files-backend: cheapen refname_available check when locking refs
[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 [<options>] [--] <repository> [<path>]
13 'git submodule' [--quiet] status [--cached] [--recursive] [--] [<path>...]
14 'git submodule' [--quiet] init [--] [<path>...]
15 'git submodule' [--quiet] deinit [-f|--force] (--all|[--] <path>...)
16 'git submodule' [--quiet] update [<options>] [--] [<path>...]
17 'git submodule' [--quiet] summary [<options>] [--] [<path>...]
18 'git submodule' [--quiet] foreach [--recursive] <command>
19 'git submodule' [--quiet] sync [--recursive] [--] [<path>...]
20 'git submodule' [--quiet] absorbgitdirs [--] [<path>...]
24 -----------
25 Inspects, updates and manages submodules.
27 A submodule allows you to keep another Git repository in a subdirectory
28 of your repository. The other repository has its own history, which does not
29 interfere with the history of the current repository. This can be used to
30 have external dependencies such as third party libraries for example.
32 When cloning or pulling a repository containing submodules however,
33 these will not be checked out by default; the 'init' and 'update'
34 subcommands will maintain submodules checked out and at
35 appropriate revision in your working tree.
37 Submodules are composed from a so-called `gitlink` tree entry
38 in the main repository that refers to a particular commit object
39 within the inner repository that is completely separate.
40 A record in the `.gitmodules` (see linkgit:gitmodules[5]) file at the
41 root of the source tree assigns a logical name to the submodule and
42 describes the default URL the submodule shall be cloned from.
43 The logical name can be used for overriding this URL within your
44 local repository configuration (see 'submodule init').
46 Submodules are not to be confused with remotes, which are other
47 repositories of the same project; submodules are meant for
48 different projects you would like to make part of your source tree,
49 while the history of the two projects still stays completely
50 independent and you cannot modify the contents of the submodule
51 from within the main project.
52 If you want to merge the project histories and want to treat the
53 aggregated whole as a single project from then on, you may want to
54 add a remote for the other project and use the 'subtree' merge strategy,
55 instead of treating the other project as a submodule. Directories
56 that come from both projects can be cloned and checked out as a whole
57 if you choose to go that route.
60 --------
61 add [-b <branch>] [-f|--force] [--name <name>] [--reference <repository>] [--depth <depth>] [--] <repository> [<path>]::
62 Add the given repository as a submodule at the given path
63 to the changeset to be committed next to the current
64 project: the current project is termed the "superproject".
65 +
66 This requires at least one argument: <repository>. The optional
67 argument <path> is the relative location for the cloned submodule
68 to exist in the superproject. If <path> is not given, the
69 "humanish" part of the source repository is used ("repo" for
70 "/path/to/repo.git" and "foo" for "host.xz:foo/.git").
71 The <path> is also used as the submodule's logical name in its
72 configuration entries unless `--name` is used to specify a logical name.
73 +
74 <repository> is the URL of the new submodule's origin repository.
75 This may be either an absolute URL, or (if it begins with ./
76 or ../), the location relative to the superproject's default remote
77 repository (Please note that to specify a repository 'foo.git'
78 which is located right next to a superproject 'bar.git', you'll
79 have to use '../foo.git' instead of './foo.git' - as one might expect
80 when following the rules for relative URLs - because the evaluation
81 of relative URLs in Git is identical to that of relative directories).
82 +
83 The default remote is the remote of the remote tracking branch
84 of the current branch. If no such remote tracking branch exists or
85 the HEAD is detached, "origin" is assumed to be the default remote.
86 If the superproject doesn't have a default remote configured
87 the superproject is its own authoritative upstream and the current
88 working directory is used instead.
89 +
90 <path> is the relative location for the cloned submodule to
91 exist in the superproject. If <path> does not exist, then the
92 submodule is created by cloning from the named URL. If <path> does
93 exist and is already a valid Git repository, then this is added
94 to the changeset without cloning. This second form is provided
95 to ease creating a new submodule from scratch, and presumes
96 the user will later push the submodule to the given URL.
97 +
98 In either case, the given URL is recorded into .gitmodules for
99 use by subsequent users cloning the superproject. If the URL is
100 given relative to the superproject's repository, the presumption
101 is the superproject and submodule repositories will be kept
102 together in the same relative location, and only the
103 superproject's URL needs to be provided: git-submodule will correctly
104 locate the submodule using the relative URL in .gitmodules.
106 status [--cached] [--recursive] [--] [<path>...]::
107 Show the status of the submodules. This will print the SHA-1 of the
108 currently checked out commit for each submodule, along with the
109 submodule path and the output of 'git describe' for the
110 SHA-1. Each SHA-1 will be prefixed with `-` if the submodule is not
111 initialized, `+` if the currently checked out submodule commit
112 does not match the SHA-1 found in the index of the containing
113 repository and `U` if the submodule has merge conflicts.
114 +
115 If `--recursive` is specified, this command will recurse into nested
116 submodules, and show their status as well.
117 +
118 If you are only interested in changes of the currently initialized
119 submodules with respect to the commit recorded in the index or the HEAD,
120 linkgit:git-status[1] and linkgit:git-diff[1] will provide that information
121 too (and can also report changes to a submodule's work tree).
123 init [--] [<path>...]::
124 Initialize the submodules recorded in the index (which were
125 added and committed elsewhere) by setting `submodule.$name.url`
126 in .git/config. It uses the same setting from .gitmodules as
127 a template. If the URL is relative, it will be resolved using
128 the default remote. If there is no default remote, the current
129 repository will be assumed to be upstream.
130 +
131 Optional <path> arguments limit which submodules will be initialized.
132 If no path is specified and has been configured, submodules
133 configured to be active will be initialized, otherwise all submodules are
134 initialized.
135 +
136 When present, it will also copy the value of `submodule.$name.update`.
137 This command does not alter existing information in .git/config.
138 You can then customize the submodule clone URLs in .git/config
139 for your local setup and proceed to `git submodule update`;
140 you can also just use `git submodule update --init` without
141 the explicit 'init' step if you do not intend to customize
142 any submodule locations.
143 +
144 See the add subcommand for the defintion of default remote.
146 deinit [-f|--force] (--all|[--] <path>...)::
147 Unregister the given submodules, i.e. remove the whole
148 `submodule.$name` section from .git/config together with their work
149 tree. Further calls to `git submodule update`, `git submodule foreach`
150 and `git submodule sync` will skip any unregistered submodules until
151 they are initialized again, so use this command if you don't want to
152 have a local checkout of the submodule in your working tree anymore. If
153 you really want to remove a submodule from the repository and commit
154 that use linkgit:git-rm[1] instead.
155 +
156 When the command is run without pathspec, it errors out,
157 instead of deinit-ing everything, to prevent mistakes.
158 +
159 If `--force` is specified, the submodule's working tree will
160 be removed even if it contains local modifications.
162 update [--init] [--remote] [-N|--no-fetch] [--[no-]recommend-shallow] [-f|--force] [--checkout|--rebase|--merge] [--reference <repository>] [--depth <depth>] [--recursive] [--jobs <n>] [--] [<path>...]::
163 +
164 --
165 Update the registered submodules to match what the superproject
166 expects by cloning missing submodules and updating the working tree of
167 the submodules. The "updating" can be done in several ways depending
168 on command line options and the value of `submodule.<name>.update`
169 configuration variable. The command line option takes precedence over
170 the configuration variable. if neither is given, a checkout is performed.
171 update procedures supported both from the command line as well as setting
172 `submodule.<name>.update`:
174 checkout;; the commit recorded in the superproject will be
175 checked out in the submodule on a detached HEAD.
176 +
177 If `--force` is specified, the submodule will be checked out (using
178 `git checkout --force` if appropriate), even if the commit specified
179 in the index of the containing repository already matches the commit
180 checked out in the submodule.
182 rebase;; the current branch of the submodule will be rebased
183 onto the commit recorded in the superproject.
185 merge;; the commit recorded in the superproject will be merged
186 into the current branch in the submodule.
188 The following procedures are only available via the `submodule.<name>.update`
189 configuration variable:
191 custom command;; arbitrary shell command that takes a single
192 argument (the sha1 of the commit recorded in the
193 superproject) is executed. When `submodule.<name>.update`
194 is set to '!command', the remainder after the exclamation mark
195 is the custom command.
197 none;; the submodule is not updated.
199 If the submodule is not yet initialized, and you just want to use the
200 setting as stored in .gitmodules, you can automatically initialize the
201 submodule with the `--init` option.
203 If `--recursive` is specified, this command will recurse into the
204 registered submodules, and update any nested submodules within.
205 --
206 summary [--cached|--files] [(-n|--summary-limit) <n>] [commit] [--] [<path>...]::
207 Show commit summary between the given commit (defaults to HEAD) and
208 working tree/index. For a submodule in question, a series of commits
209 in the submodule between the given super project commit and the
210 index or working tree (switched by `--cached`) are shown. If the option
211 `--files` is given, show the series of commits in the submodule between
212 the index of the super project and the working tree of the submodule
213 (this option doesn't allow to use the `--cached` option or to provide an
214 explicit commit).
215 +
216 Using the `--submodule=log` option with linkgit:git-diff[1] will provide that
217 information too.
219 foreach [--recursive] <command>::
220 Evaluates an arbitrary shell command in each checked out submodule.
221 The command has access to the variables $name, $path, $sha1 and
222 $toplevel:
223 $name is the name of the relevant submodule section in .gitmodules,
224 $path is the name of the submodule directory relative to the
225 superproject, $sha1 is the commit as recorded in the superproject,
226 and $toplevel is the absolute path to the top-level of the superproject.
227 Any submodules defined in the superproject but not checked out are
228 ignored by this command. Unless given `--quiet`, foreach prints the name
229 of each submodule before evaluating the command.
230 If `--recursive` is given, submodules are traversed recursively (i.e.
231 the given shell command is evaluated in nested submodules as well).
232 A non-zero return from the command in any submodule causes
233 the processing to terminate. This can be overridden by adding '|| :'
234 to the end of the command.
235 +
236 As an example, the command below will show the path and currently
237 checked out commit for each submodule:
238 +
239 --------------
240 git submodule foreach 'echo $path `git rev-parse HEAD`'
241 --------------
243 sync [--recursive] [--] [<path>...]::
244 Synchronizes submodules' remote URL configuration setting
245 to the value specified in .gitmodules. It will only affect those
246 submodules which already have a URL entry in .git/config (that is the
247 case when they are initialized or freshly added). This is useful when
248 submodule URLs change upstream and you need to update your local
249 repositories accordingly.
250 +
251 "git submodule sync" synchronizes all submodules while
252 "git submodule sync \-- A" synchronizes submodule "A" only.
253 +
254 If `--recursive` is specified, this command will recurse into the
255 registered submodules, and sync any nested submodules within.
257 absorbgitdirs::
258 If a git directory of a submodule is inside the submodule,
259 move the git directory of the submodule into its superprojects
260 `$GIT_DIR/modules` path and then connect the git directory and
261 its working directory by setting the `core.worktree` and adding
262 a .git file pointing to the git directory embedded in the
263 superprojects git directory.
264 +
265 A repository that was cloned independently and later added as a submodule or
266 old setups have the submodules git directory inside the submodule instead of
267 embedded into the superprojects git directory.
268 +
269 This command is recursive by default.
272 -------
273 -q::
274 --quiet::
275 Only print error messages.
277 --all::
278 This option is only valid for the deinit command. Unregister all
279 submodules in the working tree.
281 -b::
282 --branch::
283 Branch of repository to add as submodule.
284 The name of the branch is recorded as `submodule.<name>.branch` in
285 `.gitmodules` for `update --remote`. A special value of `.` is used to
286 indicate that the name of the branch in the submodule should be the
287 same name as the current branch in the current repository.
289 -f::
290 --force::
291 This option is only valid for add, deinit and update commands.
292 When running add, allow adding an otherwise ignored submodule path.
293 When running deinit the submodule working trees will be removed even
294 if they contain local changes.
295 When running update (only effective with the checkout procedure),
296 throw away local changes in submodules when switching to a
297 different commit; and always run a checkout operation in the
298 submodule, even if the commit listed in the index of the
299 containing repository matches the commit checked out in the
300 submodule.
302 --cached::
303 This option is only valid for status and summary commands. These
304 commands typically use the commit found in the submodule HEAD, but
305 with this option, the commit stored in the index is used instead.
307 --files::
308 This option is only valid for the summary command. This command
309 compares the commit in the index with that in the submodule HEAD
310 when this option is used.
312 -n::
313 --summary-limit::
314 This option is only valid for the summary command.
315 Limit the summary size (number of commits shown in total).
316 Giving 0 will disable the summary; a negative number means unlimited
317 (the default). This limit only applies to modified submodules. The
318 size is always limited to 1 for added/deleted/typechanged submodules.
320 --remote::
321 This option is only valid for the update command. Instead of using
322 the superproject's recorded SHA-1 to update the submodule, use the
323 status of the submodule's remote-tracking branch. The remote used
324 is branch's remote (`branch.<name>.remote`), defaulting to `origin`.
325 The remote branch used defaults to `master`, but the branch name may
326 be overridden by setting the `submodule.<name>.branch` option in
327 either `.gitmodules` or `.git/config` (with `.git/config` taking
328 precedence).
329 +
330 This works for any of the supported update procedures (`--checkout`,
331 `--rebase`, etc.). The only change is the source of the target SHA-1.
332 For example, `submodule update --remote --merge` will merge upstream
333 submodule changes into the submodules, while `submodule update
334 --merge` will merge superproject gitlink changes into the submodules.
335 +
336 In order to ensure a current tracking branch state, `update --remote`
337 fetches the submodule's remote repository before calculating the
338 SHA-1. If you don't want to fetch, you should use `submodule update
339 --remote --no-fetch`.
340 +
341 Use this option to integrate changes from the upstream subproject with
342 your submodule's current HEAD. Alternatively, you can run `git pull`
343 from the submodule, which is equivalent except for the remote branch
344 name: `update --remote` uses the default upstream repository and
345 `submodule.<name>.branch`, while `git pull` uses the submodule's
346 `branch.<name>.merge`. Prefer `submodule.<name>.branch` if you want
347 to distribute the default upstream branch with the superproject and
348 `branch.<name>.merge` if you want a more native feel while working in
349 the submodule itself.
351 -N::
352 --no-fetch::
353 This option is only valid for the update command.
354 Don't fetch new objects from the remote site.
356 --checkout::
357 This option is only valid for the update command.
358 Checkout the commit recorded in the superproject on a detached HEAD
359 in the submodule. This is the default behavior, the main use of
360 this option is to override `submodule.$name.update` when set to
361 a value other than `checkout`.
362 If the key `submodule.$name.update` is either not explicitly set or
363 set to `checkout`, this option is implicit.
365 --merge::
366 This option is only valid for the update command.
367 Merge the commit recorded in the superproject into the current branch
368 of the submodule. If this option is given, the submodule's HEAD will
369 not be detached. If a merge failure prevents this process, you will
370 have to resolve the resulting conflicts within the submodule with the
371 usual conflict resolution tools.
372 If the key `submodule.$name.update` is set to `merge`, this option is
373 implicit.
375 --rebase::
376 This option is only valid for the update command.
377 Rebase the current branch onto the commit recorded in the
378 superproject. If this option is given, the submodule's HEAD will not
379 be detached. If a merge failure prevents this process, you will have
380 to resolve these failures with linkgit:git-rebase[1].
381 If the key `submodule.$name.update` is set to `rebase`, this option is
382 implicit.
384 --init::
385 This option is only valid for the update command.
386 Initialize all submodules for which "git submodule init" has not been
387 called so far before updating.
389 --name::
390 This option is only valid for the add command. It sets the submodule's
391 name to the given string instead of defaulting to its path. The name
392 must be valid as a directory name and may not end with a '/'.
394 --reference <repository>::
395 This option is only valid for add and update commands. These
396 commands sometimes need to clone a remote repository. In this case,
397 this option will be passed to the linkgit:git-clone[1] command.
398 +
399 *NOTE*: Do *not* use this option unless you have read the note
400 for linkgit:git-clone[1]'s `--reference` and `--shared` options carefully.
402 --recursive::
403 This option is only valid for foreach, update, status and sync commands.
404 Traverse submodules recursively. The operation is performed not
405 only in the submodules of the current repo, but also
406 in any nested submodules inside those submodules (and so on).
408 --depth::
409 This option is valid for add and update commands. Create a 'shallow'
410 clone with a history truncated to the specified number of revisions.
411 See linkgit:git-clone[1]
413 --[no-]recommend-shallow::
414 This option is only valid for the update command.
415 The initial clone of a submodule will use the recommended
416 `submodule.<name>.shallow` as provided by the .gitmodules file
417 by default. To ignore the suggestions use `--no-recommend-shallow`.
419 -j <n>::
420 --jobs <n>::
421 This option is only valid for the update command.
422 Clone new submodules in parallel with as many jobs.
423 Defaults to the `submodule.fetchJobs` option.
425 <path>...::
426 Paths to submodule(s). When specified this will restrict the command
427 to only operate on the submodules found at the specified paths.
428 (This argument is required with add).
431 -----
432 When initializing submodules, a .gitmodules file in the top-level directory
433 of the containing repository is used to find the url of each submodule.
434 This file should be formatted in the same way as `$GIT_DIR/config`. The key
435 to each submodule url is "submodule.$name.url". See linkgit:gitmodules[5]
436 for details.
438 GIT
439 ---
440 Part of the linkgit:git[1] suite