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