GITREPOSITORY-LAYOU(5) Git Manual GITREPOSITORY-LAYOU(5)
NAME gitrepository-layout - Git Repository Layout
DESCRIPTION You may find these things in your git repository (.git directory for a repository associated with your working tree, or <project>.git directory for a public bare repository. It is also possible to have a working tree where .git is a plain ascii file containing gitdir: <path>, i.e. the path to the real 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 couple of ways to violate it.
1. You could populate the repository by running a commit walker without -a option. Depending on which options are given, you could have only commit objects without associated blobs and trees this way, for example. A repository with this kind of incomplete object store is not suitable to be published to the outside world but sometimes useful for private repository.
2. You also could have an incomplete but locally usable repository by cloning shallowly. See git-clone(1).
3. You can be using objects/info/alternates mechanism, or $GIT_ALTERNATE_OBJECT_DIRECTORIES mechanism 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 right object stores it borrows from.
objects/[0-9a-f][0-9a-f] Traditionally, each object is stored in its own file. They are split into 256 subdirectories using the first two letters from its object name to keep the number of directory entries objects directory itself needs to hold. 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 keep objects reachable from refs found in this directory and its subdirectories.
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.
packed-refs records the same information as refs/heads/, refs/tags/, and friends record in a more efficient way. See git-pack-refs(1).
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, and almost all commands work identically as normal. See git-checkout(1) for details.
branches A slightly deprecated way to store shorthands to be used to specify URL to git fetch, git pull and git push commands is to store a file in branches/<name> and give name to these commands in place of repository argument.
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.
index The current index file for the repository. It is usually not found in a bare repository.
info Additional information about the repository is recorded in this directory.
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.
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).
remotes Stores shorthands to be used to give URL and default refnames to interact with remote repository to git fetch, git pull and git push commands.
logs Records of changes made to refs are stored in this directory. See git-update-ref(1) for more information.
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).
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 Uses Manual
GIT Part of the git(1) suite.
NOTES 1. The Git Users Manual file:///usr/share/doc/git-1.7.1/user-manual.html
Git 1.7.1 12/08/2016 GITREPOSITORY-LAYOU(5)