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