GITREPOSITORY-LAYOU(5) Git Manual GITREPOSITORY-LAYOU(5)
NAME
gitrepository-layout - Git Repository Layout
SYNOPSIS
$GIT_DIR/*
DESCRIPTION
A Git repository comes in two different flavours:
o a .git directory at the root of the working tree;
o a <project>.git directory that is a bare repository (i.e. without its own working tree), that is typically used for exchanging
histories with others by pushing into it and fetching from it.
Note: Also you can have a plain text file .git at the root of your working tree, containing gitdir: <path> to point at the real directory
that has the repository. This mechanism is often used for a working tree of a submodule checkout, to allow you in the containing
superproject to git checkout a branch that does not have the submodule. The checkout has to remove the entire submodule working tree,
without losing the submodule repository.
These things may exist in a Git repository.
objects
Object store associated with this repository. Usually an object store is self sufficient (i.e. all the objects that are referred to by
an object found in it are also found in it), but there are a few ways to violate it.
1. You could have an incomplete but locally usable repository by creating a shallow clone. See git-clone(1).
2. You could be using the objects/info/alternates or $GIT_ALTERNATE_OBJECT_DIRECTORIES mechanisms to borrow objects from other object
stores. A repository with this kind of incomplete object store is not suitable to be published for use with dumb transports but
otherwise is OK as long as objects/info/alternates points at the object stores it borrows from.
This directory is ignored if $GIT_COMMON_DIR is set and "$GIT_COMMON_DIR/objects" will be used instead.
objects/[0-9a-f][0-9a-f]
A newly created object is stored in its own file. The objects are splayed over 256 subdirectories using the first two characters of the
sha1 object name to keep the number of directory entries in objects itself to a manageable number. Objects found here are often called
unpacked (or loose) objects.
objects/pack
Packs (files that store many object in compressed form, along with index files to allow them to be randomly accessed) are found in this
directory.
objects/info
Additional information about the object store is recorded in this directory.
objects/info/packs
This file is to help dumb transports discover what packs are available in this object store. Whenever a pack is added or removed, git
update-server-info should be run to keep this file up to date if the repository is published for dumb transports. git repack does this
by default.
objects/info/alternates
This file records paths to alternate object stores that this object store borrows objects from, one pathname per line. Note that not
only native Git tools use it locally, but the HTTP fetcher also tries to use it remotely; this will usually work if you have relative
paths (relative to the object database, not to the repository!) in your alternates file, but it will not work if you use absolute paths
unless the absolute path in filesystem and web URL is the same. See also objects/info/http-alternates.
objects/info/http-alternates
This file records URLs to alternate object stores that this object store borrows objects from, to be used when the repository is
fetched over HTTP.
refs
References are stored in subdirectories of this directory. The git prune command knows to preserve objects reachable from refs found in
this directory and its subdirectories. This directory is ignored if $GIT_COMMON_DIR is set and "$GIT_COMMON_DIR/refs" will be used
instead.
refs/heads/name
records tip-of-the-tree commit objects of branch name
refs/tags/name
records any object name (not necessarily a commit object, or a tag object that points at a commit object).
refs/remotes/name
records tip-of-the-tree commit objects of branches copied from a remote repository.
refs/replace/<obj-sha1>
records the SHA-1 of the object that replaces <obj-sha1>. This is similar to info/grafts and is internally used and maintained by git-
replace(1). Such refs can be exchanged between repositories while grafts are not.
packed-refs
records the same information as refs/heads/, refs/tags/, and friends record in a more efficient way. See git-pack-refs(1). This file is
ignored if $GIT_COMMON_DIR is set and "$GIT_COMMON_DIR/packed-refs" will be used instead.
HEAD
A symref (see glossary) to the refs/heads/ namespace describing the currently active branch. It does not mean much if the repository is
not associated with any working tree (i.e. a bare repository), but a valid Git repository must have the HEAD file; some porcelains may
use it to guess the designated "default" branch of the repository (usually master). It is legal if the named branch name does not (yet)
exist. In some legacy setups, it is a symbolic link instead of a symref that points at the current branch.
HEAD can also record a specific commit directly, instead of being a symref to point at the current branch. Such a state is often called
detached HEAD. See git-checkout(1) for details.
config
Repository specific configuration file. This file is ignored if $GIT_COMMON_DIR is set and "$GIT_COMMON_DIR/config" will be used
instead.
branches
A slightly deprecated way to store shorthands to be used to specify a URL to git fetch, git pull and git push. A file can be stored as
branches/<name> and then name can be given to these commands in place of repository argument. See the REMOTES section in git-fetch(1)
for details. This mechanism is legacy and not likely to be found in modern repositories. This directory is ignored if $GIT_COMMON_DIR
is set and "$GIT_COMMON_DIR/branches" will be used instead.
hooks
Hooks are customization scripts used by various Git commands. A handful of sample hooks are installed when git init is run, but all of
them are disabled by default. To enable, the .sample suffix has to be removed from the filename by renaming. Read githooks(5) for more
details about each hook. This directory is ignored if $GIT_COMMON_DIR is set and "$GIT_COMMON_DIR/hooks" will be used instead.
index
The current index file for the repository. It is usually not found in a bare repository.
sharedindex.<SHA-1>
The shared index part, to be referenced by $GIT_DIR/index and other temporary index files. Only valid in split index mode.
info
Additional information about the repository is recorded in this directory. This directory is ignored if $GIT_COMMON_DIR is set and
"$GIT_COMMON_DIR/info" will be used instead.
info/refs
This file helps dumb transports discover what refs are available in this repository. If the repository is published for dumb
transports, this file should be regenerated by git update-server-info every time a tag or branch is created or modified. This is
normally done from the hooks/update hook, which is run by the git-receive-pack command when you git push into the repository.
info/grafts
This file records fake commit ancestry information, to pretend the set of parents a commit has is different from how the commit was
actually created. One record per line describes a commit and its fake parents by listing their 40-byte hexadecimal object names
separated by a space and terminated by a newline.
Note that the grafts mechanism is outdated and can lead to problems transferring objects between repositories; see git-replace(1) for a
more flexible and robust system to do the same thing.
info/exclude
This file, by convention among Porcelains, stores the exclude pattern list. .gitignore is the per-directory ignore file. git status,
git add, git rm and git clean look at it but the core Git commands do not look at it. See also: gitignore(5).
info/attributes
Defines which attributes to assign to a path, similar to per-directory .gitattributes files. See also: gitattributes(5).
info/sparse-checkout
This file stores sparse checkout patterns. See also: git-read-tree(1).
remotes
Stores shorthands for URL and default refnames for use when interacting with remote repositories via git fetch, git pull and git push
commands. See the REMOTES section in git-fetch(1) for details. This mechanism is legacy and not likely to be found in modern
repositories. This directory is ignored if $GIT_COMMON_DIR is set and "$GIT_COMMON_DIR/remotes" will be used instead.
logs
Records of changes made to refs are stored in this directory. See git-update-ref(1) for more information. This directory is ignored if
$GIT_COMMON_DIR is set and "$GIT_COMMON_DIR/logs" will be used instead.
logs/refs/heads/name
Records all changes made to the branch tip named name.
logs/refs/tags/name
Records all changes made to the tag named name.
shallow
This is similar to info/grafts but is internally used and maintained by shallow clone mechanism. See --depth option to git-clone(1) and
git-fetch(1). This file is ignored if $GIT_COMMON_DIR is set and "$GIT_COMMON_DIR/shallow" will be used instead.
commondir
If this file exists, $GIT_COMMON_DIR (see git(1)) will be set to the path specified in this file if it is not explicitly set. If the
specified path is relative, it is relative to $GIT_DIR. The repository with commondir is incomplete without the repository pointed by
"commondir".
modules
Contains the git-repositories of the submodules.
worktrees
Contains administrative data for linked working trees. Each subdirectory contains the working tree-related part of a linked working
tree. This directory is ignored if $GIT_COMMON_DIR is set, in which case "$GIT_COMMON_DIR/worktrees" will be used instead.
worktrees/<id>/gitdir
A text file containing the absolute path back to the .git file that points to here. This is used to check if the linked repository has
been manually removed and there is no need to keep this directory any more. The mtime of this file should be updated every time the
linked repository is accessed.
worktrees/<id>/locked
If this file exists, the linked working tree may be on a portable device and not available. The presence of this file prevents
worktrees/<id> from being pruned either automatically or manually by git worktree prune. The file may contain a string explaining why
the repository is locked.
worktrees/<id>/link
If this file exists, it is a hard link to the linked .git file. It is used to detect if the linked repository is manually removed.
SEE ALSO
git-init(1), git-clone(1), git-fetch(1), git-pack-refs(1), git-gc(1), git-checkout(1), gitglossary(7), The Git User's Manual[1]
GIT
Part of the git(1) suite
NOTES
1. The Git User's Manual
file:///usr/share/doc/git/html/user-manual.html
Git 2.17.1 10/05/2018 GITREPOSITORY-LAYOU(5)