Update manual pages (2.48.0)

Updated via the `update-git-version-and-manual-pages.yml` GitHub workflow.

Author: ttaylorr

external/docs/asciidoc/01b5e6ec0df82b2dc404b8f80142b400ab9d20ab

@@ -0,0 +1,381 @@
+gitrepository-layout(5)
+=======================
+
+NAME
+----
+gitrepository-layout - Git Repository Layout
+
+SYNOPSIS
+--------
+$GIT_DIR/*
+
+DESCRIPTION
+-----------
+
+A Git repository comes in two different flavours:
+
+ * a `.git` directory at the root of the working tree;
+
+ * a `<project>.git` directory that is a 'bare' repository
+   (i.e. without its own working tree), that is typically used for
+   exchanging histories with others by pushing into it and fetching
+   from it.
+
+*Note*: Also you can have a plain text file `.git` at the root of
+your working tree, containing `gitdir: <path>` to point at the real
+directory that has the repository.
+This mechanism is called a 'gitfile' and is usually managed via the
+`git submodule` and `git worktree` commands. It is often used for
+a working tree of a submodule checkout, to allow you in the
+containing superproject to `git checkout` a branch that does not
+have the submodule.  The `checkout` has to remove the entire
+submodule working tree, without losing the submodule repository.
+
+These things may exist in a Git repository.
+
+objects::
+	Object store associated with this repository.  Usually
+	an object store is self sufficient (i.e. all the objects
+	that are referred to by an object found in it are also
+	found in it), but there are a few ways to violate it.
++
+. You could have an incomplete but locally usable repository
+by creating a shallow clone.  See linkgit:git-clone[1].
+. You could be using the `objects/info/alternates` or
+`$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 objects 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 (except refs/bisect,
+	refs/rewritten and refs/worktree) 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 linkgit: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
+	linkgit: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 linkgit: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.
+
+config.worktree::
+	Working directory specific configuration file for the main
+	working directory in multiple working directory setup (see
+	linkgit:git-worktree[1]).
+
+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
+	linkgit: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 linkgit: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.
+
+common::
+	When multiple working trees are used, most of files in
+	$GIT_DIR are per-worktree with a few known exceptions. All
+	files under 'common' however will be shared between all
+	working trees.
+
+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 linkgit: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: linkgit:gitignore[5].
+
+info/attributes::
+	Defines which attributes to assign to a path, similar to per-directory
+	`.gitattributes` files.   See also: linkgit:gitattributes[5].
+
+info/sparse-checkout::
+	This file stores sparse checkout patterns.
+	See also: linkgit: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 linkgit: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 linkgit:git-update-ref[1] for more information. This
+	directory is ignored (except logs/HEAD) 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 linkgit:git-clone[1] and linkgit: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 linkgit: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>/config.worktree::
+	Working directory specific configuration file.
+
+== Git Repository Format Versions
+
+Every git repository is marked with a numeric version in the
+`core.repositoryformatversion` key of its `config` file. This version
+specifies the rules for operating on the on-disk repository data. An
+implementation of git which does not understand a particular version
+advertised by an on-disk repository MUST NOT operate on that repository;
+doing so risks not only producing wrong results, but actually losing
+data.
+
+Because of this rule, version bumps should be kept to an absolute
+minimum. Instead, we generally prefer these strategies:
+
+  - bumping format version numbers of individual data files (e.g.,
+    index, packfiles, etc). This restricts the incompatibilities only to
+    those files.
+
+  - introducing new data that gracefully degrades when used by older
+    clients (e.g., pack bitmap files are ignored by older clients, which
+    simply do not take advantage of the optimization they provide).
+
+A whole-repository format version bump should only be part of a change
+that cannot be independently versioned. For instance, if one were to
+change the reachability rules for objects, or the rules for locking
+refs, that would require a bump of the repository format version.
+
+Note that this applies only to accessing the repository's disk contents
+directly. An older client which understands only format `0` may still
+connect via `git://` to a repository using format `1`, as long as the
+server process understands format `1`.
+
+The preferred strategy for rolling out a version bump (whether whole
+repository or for a single file) is to teach git to read the new format,
+and allow writing the new format with a config switch or command line
+option (for experimentation or for those who do not care about backwards
+compatibility with older gits). Then after a long period to allow the
+reading capability to become common, we may switch to writing the new
+format by default.
+
+The currently defined format versions are:
+
+=== Version `0`
+
+This is the format defined by the initial version of git, including but
+not limited to the format of the repository directory, the repository
+configuration file, and the object and ref storage. Specifying the
+complete behavior of git is beyond the scope of this document.
+
+=== Version `1`
+
+This format is identical to version `0`, with the following exceptions:
+
+  1. When reading the `core.repositoryformatversion` variable, a git
+     implementation which supports version 1 MUST also read any
+     configuration keys found in the `extensions` section of the
+     configuration file.
+
+  2. If a version-1 repository specifies any `extensions.*` keys that
+     the running git has not implemented, the operation MUST NOT
+     proceed. Similarly, if the value of any known key is not understood
+     by the implementation, the operation MUST NOT proceed.
+
+Note that if no extensions are specified in the config file, then
+`core.repositoryformatversion` SHOULD be set to `0` (setting it to `1`
+provides no benefit, and makes the repository incompatible with older
+implementations of git).
+
+The defined extensions are given in the `extensions.*` section of
+linkgit:git-config[1]. Any implementation wishing to define a new
+extension should make a note of it there, in order to claim the name.
+
+
+SEE ALSO
+--------
+linkgit:git-init[1],
+linkgit:git-clone[1],
+linkgit:git-config[1],
+linkgit:git-fetch[1],
+linkgit:git-pack-refs[1],
+linkgit:git-gc[1],
+linkgit:git-checkout[1],
+linkgit:gitglossary[7],
+link:/docs/user-manual[The Git User's Manual]
+
+GIT
+---
+Part of the linkgit:git[1] suite