Merge branch 'fc/remote-bzr'
[git/git.git] / Documentation / git-submodule.txt
1 git-submodule(1)
2 ================
3
4 NAME
5 ----
6 git-submodule - Initialize, update or inspect submodules
7
8
9 SYNOPSIS
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] update [--init] [--remote] [-N|--no-fetch] [--rebase]
17 [--reference <repository>] [--merge] [--recursive] [--] [<path>...]
18 'git submodule' [--quiet] summary [--cached|--files] [(-n|--summary-limit) <n>]
19 [commit] [--] [<path>...]
20 'git submodule' [--quiet] foreach [--recursive] <command>
21 'git submodule' [--quiet] sync [--] [<path>...]
22
23
24 DESCRIPTION
25 -----------
26 Submodules allow foreign repositories to be embedded within
27 a dedicated subdirectory of the source tree, always pointed
28 at a particular commit.
29
30 They are not to be confused with remotes, which are meant mainly
31 for branches of the same project; submodules are meant for
32 different projects you would like to make part of your source tree,
33 while the history of the two projects still stays completely
34 independent and you cannot modify the contents of the submodule
35 from within the main project.
36 If you want to merge the project histories and want to treat the
37 aggregated whole as a single project from then on, you may want to
38 add a remote for the other project and use the 'subtree' merge strategy,
39 instead of treating the other project as a submodule. Directories
40 that come from both projects can be cloned and checked out as a whole
41 if you choose to go that route.
42
43 Submodules are composed from a so-called `gitlink` tree entry
44 in the main repository that refers to a particular commit object
45 within the inner repository that is completely separate.
46 A record in the `.gitmodules` (see linkgit:gitmodules[5]) file at the
47 root of the source tree assigns a logical name to the submodule and
48 describes the default URL the submodule shall be cloned from.
49 The logical name can be used for overriding this URL within your
50 local repository configuration (see 'submodule init').
51
52 This command will manage the tree entries and contents of the
53 gitmodules file for you, as well as inspect the status of your
54 submodules and update them.
55 When adding a new submodule to the tree, the 'add' subcommand
56 is to be used. However, when pulling a tree containing submodules,
57 these will not be checked out by default;
58 the 'init' and 'update' subcommands will maintain submodules
59 checked out and at appropriate revision in your working tree.
60 You can briefly inspect the up-to-date status of your submodules
61 using the 'status' subcommand and get a detailed overview of the
62 difference between the index and checkouts using the 'summary'
63 subcommand.
64
65
66 COMMANDS
67 --------
68 add::
69 Add the given repository as a submodule at the given path
70 to the changeset to be committed next to the current
71 project: the current project is termed the "superproject".
72 +
73 This requires at least one argument: <repository>. The optional
74 argument <path> is the relative location for the cloned submodule
75 to exist in the superproject. If <path> is not given, the
76 "humanish" part of the source repository is used ("repo" for
77 "/path/to/repo.git" and "foo" for "host.xz:foo/.git").
78 +
79 <repository> is the URL of the new submodule's origin repository.
80 This may be either an absolute URL, or (if it begins with ./
81 or ../), the location relative to the superproject's origin
82 repository (Please note that to specify a repository 'foo.git'
83 which is located right next to a superproject 'bar.git', you'll
84 have to use '../foo.git' instead of './foo.git' - as one might expect
85 when following the rules for relative URLs - because the evaluation
86 of relative URLs in Git is identical to that of relative directories).
87 If the superproject doesn't have an origin configured
88 the superproject is its own authoritative upstream and the current
89 working directory is used instead.
90 +
91 <path> is the relative location for the cloned submodule to
92 exist in the superproject. If <path> does not exist, then the
93 submodule is created by cloning from the named URL. If <path> does
94 exist and is already a valid git repository, then this is added
95 to the changeset without cloning. This second form is provided
96 to ease creating a new submodule from scratch, and presumes
97 the user will later push the submodule to the given URL.
98 +
99 In either case, the given URL is recorded into .gitmodules for
100 use by subsequent users cloning the superproject. If the URL is
101 given relative to the superproject's repository, the presumption
102 is the superproject and submodule repositories will be kept
103 together in the same relative location, and only the
104 superproject's URL needs to be provided: git-submodule will correctly
105 locate the submodule using the relative URL in .gitmodules.
106
107 status::
108 Show the status of the submodules. This will print the SHA-1 of the
109 currently checked out commit for each submodule, along with the
110 submodule path and the output of 'git describe' for the
111 SHA-1. Each SHA-1 will be prefixed with `-` if the submodule is not
112 initialized, `+` if the currently checked out submodule commit
113 does not match the SHA-1 found in the index of the containing
114 repository and `U` if the submodule has merge conflicts.
115 +
116 If `--recursive` is specified, this command will recurse into nested
117 submodules, and show their status as well.
118 +
119 If you are only interested in changes of the currently initialized
120 submodules with respect to the commit recorded in the index or the HEAD,
121 linkgit:git-status[1] and linkgit:git-diff[1] will provide that information
122 too (and can also report changes to a submodule's work tree).
123
124 init::
125 Initialize the submodules, i.e. register each submodule name
126 and url found in .gitmodules into .git/config.
127 It will also copy the value of `submodule.$name.update` into
128 .git/config.
129 The key used in .git/config is `submodule.$name.url`.
130 This command does not alter existing information in .git/config.
131 You can then customize the submodule clone URLs in .git/config
132 for your local setup and proceed to `git submodule update`;
133 you can also just use `git submodule update --init` without
134 the explicit 'init' step if you do not intend to customize
135 any submodule locations.
136
137 update::
138 Update the registered submodules, i.e. clone missing submodules and
139 checkout the commit specified in the index of the containing repository.
140 This will make the submodules HEAD be detached unless `--rebase` or
141 `--merge` is specified or the key `submodule.$name.update` is set to
142 `rebase`, `merge` or `none`. `none` can be overridden by specifying
143 `--checkout`.
144 +
145 If the submodule is not yet initialized, and you just want to use the
146 setting as stored in .gitmodules, you can automatically initialize the
147 submodule with the `--init` option.
148 +
149 If `--recursive` is specified, this command will recurse into the
150 registered submodules, and update any nested submodules within.
151 +
152 If `--force` is specified, the submodule will be checked out (using
153 `git checkout --force` if appropriate), even if the commit specified in the
154 index of the containing repository already matches the commit checked out in
155 the submodule.
156
157 summary::
158 Show commit summary between the given commit (defaults to HEAD) and
159 working tree/index. For a submodule in question, a series of commits
160 in the submodule between the given super project commit and the
161 index or working tree (switched by `--cached`) are shown. If the option
162 `--files` is given, show the series of commits in the submodule between
163 the index of the super project and the working tree of the submodule
164 (this option doesn't allow to use the `--cached` option or to provide an
165 explicit commit).
166 +
167 Using the `--submodule=log` option with linkgit:git-diff[1] will provide that
168 information too.
169
170 foreach::
171 Evaluates an arbitrary shell command in each checked out submodule.
172 The command has access to the variables $name, $path, $sha1 and
173 $toplevel:
174 $name is the name of the relevant submodule section in .gitmodules,
175 $path is the name of the submodule directory relative to the
176 superproject, $sha1 is the commit as recorded in the superproject,
177 and $toplevel is the absolute path to the top-level of the superproject.
178 Any submodules defined in the superproject but not checked out are
179 ignored by this command. Unless given `--quiet`, foreach prints the name
180 of each submodule before evaluating the command.
181 If `--recursive` is given, submodules are traversed recursively (i.e.
182 the given shell command is evaluated in nested submodules as well).
183 A non-zero return from the command in any submodule causes
184 the processing to terminate. This can be overridden by adding '|| :'
185 to the end of the command.
186 +
187 As an example, +git submodule foreach \'echo $path {backtick}git
188 rev-parse HEAD{backtick}'+ will show the path and currently checked out
189 commit for each submodule.
190
191 sync::
192 Synchronizes submodules' remote URL configuration setting
193 to the value specified in .gitmodules. It will only affect those
194 submodules which already have a URL entry in .git/config (that is the
195 case when they are initialized or freshly added). This is useful when
196 submodule URLs change upstream and you need to update your local
197 repositories accordingly.
198 +
199 "git submodule sync" synchronizes all submodules while
200 "git submodule sync \-- A" synchronizes submodule "A" only.
201
202 OPTIONS
203 -------
204 -q::
205 --quiet::
206 Only print error messages.
207
208 -b::
209 --branch::
210 Branch of repository to add as submodule.
211 The name of the branch is recorded as `submodule.<path>.branch` in
212 `.gitmodules` for `update --remote`.
213
214 -f::
215 --force::
216 This option is only valid for add and update commands.
217 When running add, allow adding an otherwise ignored submodule path.
218 When running update, throw away local changes in submodules when
219 switching to a different commit; and always run a checkout operation
220 in the submodule, even if the commit listed in the index of the
221 containing repository matches the commit checked out in the submodule.
222
223 --cached::
224 This option is only valid for status and summary commands. These
225 commands typically use the commit found in the submodule HEAD, but
226 with this option, the commit stored in the index is used instead.
227
228 --files::
229 This option is only valid for the summary command. This command
230 compares the commit in the index with that in the submodule HEAD
231 when this option is used.
232
233 -n::
234 --summary-limit::
235 This option is only valid for the summary command.
236 Limit the summary size (number of commits shown in total).
237 Giving 0 will disable the summary; a negative number means unlimited
238 (the default). This limit only applies to modified submodules. The
239 size is always limited to 1 for added/deleted/typechanged submodules.
240
241 --remote::
242 This option is only valid for the update command. Instead of using
243 the superproject's recorded SHA-1 to update the submodule, use the
244 status of the submodule's remote tracking branch. The remote used
245 is branch's remote (`branch.<name>.remote`), defaulting to `origin`.
246 The remote branch used defaults to `master`, but the branch name may
247 be overridden by setting the `submodule.<name>.branch` option in
248 either `.gitmodules` or `.git/config` (with `.git/config` taking
249 precedence).
250 +
251 This works for any of the supported update procedures (`--checkout`,
252 `--rebase`, etc.). The only change is the source of the target SHA-1.
253 For example, `submodule update --remote --merge` will merge upstream
254 submodule changes into the submodules, while `submodule update
255 --merge` will merge superproject gitlink changes into the submodules.
256 +
257 In order to ensure a current tracking branch state, `update --remote`
258 fetches the submodule's remote repository before calculating the
259 SHA-1. If you don't want to fetch, you should use `submodule update
260 --remote --no-fetch`.
261
262 -N::
263 --no-fetch::
264 This option is only valid for the update command.
265 Don't fetch new objects from the remote site.
266
267 --merge::
268 This option is only valid for the update command.
269 Merge the commit recorded in the superproject into the current branch
270 of the submodule. If this option is given, the submodule's HEAD will
271 not be detached. If a merge failure prevents this process, you will
272 have to resolve the resulting conflicts within the submodule with the
273 usual conflict resolution tools.
274 If the key `submodule.$name.update` is set to `merge`, this option is
275 implicit.
276
277 --rebase::
278 This option is only valid for the update command.
279 Rebase the current branch onto the commit recorded in the
280 superproject. If this option is given, the submodule's HEAD will not
281 be detached. If a merge failure prevents this process, you will have
282 to resolve these failures with linkgit:git-rebase[1].
283 If the key `submodule.$name.update` is set to `rebase`, this option is
284 implicit.
285
286 --init::
287 This option is only valid for the update command.
288 Initialize all submodules for which "git submodule init" has not been
289 called so far before updating.
290
291 --name::
292 This option is only valid for the add command. It sets the submodule's
293 name to the given string instead of defaulting to its path. The name
294 must be valid as a directory name and may not end with a '/'.
295
296 --reference <repository>::
297 This option is only valid for add and update commands. These
298 commands sometimes need to clone a remote repository. In this case,
299 this option will be passed to the linkgit:git-clone[1] command.
300 +
301 *NOTE*: Do *not* use this option unless you have read the note
302 for linkgit:git-clone[1]'s `--reference` and `--shared` options carefully.
303
304 --recursive::
305 This option is only valid for foreach, update and status commands.
306 Traverse submodules recursively. The operation is performed not
307 only in the submodules of the current repo, but also
308 in any nested submodules inside those submodules (and so on).
309
310 <path>...::
311 Paths to submodule(s). When specified this will restrict the command
312 to only operate on the submodules found at the specified paths.
313 (This argument is required with add).
314
315 FILES
316 -----
317 When initializing submodules, a .gitmodules file in the top-level directory
318 of the containing repository is used to find the url of each submodule.
319 This file should be formatted in the same way as `$GIT_DIR/config`. The key
320 to each submodule url is "submodule.$name.url". See linkgit:gitmodules[5]
321 for details.
322
323 GIT
324 ---
325 Part of the linkgit:git[1] suite