[git/git.git] / Documentation / git-submodule.txt
1 git-submodule(1)
2 ================
5 ----
6 git-submodule - Initialize, update or inspect submodules
10 --------
11 [verse]
12 'git submodule' [--quiet] add [-b <branch>] [-f|--force] [--name <name>]
13 [--reference <repository>] [--] <repository> [<path>]
14 'git submodule' [--quiet] status [--cached] [--recursive] [--] [<path>...]
15 'git submodule' [--quiet] init [--] [<path>...]
16 'git submodule' [--quiet] deinit [-f|--force] [--] <path>...
17 'git submodule' [--quiet] update [--init] [--remote] [-N|--no-fetch]
18 [-f|--force] [--rebase] [--reference <repository>]
19 [--merge] [--recursive] [--] [<path>...]
20 'git submodule' [--quiet] summary [--cached|--files] [(-n|--summary-limit) <n>]
21 [commit] [--] [<path>...]
22 'git submodule' [--quiet] foreach [--recursive] <command>
23 'git submodule' [--quiet] sync [--] [<path>...]
27 -----------
28 Submodules allow foreign repositories to be embedded within
29 a dedicated subdirectory of the source tree, always pointed
30 at a particular commit.
32 They are not to be confused with remotes, which are meant mainly
33 for branches of the same project; submodules are meant for
34 different projects you would like to make part of your source tree,
35 while the history of the two projects still stays completely
36 independent and you cannot modify the contents of the submodule
37 from within the main project.
38 If you want to merge the project histories and want to treat the
39 aggregated whole as a single project from then on, you may want to
40 add a remote for the other project and use the 'subtree' merge strategy,
41 instead of treating the other project as a submodule. Directories
42 that come from both projects can be cloned and checked out as a whole
43 if you choose to go that route.
45 Submodules are composed from a so-called `gitlink` tree entry
46 in the main repository that refers to a particular commit object
47 within the inner repository that is completely separate.
48 A record in the `.gitmodules` (see linkgit:gitmodules[5]) file at the
49 root of the source tree assigns a logical name to the submodule and
50 describes the default URL the submodule shall be cloned from.
51 The logical name can be used for overriding this URL within your
52 local repository configuration (see 'submodule init').
54 This command will manage the tree entries and contents of the
55 gitmodules file for you, as well as inspect the status of your
56 submodules and update them.
57 When adding a new submodule to the tree, the 'add' subcommand
58 is to be used. However, when pulling a tree containing submodules,
59 these will not be checked out by default;
60 the 'init' and 'update' subcommands will maintain submodules
61 checked out and at appropriate revision in your working tree.
62 You can briefly inspect the up-to-date status of your submodules
63 using the 'status' subcommand and get a detailed overview of the
64 difference between the index and checkouts using the 'summary'
65 subcommand.
69 --------
70 add::
71 Add the given repository as a submodule at the given path
72 to the changeset to be committed next to the current
73 project: the current project is termed the "superproject".
74 +
75 This requires at least one argument: <repository>. The optional
76 argument <path> is the relative location for the cloned submodule
77 to exist in the superproject. If <path> is not given, the
78 "humanish" part of the source repository is used ("repo" for
79 "/path/to/repo.git" and "foo" for "host.xz:foo/.git").
80 The <path> is also used as the submodule's logical name in its
81 configuration entries unless `--name` is used to specify a logical name.
82 +
83 <repository> is the URL of the new submodule's origin repository.
84 This may be either an absolute URL, or (if it begins with ./
85 or ../), the location relative to the superproject's origin
86 repository (Please note that to specify a repository 'foo.git'
87 which is located right next to a superproject 'bar.git', you'll
88 have to use '../foo.git' instead of './foo.git' - as one might expect
89 when following the rules for relative URLs - because the evaluation
90 of relative URLs in Git is identical to that of relative directories).
91 If the superproject doesn't have an origin configured
92 the superproject is its own authoritative upstream and the current
93 working directory is used instead.
94 +
95 <path> is the relative location for the cloned submodule to
96 exist in the superproject. If <path> does not exist, then the
97 submodule is created by cloning from the named URL. If <path> does
98 exist and is already a valid Git repository, then this is added
99 to the changeset without cloning. This second form is provided
100 to ease creating a new submodule from scratch, and presumes
101 the user will later push the submodule to the given URL.
102 +
103 In either case, the given URL is recorded into .gitmodules for
104 use by subsequent users cloning the superproject. If the URL is
105 given relative to the superproject's repository, the presumption
106 is the superproject and submodule repositories will be kept
107 together in the same relative location, and only the
108 superproject's URL needs to be provided: git-submodule will correctly
109 locate the submodule using the relative URL in .gitmodules.
111 status::
112 Show the status of the submodules. This will print the SHA-1 of the
113 currently checked out commit for each submodule, along with the
114 submodule path and the output of 'git describe' for the
115 SHA-1. Each SHA-1 will be prefixed with `-` if the submodule is not
116 initialized, `+` if the currently checked out submodule commit
117 does not match the SHA-1 found in the index of the containing
118 repository and `U` if the submodule has merge conflicts.
119 +
120 If `--recursive` is specified, this command will recurse into nested
121 submodules, and show their status as well.
122 +
123 If you are only interested in changes of the currently initialized
124 submodules with respect to the commit recorded in the index or the HEAD,
125 linkgit:git-status[1] and linkgit:git-diff[1] will provide that information
126 too (and can also report changes to a submodule's work tree).
128 init::
129 Initialize the submodules recorded in the index (which were
130 added and committed elsewhere) by copying submodule
131 names and urls from .gitmodules to .git/config.
132 Optional <path> arguments limit which submodules will be initialized.
133 It will also copy the value of `submodule.$name.update` into
134 .git/config.
135 The key used in .git/config is `submodule.$name.url`.
136 This command does not alter existing information in .git/config.
137 You can then customize the submodule clone URLs in .git/config
138 for your local setup and proceed to `git submodule update`;
139 you can also just use `git submodule update --init` without
140 the explicit 'init' step if you do not intend to customize
141 any submodule locations.
143 deinit::
144 Unregister the given submodules, i.e. remove the whole
145 `submodule.$name` section from .git/config together with their work
146 tree. Further calls to `git submodule update`, `git submodule foreach`
147 and `git submodule sync` will skip any unregistered submodules until
148 they are initialized again, so use this command if you don't want to
149 have a local checkout of the submodule in your work tree anymore. If
150 you really want to remove a submodule from the repository and commit
151 that use linkgit:git-rm[1] instead.
152 +
153 If `--force` is specified, the submodule's work tree will be removed even if
154 it contains local modifications.
156 update::
157 Update the registered submodules, i.e. clone missing submodules and
158 checkout the commit specified in the index of the containing repository.
159 This will make the submodules HEAD be detached unless `--rebase` or
160 `--merge` is specified or the key `submodule.$name.update` is set to
161 `rebase`, `merge` or `none`. `none` can be overridden by specifying
162 `--checkout`.
163 +
164 If the submodule is not yet initialized, and you just want to use the
165 setting as stored in .gitmodules, you can automatically initialize the
166 submodule with the `--init` option.
167 +
168 If `--recursive` is specified, this command will recurse into the
169 registered submodules, and update any nested submodules within.
170 +
171 If `--force` is specified, the submodule will be checked out (using
172 `git checkout --force` if appropriate), even if the commit specified in the
173 index of the containing repository already matches the commit checked out in
174 the submodule.
176 summary::
177 Show commit summary between the given commit (defaults to HEAD) and
178 working tree/index. For a submodule in question, a series of commits
179 in the submodule between the given super project commit and the
180 index or working tree (switched by `--cached`) are shown. If the option
181 `--files` is given, show the series of commits in the submodule between
182 the index of the super project and the working tree of the submodule
183 (this option doesn't allow to use the `--cached` option or to provide an
184 explicit commit).
185 +
186 Using the `--submodule=log` option with linkgit:git-diff[1] will provide that
187 information too.
189 foreach::
190 Evaluates an arbitrary shell command in each checked out submodule.
191 The command has access to the variables $name, $path, $sha1 and
192 $toplevel:
193 $name is the name of the relevant submodule section in .gitmodules,
194 $path is the name of the submodule directory relative to the
195 superproject, $sha1 is the commit as recorded in the superproject,
196 and $toplevel is the absolute path to the top-level of the superproject.
197 Any submodules defined in the superproject but not checked out are
198 ignored by this command. Unless given `--quiet`, foreach prints the name
199 of each submodule before evaluating the command.
200 If `--recursive` is given, submodules are traversed recursively (i.e.
201 the given shell command is evaluated in nested submodules as well).
202 A non-zero return from the command in any submodule causes
203 the processing to terminate. This can be overridden by adding '|| :'
204 to the end of the command.
205 +
206 As an example, +git submodule foreach \'echo $path {backtick}git
207 rev-parse HEAD{backtick}'+ will show the path and currently checked out
208 commit for each submodule.
210 sync::
211 Synchronizes submodules' remote URL configuration setting
212 to the value specified in .gitmodules. It will only affect those
213 submodules which already have a URL entry in .git/config (that is the
214 case when they are initialized or freshly added). This is useful when
215 submodule URLs change upstream and you need to update your local
216 repositories accordingly.
217 +
218 "git submodule sync" synchronizes all submodules while
219 "git submodule sync \-- A" synchronizes submodule "A" only.
222 -------
223 -q::
224 --quiet::
225 Only print error messages.
227 -b::
228 --branch::
229 Branch of repository to add as submodule.
230 The name of the branch is recorded as `submodule.<path>.branch` in
231 `.gitmodules` for `update --remote`.
233 -f::
234 --force::
235 This option is only valid for add, deinit and update commands.
236 When running add, allow adding an otherwise ignored submodule path.
237 When running deinit the submodule work trees will be removed even if
238 they contain local changes.
239 When running update, throw away local changes in submodules when
240 switching to a different commit; and always run a checkout operation
241 in the submodule, even if the commit listed in the index of the
242 containing repository matches the commit checked out in the submodule.
244 --cached::
245 This option is only valid for status and summary commands. These
246 commands typically use the commit found in the submodule HEAD, but
247 with this option, the commit stored in the index is used instead.
249 --files::
250 This option is only valid for the summary command. This command
251 compares the commit in the index with that in the submodule HEAD
252 when this option is used.
254 -n::
255 --summary-limit::
256 This option is only valid for the summary command.
257 Limit the summary size (number of commits shown in total).
258 Giving 0 will disable the summary; a negative number means unlimited
259 (the default). This limit only applies to modified submodules. The
260 size is always limited to 1 for added/deleted/typechanged submodules.
262 --remote::
263 This option is only valid for the update command. Instead of using
264 the superproject's recorded SHA-1 to update the submodule, use the
265 status of the submodule's remote tracking branch. The remote used
266 is branch's remote (`branch.<name>.remote`), defaulting to `origin`.
267 The remote branch used defaults to `master`, but the branch name may
268 be overridden by setting the `submodule.<name>.branch` option in
269 either `.gitmodules` or `.git/config` (with `.git/config` taking
270 precedence).
271 +
272 This works for any of the supported update procedures (`--checkout`,
273 `--rebase`, etc.). The only change is the source of the target SHA-1.
274 For example, `submodule update --remote --merge` will merge upstream
275 submodule changes into the submodules, while `submodule update
276 --merge` will merge superproject gitlink changes into the submodules.
277 +
278 In order to ensure a current tracking branch state, `update --remote`
279 fetches the submodule's remote repository before calculating the
280 SHA-1. If you don't want to fetch, you should use `submodule update
281 --remote --no-fetch`.
283 -N::
284 --no-fetch::
285 This option is only valid for the update command.
286 Don't fetch new objects from the remote site.
288 --merge::
289 This option is only valid for the update command.
290 Merge the commit recorded in the superproject into the current branch
291 of the submodule. If this option is given, the submodule's HEAD will
292 not be detached. If a merge failure prevents this process, you will
293 have to resolve the resulting conflicts within the submodule with the
294 usual conflict resolution tools.
295 If the key `submodule.$name.update` is set to `merge`, this option is
296 implicit.
298 --rebase::
299 This option is only valid for the update command.
300 Rebase the current branch onto the commit recorded in the
301 superproject. If this option is given, the submodule's HEAD will not
302 be detached. If a merge failure prevents this process, you will have
303 to resolve these failures with linkgit:git-rebase[1].
304 If the key `submodule.$name.update` is set to `rebase`, this option is
305 implicit.
307 --init::
308 This option is only valid for the update command.
309 Initialize all submodules for which "git submodule init" has not been
310 called so far before updating.
312 --name::
313 This option is only valid for the add command. It sets the submodule's
314 name to the given string instead of defaulting to its path. The name
315 must be valid as a directory name and may not end with a '/'.
317 --reference <repository>::
318 This option is only valid for add and update commands. These
319 commands sometimes need to clone a remote repository. In this case,
320 this option will be passed to the linkgit:git-clone[1] command.
321 +
322 *NOTE*: Do *not* use this option unless you have read the note
323 for linkgit:git-clone[1]'s `--reference` and `--shared` options carefully.
325 --recursive::
326 This option is only valid for foreach, update and status commands.
327 Traverse submodules recursively. The operation is performed not
328 only in the submodules of the current repo, but also
329 in any nested submodules inside those submodules (and so on).
331 <path>...::
332 Paths to submodule(s). When specified this will restrict the command
333 to only operate on the submodules found at the specified paths.
334 (This argument is required with add).
337 -----
338 When initializing submodules, a .gitmodules file in the top-level directory
339 of the containing repository is used to find the url of each submodule.
340 This file should be formatted in the same way as `$GIT_DIR/config`. The key
341 to each submodule url is "submodule.$name.url". See linkgit:gitmodules[5]
342 for details.
344 GIT
345 ---
346 Part of the linkgit:git[1] suite