347
348 HEAD (refers to branch 'master')
349 |
350 v
351 a---b---c---d branch 'master' (refers to commit 'd')
352 ^
353 |
354 tag 'v2.0' (refers to commit 'b')
355 ------------
356
357 It is sometimes useful to be able to checkout a commit that is not at
358 the tip of any named branch, or even to create a new commit that is not
359 referenced by a named branch. Let's look at what happens when we
360 checkout commit 'b' (here we show two ways this may be done):
361
362 ------------
363 $ git checkout v2.0 # or
364 $ git checkout master^^
365
366 HEAD (refers to commit 'b')
367 |
368 v
369 a---b---c---d branch 'master' (refers to commit 'd')
370 ^
371 |
372 tag 'v2.0' (refers to commit 'b')
373 ------------
374
375 Notice that regardless of which checkout command we use, HEAD now refers
376 directly to commit 'b'. This is known as being in detached HEAD state.
377 It means simply that HEAD refers to a specific commit, as opposed to
378 referring to a named branch. Let's see what happens when we create a commit:
379
380 ------------
381 $ edit; git add; git commit
382
383 HEAD (refers to commit 'e')
384 |
385 v
386 e
387 /
388 a---b---c---d branch 'master' (refers to commit 'd')
389 ^
390 |
391 tag 'v2.0' (refers to commit 'b')
392 ------------
393
394 There is now a new commit 'e', but it is referenced only by HEAD. We can
395 of course add yet another commit in this state:
396
397 ------------
398 $ edit; git add; git commit
399
400 HEAD (refers to commit 'f')
401 |
402 v
403 e---f
404 /
405 a---b---c---d branch 'master' (refers to commit 'd')
406 ^
407 |
408 tag 'v2.0' (refers to commit 'b')
409 ------------
410
411 In fact, we can perform all the normal Git operations. But, let's look
412 at what happens when we then checkout master:
413
414 ------------
415 $ git checkout master
416
417 HEAD (refers to branch 'master')
418 e---f |
419 / v
420 a---b---c---d branch 'master' (refers to commit 'd')
421 ^
422 |
423 tag 'v2.0' (refers to commit 'b')
424 ------------
425
426 It is important to realize that at this point nothing refers to commit
427 'f'. Eventually commit 'f' (and by extension commit 'e') will be deleted
428 by the routine Git garbage collection process, unless we create a reference
429 before that happens. If we have not yet moved away from commit 'f',
430 any of these will create a reference to it:
431
432 ------------
433 $ git checkout -b foo <1>
434 $ git branch foo <2>
435 $ git tag foo <3>
436 ------------
437
438 <1> creates a new branch 'foo', which refers to commit 'f', and then
439 updates HEAD to refer to branch 'foo'. In other words, we'll no longer
440 be in detached HEAD state after this command.
441
442 <2> similarly creates a new branch 'foo', which refers to commit 'f',
443 but leaves HEAD detached.
444
445 <3> creates a new tag 'foo', which refers to commit 'f',
446 leaving HEAD detached.
447
448 If we have moved away from commit 'f', then we must first recover its object
449 name (typically by using git reflog), and then we can create a reference to
450 it. For example, to see the last two commits to which HEAD referred, we
451 can use either of these commands:
452
453 ------------
454 $ git reflog -2 HEAD # or
455 $ git log -g -2 HEAD
456 ------------
457
458 ARGUMENT DISAMBIGUATION
459 -----------------------
460
461 When there is only one argument given and it is not `--` (e.g. "git
462 checkout abc"), and when the argument is both a valid `<tree-ish>`
463 (e.g. a branch "abc" exists) and a valid `<pathspec>` (e.g. a file
464 or a directory whose name is "abc" exists), Git would usually ask
465 you to disambiguate. Because checking out a branch is so common an
466 operation, however, "git checkout abc" takes "abc" as a `<tree-ish>`
467 in such a situation. Use `git checkout -- <pathspec>` if you want
468 to checkout these paths out of the index.
469
470 EXAMPLES
471 --------
472
473 . The following sequence checks out the `master` branch, reverts
474 the `Makefile` to two revisions back, deletes hello.c by
475 mistake, and gets it back from the index.
476 +
477 ------------
478 $ git checkout master <1>
479 $ git checkout master~2 Makefile <2>
480 $ rm -f hello.c
481 $ git checkout hello.c <3>
482 ------------
483 +
484 <1> switch branch
485 <2> take a file out of another commit
486 <3> restore hello.c from the index
487 +
488 If you want to check out _all_ C source files out of the index,
489 you can say
490 +
491 ------------
492 $ git checkout -- '*.c'
493 ------------
494 +
495 Note the quotes around `*.c`. The file `hello.c` will also be
496 checked out, even though it is no longer in the working tree,
497 because the file globbing is used to match entries in the index
498 (not in the working tree by the shell).
499 +
500 If you have an unfortunate branch that is named `hello.c`, this
501 step would be confused as an instruction to switch to that branch.
502 You should instead write:
503 +
504 ------------
505 $ git checkout -- hello.c
506 ------------
507
508 . After working in the wrong branch, switching to the correct
509 branch would be done using:
510 +
511 ------------
512 $ git checkout mytopic
513 ------------
514 +
515 However, your "wrong" branch and correct "mytopic" branch may
516 differ in files that you have modified locally, in which case
517 the above checkout would fail like this:
518 +
519 ------------
520 $ git checkout mytopic
521 error: You have local changes to 'frotz'; not switching branches.
522 ------------
523 +
524 You can give the `-m` flag to the command, which would try a
525 three-way merge:
526 +
527 ------------
528 $ git checkout -m mytopic
529 Auto-merging frotz
530 ------------
531 +
532 After this three-way merge, the local modifications are _not_
533 registered in your index file, so `git diff` would show you what
534 changes you made since the tip of the new branch.
535
536 . When a merge conflict happens during switching branches with
537 the `-m` option, you would see something like this:
538 +
539 ------------
540 $ git checkout -m mytopic
541 Auto-merging frotz
542 ERROR: Merge conflict in frotz
543 fatal: merge program failed
544 ------------
545 +
546 At this point, `git diff` shows the changes cleanly merged as in
547 the previous example, as well as the changes in the conflicted
548 files. Edit and resolve the conflict and mark it resolved with
549 `git add` as usual:
550 +
551 ------------
552 $ edit frotz
553 $ git add frotz
554 ------------
555
556 GIT
557 ---
558 Part of the linkgit:git[1] suite