submodule sync: do not auto-vivify uninteresting submodule
[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]
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>...]
21
22
23 DESCRIPTION
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.
28
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.
41
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').
50
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.
63
64
65 COMMANDS
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.
98
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 and `+` if the currently checked out submodule commit
105 does not match the SHA-1 found in the index of the containing
106 repository. This command is the default command for 'git submodule'.
107 +
108 If '--recursive' is specified, this command will recurse into nested
109 submodules, and show their status as well.
110
111 init::
112 Initialize the submodules, i.e. register each submodule name
113 and url found in .gitmodules into .git/config.
114 The key used in .git/config is `submodule.$name.url`.
115 This command does not alter existing information in .git/config.
116 You can then customize the submodule clone URLs in .git/config
117 for your local setup and proceed to `git submodule update`;
118 you can also just use `git submodule update --init` without
119 the explicit 'init' step if you do not intend to customize
120 any submodule locations.
121
122 update::
123 Update the registered submodules, i.e. clone missing submodules and
124 checkout the commit specified in the index of the containing repository.
125 This will make the submodules HEAD be detached unless '--rebase' or
126 '--merge' is specified or the key `submodule.$name.update` is set to
127 `rebase` or `merge`.
128 +
129 If the submodule is not yet initialized, and you just want to use the
130 setting as stored in .gitmodules, you can automatically initialize the
131 submodule with the --init option.
132 +
133 If '--recursive' is specified, this command will recurse into the
134 registered submodules, and update any nested submodules within.
135
136 summary::
137 Show commit summary between the given commit (defaults to HEAD) and
138 working tree/index. For a submodule in question, a series of commits
139 in the submodule between the given super project commit and the
140 index or working tree (switched by --cached) are shown. If the option
141 --files is given, show the series of commits in the submodule between
142 the index of the super project and the working tree of the submodule
143 (this option doesn't allow to use the --cached option or to provide an
144 explicit commit).
145
146 foreach::
147 Evaluates an arbitrary shell command in each checked out submodule.
148 The command has access to the variables $name, $path, $sha1 and
149 $toplevel:
150 $name is the name of the relevant submodule section in .gitmodules,
151 $path is the name of the submodule directory relative to the
152 superproject, $sha1 is the commit as recorded in the superproject,
153 and $toplevel is the absolute path to the top-level of the superproject.
154 Any submodules defined in the superproject but not checked out are
155 ignored by this command. Unless given --quiet, foreach prints the name
156 of each submodule before evaluating the command.
157 If --recursive is given, submodules are traversed recursively (i.e.
158 the given shell command is evaluated in nested submodules as well).
159 A non-zero return from the command in any submodule causes
160 the processing to terminate. This can be overridden by adding '|| :'
161 to the end of the command.
162 +
163 As an example, +git submodule foreach \'echo $path {backtick}git
164 rev-parse HEAD{backtick}'+ will show the path and currently checked out
165 commit for each submodule.
166
167 sync::
168 Synchronizes submodules' remote URL configuration setting
169 to the value specified in .gitmodules. It will only affect those
170 submodules which already have an url entry in .git/config (that is the
171 case when they are initialized or freshly added). This is useful when
172 submodule URLs change upstream and you need to update your local
173 repositories accordingly.
174 +
175 "git submodule sync" synchronizes all submodules while
176 "git submodule sync -- A" synchronizes submodule "A" only.
177
178 OPTIONS
179 -------
180 -q::
181 --quiet::
182 Only print error messages.
183
184 -b::
185 --branch::
186 Branch of repository to add as submodule.
187
188 -f::
189 --force::
190 This option is only valid for the add command.
191 Allow adding an otherwise ignored submodule path.
192
193 --cached::
194 This option is only valid for status and summary commands. These
195 commands typically use the commit found in the submodule HEAD, but
196 with this option, the commit stored in the index is used instead.
197
198 --files::
199 This option is only valid for the summary command. This command
200 compares the commit in the index with that in the submodule HEAD
201 when this option is used.
202
203 -n::
204 --summary-limit::
205 This option is only valid for the summary command.
206 Limit the summary size (number of commits shown in total).
207 Giving 0 will disable the summary; a negative number means unlimited
208 (the default). This limit only applies to modified submodules. The
209 size is always limited to 1 for added/deleted/typechanged submodules.
210
211 -N::
212 --no-fetch::
213 This option is only valid for the update command.
214 Don't fetch new objects from the remote site.
215
216 --merge::
217 This option is only valid for the update command.
218 Merge the commit recorded in the superproject into the current branch
219 of the submodule. If this option is given, the submodule's HEAD will
220 not be detached. If a merge failure prevents this process, you will
221 have to resolve the resulting conflicts within the submodule with the
222 usual conflict resolution tools.
223 If the key `submodule.$name.update` is set to `merge`, this option is
224 implicit.
225
226 --rebase::
227 This option is only valid for the update command.
228 Rebase the current branch onto the commit recorded in the
229 superproject. If this option is given, the submodule's HEAD will not
230 be detached. If a merge failure prevents this process, you will have
231 to resolve these failures with linkgit:git-rebase[1].
232 If the key `submodule.$name.update` is set to `rebase`, this option is
233 implicit.
234
235 --reference <repository>::
236 This option is only valid for add and update commands. These
237 commands sometimes need to clone a remote repository. In this case,
238 this option will be passed to the linkgit:git-clone[1] command.
239 +
240 *NOTE*: Do *not* use this option unless you have read the note
241 for linkgit:git-clone[1]'s --reference and --shared options carefully.
242
243 --recursive::
244 This option is only valid for foreach, update and status commands.
245 Traverse submodules recursively. The operation is performed not
246 only in the submodules of the current repo, but also
247 in any nested submodules inside those submodules (and so on).
248
249 <path>...::
250 Paths to submodule(s). When specified this will restrict the command
251 to only operate on the submodules found at the specified paths.
252 (This argument is required with add).
253
254 FILES
255 -----
256 When initializing submodules, a .gitmodules file in the top-level directory
257 of the containing repository is used to find the url of each submodule.
258 This file should be formatted in the same way as `$GIT_DIR/config`. The key
259 to each submodule url is "submodule.$name.url". See linkgit:gitmodules[5]
260 for details.
261
262
263 AUTHOR
264 ------
265 Written by Lars Hjemli <hjemli@gmail.com>
266
267 GIT
268 ---
269 Part of the linkgit:git[1] suite