Documentation/gitrepository-layout.txt

   1 gitrepository-layout(5)
   2 =======================
   3
   4 NAME
   5 ----
   6 gitrepository-layout - Git Repository Layout
   7
   8 SYNOPSIS
   9 --------
  10 $GIT_DIR/*
  11
  12 DESCRIPTION
  13 -----------
  14
  15 A Git repository comes in two different flavours:
  16
  17  * a `.git` directory at the root of the working tree;
  18
  19  * a `<project>.git` directory that is a 'bare' repository
  20    (i.e. without its own working tree), that is typically used for
  21    exchanging histories with others by pushing into it and fetching
  22    from it.
  23
  24 *Note*: Also you can have a plain text file `.git` at the root of
  25 your working tree, containing `gitdir: <path>` to point at the real
  26 directory that has the repository.  This mechanism is often used for
  27 a working tree of a submodule checkout, to allow you in the
  28 containing superproject to `git checkout` a branch that does not
  29 have the submodule.  The `checkout` has to remove the entire
  30 submodule working tree, without losing the submodule repository.
  31
  32 These things may exist in a Git repository.
  33
  34 objects::
  35         Object store associated with this repository.  Usually
  36         an object store is self sufficient (i.e. all the objects
  37         that are referred to by an object found in it are also
  38         found in it), but there are a few ways to violate it.
  39 +
  40 . You could have an incomplete but locally usable repository
  41 by creating a shallow clone.  See linkgit:git-clone[1].
  42 . You could be using the `objects/info/alternates` or
  43 `$GIT_ALTERNATE_OBJECT_DIRECTORIES` mechanisms to 'borrow'
  44 objects from other object stores.  A repository with this kind
  45 of incomplete object store is not suitable to be published for
  46 use with dumb transports but otherwise is OK as long as
  47 `objects/info/alternates` points at the object stores it
  48 borrows from.
  49 +
  50 This directory is ignored if $GIT_COMMON_DIR is set and
  51 "$GIT_COMMON_DIR/objects" will be used instead.
  52
  53 objects/[0-9a-f][0-9a-f]::
  54         A newly created object is stored in its own file.
  55         The objects are splayed over 256 subdirectories using
  56         the first two characters of the sha1 object name to
  57         keep the number of directory entries in `objects`
  58         itself to a manageable number. Objects found
  59         here are often called 'unpacked' (or 'loose') objects.
  60
  61 objects/pack::
  62         Packs (files that store many object in compressed form,
  63         along with index files to allow them to be randomly
  64         accessed) are found in this directory.
  65
  66 objects/info::
  67         Additional information about the object store is
  68         recorded in this directory.
  69
  70 objects/info/packs::
  71         This file is to help dumb transports discover what packs
  72         are available in this object store.  Whenever a pack is
  73         added or removed, `git update-server-info` should be run
  74         to keep this file up to date if the repository is
  75         published for dumb transports.  'git repack' does this
  76         by default.
  77
  78 objects/info/alternates::
  79         This file records paths to alternate object stores that
  80         this object store borrows objects from, one pathname per
  81         line. Note that not only native Git tools use it locally,
  82         but the HTTP fetcher also tries to use it remotely; this
  83         will usually work if you have relative paths (relative
  84         to the object database, not to the repository!) in your
  85         alternates file, but it will not work if you use absolute
  86         paths unless the absolute path in filesystem and web URL
  87         is the same. See also `objects/info/http-alternates`.
  88
  89 objects/info/http-alternates::
  90         This file records URLs to alternate object stores that
  91         this object store borrows objects from, to be used when
  92         the repository is fetched over HTTP.
  93
  94 refs::
  95         References are stored in subdirectories of this
  96         directory.  The 'git prune' command knows to preserve
  97         objects reachable from refs found in this directory and
  98         its subdirectories.
  99         This directory is ignored (except refs/bisect and
 100         refs/worktree) if $GIT_COMMON_DIR is set and
 101         "$GIT_COMMON_DIR/refs" will be used instead.
 102
 103 refs/heads/`name`::
 104         records tip-of-the-tree commit objects of branch `name`
 105
 106 refs/tags/`name`::
 107         records any object name (not necessarily a commit
 108         object, or a tag object that points at a commit object).
 109
 110 refs/remotes/`name`::
 111         records tip-of-the-tree commit objects of branches copied
 112         from a remote repository.
 113
 114 refs/replace/`<obj-sha1>`::
 115         records the SHA-1 of the object that replaces `<obj-sha1>`.
 116         This is similar to info/grafts and is internally used and
 117         maintained by linkgit:git-replace[1]. Such refs can be exchanged
 118         between repositories while grafts are not.
 119
 120 packed-refs::
 121         records the same information as refs/heads/, refs/tags/,
 122         and friends record in a more efficient way.  See
 123         linkgit:git-pack-refs[1]. This file is ignored if $GIT_COMMON_DIR
 124         is set and "$GIT_COMMON_DIR/packed-refs" will be used instead.
 125
 126 HEAD::
 127         A symref (see glossary) to the `refs/heads/` namespace
 128         describing the currently active branch.  It does not mean
 129         much if the repository is not associated with any working tree
 130         (i.e. a 'bare' repository), but a valid Git repository
 131         *must* have the HEAD file; some porcelains may use it to
 132         guess the designated "default" branch of the repository
 133         (usually 'master').  It is legal if the named branch
 134         'name' does not (yet) exist.  In some legacy setups, it is
 135         a symbolic link instead of a symref that points at the current
 136         branch.
 137 +
 138 HEAD can also record a specific commit directly, instead of
 139 being a symref to point at the current branch.  Such a state
 140 is often called 'detached HEAD.'  See linkgit:git-checkout[1]
 141 for details.
 142
 143 config::
 144         Repository specific configuration file. This file is ignored
 145         if $GIT_COMMON_DIR is set and "$GIT_COMMON_DIR/config" will be
 146         used instead.
 147
 148 config.worktree::
 149         Working directory specific configuration file for the main
 150         working directory in multiple working directory setup (see
 151         linkgit:git-worktree[1]).
 152
 153 branches::
 154         A slightly deprecated way to store shorthands to be used
 155         to specify a URL to 'git fetch', 'git pull' and 'git push'.
 156         A file can be stored as `branches/<name>` and then
 157         'name' can be given to these commands in place of
 158         'repository' argument.  See the REMOTES section in
 159         linkgit:git-fetch[1] for details.  This mechanism is legacy
 160         and not likely to be found in modern repositories. This
 161         directory is ignored if $GIT_COMMON_DIR is set and
 162         "$GIT_COMMON_DIR/branches" will be used instead.
 163
 164
 165 hooks::
 166         Hooks are customization scripts used by various Git
 167         commands.  A handful of sample hooks are installed when
 168         'git init' is run, but all of them are disabled by
 169         default.  To enable, the `.sample` suffix has to be
 170         removed from the filename by renaming.
 171         Read linkgit:githooks[5] for more details about
 172         each hook. This directory is ignored if $GIT_COMMON_DIR is set
 173         and "$GIT_COMMON_DIR/hooks" will be used instead.
 174
 175 common::
 176         When multiple working trees are used, most of files in
 177         $GIT_DIR are per-worktree with a few known exceptions. All
 178         files under 'common' however will be shared between all
 179         working trees.
 180
 181 index::
 182         The current index file for the repository.  It is
 183         usually not found in a bare repository.
 184
 185 sharedindex.<SHA-1>::
 186         The shared index part, to be referenced by $GIT_DIR/index and
 187         other temporary index files. Only valid in split index mode.
 188
 189 info::
 190         Additional information about the repository is recorded
 191         in this directory. This directory is ignored if $GIT_COMMON_DIR
 192         is set and "$GIT_COMMON_DIR/info" will be used instead.
 193
 194 info/refs::
 195         This file helps dumb transports discover what refs are
 196         available in this repository.  If the repository is
 197         published for dumb transports, this file should be
 198         regenerated by 'git update-server-info' every time a tag
 199         or branch is created or modified.  This is normally done
 200         from the `hooks/update` hook, which is run by the
 201         'git-receive-pack' command when you 'git push' into the
 202         repository.
 203
 204 info/grafts::
 205         This file records fake commit ancestry information, to
 206         pretend the set of parents a commit has is different
 207         from how the commit was actually created.  One record
 208         per line describes a commit and its fake parents by
 209         listing their 40-byte hexadecimal object names separated
 210         by a space and terminated by a newline.
 211 +
 212 Note that the grafts mechanism is outdated and can lead to problems
 213 transferring objects between repositories; see linkgit:git-replace[1]
 214 for a more flexible and robust system to do the same thing.
 215
 216 info/exclude::
 217         This file, by convention among Porcelains, stores the
 218         exclude pattern list. `.gitignore` is the per-directory
 219         ignore file.  'git status', 'git add', 'git rm' and
 220         'git clean' look at it but the core Git commands do not look
 221         at it.  See also: linkgit:gitignore[5].
 222
 223 info/attributes::
 224         Defines which attributes to assign to a path, similar to per-directory
 225         `.gitattributes` files.   See also: linkgit:gitattributes[5].
 226
 227 info/sparse-checkout::
 228         This file stores sparse checkout patterns.
 229         See also: linkgit:git-read-tree[1].
 230
 231 remotes::
 232         Stores shorthands for URL and default refnames for use
 233         when interacting with remote repositories via 'git fetch',
 234         'git pull' and 'git push' commands.  See the REMOTES section
 235         in linkgit:git-fetch[1] for details.  This mechanism is legacy
 236         and not likely to be found in modern repositories. This
 237         directory is ignored if $GIT_COMMON_DIR is set and
 238         "$GIT_COMMON_DIR/remotes" will be used instead.
 239
 240 logs::
 241         Records of changes made to refs are stored in this directory.
 242         See linkgit:git-update-ref[1] for more information. This
 243         directory is ignored if $GIT_COMMON_DIR is set and
 244         "$GIT_COMMON_DIR/logs" will be used instead.
 245
 246 logs/refs/heads/`name`::
 247         Records all changes made to the branch tip named `name`.
 248
 249 logs/refs/tags/`name`::
 250         Records all changes made to the tag named `name`.
 251
 252 shallow::
 253         This is similar to `info/grafts` but is internally used
 254         and maintained by shallow clone mechanism.  See `--depth`
 255         option to linkgit:git-clone[1] and linkgit:git-fetch[1]. This
 256         file is ignored if $GIT_COMMON_DIR is set and
 257         "$GIT_COMMON_DIR/shallow" will be used instead.
 258
 259 commondir::
 260         If this file exists, $GIT_COMMON_DIR (see linkgit:git[1]) will
 261         be set to the path specified in this file if it is not
 262         explicitly set. If the specified path is relative, it is
 263         relative to $GIT_DIR. The repository with commondir is
 264         incomplete without the repository pointed by "commondir".
 265
 266 modules::
 267         Contains the git-repositories of the submodules.
 268
 269 worktrees::
 270         Contains administrative data for linked
 271         working trees. Each subdirectory contains the working tree-related
 272         part of a linked working tree. This directory is ignored if
 273         $GIT_COMMON_DIR is set, in which case
 274         "$GIT_COMMON_DIR/worktrees" will be used instead.
 275
 276 worktrees/<id>/gitdir::
 277         A text file containing the absolute path back to the .git file
 278         that points to here. This is used to check if the linked
 279         repository has been manually removed and there is no need to
 280         keep this directory any more. The mtime of this file should be
 281         updated every time the linked repository is accessed.
 282
 283 worktrees/<id>/locked::
 284         If this file exists, the linked working tree may be on a
 285         portable device and not available. The presence of this file
 286         prevents `worktrees/<id>` from being pruned either automatically
 287         or manually by `git worktree prune`. The file may contain a string
 288         explaining why the repository is locked.
 289
 290 worktrees/<id>/config.worktree::
 291         Working directory specific configuration file.
 292
 293 include::technical/repository-version.txt[]
 294
 295 SEE ALSO
 296 --------
 297 linkgit:git-init[1],
 298 linkgit:git-clone[1],
 299 linkgit:git-fetch[1],
 300 linkgit:git-pack-refs[1],
 301 linkgit:git-gc[1],
 302 linkgit:git-checkout[1],
 303 linkgit:gitglossary[7],
 304 link:user-manual.html[The Git User's Manual]
 305
 306 GIT
 307 ---
 308 Part of the linkgit:git[1] suite