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NAME
git-submodule - Initialize, update or inspect submodules
SYNOPSIS
git submodule [--quiet] add [-b <branch>] [-f|--force] [--name <name>]
[--reference <repository>] [--depth <depth>] [--] <repository> [<path>]
git submodule [--quiet] status [--cached] [--recursive] [--] [<path>...]
git submodule [--quiet] init [--] [<path>...]
git submodule [--quiet] deinit [-f|--force] [--] <path>...
git submodule [--quiet] update [--init] [--remote] [-N|--no-fetch]
[-f|--force] [--rebase] [--reference <repository>] [--depth <depth>]
[--merge] [--recursive] [--] [<path>...]
git submodule [--quiet] summary [--cached|--files] [(-n|--summary-limit) <n>]
[commit] [--] [<path>...]
git submodule [--quiet] foreach [--recursive] <command>
git submodule [--quiet] sync [--] [<path>...]
DESCRIPTION
Submodules allow foreign repositories to be embedded within a dedicated subdirectory of the source tree,
always pointed at a particular commit.
They are not to be confused with remotes, which are meant mainly for branches of the same project;
submodules are meant for different projects you would like to make part of your source tree, while the
history of the two projects still stays completely independent and you cannot modify the contents of the
submodule from within the main project. If you want to merge the project histories and want to treat the
aggregated whole as a single project from then on, you may want to add a remote for the other project and
use the subtree merge strategy, instead of treating the other project as a submodule. Directories that
come from both projects can be cloned and checked out as a whole if you choose to go that route.
Submodules are composed from a so-called gitlink tree entry in the main repository that refers to a
particular commit object within the inner repository that is completely separate. A record in the
.gitmodules (see gitmodules(5)) file at the root of the source tree assigns a logical name to the
submodule and describes the default URL the submodule shall be cloned from. The logical name can be used
for overriding this URL within your local repository configuration (see submodule init).
This command will manage the tree entries and contents of the gitmodules file for you, as well as inspect
the status of your submodules and update them. When adding a new submodule to the tree, the add
subcommand is to be used. However, when pulling a tree containing submodules, these will not be checked
out by default; the init and update subcommands will maintain submodules checked out and at appropriate
revision in your working tree. You can briefly inspect the up-to-date status of your submodules using the
status subcommand and get a detailed overview of the difference between the index and checkouts using the
summary subcommand.
COMMANDS
add
Add the given repository as a submodule at the given path to the changeset to be committed next to
the current project: the current project is termed the "superproject".
This requires at least one argument: <repository>. The optional argument <path> is the relative
location for the cloned submodule to exist in the superproject. If <path> is not given, the
"humanish" part of the source repository is used ("repo" for "/path/to/repo.git" and "foo" for
"host.xz:foo/.git"). The <path> is also used as the submodule’s logical name in its configuration
entries unless --name is used to specify a logical name.
<repository> is the URL of the new submodule’s origin repository. This may be either an absolute URL,
or (if it begins with ./ or ../), the location relative to the superproject’s origin repository
(Please note that to specify a repository foo.git which is located right next to a superproject
bar.git, you’ll have to use ../foo.git instead of ./foo.git - as one might expect when following the
rules for relative URLs - because the evaluation of relative URLs in Git is identical to that of
relative directories). If the superproject doesn’t have an origin configured the superproject is its
own authoritative upstream and the current working directory is used instead.
<path> is the relative location for the cloned submodule to exist in the superproject. If <path> does
not exist, then the submodule is created by cloning from the named URL. If <path> does exist and is
already a valid Git repository, then this is added to the changeset without cloning. This second form
is provided to ease creating a new submodule from scratch, and presumes the user will later push the
submodule to the given URL.
In either case, the given URL is recorded into .gitmodules for use by subsequent users cloning the
superproject. If the URL is given relative to the superproject’s repository, the presumption is the
superproject and submodule repositories will be kept together in the same relative location, and only
the superproject’s URL needs to be provided: git-submodule will correctly locate the submodule using
the relative URL in .gitmodules.
status
Show the status of the submodules. This will print the SHA-1 of the currently checked out commit for
each submodule, along with the submodule path and the output of git describe for the SHA-1. Each
SHA-1 will be prefixed with - if the submodule is not initialized, + if the currently checked out
submodule commit does not match the SHA-1 found in the index of the containing repository and U if
the submodule has merge conflicts.
If --recursive is specified, this command will recurse into nested submodules, and show their status
as well.
If you are only interested in changes of the currently initialized submodules with respect to the
commit recorded in the index or the HEAD, git-status(1) and git-diff(1) will provide that information
too (and can also report changes to a submodule’s work tree).
init
Initialize the submodules recorded in the index (which were added and committed elsewhere) by copying
submodule names and urls from .gitmodules to .git/config. Optional <path> arguments limit which
submodules will be initialized. It will also copy the value of submodule.$name.update into
.git/config. The key used in .git/config is submodule.$name.url. This command does not alter existing
information in .git/config. You can then customize the submodule clone URLs in .git/config for your
local setup and proceed to git submodule update; you can also just use git submodule update --init
without the explicit init step if you do not intend to customize any submodule locations.
deinit
Unregister the given submodules, i.e. remove the whole submodule.$name section from .git/config
together with their work tree. Further calls to git submodule update, git submodule foreach and git
submodule sync will skip any unregistered submodules until they are initialized again, so use this
command if you don’t want to have a local checkout of the submodule in your work tree anymore. If you
really want to remove a submodule from the repository and commit that use git-rm(1) instead.
If --force is specified, the submodule’s work tree will be removed even if it contains local
modifications.
update
Update the registered submodules, i.e. clone missing submodules and checkout the commit specified in
the index of the containing repository. This will make the submodules HEAD be detached unless
--rebase or --merge is specified or the key submodule.$name.update is set to rebase, merge or none.
none can be overridden by specifying --checkout. Setting the key submodule.$name.update to !command
will cause command to be run. command can be any arbitrary shell command that takes a single
argument, namely the sha1 to update to.
If the submodule is not yet initialized, and you just want to use the setting as stored in
.gitmodules, you can automatically initialize the submodule with the --init option.
If --recursive is specified, this command will recurse into the registered submodules, and update any
nested submodules within.
If --force is specified, the submodule will be checked out (using git checkout --force if
appropriate), even if the commit specified in the index of the containing repository already matches
the commit checked out in the submodule.
summary
Show commit summary between the given commit (defaults to HEAD) and working tree/index. For a
submodule in question, a series of commits in the submodule between the given super project commit
and the index or working tree (switched by --cached) are shown. If the option --files is given, show
the series of commits in the submodule between the index of the super project and the working tree of
the submodule (this option doesn’t allow to use the --cached option or to provide an explicit
commit).
Using the --submodule=log option with git-diff(1) will provide that information too.
foreach
Evaluates an arbitrary shell command in each checked out submodule. The command has access to the
variables $name, $path, $sha1 and $toplevel: $name is the name of the relevant submodule section in
.gitmodules, $path is the name of the submodule directory relative to the superproject, $sha1 is the
commit as recorded in the superproject, and $toplevel is the absolute path to the top-level of the
superproject. Any submodules defined in the superproject but not checked out are ignored by this
command. Unless given --quiet, foreach prints the name of each submodule before evaluating the
command. If --recursive is given, submodules are traversed recursively (i.e. the given shell command
is evaluated in nested submodules as well). A non-zero return from the command in any submodule
causes the processing to terminate. This can be overridden by adding || : to the end of the command.
As an example, git submodule foreach 'echo $path `git rev-parse HEAD`' will show the path and
currently checked out commit for each submodule.
sync
Synchronizes submodules' remote URL configuration setting to the value specified in .gitmodules. It
will only affect those submodules which already have a URL entry in .git/config (that is the case
when they are initialized or freshly added). This is useful when submodule URLs change upstream and
you need to update your local repositories accordingly.
"git submodule sync" synchronizes all submodules while "git submodule sync -- A" synchronizes
submodule "A" only.
OPTIONS
-q, --quiet
Only print error messages.
-b, --branch
Branch of repository to add as submodule. The name of the branch is recorded as
submodule.<path>.branch in .gitmodules for update --remote.
-f, --force
This option is only valid for add, deinit and update commands. When running add, allow adding an
otherwise ignored submodule path. When running deinit the submodule work trees will be removed even
if they contain local changes. When running update, throw away local changes in submodules when
switching to a different commit; and always run a checkout operation in the submodule, even if the
commit listed in the index of the containing repository matches the commit checked out in the
submodule.
--cached
This option is only valid for status and summary commands. These commands typically use the commit
found in the submodule HEAD, but with this option, the commit stored in the index is used instead.
--files
This option is only valid for the summary command. This command compares the commit in the index with
that in the submodule HEAD when this option is used.
-n, --summary-limit
This option is only valid for the summary command. Limit the summary size (number of commits shown in
total). Giving 0 will disable the summary; a negative number means unlimited (the default). This
limit only applies to modified submodules. The size is always limited to 1 for
added/deleted/typechanged submodules.
--remote
This option is only valid for the update command. Instead of using the superproject’s recorded SHA-1
to update the submodule, use the status of the submodule’s remote-tracking branch. The remote used is
branch’s remote (branch.<name>.remote), defaulting to origin. The remote branch used defaults to
master, but the branch name may be overridden by setting the submodule.<name>.branch option in either
.gitmodules or .git/config (with .git/config taking precedence).
This works for any of the supported update procedures (--checkout, --rebase, etc.). The only change
is the source of the target SHA-1. For example, submodule update --remote --merge will merge upstream
submodule changes into the submodules, while submodule update --merge will merge superproject gitlink
changes into the submodules.
In order to ensure a current tracking branch state, update --remote fetches the submodule’s remote
repository before calculating the SHA-1. If you don’t want to fetch, you should use submodule update
--remote --no-fetch.
-N, --no-fetch
This option is only valid for the update command. Don’t fetch new objects from the remote site.
--merge
This option is only valid for the update command. Merge the commit recorded in the superproject into
the current branch of the submodule. If this option is given, the submodule’s HEAD will not be
detached. If a merge failure prevents this process, you will have to resolve the resulting conflicts
within the submodule with the usual conflict resolution tools. If the key submodule.$name.update is
set to merge, this option is implicit.
--rebase
This option is only valid for the update command. Rebase the current branch onto the commit recorded
in the superproject. If this option is given, the submodule’s HEAD will not be detached. If a merge
failure prevents this process, you will have to resolve these failures with git-rebase(1). If the key
submodule.$name.update is set to rebase, this option is implicit.
--init
This option is only valid for the update command. Initialize all submodules for which "git submodule
init" has not been called so far before updating.
--name
This option is only valid for the add command. It sets the submodule’s name to the given string
instead of defaulting to its path. The name must be valid as a directory name and may not end with a
/.
--reference <repository>
This option is only valid for add and update commands. These commands sometimes need to clone a
remote repository. In this case, this option will be passed to the git-clone(1) command.
NOTE: Do not use this option unless you have read the note for git-clone(1)'s --reference and
--shared options carefully.
--recursive
This option is only valid for foreach, update and status commands. Traverse submodules recursively.
The operation is performed not only in the submodules of the current repo, but also in any nested
submodules inside those submodules (and so on).
--depth
This option is valid for add and update commands. Create a shallow clone with a history truncated to
the specified number of revisions. See git-clone(1)
<path>...
Paths to submodule(s). When specified this will restrict the command to only operate on the
submodules found at the specified paths. (This argument is required with add).
FILES
When initializing submodules, a .gitmodules file in the top-level directory of the containing repository
is used to find the url of each submodule. This file should be formatted in the same way as
$GIT_DIR/config. The key to each submodule url is "submodule.$name.url". See gitmodules(5) for details.
GIT
Part of the git(1) suite
Git 1.9.1 11/27/2018 GIT-SUBMODULE(1)