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] [--] <repository> <path>
  13 'git submodule' [--quiet] status [--cached] [--] [<path>...]
  14 'git submodule' [--quiet] init [--] [<path>...]
  15 'git submodule' [--quiet] update [--init] [-N|--no-fetch] [--rebase] [--] [<path>...]
  16 'git submodule' [--quiet] summary [--summary-limit <n>] [commit] [--] [<path>...]
  17 'git submodule' [--quiet] foreach <command>
  18 'git submodule' [--quiet] sync [--] [<path>...]
  19
  20
  21 DESCRIPTION
  22 -----------
  23 Submodules allow foreign repositories to be embedded within
  24 a dedicated subdirectory of the source tree, always pointed
  25 at a particular commit.
  26
  27 They are not to be confused with remotes, which are meant mainly
  28 for branches of the same project; submodules are meant for
  29 different projects you would like to make part of your source tree,
  30 while the history of the two projects still stays completely
  31 independent and you cannot modify the contents of the submodule
  32 from within the main project.
  33 If you want to merge the project histories and want to treat the
  34 aggregated whole as a single project from then on, you may want to
  35 add a remote for the other project and use the 'subtree' merge strategy,
  36 instead of treating the other project as a submodule. Directories
  37 that come from both projects can be cloned and checked out as a whole
  38 if you choose to go that route.
  39
  40 Submodules are composed from a so-called `gitlink` tree entry
  41 in the main repository that refers to a particular commit object
  42 within the inner repository that is completely separate.
  43 A record in the `.gitmodules` file at the root of the source
  44 tree assigns a logical name to the submodule and describes
  45 the default URL the submodule shall be cloned from.
  46 The logical name can be used for overriding this URL within your
  47 local repository configuration (see 'submodule init').
  48
  49 This command will manage the tree entries and contents of the
  50 gitmodules file for you, as well as inspect the status of your
  51 submodules and update them.
  52 When adding a new submodule to the tree, the 'add' subcommand
  53 is to be used.  However, when pulling a tree containing submodules,
  54 these will not be checked out by default;
  55 the 'init' and 'update' subcommands will maintain submodules
  56 checked out and at appropriate revision in your working tree.
  57 You can briefly inspect the up-to-date status of your submodules
  58 using the 'status' subcommand and get a detailed overview of the
  59 difference between the index and checkouts using the 'summary'
  60 subcommand.
  61
  62
  63 COMMANDS
  64 --------
  65 add::
  66         Add the given repository as a submodule at the given path
  67         to the changeset to be committed next to the current
  68         project: the current project is termed the "superproject".
  69 +
  70 This requires two arguments: <repository> and <path>.
  71 +
  72 <repository> is the URL of the new submodule's origin repository.
  73 This may be either an absolute URL, or (if it begins with ./
  74 or ../), the location relative to the superproject's origin
  75 repository.
  76 +
  77 <path> is the relative location for the cloned submodule to
  78 exist in the superproject. If <path> does not exist, then the
  79 submodule is created by cloning from the named URL. If <path> does
  80 exist and is already a valid git repository, then this is added
  81 to the changeset without cloning. This second form is provided
  82 to ease creating a new submodule from scratch, and presumes
  83 the user will later push the submodule to the given URL.
  84 +
  85 In either case, the given URL is recorded into .gitmodules for
  86 use by subsequent users cloning the superproject. If the URL is
  87 given relative to the superproject's repository, the presumption
  88 is the superproject and submodule repositories will be kept
  89 together in the same relative location, and only the
  90 superproject's URL needs to be provided: git-submodule will correctly
  91 locate the submodule using the relative URL in .gitmodules.
  92
  93 status::
  94         Show the status of the submodules. This will print the SHA-1 of the
  95         currently checked out commit for each submodule, along with the
  96         submodule path and the output of 'git-describe' for the
  97         SHA-1. Each SHA-1 will be prefixed with `-` if the submodule is not
  98         initialized and `+` if the currently checked out submodule commit
  99         does not match the SHA-1 found in the index of the containing
 100         repository. This command is the default command for 'git-submodule'.
 101
 102 init::
 103         Initialize the submodules, i.e. register each submodule name
 104         and url found in .gitmodules into .git/config.
 105         The key used in .git/config is `submodule.$name.url`.
 106         This command does not alter existing information in .git/config.
 107         You can then customize the submodule clone URLs in .git/config
 108         for your local setup and proceed to 'git submodule update';
 109         you can also just use 'git submodule update --init' without
 110         the explicit 'init' step if you do not intend to customize
 111         any submodule locations.
 112
 113 update::
 114         Update the registered submodules, i.e. clone missing submodules and
 115         checkout the commit specified in the index of the containing repository.
 116         This will make the submodules HEAD be detached unless '--rebase' or
 117         '--merge' is specified or the key `submodule.$name.update` is set to
 118         `rebase` or `merge`.
 119 +
 120 If the submodule is not yet initialized, and you just want to use the
 121 setting as stored in .gitmodules, you can automatically initialize the
 122 submodule with the --init option.
 123
 124 summary::
 125         Show commit summary between the given commit (defaults to HEAD) and
 126         working tree/index. For a submodule in question, a series of commits
 127         in the submodule between the given super project commit and the
 128         index or working tree (switched by --cached) are shown.
 129
 130 foreach::
 131         Evaluates an arbitrary shell command in each checked out submodule.
 132         The command has access to the variables $path and $sha1:
 133         $path is the name of the submodule directory relative to the
 134         superproject, and $sha1 is the commit as recorded in the superproject.
 135         Any submodules defined in the superproject but not checked out are
 136         ignored by this command. Unless given --quiet, foreach prints the name
 137         of each submodule before evaluating the command.
 138         A non-zero return from the command in any submodule causes
 139         the processing to terminate. This can be overridden by adding '|| :'
 140         to the end of the command.
 141 +
 142 As an example, "git submodule foreach 'echo $path `git rev-parse HEAD`' will
 143 show the path and currently checked out commit for each submodule.
 144
 145 sync::
 146         Synchronizes submodules' remote URL configuration setting
 147         to the value specified in .gitmodules.  This is useful when
 148         submodule URLs change upstream and you need to update your local
 149         repositories accordingly.
 150 +
 151 "git submodule sync" synchronizes all submodules while
 152 "git submodule sync -- A" synchronizes submodule "A" only.
 153
 154 OPTIONS
 155 -------
 156 -q::
 157 --quiet::
 158         Only print error messages.
 159
 160 -b::
 161 --branch::
 162         Branch of repository to add as submodule.
 163
 164 --cached::
 165         This option is only valid for status and summary commands.  These
 166         commands typically use the commit found in the submodule HEAD, but
 167         with this option, the commit stored in the index is used instead.
 168
 169 -n::
 170 --summary-limit::
 171         This option is only valid for the summary command.
 172         Limit the summary size (number of commits shown in total).
 173         Giving 0 will disable the summary; a negative number means unlimited
 174         (the default). This limit only applies to modified submodules. The
 175         size is always limited to 1 for added/deleted/typechanged submodules.
 176
 177 -N::
 178 --no-fetch::
 179         This option is only valid for the update command.
 180         Don't fetch new objects from the remote site.
 181
 182 --rebase::
 183         This option is only valid for the update command.
 184         Rebase the current branch onto the commit recorded in the
 185         superproject. If this option is given, the submodule's HEAD will not
 186         be detached. If a a merge failure prevents this process, you will have
 187         to resolve these failures with linkgit:git-rebase[1].
 188         If the key `submodule.$name.update` is set to `rebase`, this option is
 189         implicit.
 190
 191 --merge::
 192         This option is only valid for the update command.
 193         Merge the commit recorded in the superproject into the current branch
 194         of the submodule. If this option is given, the submodule's HEAD will
 195         not be detached. If a merge failure prevents this process, you will
 196         have to resolve the resulting conflicts within the submodule with the
 197         usual conflict resolution tools.
 198         If the key `submodule.$name.update` is set to `merge`, this option is
 199         implicit.
 200
 201 <path>...::
 202         Paths to submodule(s). When specified this will restrict the command
 203         to only operate on the submodules found at the specified paths.
 204         (This argument is required with add).
 205
 206 FILES
 207 -----
 208 When initializing submodules, a .gitmodules file in the top-level directory
 209 of the containing repository is used to find the url of each submodule.
 210 This file should be formatted in the same way as `$GIT_DIR/config`. The key
 211 to each submodule url is "submodule.$name.url".  See linkgit:gitmodules[5]
 212 for details.
 213
 214
 215 AUTHOR
 216 ------
 217 Written by Lars Hjemli <hjemli@gmail.com>
 218
 219 GIT
 220 ---
 221 Part of the linkgit:git[1] suite