91294f89c89dbbfef93bbb7f38074827938f48f6
[git/git.git] / Documentation / git-checkout.txt
1 git-checkout(1)
2 ===============
3
4 NAME
5 ----
6 git-checkout - Checkout a branch or paths to the working tree
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' [-p|--patch] [<tree-ish>] [--] [<paths>...]
17
18 DESCRIPTION
19 -----------
20 Updates files in the working tree to match the version in the index
21 or the specified tree. If no paths are given, 'git checkout' will
22 also update `HEAD` to set the specified branch as the current
23 branch.
24
25 'git checkout' <branch>::
26 To prepare for working on <branch>, switch to it by updating
27 the index and the files in the working tree, and by pointing
28 HEAD at the branch. Local modifications to the files in the
29 working tree are kept, so that they can be committed to the
30 <branch>.
31 +
32 If <branch> is not found but there does exist a tracking branch in
33 exactly one remote (call it <remote>) with a matching name, treat as
34 equivalent to
35 +
36 ------------
37 $ git checkout -b <branch> --track <remote>/<branch>
38 ------------
39 +
40 You could omit <branch>, in which case the command degenerates to
41 "check out the current branch", which is a glorified no-op with a
42 rather expensive side-effects to show only the tracking information,
43 if exists, for the current branch.
44
45 'git checkout' -b|-B <new_branch> [<start point>]::
46
47 Specifying `-b` causes a new branch to be created as if
48 linkgit:git-branch[1] were called and then checked out. In
49 this case you can use the `--track` or `--no-track` options,
50 which will be passed to 'git branch'. As a convenience,
51 `--track` without `-b` implies branch creation; see the
52 description of `--track` below.
53 +
54 If `-B` is given, <new_branch> is created if it doesn't exist; otherwise, it
55 is reset. This is the transactional equivalent of
56 +
57 ------------
58 $ git branch -f <branch> [<start point>]
59 $ git checkout <branch>
60 ------------
61 +
62 that is to say, the branch is not reset/created unless "git checkout" is
63 successful.
64
65 'git checkout' --detach [<branch>]::
66 'git checkout' [--detach] <commit>::
67
68 Prepare to work on top of <commit>, by detaching HEAD at it
69 (see "DETACHED HEAD" section), and updating the index and the
70 files in the working tree. Local modifications to the files
71 in the working tree are kept, so that the resulting working
72 tree will be the state recorded in the commit plus the local
73 modifications.
74 +
75 When the <commit> argument is a branch name, the `--detach` option can
76 be used to detach HEAD at the tip of the branch (`git checkout
77 <branch>` would check out that branch without detaching HEAD).
78 +
79 Omitting <branch> detaches HEAD at the tip of the current branch.
80
81 'git checkout' [-p|--patch] [<tree-ish>] [--] <pathspec>...::
82
83 When <paths> or `--patch` are given, 'git checkout' does *not*
84 switch branches. It updates the named paths in the working tree
85 from the index file or from a named <tree-ish> (most often a
86 commit). In this case, the `-b` and `--track` options are
87 meaningless and giving either of them results in an error. The
88 <tree-ish> argument can be used to specify a specific tree-ish
89 (i.e. commit, tag or tree) to update the index for the given
90 paths before updating the working tree.
91 +
92 The index may contain unmerged entries because of a previous failed merge.
93 By default, if you try to check out such an entry from the index, the
94 checkout operation will fail and nothing will be checked out.
95 Using `-f` will ignore these unmerged entries. The contents from a
96 specific side of the merge can be checked out of the index by
97 using `--ours` or `--theirs`. With `-m`, changes made to the working tree
98 file can be discarded to re-create the original conflicted merge result.
99
100 OPTIONS
101 -------
102 -q::
103 --quiet::
104 Quiet, suppress feedback messages.
105
106 -f::
107 --force::
108 When switching branches, proceed even if the index or the
109 working tree differs from HEAD. This is used to throw away
110 local changes.
111 +
112 When checking out paths from the index, do not fail upon unmerged
113 entries; instead, unmerged entries are ignored.
114
115 --ours::
116 --theirs::
117 When checking out paths from the index, check out stage #2
118 ('ours') or #3 ('theirs') for unmerged paths.
119
120 -b <new_branch>::
121 Create a new branch named <new_branch> and start it at
122 <start_point>; see linkgit:git-branch[1] for details.
123
124 -B <new_branch>::
125 Creates the branch <new_branch> and start it at <start_point>;
126 if it already exists, then reset it to <start_point>. This is
127 equivalent to running "git branch" with "-f"; see
128 linkgit:git-branch[1] for details.
129
130 -t::
131 --track::
132 When creating a new branch, set up "upstream" configuration. See
133 "--track" in linkgit:git-branch[1] for details.
134 +
135 If no '-b' option is given, the name of the new branch will be
136 derived from the remote-tracking branch, by looking at the local part of
137 the refspec configured for the corresponding remote, and then stripping
138 the initial part up to the "*".
139 This would tell us to use "hack" as the local branch when branching
140 off of "origin/hack" (or "remotes/origin/hack", or even
141 "refs/remotes/origin/hack"). If the given name has no slash, or the above
142 guessing results in an empty name, the guessing is aborted. You can
143 explicitly give a name with '-b' in such a case.
144
145 --no-track::
146 Do not set up "upstream" configuration, even if the
147 branch.autosetupmerge configuration variable is true.
148
149 -l::
150 Create the new branch's reflog; see linkgit:git-branch[1] for
151 details.
152
153 --detach::
154 Rather than checking out a branch to work on it, check out a
155 commit for inspection and discardable experiments.
156 This is the default behavior of "git checkout <commit>" when
157 <commit> is not a branch name. See the "DETACHED HEAD" section
158 below for details.
159
160 --orphan <new_branch>::
161 Create a new 'orphan' branch, named <new_branch>, started from
162 <start_point> and switch to it. The first commit made on this
163 new branch will have no parents and it will be the root of a new
164 history totally disconnected from all the other branches and
165 commits.
166 +
167 The index and the working tree are adjusted as if you had previously run
168 "git checkout <start_point>". This allows you to start a new history
169 that records a set of paths similar to <start_point> by easily running
170 "git commit -a" to make the root commit.
171 +
172 This can be useful when you want to publish the tree from a commit
173 without exposing its full history. You might want to do this to publish
174 an open source branch of a project whose current tree is "clean", but
175 whose full history contains proprietary or otherwise encumbered bits of
176 code.
177 +
178 If you want to start a disconnected history that records a set of paths
179 that is totally different from the one of <start_point>, then you should
180 clear the index and the working tree right after creating the orphan
181 branch by running "git rm -rf ." from the top level of the working tree.
182 Afterwards you will be ready to prepare your new files, repopulating the
183 working tree, by copying them from elsewhere, extracting a tarball, etc.
184
185 --ignore-skip-worktree-bits::
186 In sparse checkout mode, `git checkout -- <paths>` would
187 update only entries matched by <paths> and sparse patterns
188 in $GIT_DIR/info/sparse-checkout. This option ignores
189 the sparse patterns and adds back any files in <paths>.
190
191 -m::
192 --merge::
193 When switching branches,
194 if you have local modifications to one or more files that
195 are different between the current branch and the branch to
196 which you are switching, the command refuses to switch
197 branches in order to preserve your modifications in context.
198 However, with this option, a three-way merge between the current
199 branch, your working tree contents, and the new branch
200 is done, and you will be on the new branch.
201 +
202 When a merge conflict happens, the index entries for conflicting
203 paths are left unmerged, and you need to resolve the conflicts
204 and mark the resolved paths with `git add` (or `git rm` if the merge
205 should result in deletion of the path).
206 +
207 When checking out paths from the index, this option lets you recreate
208 the conflicted merge in the specified paths.
209
210 --conflict=<style>::
211 The same as --merge option above, but changes the way the
212 conflicting hunks are presented, overriding the
213 merge.conflictstyle configuration variable. Possible values are
214 "merge" (default) and "diff3" (in addition to what is shown by
215 "merge" style, shows the original contents).
216
217 -p::
218 --patch::
219 Interactively select hunks in the difference between the
220 <tree-ish> (or the index, if unspecified) and the working
221 tree. The chosen hunks are then applied in reverse to the
222 working tree (and if a <tree-ish> was specified, the index).
223 +
224 This means that you can use `git checkout -p` to selectively discard
225 edits from your current working tree. See the ``Interactive Mode''
226 section of linkgit:git-add[1] to learn how to operate the `--patch` mode.
227
228 <branch>::
229 Branch to checkout; if it refers to a branch (i.e., a name that,
230 when prepended with "refs/heads/", is a valid ref), then that
231 branch is checked out. Otherwise, if it refers to a valid
232 commit, your HEAD becomes "detached" and you are no longer on
233 any branch (see below for details).
234 +
235 As a special case, the `"@{-N}"` syntax for the N-th last branch
236 checks out the branch (instead of detaching). You may also specify
237 `-` which is synonymous with `"@{-1}"`.
238 +
239 As a further special case, you may use `"A...B"` as a shortcut for the
240 merge base of `A` and `B` if there is exactly one merge base. You can
241 leave out at most one of `A` and `B`, in which case it defaults to `HEAD`.
242
243 <new_branch>::
244 Name for the new branch.
245
246 <start_point>::
247 The name of a commit at which to start the new branch; see
248 linkgit:git-branch[1] for details. Defaults to HEAD.
249
250 <tree-ish>::
251 Tree to checkout from (when paths are given). If not specified,
252 the index will be used.
253
254
255
256 DETACHED HEAD
257 -------------
258 HEAD normally refers to a named branch (e.g. 'master'). Meanwhile, each
259 branch refers to a specific commit. Let's look at a repo with three
260 commits, one of them tagged, and with branch 'master' checked out:
261
262 ------------
263 HEAD (refers to branch 'master')
264 |
265 v
266 a---b---c branch 'master' (refers to commit 'c')
267 ^
268 |
269 tag 'v2.0' (refers to commit 'b')
270 ------------
271
272 When a commit is created in this state, the branch is updated to refer to
273 the new commit. Specifically, 'git commit' creates a new commit 'd', whose
274 parent is commit 'c', and then updates branch 'master' to refer to new
275 commit 'd'. HEAD still refers to branch 'master' and so indirectly now refers
276 to commit 'd':
277
278 ------------
279 $ edit; git add; git commit
280
281 HEAD (refers to branch 'master')
282 |
283 v
284 a---b---c---d branch 'master' (refers to commit 'd')
285 ^
286 |
287 tag 'v2.0' (refers to commit 'b')
288 ------------
289
290 It is sometimes useful to be able to checkout a commit that is not at
291 the tip of any named branch, or even to create a new commit that is not
292 referenced by a named branch. Let's look at what happens when we
293 checkout commit 'b' (here we show two ways this may be done):
294
295 ------------
296 $ git checkout v2.0 # or
297 $ git checkout master^^
298
299 HEAD (refers to commit 'b')
300 |
301 v
302 a---b---c---d branch 'master' (refers to commit 'd')
303 ^
304 |
305 tag 'v2.0' (refers to commit 'b')
306 ------------
307
308 Notice that regardless of which checkout command we use, HEAD now refers
309 directly to commit 'b'. This is known as being in detached HEAD state.
310 It means simply that HEAD refers to a specific commit, as opposed to
311 referring to a named branch. Let's see what happens when we create a commit:
312
313 ------------
314 $ edit; git add; git commit
315
316 HEAD (refers to commit 'e')
317 |
318 v
319 e
320 /
321 a---b---c---d branch 'master' (refers to commit 'd')
322 ^
323 |
324 tag 'v2.0' (refers to commit 'b')
325 ------------
326
327 There is now a new commit 'e', but it is referenced only by HEAD. We can
328 of course add yet another commit in this state:
329
330 ------------
331 $ edit; git add; git commit
332
333 HEAD (refers to commit 'f')
334 |
335 v
336 e---f
337 /
338 a---b---c---d branch 'master' (refers to commit 'd')
339 ^
340 |
341 tag 'v2.0' (refers to commit 'b')
342 ------------
343
344 In fact, we can perform all the normal Git operations. But, let's look
345 at what happens when we then checkout master:
346
347 ------------
348 $ git checkout master
349
350 HEAD (refers to branch 'master')
351 e---f |
352 / v
353 a---b---c---d branch 'master' (refers to commit 'd')
354 ^
355 |
356 tag 'v2.0' (refers to commit 'b')
357 ------------
358
359 It is important to realize that at this point nothing refers to commit
360 'f'. Eventually commit 'f' (and by extension commit 'e') will be deleted
361 by the routine Git garbage collection process, unless we create a reference
362 before that happens. If we have not yet moved away from commit 'f',
363 any of these will create a reference to it:
364
365 ------------
366 $ git checkout -b foo <1>
367 $ git branch foo <2>
368 $ git tag foo <3>
369 ------------
370
371 <1> creates a new branch 'foo', which refers to commit 'f', and then
372 updates HEAD to refer to branch 'foo'. In other words, we'll no longer
373 be in detached HEAD state after this command.
374
375 <2> similarly creates a new branch 'foo', which refers to commit 'f',
376 but leaves HEAD detached.
377
378 <3> creates a new tag 'foo', which refers to commit 'f',
379 leaving HEAD detached.
380
381 If we have moved away from commit 'f', then we must first recover its object
382 name (typically by using git reflog), and then we can create a reference to
383 it. For example, to see the last two commits to which HEAD referred, we
384 can use either of these commands:
385
386 ------------
387 $ git reflog -2 HEAD # or
388 $ git log -g -2 HEAD
389 ------------
390
391 EXAMPLES
392 --------
393
394 . The following sequence checks out the `master` branch, reverts
395 the `Makefile` to two revisions back, deletes hello.c by
396 mistake, and gets it back from the index.
397 +
398 ------------
399 $ git checkout master <1>
400 $ git checkout master~2 Makefile <2>
401 $ rm -f hello.c
402 $ git checkout hello.c <3>
403 ------------
404 +
405 <1> switch branch
406 <2> take a file out of another commit
407 <3> restore hello.c from the index
408 +
409 If you want to check out _all_ C source files out of the index,
410 you can say
411 +
412 ------------
413 $ git checkout -- '*.c'
414 ------------
415 +
416 Note the quotes around `*.c`. The file `hello.c` will also be
417 checked out, even though it is no longer in the working tree,
418 because the file globbing is used to match entries in the index
419 (not in the working tree by the shell).
420 +
421 If you have an unfortunate branch that is named `hello.c`, this
422 step would be confused as an instruction to switch to that branch.
423 You should instead write:
424 +
425 ------------
426 $ git checkout -- hello.c
427 ------------
428
429 . After working in the wrong branch, switching to the correct
430 branch would be done using:
431 +
432 ------------
433 $ git checkout mytopic
434 ------------
435 +
436 However, your "wrong" branch and correct "mytopic" branch may
437 differ in files that you have modified locally, in which case
438 the above checkout would fail like this:
439 +
440 ------------
441 $ git checkout mytopic
442 error: You have local changes to 'frotz'; not switching branches.
443 ------------
444 +
445 You can give the `-m` flag to the command, which would try a
446 three-way merge:
447 +
448 ------------
449 $ git checkout -m mytopic
450 Auto-merging frotz
451 ------------
452 +
453 After this three-way merge, the local modifications are _not_
454 registered in your index file, so `git diff` would show you what
455 changes you made since the tip of the new branch.
456
457 . When a merge conflict happens during switching branches with
458 the `-m` option, you would see something like this:
459 +
460 ------------
461 $ git checkout -m mytopic
462 Auto-merging frotz
463 ERROR: Merge conflict in frotz
464 fatal: merge program failed
465 ------------
466 +
467 At this point, `git diff` shows the changes cleanly merged as in
468 the previous example, as well as the changes in the conflicted
469 files. Edit and resolve the conflict and mark it resolved with
470 `git add` as usual:
471 +
472 ------------
473 $ edit frotz
474 $ git add frotz
475 ------------
476
477 GIT
478 ---
479 Part of the linkgit:git[1] suite