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diff --git a/Documentation/git.txt b/Documentation/git.txt new file mode 100644 index 0000000000..483a1f3547 --- /dev/null +++ b/Documentation/git.txt @@ -0,0 +1,838 @@ +git(1) +====== + +NAME +---- +git - the stupid content tracker + + +SYNOPSIS +-------- +[verse] +'git' [--version] [--help] [-C <path>] [-c <name>=<value>] + [--exec-path[=<path>]] [--html-path] [--man-path] [--info-path] + [-p|--paginate|--no-pager] [--no-replace-objects] [--bare] + [--git-dir=<path>] [--work-tree=<path>] [--namespace=<name>] + [--super-prefix=<path>] + <command> [<args>] + +DESCRIPTION +----------- +Git is a fast, scalable, distributed revision control system with an +unusually rich command set that provides both high-level operations +and full access to internals. + +See linkgit:gittutorial[7] to get started, then see +linkgit:giteveryday[7] for a useful minimum set of +commands. The link:user-manual.html[Git User's Manual] has a more +in-depth introduction. + +After you mastered the basic concepts, you can come back to this +page to learn what commands Git offers. You can learn more about +individual Git commands with "git help command". linkgit:gitcli[7] +manual page gives you an overview of the command-line command syntax. + +A formatted and hyperlinked copy of the latest Git documentation +can be viewed at `https://git.github.io/htmldocs/git.html`. + + +OPTIONS +------- +--version:: + Prints the Git suite version that the 'git' program came from. + +--help:: + Prints the synopsis and a list of the most commonly used + commands. If the option `--all` or `-a` is given then all + available commands are printed. If a Git command is named this + option will bring up the manual page for that command. ++ +Other options are available to control how the manual page is +displayed. See linkgit:git-help[1] for more information, +because `git --help ...` is converted internally into `git +help ...`. + +-C <path>:: + Run as if git was started in '<path>' instead of the current working + directory. When multiple `-C` options are given, each subsequent + non-absolute `-C <path>` is interpreted relative to the preceding `-C + <path>`. ++ +This option affects options that expect path name like `--git-dir` and +`--work-tree` in that their interpretations of the path names would be +made relative to the working directory caused by the `-C` option. For +example the following invocations are equivalent: + + git --git-dir=a.git --work-tree=b -C c status + git --git-dir=c/a.git --work-tree=c/b status + +-c <name>=<value>:: + Pass a configuration parameter to the command. The value + given will override values from configuration files. + The <name> is expected in the same format as listed by + 'git config' (subkeys separated by dots). ++ +Note that omitting the `=` in `git -c foo.bar ...` is allowed and sets +`foo.bar` to the boolean true value (just like `[foo]bar` would in a +config file). Including the equals but with an empty value (like `git -c +foo.bar= ...`) sets `foo.bar` to the empty string which `git config +--bool` will convert to `false`. + +--exec-path[=<path>]:: + Path to wherever your core Git programs are installed. + This can also be controlled by setting the GIT_EXEC_PATH + environment variable. If no path is given, 'git' will print + the current setting and then exit. + +--html-path:: + Print the path, without trailing slash, where Git's HTML + documentation is installed and exit. + +--man-path:: + Print the manpath (see `man(1)`) for the man pages for + this version of Git and exit. + +--info-path:: + Print the path where the Info files documenting this + version of Git are installed and exit. + +-p:: +--paginate:: + Pipe all output into 'less' (or if set, $PAGER) if standard + output is a terminal. This overrides the `pager.<cmd>` + configuration options (see the "Configuration Mechanism" section + below). + +--no-pager:: + Do not pipe Git output into a pager. + +--git-dir=<path>:: + Set the path to the repository. This can also be controlled by + setting the `GIT_DIR` environment variable. It can be an absolute + path or relative path to current working directory. + +--work-tree=<path>:: + Set the path to the working tree. It can be an absolute path + or a path relative to the current working directory. + This can also be controlled by setting the GIT_WORK_TREE + environment variable and the core.worktree configuration + variable (see core.worktree in linkgit:git-config[1] for a + more detailed discussion). + +--namespace=<path>:: + Set the Git namespace. See linkgit:gitnamespaces[7] for more + details. Equivalent to setting the `GIT_NAMESPACE` environment + variable. + +--super-prefix=<path>:: + Currently for internal use only. Set a prefix which gives a path from + above a repository down to its root. One use is to give submodules + context about the superproject that invoked it. + +--bare:: + Treat the repository as a bare repository. If GIT_DIR + environment is not set, it is set to the current working + directory. + +--no-replace-objects:: + Do not use replacement refs to replace Git objects. See + linkgit:git-replace[1] for more information. + +--literal-pathspecs:: + Treat pathspecs literally (i.e. no globbing, no pathspec magic). + This is equivalent to setting the `GIT_LITERAL_PATHSPECS` environment + variable to `1`. + +--glob-pathspecs:: + Add "glob" magic to all pathspec. This is equivalent to setting + the `GIT_GLOB_PATHSPECS` environment variable to `1`. Disabling + globbing on individual pathspecs can be done using pathspec + magic ":(literal)" + +--noglob-pathspecs:: + Add "literal" magic to all pathspec. This is equivalent to setting + the `GIT_NOGLOB_PATHSPECS` environment variable to `1`. Enabling + globbing on individual pathspecs can be done using pathspec + magic ":(glob)" + +--icase-pathspecs:: + Add "icase" magic to all pathspec. This is equivalent to setting + the `GIT_ICASE_PATHSPECS` environment variable to `1`. + +--no-optional-locks:: + Do not perform optional operations that require locks. This is + equivalent to setting the `GIT_OPTIONAL_LOCKS` to `0`. + +GIT COMMANDS +------------ + +We divide Git into high level ("porcelain") commands and low level +("plumbing") commands. + +High-level commands (porcelain) +------------------------------- + +We separate the porcelain commands into the main commands and some +ancillary user utilities. + +Main porcelain commands +~~~~~~~~~~~~~~~~~~~~~~~ + +include::cmds-mainporcelain.txt[] + +Ancillary Commands +~~~~~~~~~~~~~~~~~~ +Manipulators: + +include::cmds-ancillarymanipulators.txt[] + +Interrogators: + +include::cmds-ancillaryinterrogators.txt[] + + +Interacting with Others +~~~~~~~~~~~~~~~~~~~~~~~ + +These commands are to interact with foreign SCM and with other +people via patch over e-mail. + +include::cmds-foreignscminterface.txt[] + + +Low-level commands (plumbing) +----------------------------- + +Although Git includes its +own porcelain layer, its low-level commands are sufficient to support +development of alternative porcelains. Developers of such porcelains +might start by reading about linkgit:git-update-index[1] and +linkgit:git-read-tree[1]. + +The interface (input, output, set of options and the semantics) +to these low-level commands are meant to be a lot more stable +than Porcelain level commands, because these commands are +primarily for scripted use. The interface to Porcelain commands +on the other hand are subject to change in order to improve the +end user experience. + +The following description divides +the low-level commands into commands that manipulate objects (in +the repository, index, and working tree), commands that interrogate and +compare objects, and commands that move objects and references between +repositories. + + +Manipulation commands +~~~~~~~~~~~~~~~~~~~~~ + +include::cmds-plumbingmanipulators.txt[] + + +Interrogation commands +~~~~~~~~~~~~~~~~~~~~~~ + +include::cmds-plumbinginterrogators.txt[] + +In general, the interrogate commands do not touch the files in +the working tree. + + +Synching repositories +~~~~~~~~~~~~~~~~~~~~~ + +include::cmds-synchingrepositories.txt[] + +The following are helper commands used by the above; end users +typically do not use them directly. + +include::cmds-synchelpers.txt[] + + +Internal helper commands +~~~~~~~~~~~~~~~~~~~~~~~~ + +These are internal helper commands used by other commands; end +users typically do not use them directly. + +include::cmds-purehelpers.txt[] + + +Configuration Mechanism +----------------------- + +Git uses a simple text format to store customizations that are per +repository and are per user. Such a configuration file may look +like this: + +------------ +# +# A '#' or ';' character indicates a comment. +# + +; core variables +[core] + ; Don't trust file modes + filemode = false + +; user identity +[user] + name = "Junio C Hamano" + email = "gitster@pobox.com" + +------------ + +Various commands read from the configuration file and adjust +their operation accordingly. See linkgit:git-config[1] for a +list and more details about the configuration mechanism. + + +Identifier Terminology +---------------------- +<object>:: + Indicates the object name for any type of object. + +<blob>:: + Indicates a blob object name. + +<tree>:: + Indicates a tree object name. + +<commit>:: + Indicates a commit object name. + +<tree-ish>:: + Indicates a tree, commit or tag object name. A + command that takes a <tree-ish> argument ultimately wants to + operate on a <tree> object but automatically dereferences + <commit> and <tag> objects that point at a <tree>. + +<commit-ish>:: + Indicates a commit or tag object name. A + command that takes a <commit-ish> argument ultimately wants to + operate on a <commit> object but automatically dereferences + <tag> objects that point at a <commit>. + +<type>:: + Indicates that an object type is required. + Currently one of: `blob`, `tree`, `commit`, or `tag`. + +<file>:: + Indicates a filename - almost always relative to the + root of the tree structure `GIT_INDEX_FILE` describes. + +Symbolic Identifiers +-------------------- +Any Git command accepting any <object> can also use the following +symbolic notation: + +HEAD:: + indicates the head of the current branch. + +<tag>:: + a valid tag 'name' + (i.e. a `refs/tags/<tag>` reference). + +<head>:: + a valid head 'name' + (i.e. a `refs/heads/<head>` reference). + +For a more complete list of ways to spell object names, see +"SPECIFYING REVISIONS" section in linkgit:gitrevisions[7]. + + +File/Directory Structure +------------------------ + +Please see the linkgit:gitrepository-layout[5] document. + +Read linkgit:githooks[5] for more details about each hook. + +Higher level SCMs may provide and manage additional information in the +`$GIT_DIR`. + + +Terminology +----------- +Please see linkgit:gitglossary[7]. + + +Environment Variables +--------------------- +Various Git commands use the following environment variables: + +The Git Repository +~~~~~~~~~~~~~~~~~~ +These environment variables apply to 'all' core Git commands. Nb: it +is worth noting that they may be used/overridden by SCMS sitting above +Git so take care if using a foreign front-end. + +`GIT_INDEX_FILE`:: + This environment allows the specification of an alternate + index file. If not specified, the default of `$GIT_DIR/index` + is used. + +`GIT_INDEX_VERSION`:: + This environment variable allows the specification of an index + version for new repositories. It won't affect existing index + files. By default index file version 2 or 3 is used. See + linkgit:git-update-index[1] for more information. + +`GIT_OBJECT_DIRECTORY`:: + If the object storage directory is specified via this + environment variable then the sha1 directories are created + underneath - otherwise the default `$GIT_DIR/objects` + directory is used. + +`GIT_ALTERNATE_OBJECT_DIRECTORIES`:: + Due to the immutable nature of Git objects, old objects can be + archived into shared, read-only directories. This variable + specifies a ":" separated (on Windows ";" separated) list + of Git object directories which can be used to search for Git + objects. New objects will not be written to these directories. ++ + Entries that begin with `"` (double-quote) will be interpreted + as C-style quoted paths, removing leading and trailing + double-quotes and respecting backslash escapes. E.g., the value + `"path-with-\"-and-:-in-it":vanilla-path` has two paths: + `path-with-"-and-:-in-it` and `vanilla-path`. + +`GIT_DIR`:: + If the `GIT_DIR` environment variable is set then it + specifies a path to use instead of the default `.git` + for the base of the repository. + The `--git-dir` command-line option also sets this value. + +`GIT_WORK_TREE`:: + Set the path to the root of the working tree. + This can also be controlled by the `--work-tree` command-line + option and the core.worktree configuration variable. + +`GIT_NAMESPACE`:: + Set the Git namespace; see linkgit:gitnamespaces[7] for details. + The `--namespace` command-line option also sets this value. + +`GIT_CEILING_DIRECTORIES`:: + This should be a colon-separated list of absolute paths. If + set, it is a list of directories that Git should not chdir up + into while looking for a repository directory (useful for + excluding slow-loading network directories). It will not + exclude the current working directory or a GIT_DIR set on the + command line or in the environment. Normally, Git has to read + the entries in this list and resolve any symlink that + might be present in order to compare them with the current + directory. However, if even this access is slow, you + can add an empty entry to the list to tell Git that the + subsequent entries are not symlinks and needn't be resolved; + e.g., + `GIT_CEILING_DIRECTORIES=/maybe/symlink::/very/slow/non/symlink`. + +`GIT_DISCOVERY_ACROSS_FILESYSTEM`:: + When run in a directory that does not have ".git" repository + directory, Git tries to find such a directory in the parent + directories to find the top of the working tree, but by default it + does not cross filesystem boundaries. This environment variable + can be set to true to tell Git not to stop at filesystem + boundaries. Like `GIT_CEILING_DIRECTORIES`, this will not affect + an explicit repository directory set via `GIT_DIR` or on the + command line. + +`GIT_COMMON_DIR`:: + If this variable is set to a path, non-worktree files that are + normally in $GIT_DIR will be taken from this path + instead. Worktree-specific files such as HEAD or index are + taken from $GIT_DIR. See linkgit:gitrepository-layout[5] and + linkgit:git-worktree[1] for + details. This variable has lower precedence than other path + variables such as GIT_INDEX_FILE, GIT_OBJECT_DIRECTORY... + +Git Commits +~~~~~~~~~~~ +`GIT_AUTHOR_NAME`:: +`GIT_AUTHOR_EMAIL`:: +`GIT_AUTHOR_DATE`:: +`GIT_COMMITTER_NAME`:: +`GIT_COMMITTER_EMAIL`:: +`GIT_COMMITTER_DATE`:: +'EMAIL':: + see linkgit:git-commit-tree[1] + +Git Diffs +~~~~~~~~~ +`GIT_DIFF_OPTS`:: + Only valid setting is "--unified=??" or "-u??" to set the + number of context lines shown when a unified diff is created. + This takes precedence over any "-U" or "--unified" option + value passed on the Git diff command line. + +`GIT_EXTERNAL_DIFF`:: + When the environment variable `GIT_EXTERNAL_DIFF` is set, the + program named by it is called, instead of the diff invocation + described above. For a path that is added, removed, or modified, + `GIT_EXTERNAL_DIFF` is called with 7 parameters: + + path old-file old-hex old-mode new-file new-hex new-mode ++ +where: + + <old|new>-file:: are files GIT_EXTERNAL_DIFF can use to read the + contents of <old|new>, + <old|new>-hex:: are the 40-hexdigit SHA-1 hashes, + <old|new>-mode:: are the octal representation of the file modes. ++ +The file parameters can point at the user's working file +(e.g. `new-file` in "git-diff-files"), `/dev/null` (e.g. `old-file` +when a new file is added), or a temporary file (e.g. `old-file` in the +index). `GIT_EXTERNAL_DIFF` should not worry about unlinking the +temporary file --- it is removed when `GIT_EXTERNAL_DIFF` exits. ++ +For a path that is unmerged, `GIT_EXTERNAL_DIFF` is called with 1 +parameter, <path>. ++ +For each path `GIT_EXTERNAL_DIFF` is called, two environment variables, +`GIT_DIFF_PATH_COUNTER` and `GIT_DIFF_PATH_TOTAL` are set. + +`GIT_DIFF_PATH_COUNTER`:: + A 1-based counter incremented by one for every path. + +`GIT_DIFF_PATH_TOTAL`:: + The total number of paths. + +other +~~~~~ +`GIT_MERGE_VERBOSITY`:: + A number controlling the amount of output shown by + the recursive merge strategy. Overrides merge.verbosity. + See linkgit:git-merge[1] + +`GIT_PAGER`:: + This environment variable overrides `$PAGER`. If it is set + to an empty string or to the value "cat", Git will not launch + a pager. See also the `core.pager` option in + linkgit:git-config[1]. + +`GIT_EDITOR`:: + This environment variable overrides `$EDITOR` and `$VISUAL`. + It is used by several Git commands when, on interactive mode, + an editor is to be launched. See also linkgit:git-var[1] + and the `core.editor` option in linkgit:git-config[1]. + +`GIT_SSH`:: +`GIT_SSH_COMMAND`:: + If either of these environment variables is set then 'git fetch' + and 'git push' will use the specified command instead of 'ssh' + when they need to connect to a remote system. + The command will be given exactly two or four arguments: the + 'username@host' (or just 'host') from the URL and the shell + command to execute on that remote system, optionally preceded by + `-p` (literally) and the 'port' from the URL when it specifies + something other than the default SSH port. ++ +`$GIT_SSH_COMMAND` takes precedence over `$GIT_SSH`, and is interpreted +by the shell, which allows additional arguments to be included. +`$GIT_SSH` on the other hand must be just the path to a program +(which can be a wrapper shell script, if additional arguments are +needed). ++ +Usually it is easier to configure any desired options through your +personal `.ssh/config` file. Please consult your ssh documentation +for further details. + +`GIT_SSH_VARIANT`:: + If this environment variable is set, it overrides Git's autodetection + whether `GIT_SSH`/`GIT_SSH_COMMAND`/`core.sshCommand` refer to OpenSSH, + plink or tortoiseplink. This variable overrides the config setting + `ssh.variant` that serves the same purpose. + +`GIT_ASKPASS`:: + If this environment variable is set, then Git commands which need to + acquire passwords or passphrases (e.g. for HTTP or IMAP authentication) + will call this program with a suitable prompt as command-line argument + and read the password from its STDOUT. See also the `core.askPass` + option in linkgit:git-config[1]. + +`GIT_TERMINAL_PROMPT`:: + If this environment variable is set to `0`, git will not prompt + on the terminal (e.g., when asking for HTTP authentication). + +`GIT_CONFIG_NOSYSTEM`:: + Whether to skip reading settings from the system-wide + `$(prefix)/etc/gitconfig` file. This environment variable can + be used along with `$HOME` and `$XDG_CONFIG_HOME` to create a + predictable environment for a picky script, or you can set it + temporarily to avoid using a buggy `/etc/gitconfig` file while + waiting for someone with sufficient permissions to fix it. + +`GIT_FLUSH`:: + If this environment variable is set to "1", then commands such + as 'git blame' (in incremental mode), 'git rev-list', 'git log', + 'git check-attr' and 'git check-ignore' will + force a flush of the output stream after each record have been + flushed. If this + variable is set to "0", the output of these commands will be done + using completely buffered I/O. If this environment variable is + not set, Git will choose buffered or record-oriented flushing + based on whether stdout appears to be redirected to a file or not. + +`GIT_TRACE`:: + Enables general trace messages, e.g. alias expansion, built-in + command execution and external command execution. ++ +If this variable is set to "1", "2" or "true" (comparison +is case insensitive), trace messages will be printed to +stderr. ++ +If the variable is set to an integer value greater than 2 +and lower than 10 (strictly) then Git will interpret this +value as an open file descriptor and will try to write the +trace messages into this file descriptor. ++ +Alternatively, if the variable is set to an absolute path +(starting with a '/' character), Git will interpret this +as a file path and will try to write the trace messages +into it. ++ +Unsetting the variable, or setting it to empty, "0" or +"false" (case insensitive) disables trace messages. + +`GIT_TRACE_FSMONITOR`:: + Enables trace messages for the filesystem monitor extension. + See `GIT_TRACE` for available trace output options. + +`GIT_TRACE_PACK_ACCESS`:: + Enables trace messages for all accesses to any packs. For each + access, the pack file name and an offset in the pack is + recorded. This may be helpful for troubleshooting some + pack-related performance problems. + See `GIT_TRACE` for available trace output options. + +`GIT_TRACE_PACKET`:: + Enables trace messages for all packets coming in or out of a + given program. This can help with debugging object negotiation + or other protocol issues. Tracing is turned off at a packet + starting with "PACK" (but see `GIT_TRACE_PACKFILE` below). + See `GIT_TRACE` for available trace output options. + +`GIT_TRACE_PACKFILE`:: + Enables tracing of packfiles sent or received by a + given program. Unlike other trace output, this trace is + verbatim: no headers, and no quoting of binary data. You almost + certainly want to direct into a file (e.g., + `GIT_TRACE_PACKFILE=/tmp/my.pack`) rather than displaying it on + the terminal or mixing it with other trace output. ++ +Note that this is currently only implemented for the client side +of clones and fetches. + +`GIT_TRACE_PERFORMANCE`:: + Enables performance related trace messages, e.g. total execution + time of each Git command. + See `GIT_TRACE` for available trace output options. + +`GIT_TRACE_SETUP`:: + Enables trace messages printing the .git, working tree and current + working directory after Git has completed its setup phase. + See `GIT_TRACE` for available trace output options. + +`GIT_TRACE_SHALLOW`:: + Enables trace messages that can help debugging fetching / + cloning of shallow repositories. + See `GIT_TRACE` for available trace output options. + +`GIT_TRACE_CURL`:: + Enables a curl full trace dump of all incoming and outgoing data, + including descriptive information, of the git transport protocol. + This is similar to doing curl `--trace-ascii` on the command line. + This option overrides setting the `GIT_CURL_VERBOSE` environment + variable. + See `GIT_TRACE` for available trace output options. + +`GIT_LITERAL_PATHSPECS`:: + Setting this variable to `1` will cause Git to treat all + pathspecs literally, rather than as glob patterns. For example, + running `GIT_LITERAL_PATHSPECS=1 git log -- '*.c'` will search + for commits that touch the path `*.c`, not any paths that the + glob `*.c` matches. You might want this if you are feeding + literal paths to Git (e.g., paths previously given to you by + `git ls-tree`, `--raw` diff output, etc). + +`GIT_GLOB_PATHSPECS`:: + Setting this variable to `1` will cause Git to treat all + pathspecs as glob patterns (aka "glob" magic). + +`GIT_NOGLOB_PATHSPECS`:: + Setting this variable to `1` will cause Git to treat all + pathspecs as literal (aka "literal" magic). + +`GIT_ICASE_PATHSPECS`:: + Setting this variable to `1` will cause Git to treat all + pathspecs as case-insensitive. + +`GIT_REFLOG_ACTION`:: + When a ref is updated, reflog entries are created to keep + track of the reason why the ref was updated (which is + typically the name of the high-level command that updated + the ref), in addition to the old and new values of the ref. + A scripted Porcelain command can use set_reflog_action + helper function in `git-sh-setup` to set its name to this + variable when it is invoked as the top level command by the + end user, to be recorded in the body of the reflog. + +`GIT_REF_PARANOIA`:: + If set to `1`, include broken or badly named refs when iterating + over lists of refs. In a normal, non-corrupted repository, this + does nothing. However, enabling it may help git to detect and + abort some operations in the presence of broken refs. Git sets + this variable automatically when performing destructive + operations like linkgit:git-prune[1]. You should not need to set + it yourself unless you want to be paranoid about making sure + an operation has touched every ref (e.g., because you are + cloning a repository to make a backup). + +`GIT_ALLOW_PROTOCOL`:: + If set to a colon-separated list of protocols, behave as if + `protocol.allow` is set to `never`, and each of the listed + protocols has `protocol.<name>.allow` set to `always` + (overriding any existing configuration). In other words, any + protocol not mentioned will be disallowed (i.e., this is a + whitelist, not a blacklist). See the description of + `protocol.allow` in linkgit:git-config[1] for more details. + +`GIT_PROTOCOL_FROM_USER`:: + Set to 0 to prevent protocols used by fetch/push/clone which are + configured to the `user` state. This is useful to restrict recursive + submodule initialization from an untrusted repository or for programs + which feed potentially-untrusted URLS to git commands. See + linkgit:git-config[1] for more details. + +`GIT_OPTIONAL_LOCKS`:: + If set to `0`, Git will complete any requested operation without + performing any optional sub-operations that require taking a lock. + For example, this will prevent `git status` from refreshing the + index as a side effect. This is useful for processes running in + the background which do not want to cause lock contention with + other operations on the repository. Defaults to `1`. + +`GIT_REDIRECT_STDIN`:: +`GIT_REDIRECT_STDOUT`:: +`GIT_REDIRECT_STDERR`:: + Windows-only: allow redirecting the standard input/output/error + handles to paths specified by the environment variables. This is + particularly useful in multi-threaded applications where the + canonical way to pass standard handles via `CreateProcess()` is + not an option because it would require the handles to be marked + inheritable (and consequently *every* spawned process would + inherit them, possibly blocking regular Git operations). The + primary intended use case is to use named pipes for communication + (e.g. `\\.\pipe\my-git-stdin-123`). ++ +Two special values are supported: `off` will simply close the +corresponding standard handle, and if `GIT_REDIRECT_STDERR` is +`2>&1`, standard error will be redirected to the same handle as +standard output. + +Discussion[[Discussion]] +------------------------ + +More detail on the following is available from the +link:user-manual.html#git-concepts[Git concepts chapter of the +user-manual] and linkgit:gitcore-tutorial[7]. + +A Git project normally consists of a working directory with a ".git" +subdirectory at the top level. The .git directory contains, among other +things, a compressed object database representing the complete history +of the project, an "index" file which links that history to the current +contents of the working tree, and named pointers into that history such +as tags and branch heads. + +The object database contains objects of three main types: blobs, which +hold file data; trees, which point to blobs and other trees to build up +directory hierarchies; and commits, which each reference a single tree +and some number of parent commits. + +The commit, equivalent to what other systems call a "changeset" or +"version", represents a step in the project's history, and each parent +represents an immediately preceding step. Commits with more than one +parent represent merges of independent lines of development. + +All objects are named by the SHA-1 hash of their contents, normally +written as a string of 40 hex digits. Such names are globally unique. +The entire history leading up to a commit can be vouched for by signing +just that commit. A fourth object type, the tag, is provided for this +purpose. + +When first created, objects are stored in individual files, but for +efficiency may later be compressed together into "pack files". + +Named pointers called refs mark interesting points in history. A ref +may contain the SHA-1 name of an object or the name of another ref. Refs +with names beginning `ref/head/` contain the SHA-1 name of the most +recent commit (or "head") of a branch under development. SHA-1 names of +tags of interest are stored under `ref/tags/`. A special ref named +`HEAD` contains the name of the currently checked-out branch. + +The index file is initialized with a list of all paths and, for each +path, a blob object and a set of attributes. The blob object represents +the contents of the file as of the head of the current branch. The +attributes (last modified time, size, etc.) are taken from the +corresponding file in the working tree. Subsequent changes to the +working tree can be found by comparing these attributes. The index may +be updated with new content, and new commits may be created from the +content stored in the index. + +The index is also capable of storing multiple entries (called "stages") +for a given pathname. These stages are used to hold the various +unmerged version of a file when a merge is in progress. + +FURTHER DOCUMENTATION +--------------------- + +See the references in the "description" section to get started +using Git. The following is probably more detail than necessary +for a first-time user. + +The link:user-manual.html#git-concepts[Git concepts chapter of the +user-manual] and linkgit:gitcore-tutorial[7] both provide +introductions to the underlying Git architecture. + +See linkgit:gitworkflows[7] for an overview of recommended workflows. + +See also the link:howto-index.html[howto] documents for some useful +examples. + +The internals are documented in the +link:technical/api-index.html[Git API documentation]. + +Users migrating from CVS may also want to +read linkgit:gitcvs-migration[7]. + + +Authors +------- +Git was started by Linus Torvalds, and is currently maintained by Junio +C Hamano. Numerous contributions have come from the Git mailing list +<git@vger.kernel.org>. http://www.openhub.net/p/git/contributors/summary +gives you a more complete list of contributors. + +If you have a clone of git.git itself, the +output of linkgit:git-shortlog[1] and linkgit:git-blame[1] can show you +the authors for specific parts of the project. + +Reporting Bugs +-------------- + +Report bugs to the Git mailing list <git@vger.kernel.org> where the +development and maintenance is primarily done. You do not have to be +subscribed to the list to send a message there. + +SEE ALSO +-------- +linkgit:gittutorial[7], linkgit:gittutorial-2[7], +linkgit:giteveryday[7], linkgit:gitcvs-migration[7], +linkgit:gitglossary[7], linkgit:gitcore-tutorial[7], +linkgit:gitcli[7], link:user-manual.html[The Git User's Manual], +linkgit:gitworkflows[7] + +GIT +--- +Part of the linkgit:git[1] suite |