checkout: do not check out unmerged higher stages randomly
[git/git.git] / Documentation / git-checkout.txt
CommitLineData
215a7ad1
JH
1git-checkout(1)
2===============
7fc9d69f
JH
3
4NAME
5----
76ce9462 6git-checkout - Checkout a branch or paths to the working tree
7fc9d69f
JH
7
8SYNOPSIS
9--------
71bb1033 10[verse]
b1889c36 11'git checkout' [-q] [-f] [[--track | --no-track] -b <new_branch> [-l]] [-m] [<branch>]
b302ddd2 12'git checkout' [<tree-ish>] [--] <paths>...
7fc9d69f
JH
13
14DESCRIPTION
15-----------
4aaa7027 16
71bb1033 17When <paths> are not given, this command switches branches by
4aaa7027
JH
18updating the index and working tree to reflect the specified
19branch, <branch>, and updating HEAD to be <branch> or, if
71bb1033 20specified, <new_branch>. Using -b will cause <new_branch> to
0746d19a
PB
21be created; in this case you can use the --track or --no-track
22options, which will be passed to `git branch`.
4aaa7027
JH
23
24When <paths> are given, this command does *not* switch
25branches. It updates the named paths in the working tree from
b1889c36 26the index file (i.e. it runs `git checkout-index -f -u`), or
40c8279f
BF
27from a named commit. In
28this case, the `-f` and `-b` options are meaningless and giving
84a978f1
JH
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.
4aaa7027 33
7fc9d69f
JH
34
35OPTIONS
36-------
6124aee5 37-q::
2be7fcb4 38 Quiet, suppress feedback messages.
6124aee5 39
0270f7c5 40-f::
40c8279f
BF
41 Proceed even if the index or the working tree differs
42 from HEAD. This is used to throw away local changes.
0270f7c5
LAS
43
44-b::
2b1f4247
SP
45 Create a new branch named <new_branch> and start it at
46 <branch>. The new branch name must pass all checks defined
5162e697 47 by linkgit:git-check-ref-format[1]. Some of these checks
2b1f4247 48 may restrict the characters allowed in a branch name.
7fc9d69f 49
3240240f
SB
50-t::
51--track::
ba020ef5 52 When creating a new branch, set up configuration so that 'git-pull'
572fc81d
JS
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
ba020ef5 59 'git-checkout' and 'git-branch' to always behave as if '--no-track' were
572fc81d
JS
60 given. Set it to `always` if you want this behavior when the
61 start-point is either a local or remote branch.
0746d19a
PB
62
63--no-track::
572fc81d 64 Ignore the branch.autosetupmerge configuration variable.
0746d19a 65
969d326d 66-l::
792d2370
JK
67 Create the new branch's reflog. This activates recording of
68 all changes made to the branch ref, enabling use of date
967506bb 69 based sha1 expressions such as "<branchname>@\{yesterday}".
969d326d 70
1be0659e 71-m::
71bb1033
JL
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
1be0659e
JH
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
d7f078b8
SP
82and mark the resolved paths with `git add` (or `git rm` if the merge
83should result in deletion of the path).
1be0659e 84
0270f7c5
LAS
85<new_branch>::
86 Name for the new branch.
7fc9d69f 87
0270f7c5
LAS
88<branch>::
89 Branch to checkout; may be any object ID that resolves to a
5e1a2e8c
JH
90 commit. Defaults to HEAD.
91+
92When this parameter names a non-branch (but still a valid commit object),
93your HEAD becomes 'detached'.
94
95
96Detached HEAD
97-------------
98
99It is sometimes useful to be able to 'checkout' a commit that is
100not at the tip of one of your branches. The most obvious
101example is to check out the commit at a tagged official release
102point, like this:
103
104------------
105$ git checkout v2.6.18
106------------
107
108Earlier versions of git did not allow this and asked you to
109create a temporary branch using `-b` option, but starting from
110version 1.5.0, the above command 'detaches' your HEAD from the
111current branch and directly point at the commit named by the tag
112(`v2.6.18` in the above example).
113
114You can use usual git commands while in this state. You can use
b1889c36 115`git reset --hard $othercommit` to further move around, for
5e1a2e8c
JH
116example. You can make changes and create a new commit on top of
117a detached HEAD. You can even create a merge by using `git
118merge $othercommit`.
119
120The state you are in while your HEAD is detached is not recorded
121by any branch (which is natural --- you are not on any branch).
122What this means is that you can discard your temporary commits
123and merges by switching back to an existing branch (e.g. `git
124checkout master`), and a later `git prune` or `git gc` would
cec8d146
JH
125garbage-collect them. If you did this by mistake, you can ask
126the reflog for HEAD where you were, e.g.
127
128------------
129$ git log -g -2 HEAD
130------------
7fc9d69f 131
4aaa7027 132
1be0659e
JH
133EXAMPLES
134--------
4aaa7027 135
1be0659e 136. The following sequence checks out the `master` branch, reverts
4aaa7027
JH
137the `Makefile` to two revisions back, deletes hello.c by
138mistake, and gets it back from the index.
1be0659e 139+
4aaa7027 140------------
48aeecdc
SE
141$ git checkout master <1>
142$ git checkout master~2 Makefile <2>
4aaa7027 143$ rm -f hello.c
48aeecdc
SE
144$ git checkout hello.c <3>
145------------
146+
1e2ccd3a
JH
147<1> switch branch
148<2> take out a file out of other commit
48aeecdc 149<3> restore hello.c from HEAD of current branch
1be0659e 150+
48aeecdc
SE
151If you have an unfortunate branch that is named `hello.c`, this
152step would be confused as an instruction to switch to that branch.
153You should instead write:
1be0659e 154+
4aaa7027
JH
155------------
156$ git checkout -- hello.c
157------------
158
1be0659e 159. After working in a wrong branch, switching to the correct
71bb1033 160branch would be done using:
1be0659e
JH
161+
162------------
163$ git checkout mytopic
164------------
165+
166However, your "wrong" branch and correct "mytopic" branch may
167differ in files that you have locally modified, in which case,
168the above checkout would fail like this:
169+
170------------
171$ git checkout mytopic
172fatal: Entry 'frotz' not uptodate. Cannot merge.
173------------
174+
175You can give the `-m` flag to the command, which would try a
176three-way merge:
177+
178------------
179$ git checkout -m mytopic
180Auto-merging frotz
181------------
182+
183After this three-way merge, the local modifications are _not_
184registered in your index file, so `git diff` would show you what
185changes you made since the tip of the new branch.
186
187. When a merge conflict happens during switching branches with
188the `-m` option, you would see something like this:
189+
190------------
191$ git checkout -m mytopic
192Auto-merging frotz
193merge: warning: conflicts during merge
194ERROR: Merge conflict in frotz
195fatal: merge program failed
196------------
197+
198At this point, `git diff` shows the changes cleanly merged as in
199the previous example, as well as the changes in the conflicted
200files. Edit and resolve the conflict and mark it resolved with
d7f078b8 201`git add` as usual:
1be0659e
JH
202+
203------------
204$ edit frotz
d7f078b8 205$ git add frotz
1be0659e
JH
206------------
207
4aaa7027 208
7fc9d69f
JH
209Author
210------
211Written by Linus Torvalds <torvalds@osdl.org>
212
213Documentation
214--------------
215Documentation by Junio C Hamano and the git-list <git@vger.kernel.org>.
216
217GIT
218---
9e1f0a85 219Part of the linkgit:git[1] suite