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. If the superproject doesn't have an origin configured
  82 the superproject is its own authoritative upstream and the current
  83 working directory is used instead.
  84 +
  85 <path> is the relative location for the cloned submodule to
  86 exist in the superproject. If <path> does not exist, then the
  87 submodule is created by cloning from the named URL. If <path> does
  88 exist and is already a valid git repository, then this is added
  89 to the changeset without cloning. This second form is provided
  90 to ease creating a new submodule from scratch, and presumes
  91 the user will later push the submodule to the given URL.
  92 +
  93 In either case, the given URL is recorded into .gitmodules for
  94 use by subsequent users cloning the superproject. If the URL is
  95 given relative to the superproject's repository, the presumption
  96 is the superproject and submodule repositories will be kept
  97 together in the same relative location, and only the
  98 superproject's URL needs to be provided: git-submodule will correctly
  99 locate the submodule using the relative URL in .gitmodules.
 100
 101 status::
 102         Show the status of the submodules. This will print the SHA-1 of the
 103         currently checked out commit for each submodule, along with the
 104         submodule path and the output of 'git describe' for the
 105         SHA-1. Each SHA-1 will be prefixed with `-` if the submodule is not
 106         initialized, `+` if the currently checked out submodule commit
 107         does not match the SHA-1 found in the index of the containing
 108         repository and `U` if the submodule has merge conflicts.
 109         This command is the default command for 'git submodule'.
 110 +
 111 If '--recursive' is specified, this command will recurse into nested
 112 submodules, and show their status as well.
 113
 114 init::
 115         Initialize the submodules, i.e. register each submodule name
 116         and url found in .gitmodules into .git/config.
 117         The key used in .git/config is `submodule.$name.url`.
 118         This command does not alter existing information in .git/config.
 119         You can then customize the submodule clone URLs in .git/config
 120         for your local setup and proceed to `git submodule update`;
 121         you can also just use `git submodule update --init` without
 122         the explicit 'init' step if you do not intend to customize
 123         any submodule locations.
 124
 125 update::
 126         Update the registered submodules, i.e. clone missing submodules and
 127         checkout the commit specified in the index of the containing repository.
 128         This will make the submodules HEAD be detached unless '--rebase' or
 129         '--merge' is specified or the key `submodule.$name.update` is set to
 130         `rebase` or `merge`.
 131 +
 132 If the submodule is not yet initialized, and you just want to use the
 133 setting as stored in .gitmodules, you can automatically initialize the
 134 submodule with the --init option.
 135 +
 136 If '--recursive' is specified, this command will recurse into the
 137 registered submodules, and update any nested submodules within.
 138
 139 summary::
 140         Show commit summary between the given commit (defaults to HEAD) and
 141         working tree/index. For a submodule in question, a series of commits
 142         in the submodule between the given super project commit and the
 143         index or working tree (switched by --cached) are shown. If the option
 144         --files is given, show the series of commits in the submodule between
 145         the index of the super project and the working tree of the submodule
 146         (this option doesn't allow to use the --cached option or to provide an
 147         explicit commit).
 148
 149 foreach::
 150         Evaluates an arbitrary shell command in each checked out submodule.
 151         The command has access to the variables $name, $path, $sha1 and
 152         $toplevel:
 153         $name is the name of the relevant submodule section in .gitmodules,
 154         $path is the name of the submodule directory relative to the
 155         superproject, $sha1 is the commit as recorded in the superproject,
 156         and $toplevel is the absolute path to the top-level of the superproject.
 157         Any submodules defined in the superproject but not checked out are
 158         ignored by this command. Unless given --quiet, foreach prints the name
 159         of each submodule before evaluating the command.
 160         If --recursive is given, submodules are traversed recursively (i.e.
 161         the given shell command is evaluated in nested submodules as well).
 162         A non-zero return from the command in any submodule causes
 163         the processing to terminate. This can be overridden by adding '|| :'
 164         to the end of the command.
 165 +
 166 As an example, +git submodule foreach \'echo $path {backtick}git
 167 rev-parse HEAD{backtick}'+ will show the path and currently checked out
 168 commit for each submodule.
 169
 170 sync::
 171         Synchronizes submodules' remote URL configuration setting
 172         to the value specified in .gitmodules. It will only affect those
 173         submodules which already have an url entry in .git/config (that is the
 174         case when they are initialized or freshly added). This is useful when
 175         submodule URLs change upstream and you need to update your local
 176         repositories accordingly.
 177 +
 178 "git submodule sync" synchronizes all submodules while
 179 "git submodule sync -- A" synchronizes submodule "A" only.
 180
 181 OPTIONS
 182 -------
 183 -q::
 184 --quiet::
 185         Only print error messages.
 186
 187 -b::
 188 --branch::
 189         Branch of repository to add as submodule.
 190
 191 -f::
 192 --force::
 193         This option is only valid for add and update commands.
 194         When running add, allow adding an otherwise ignored submodule path.
 195         When running update, throw away local changes in submodules when
 196         switching to a different commit.
 197
 198 --cached::
 199         This option is only valid for status and summary commands.  These
 200         commands typically use the commit found in the submodule HEAD, but
 201         with this option, the commit stored in the index is used instead.
 202
 203 --files::
 204         This option is only valid for the summary command. This command
 205         compares the commit in the index with that in the submodule HEAD
 206         when this option is used.
 207
 208 -n::
 209 --summary-limit::
 210         This option is only valid for the summary command.
 211         Limit the summary size (number of commits shown in total).
 212         Giving 0 will disable the summary; a negative number means unlimited
 213         (the default). This limit only applies to modified submodules. The
 214         size is always limited to 1 for added/deleted/typechanged submodules.
 215
 216 -N::
 217 --no-fetch::
 218         This option is only valid for the update command.
 219         Don't fetch new objects from the remote site.
 220
 221 --merge::
 222         This option is only valid for the update command.
 223         Merge the commit recorded in the superproject into the current branch
 224         of the submodule. If this option is given, the submodule's HEAD will
 225         not be detached. If a merge failure prevents this process, you will
 226         have to resolve the resulting conflicts within the submodule with the
 227         usual conflict resolution tools.
 228         If the key `submodule.$name.update` is set to `merge`, this option is
 229         implicit.
 230
 231 --rebase::
 232         This option is only valid for the update command.
 233         Rebase the current branch onto the commit recorded in the
 234         superproject. If this option is given, the submodule's HEAD will not
 235         be detached. If a merge failure prevents this process, you will have
 236         to resolve these failures with linkgit:git-rebase[1].
 237         If the key `submodule.$name.update` is set to `rebase`, this option is
 238         implicit.
 239
 240 --reference <repository>::
 241         This option is only valid for add and update commands.  These
 242         commands sometimes need to clone a remote repository. In this case,
 243         this option will be passed to the linkgit:git-clone[1] command.
 244 +
 245 *NOTE*: Do *not* use this option unless you have read the note
 246 for linkgit:git-clone[1]'s --reference and --shared options carefully.
 247
 248 --recursive::
 249         This option is only valid for foreach, update and status commands.
 250         Traverse submodules recursively. The operation is performed not
 251         only in the submodules of the current repo, but also
 252         in any nested submodules inside those submodules (and so on).
 253
 254 <path>...::
 255         Paths to submodule(s). When specified this will restrict the command
 256         to only operate on the submodules found at the specified paths.
 257         (This argument is required with add).
 258
 259 FILES
 260 -----
 261 When initializing submodules, a .gitmodules file in the top-level directory
 262 of the containing repository is used to find the url of each submodule.
 263 This file should be formatted in the same way as `$GIT_DIR/config`. The key
 264 to each submodule url is "submodule.$name.url".  See linkgit:gitmodules[5]
 265 for details.
 266
 267 GIT
 268 ---
 269 Part of the linkgit:git[1] suite