git-submodule - Add 'foreach' subcommand
[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] [--] <repository> <path>
13 'git submodule' [--quiet] status [--cached] [--] [<path>...]
14 'git submodule' [--quiet] init [--] [<path>...]
15 'git submodule' [--quiet] update [--init] [--] [<path>...]
16 'git submodule' [--quiet] summary [--summary-limit <n>] [commit] [--] [<path>...]
17 'git submodule' [--quiet] foreach <command>
18
19
20 DESCRIPTION
21 -----------
22 Submodules allow foreign repositories to be embedded within
23 a dedicated subdirectory of the source tree, always pointed
24 at a particular commit.
25
26 They are not to be confused with remotes, which are meant mainly
27 for branches of the same project; submodules are meant for
28 different projects you would like to make part of your source tree,
29 while the history of the two projects still stays completely
30 independent and you cannot modify the contents of the submodule
31 from within the main project.
32 If you want to merge the project histories and want to treat the
33 aggregated whole as a single project from then on, you may want to
34 add a remote for the other project and use the 'subtree' merge strategy,
35 instead of treating the other project as a submodule. Directories
36 that come from both projects can be cloned and checked out as a whole
37 if you choose to go that route.
38
39 Submodules are composed from a so-called `gitlink` tree entry
40 in the main repository that refers to a particular commit object
41 within the inner repository that is completely separate.
42 A record in the `.gitmodules` file at the root of the source
43 tree assigns a logical name to the submodule and describes
44 the default URL the submodule shall be cloned from.
45 The logical name can be used for overriding this URL within your
46 local repository configuration (see 'submodule init').
47
48 This command will manage the tree entries and contents of the
49 gitmodules file for you, as well as inspect the status of your
50 submodules and update them.
51 When adding a new submodule to the tree, the 'add' subcommand
52 is to be used. However, when pulling a tree containing submodules,
53 these will not be checked out by default;
54 the 'init' and 'update' subcommands will maintain submodules
55 checked out and at appropriate revision in your working tree.
56 You can briefly inspect the up-to-date status of your submodules
57 using the 'status' subcommand and get a detailed overview of the
58 difference between the index and checkouts using the 'summary'
59 subcommand.
60
61
62 COMMANDS
63 --------
64 add::
65 Add the given repository as a submodule at the given path
66 to the changeset to be committed next to the current
67 project: the current project is termed the "superproject".
68 +
69 This requires two arguments: <repository> and <path>.
70 +
71 <repository> is the URL of the new submodule's origin repository.
72 This may be either an absolute URL, or (if it begins with ./
73 or ../), the location relative to the superproject's origin
74 repository.
75 +
76 <path> is the relative location for the cloned submodule to
77 exist in the superproject. If <path> does not exist, then the
78 submodule is created by cloning from the named URL. If <path> does
79 exist and is already a valid git repository, then this is added
80 to the changeset without cloning. This second form is provided
81 to ease creating a new submodule from scratch, and presumes
82 the user will later push the submodule to the given URL.
83 +
84 In either case, the given URL is recorded into .gitmodules for
85 use by subsequent users cloning the superproject. If the URL is
86 given relative to the superproject's repository, the presumption
87 is the superproject and submodule repositories will be kept
88 together in the same relative location, and only the
89 superproject's URL need be provided: git-submodule will correctly
90 locate the submodule using the relative URL in .gitmodules.
91
92 status::
93 Show the status of the submodules. This will print the SHA-1 of the
94 currently checked out commit for each submodule, along with the
95 submodule path and the output of 'git-describe' for the
96 SHA-1. Each SHA-1 will be prefixed with `-` if the submodule is not
97 initialized and `+` if the currently checked out submodule commit
98 does not match the SHA-1 found in the index of the containing
99 repository. This command is the default command for 'git-submodule'.
100
101 init::
102 Initialize the submodules, i.e. register each submodule name
103 and url found in .gitmodules into .git/config.
104 The key used in .git/config is `submodule.$name.url`.
105 This command does not alter existing information in .git/config.
106 You can then customize the submodule clone URLs in .git/config
107 for your local setup and proceed to 'git submodule update';
108 you can also just use 'git submodule update --init' without
109 the explicit 'init' step if you do not intend to customize
110 any submodule locations.
111
112 update::
113 Update the registered submodules, i.e. clone missing submodules and
114 checkout the commit specified in the index of the containing repository.
115 This will make the submodules HEAD be detached.
116 +
117 If the submodule is not yet initialized, and you just want to use the
118 setting as stored in .gitmodules, you can automatically initialize the
119 submodule with the --init option.
120
121 summary::
122 Show commit summary between the given commit (defaults to HEAD) and
123 working tree/index. For a submodule in question, a series of commits
124 in the submodule between the given super project commit and the
125 index or working tree (switched by --cached) are shown.
126
127 foreach::
128 Evaluates an arbitrary shell command in each checked out submodule.
129 The command has access to the variables $path and $sha1:
130 $path is the name of the submodule directory relative to the
131 superproject, and $sha1 is the commit as recorded in the superproject.
132 Any submodules defined in the superproject but not checked out are
133 ignored by this command. Unless given --quiet, foreach prints the name
134 of each submodule before evaluating the command.
135 A non-zero return from the command in any submodule causes
136 the processing to terminate. This can be overridden by adding '|| :'
137 to the end of the command.
138 +
139 As an example, "git submodule foreach 'echo $path `git rev-parse HEAD`' will
140 show the path and currently checked out commit for each submodule.
141
142
143 OPTIONS
144 -------
145 -q::
146 --quiet::
147 Only print error messages.
148
149 -b::
150 --branch::
151 Branch of repository to add as submodule.
152
153 --cached::
154 This option is only valid for status and summary commands. These
155 commands typically use the commit found in the submodule HEAD, but
156 with this option, the commit stored in the index is used instead.
157
158 -n::
159 --summary-limit::
160 This option is only valid for the summary command.
161 Limit the summary size (number of commits shown in total).
162 Giving 0 will disable the summary; a negative number means unlimited
163 (the default). This limit only applies to modified submodules. The
164 size is always limited to 1 for added/deleted/typechanged submodules.
165
166 <path>...::
167 Paths to submodule(s). When specified this will restrict the command
168 to only operate on the submodules found at the specified paths.
169 (This argument is required with add).
170
171 FILES
172 -----
173 When initializing submodules, a .gitmodules file in the top-level directory
174 of the containing repository is used to find the url of each submodule.
175 This file should be formatted in the same way as `$GIT_DIR/config`. The key
176 to each submodule url is "submodule.$name.url". See linkgit:gitmodules[5]
177 for details.
178
179
180 AUTHOR
181 ------
182 Written by Lars Hjemli <hjemli@gmail.com>
183
184 GIT
185 ---
186 Part of the linkgit:git[1] suite