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