Merge branch 'sp/doc-info-attributes'
[git/git.git] / 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. This directory is ignored if $GIT_COMMON_DIR
99 is set and "$GIT_COMMON_DIR/refs" will be used instead.
100
101 refs/heads/`name`::
102 records tip-of-the-tree commit objects of branch `name`
103
104 refs/tags/`name`::
105 records any object name (not necessarily a commit
106 object, or a tag object that points at a commit object).
107
108 refs/remotes/`name`::
109 records tip-of-the-tree commit objects of branches copied
110 from a remote repository.
111
112 refs/replace/`<obj-sha1>`::
113 records the SHA-1 of the object that replaces `<obj-sha1>`.
114 This is similar to info/grafts and is internally used and
115 maintained by linkgit:git-replace[1]. Such refs can be exchanged
116 between repositories while grafts are not.
117
118 packed-refs::
119 records the same information as refs/heads/, refs/tags/,
120 and friends record in a more efficient way. See
121 linkgit:git-pack-refs[1]. This file is ignored if $GIT_COMMON_DIR
122 is set and "$GIT_COMMON_DIR/packed-refs" will be used instead.
123
124 HEAD::
125 A symref (see glossary) to the `refs/heads/` namespace
126 describing the currently active branch. It does not mean
127 much if the repository is not associated with any working tree
128 (i.e. a 'bare' repository), but a valid Git repository
129 *must* have the HEAD file; some porcelains may use it to
130 guess the designated "default" branch of the repository
131 (usually 'master'). It is legal if the named branch
132 'name' does not (yet) exist. In some legacy setups, it is
133 a symbolic link instead of a symref that points at the current
134 branch.
135 +
136 HEAD can also record a specific commit directly, instead of
137 being a symref to point at the current branch. Such a state
138 is often called 'detached HEAD.' See linkgit:git-checkout[1]
139 for details.
140
141 config::
142 Repository specific configuration file. This file is ignored
143 if $GIT_COMMON_DIR is set and "$GIT_COMMON_DIR/config" will be
144 used instead.
145
146 branches::
147 A slightly deprecated way to store shorthands to be used
148 to specify a URL to 'git fetch', 'git pull' and 'git push'.
149 A file can be stored as `branches/<name>` and then
150 'name' can be given to these commands in place of
151 'repository' argument. See the REMOTES section in
152 linkgit:git-fetch[1] for details. This mechanism is legacy
153 and not likely to be found in modern repositories. This
154 directory is ignored if $GIT_COMMON_DIR is set and
155 "$GIT_COMMON_DIR/branches" will be used instead.
156
157
158 hooks::
159 Hooks are customization scripts used by various Git
160 commands. A handful of sample hooks are installed when
161 'git init' is run, but all of them are disabled by
162 default. To enable, the `.sample` suffix has to be
163 removed from the filename by renaming.
164 Read linkgit:githooks[5] for more details about
165 each hook. This directory is ignored if $GIT_COMMON_DIR is set
166 and "$GIT_COMMON_DIR/hooks" will be used instead.
167
168
169 index::
170 The current index file for the repository. It is
171 usually not found in a bare repository.
172
173 sharedindex.<SHA-1>::
174 The shared index part, to be referenced by $GIT_DIR/index and
175 other temporary index files. Only valid in split index mode.
176
177 info::
178 Additional information about the repository is recorded
179 in this directory. This directory is ignored if $GIT_COMMON_DIR
180 is set and "$GIT_COMMON_DIR/info" will be used instead.
181
182 info/refs::
183 This file helps dumb transports discover what refs are
184 available in this repository. If the repository is
185 published for dumb transports, this file should be
186 regenerated by 'git update-server-info' every time a tag
187 or branch is created or modified. This is normally done
188 from the `hooks/update` hook, which is run by the
189 'git-receive-pack' command when you 'git push' into the
190 repository.
191
192 info/grafts::
193 This file records fake commit ancestry information, to
194 pretend the set of parents a commit has is different
195 from how the commit was actually created. One record
196 per line describes a commit and its fake parents by
197 listing their 40-byte hexadecimal object names separated
198 by a space and terminated by a newline.
199 +
200 Note that the grafts mechanism is outdated and can lead to problems
201 transferring objects between repositories; see linkgit:git-replace[1]
202 for a more flexible and robust system to do the same thing.
203
204 info/exclude::
205 This file, by convention among Porcelains, stores the
206 exclude pattern list. `.gitignore` is the per-directory
207 ignore file. 'git status', 'git add', 'git rm' and
208 'git clean' look at it but the core Git commands do not look
209 at it. See also: linkgit:gitignore[5].
210
211 info/attributes::
212 Defines which attributes to assign to a path, similar to per-directory
213 `.gitattributes` files. See also: linkgit:gitattributes[5].
214
215 info/sparse-checkout::
216 This file stores sparse checkout patterns.
217 See also: linkgit:git-read-tree[1].
218
219 remotes::
220 Stores shorthands for URL and default refnames for use
221 when interacting with remote repositories via 'git fetch',
222 'git pull' and 'git push' commands. See the REMOTES section
223 in linkgit:git-fetch[1] for details. This mechanism is legacy
224 and not likely to be found in modern repositories. This
225 directory is ignored if $GIT_COMMON_DIR is set and
226 "$GIT_COMMON_DIR/remotes" will be used instead.
227
228 logs::
229 Records of changes made to refs are stored in this directory.
230 See linkgit:git-update-ref[1] for more information. This
231 directory is ignored if $GIT_COMMON_DIR is set and
232 "$GIT_COMMON_DIR/logs" will be used instead.
233
234 logs/refs/heads/`name`::
235 Records all changes made to the branch tip named `name`.
236
237 logs/refs/tags/`name`::
238 Records all changes made to the tag named `name`.
239
240 shallow::
241 This is similar to `info/grafts` but is internally used
242 and maintained by shallow clone mechanism. See `--depth`
243 option to linkgit:git-clone[1] and linkgit:git-fetch[1]. This
244 file is ignored if $GIT_COMMON_DIR is set and
245 "$GIT_COMMON_DIR/shallow" will be used instead.
246
247 commondir::
248 If this file exists, $GIT_COMMON_DIR (see linkgit:git[1]) will
249 be set to the path specified in this file if it is not
250 explicitly set. If the specified path is relative, it is
251 relative to $GIT_DIR. The repository with commondir is
252 incomplete without the repository pointed by "commondir".
253
254 modules::
255 Contains the git-repositories of the submodules.
256
257 worktrees::
258 Contains administrative data for linked
259 working trees. Each subdirectory contains the working tree-related
260 part of a linked working tree. This directory is ignored if
261 $GIT_COMMON_DIR is set, in which case
262 "$GIT_COMMON_DIR/worktrees" will be used instead.
263
264 worktrees/<id>/gitdir::
265 A text file containing the absolute path back to the .git file
266 that points to here. This is used to check if the linked
267 repository has been manually removed and there is no need to
268 keep this directory any more. The mtime of this file should be
269 updated every time the linked repository is accessed.
270
271 worktrees/<id>/locked::
272 If this file exists, the linked working tree may be on a
273 portable device and not available. The presence of this file
274 prevents `worktrees/<id>` from being pruned either automatically
275 or manually by `git worktree prune`. The file may contain a string
276 explaining why the repository is locked.
277
278 worktrees/<id>/link::
279 If this file exists, it is a hard link to the linked .git
280 file. It is used to detect if the linked repository is
281 manually removed.
282
283 SEE ALSO
284 --------
285 linkgit:git-init[1],
286 linkgit:git-clone[1],
287 linkgit:git-fetch[1],
288 linkgit:git-pack-refs[1],
289 linkgit:git-gc[1],
290 linkgit:git-checkout[1],
291 linkgit:gitglossary[7],
292 link:user-manual.html[The Git User's Manual]
293
294 GIT
295 ---
296 Part of the linkgit:git[1] suite