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