DESCRIPTION¶
A Git repository comes in two different flavours:
•a .git directory at the root of the working
tree;
•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.
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.
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).
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.
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.
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).
info/sparse-checkout
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.
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).
modules
Contains the git-repositories of the submodules.