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|--merge] [--reference <repository>]
                     [--depth <depth>] [--recursive] [--] [<path>...]
       git submodule [--quiet] summary [--cached|--files] [(-n|--summary-limit) <n>]
                     [commit] [--] [<path>...]
       git submodule [--quiet] foreach [--recursive] <command>
       git submodule [--quiet] sync [--recursive] [--] [<path>...]

DESCRIPTION

       Inspects, updates and manages submodules.

       A submodule allows you to keep another Git repository in a subdirectory of your repository. The other
       repository has its own history, which does not interfere with the history of the current repository. This
       can be used to have external dependencies such as third party libraries for example.

       When cloning or pulling a repository containing submodules however, 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.

       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).

       Submodules are not to be confused with remotes, which are other repositories 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.

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 to match what the superproject expects by cloning missing submodules
           and updating the working tree of the submodules. The "updating" can be done in several ways depending
           on command line options and the value of submodule.<name>.update configuration variable. Supported
           update procedures are:

           checkout
               the commit recorded in the superproject will be checked out in the submodule on a detached HEAD.
               This is done when --checkout option is given, or no option is given, and submodule.<name>.update
               is unset, or if it is set to checkout.

               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.

           rebase
               the current branch of the submodule will be rebased onto the commit recorded in the superproject.
               This is done when --rebase option is given, or no option is given, and submodule.<name>.update is
               set to rebase.

           merge
               the commit recorded in the superproject will be merged into the current branch in the submodule.
               This is done when --merge option is given, or no option is given, and submodule.<name>.update is
               set to merge.

           custom command
               arbitrary shell command that takes a single argument (the sha1 of the commit recorded in the
               superproject) is executed. This is done when no option is given, and submodule.<name>.update has
               the form of !command.

           When no option is given and submodule.<name>.update is set to none, the submodule is not updated.

           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.

       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.

           If --recursive is specified, this command will recurse into the registered submodules, and sync any
           nested submodules within.

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.<name>.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 (only effective with the checkout procedure),
           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.

           Use this option to integrate changes from the upstream subproject with your submodule’s current HEAD.
           Alternatively, you can run git pull from the submodule, which is equivalent except for the remote
           branch name: update --remote uses the default upstream repository and submodule.<name>.branch, while
           git pull uses the submodule’s branch.<name>.merge. Prefer submodule.<name>.branch if you want to
           distribute the default upstream branch with the superproject and branch.<name>.merge if you want a
           more native feel while working in the submodule itself.

       -N, --no-fetch
           This option is only valid for the update command. Don’t fetch new objects from the remote site.

       --checkout
           This option is only valid for the update command. Checkout the commit recorded in the superproject on
           a detached HEAD in the submodule. This is the default behavior, the main use of this option is to
           override submodule.$name.update when set to a value other than checkout. If the key
           submodule.$name.update is either not explicitly set or set to checkout, this option is implicit.

       --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, status and sync 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