6 git - the stupid content tracker
12 'git' [--version] [--exec-path[=<path>]] [--html-path] [--man-path] [--info-path]
13 [-p|--paginate|--no-pager] [--no-replace-objects]
14 [--bare] [--git-dir=<path>] [--work-tree=<path>]
16 [--help] <command> [<args>]
20 Git is a fast, scalable, distributed revision control system with an
21 unusually rich command set that provides both high-level operations
22 and full access to internals.
24 See linkgit:gittutorial[7] to get started, then see
25 link:everyday.html[Everyday Git] for a useful minimum set of commands, and
26 "man git-commandname" for documentation of each command. CVS users may
27 also want to read linkgit:gitcvs-migration[7]. See
28 the link:user-manual.html[Git User's Manual] for a more in-depth
31 The '<command>' is either a name of a Git command (see below) or an alias
32 as defined in the configuration file (see linkgit:git-config[1]).
34 Formatted and hyperlinked version of the latest git
35 documentation can be viewed at
36 `http://www.kernel.org/pub/software/scm/git/docs/`.
42 You are reading the documentation for the latest (possibly
43 unreleased) version of git, that is available from 'master'
44 branch of the `git.git` repository.
45 Documentation for older releases are available here:
47 * link:v1.7.6/git.html[documentation for release 1.7.6]
50 link:RelNotes/1.7.6.txt[1.7.6].
52 * link:v1.7.5.4/git.html[documentation for release 1.7.5.4]
55 link:RelNotes/1.7.5.4.txt[1.7.5.4],
56 link:RelNotes/1.7.5.3.txt[1.7.5.3],
57 link:RelNotes/1.7.5.2.txt[1.7.5.2],
58 link:RelNotes/1.7.5.1.txt[1.7.5.1],
59 link:RelNotes/1.7.5.txt[1.7.5].
61 * link:v1.7.4.5/git.html[documentation for release 1.7.4.5]
64 link:RelNotes/1.7.4.5.txt[1.7.4.5],
65 link:RelNotes/1.7.4.4.txt[1.7.4.4],
66 link:RelNotes/1.7.4.3.txt[1.7.4.3],
67 link:RelNotes/1.7.4.2.txt[1.7.4.2],
68 link:RelNotes/1.7.4.1.txt[1.7.4.1],
69 link:RelNotes/1.7.4.txt[1.7.4].
71 * link:v1.7.3.5/git.html[documentation for release 1.7.3.5]
74 link:RelNotes/1.7.3.5.txt[1.7.3.5],
75 link:RelNotes/1.7.3.4.txt[1.7.3.4],
76 link:RelNotes/1.7.3.3.txt[1.7.3.3],
77 link:RelNotes/1.7.3.2.txt[1.7.3.2],
78 link:RelNotes/1.7.3.1.txt[1.7.3.1],
79 link:RelNotes/1.7.3.txt[1.7.3].
81 * link:v1.7.2.5/git.html[documentation for release 1.7.2.5]
84 link:RelNotes/1.7.2.5.txt[1.7.2.5],
85 link:RelNotes/1.7.2.4.txt[1.7.2.4],
86 link:RelNotes/1.7.2.3.txt[1.7.2.3],
87 link:RelNotes/1.7.2.2.txt[1.7.2.2],
88 link:RelNotes/1.7.2.1.txt[1.7.2.1],
89 link:RelNotes/1.7.2.txt[1.7.2].
91 * link:v1.7.1.4/git.html[documentation for release 1.7.1.4]
94 link:RelNotes/1.7.1.4.txt[1.7.1.4],
95 link:RelNotes/1.7.1.3.txt[1.7.1.3],
96 link:RelNotes/1.7.1.2.txt[1.7.1.2],
97 link:RelNotes/1.7.1.1.txt[1.7.1.1],
98 link:RelNotes/1.7.1.txt[1.7.1].
100 * link:v1.7.0.9/git.html[documentation for release 1.7.0.9]
103 link:RelNotes/1.7.0.9.txt[1.7.0.9],
104 link:RelNotes/1.7.0.8.txt[1.7.0.8],
105 link:RelNotes/1.7.0.7.txt[1.7.0.7],
106 link:RelNotes/1.7.0.6.txt[1.7.0.6],
107 link:RelNotes/1.7.0.5.txt[1.7.0.5],
108 link:RelNotes/1.7.0.4.txt[1.7.0.4],
109 link:RelNotes/1.7.0.3.txt[1.7.0.3],
110 link:RelNotes/1.7.0.2.txt[1.7.0.2],
111 link:RelNotes/1.7.0.1.txt[1.7.0.1],
112 link:RelNotes/1.7.0.txt[1.7.0].
114 * link:v1.6.6.3/git.html[documentation for release 1.6.6.3]
117 link:RelNotes/1.6.6.3.txt[1.6.6.3],
118 link:RelNotes/1.6.6.2.txt[1.6.6.2],
119 link:RelNotes/1.6.6.1.txt[1.6.6.1],
120 link:RelNotes/1.6.6.txt[1.6.6].
122 * link:v1.6.5.9/git.html[documentation for release 1.6.5.9]
125 link:RelNotes/1.6.5.9.txt[1.6.5.9],
126 link:RelNotes/1.6.5.8.txt[1.6.5.8],
127 link:RelNotes/1.6.5.7.txt[1.6.5.7],
128 link:RelNotes/1.6.5.6.txt[1.6.5.6],
129 link:RelNotes/1.6.5.5.txt[1.6.5.5],
130 link:RelNotes/1.6.5.4.txt[1.6.5.4],
131 link:RelNotes/1.6.5.3.txt[1.6.5.3],
132 link:RelNotes/1.6.5.2.txt[1.6.5.2],
133 link:RelNotes/1.6.5.1.txt[1.6.5.1],
134 link:RelNotes/1.6.5.txt[1.6.5].
136 * link:v1.6.4.5/git.html[documentation for release 1.6.4.5]
139 link:RelNotes/1.6.4.5.txt[1.6.4.5],
140 link:RelNotes/1.6.4.4.txt[1.6.4.4],
141 link:RelNotes/1.6.4.3.txt[1.6.4.3],
142 link:RelNotes/1.6.4.2.txt[1.6.4.2],
143 link:RelNotes/1.6.4.1.txt[1.6.4.1],
144 link:RelNotes/1.6.4.txt[1.6.4].
146 * link:v1.6.3.4/git.html[documentation for release 1.6.3.4]
149 link:RelNotes/1.6.3.4.txt[1.6.3.4],
150 link:RelNotes/1.6.3.3.txt[1.6.3.3],
151 link:RelNotes/1.6.3.2.txt[1.6.3.2],
152 link:RelNotes/1.6.3.1.txt[1.6.3.1],
153 link:RelNotes/1.6.3.txt[1.6.3].
156 link:RelNotes/1.6.2.5.txt[1.6.2.5],
157 link:RelNotes/1.6.2.4.txt[1.6.2.4],
158 link:RelNotes/1.6.2.3.txt[1.6.2.3],
159 link:RelNotes/1.6.2.2.txt[1.6.2.2],
160 link:RelNotes/1.6.2.1.txt[1.6.2.1],
161 link:RelNotes/1.6.2.txt[1.6.2].
163 * link:v1.6.1.3/git.html[documentation for release 1.6.1.3]
166 link:RelNotes/1.6.1.3.txt[1.6.1.3],
167 link:RelNotes/1.6.1.2.txt[1.6.1.2],
168 link:RelNotes/1.6.1.1.txt[1.6.1.1],
169 link:RelNotes/1.6.1.txt[1.6.1].
171 * link:v1.6.0.6/git.html[documentation for release 1.6.0.6]
174 link:RelNotes/1.6.0.6.txt[1.6.0.6],
175 link:RelNotes/1.6.0.5.txt[1.6.0.5],
176 link:RelNotes/1.6.0.4.txt[1.6.0.4],
177 link:RelNotes/1.6.0.3.txt[1.6.0.3],
178 link:RelNotes/1.6.0.2.txt[1.6.0.2],
179 link:RelNotes/1.6.0.1.txt[1.6.0.1],
180 link:RelNotes/1.6.0.txt[1.6.0].
182 * link:v1.5.6.6/git.html[documentation for release 1.5.6.6]
185 link:RelNotes/1.5.6.6.txt[1.5.6.6],
186 link:RelNotes/1.5.6.5.txt[1.5.6.5],
187 link:RelNotes/1.5.6.4.txt[1.5.6.4],
188 link:RelNotes/1.5.6.3.txt[1.5.6.3],
189 link:RelNotes/1.5.6.2.txt[1.5.6.2],
190 link:RelNotes/1.5.6.1.txt[1.5.6.1],
191 link:RelNotes/1.5.6.txt[1.5.6].
193 * link:v1.5.5.6/git.html[documentation for release 1.5.5.6]
196 link:RelNotes/1.5.5.6.txt[1.5.5.6],
197 link:RelNotes/1.5.5.5.txt[1.5.5.5],
198 link:RelNotes/1.5.5.4.txt[1.5.5.4],
199 link:RelNotes/1.5.5.3.txt[1.5.5.3],
200 link:RelNotes/1.5.5.2.txt[1.5.5.2],
201 link:RelNotes/1.5.5.1.txt[1.5.5.1],
202 link:RelNotes/1.5.5.txt[1.5.5].
204 * link:v1.5.4.7/git.html[documentation for release 1.5.4.7]
207 link:RelNotes/1.5.4.7.txt[1.5.4.7],
208 link:RelNotes/1.5.4.6.txt[1.5.4.6],
209 link:RelNotes/1.5.4.5.txt[1.5.4.5],
210 link:RelNotes/1.5.4.4.txt[1.5.4.4],
211 link:RelNotes/1.5.4.3.txt[1.5.4.3],
212 link:RelNotes/1.5.4.2.txt[1.5.4.2],
213 link:RelNotes/1.5.4.1.txt[1.5.4.1],
214 link:RelNotes/1.5.4.txt[1.5.4].
216 * link:v1.5.3.8/git.html[documentation for release 1.5.3.8]
219 link:RelNotes/1.5.3.8.txt[1.5.3.8],
220 link:RelNotes/1.5.3.7.txt[1.5.3.7],
221 link:RelNotes/1.5.3.6.txt[1.5.3.6],
222 link:RelNotes/1.5.3.5.txt[1.5.3.5],
223 link:RelNotes/1.5.3.4.txt[1.5.3.4],
224 link:RelNotes/1.5.3.3.txt[1.5.3.3],
225 link:RelNotes/1.5.3.2.txt[1.5.3.2],
226 link:RelNotes/1.5.3.1.txt[1.5.3.1],
227 link:RelNotes/1.5.3.txt[1.5.3].
229 * link:v1.5.2.5/git.html[documentation for release 1.5.2.5]
232 link:RelNotes/1.5.2.5.txt[1.5.2.5],
233 link:RelNotes/1.5.2.4.txt[1.5.2.4],
234 link:RelNotes/1.5.2.3.txt[1.5.2.3],
235 link:RelNotes/1.5.2.2.txt[1.5.2.2],
236 link:RelNotes/1.5.2.1.txt[1.5.2.1],
237 link:RelNotes/1.5.2.txt[1.5.2].
239 * link:v1.5.1.6/git.html[documentation for release 1.5.1.6]
242 link:RelNotes/1.5.1.6.txt[1.5.1.6],
243 link:RelNotes/1.5.1.5.txt[1.5.1.5],
244 link:RelNotes/1.5.1.4.txt[1.5.1.4],
245 link:RelNotes/1.5.1.3.txt[1.5.1.3],
246 link:RelNotes/1.5.1.2.txt[1.5.1.2],
247 link:RelNotes/1.5.1.1.txt[1.5.1.1],
248 link:RelNotes/1.5.1.txt[1.5.1].
250 * link:v1.5.0.7/git.html[documentation for release 1.5.0.7]
253 link:RelNotes/1.5.0.7.txt[1.5.0.7],
254 link:RelNotes/1.5.0.6.txt[1.5.0.6],
255 link:RelNotes/1.5.0.5.txt[1.5.0.5],
256 link:RelNotes/1.5.0.3.txt[1.5.0.3],
257 link:RelNotes/1.5.0.2.txt[1.5.0.2],
258 link:RelNotes/1.5.0.1.txt[1.5.0.1],
259 link:RelNotes/1.5.0.txt[1.5.0].
261 * documentation for release link:v1.4.4.4/git.html[1.4.4.4],
262 link:v1.3.3/git.html[1.3.3],
263 link:v1.2.6/git.html[1.2.6],
264 link:v1.0.13/git.html[1.0.13].
273 Prints the git suite version that the 'git' program came from.
276 Prints the synopsis and a list of the most commonly used
277 commands. If the option '--all' or '-a' is given then all
278 available commands are printed. If a git command is named this
279 option will bring up the manual page for that command.
281 Other options are available to control how the manual page is
282 displayed. See linkgit:git-help[1] for more information,
283 because `git --help ...` is converted internally into `git
287 Pass a configuration parameter to the command. The value
288 given will override values from configuration files.
289 The <name> is expected in the same format as listed by
290 'git config' (subkeys separated by dots).
292 --exec-path[=<path>]::
293 Path to wherever your core git programs are installed.
294 This can also be controlled by setting the GIT_EXEC_PATH
295 environment variable. If no path is given, 'git' will print
296 the current setting and then exit.
299 Print the path, without trailing slash, where git's HTML
300 documentation is installed and exit.
303 Print the manpath (see `man(1)`) for the man pages for
304 this version of git and exit.
307 Print the path where the Info files documenting this
308 version of git are installed and exit.
312 Pipe all output into 'less' (or if set, $PAGER) if standard
313 output is a terminal. This overrides the `pager.<cmd>`
314 configuration options (see the "Configuration Mechanism" section
318 Do not pipe git output into a pager.
321 Set the path to the repository. This can also be controlled by
322 setting the GIT_DIR environment variable. It can be an absolute
323 path or relative path to current working directory.
326 Set the path to the working tree. It can be an absolute path
327 or a path relative to the current working directory.
328 This can also be controlled by setting the GIT_WORK_TREE
329 environment variable and the core.worktree configuration
330 variable (see core.worktree in linkgit:git-config[1] for a
331 more detailed discussion).
334 Treat the repository as a bare repository. If GIT_DIR
335 environment is not set, it is set to the current working
338 --no-replace-objects::
339 Do not use replacement refs to replace git objects. See
340 linkgit:git-replace[1] for more information.
343 FURTHER DOCUMENTATION
344 ---------------------
346 See the references above to get started using git. The following is
347 probably more detail than necessary for a first-time user.
349 The link:user-manual.html#git-concepts[git concepts chapter of the
350 user-manual] and linkgit:gitcore-tutorial[7] both provide
351 introductions to the underlying git architecture.
353 See linkgit:gitworkflows[7] for an overview of recommended workflows.
355 See also the link:howto-index.html[howto] documents for some useful
358 The internals are documented in the
359 link:technical/api-index.html[GIT API documentation].
364 We divide git into high level ("porcelain") commands and low level
365 ("plumbing") commands.
367 High-level commands (porcelain)
368 -------------------------------
370 We separate the porcelain commands into the main commands and some
371 ancillary user utilities.
373 Main porcelain commands
374 ~~~~~~~~~~~~~~~~~~~~~~~
376 include::cmds-mainporcelain.txt[]
382 include::cmds-ancillarymanipulators.txt[]
386 include::cmds-ancillaryinterrogators.txt[]
389 Interacting with Others
390 ~~~~~~~~~~~~~~~~~~~~~~~
392 These commands are to interact with foreign SCM and with other
393 people via patch over e-mail.
395 include::cmds-foreignscminterface.txt[]
398 Low-level commands (plumbing)
399 -----------------------------
401 Although git includes its
402 own porcelain layer, its low-level commands are sufficient to support
403 development of alternative porcelains. Developers of such porcelains
404 might start by reading about linkgit:git-update-index[1] and
405 linkgit:git-read-tree[1].
407 The interface (input, output, set of options and the semantics)
408 to these low-level commands are meant to be a lot more stable
409 than Porcelain level commands, because these commands are
410 primarily for scripted use. The interface to Porcelain commands
411 on the other hand are subject to change in order to improve the
414 The following description divides
415 the low-level commands into commands that manipulate objects (in
416 the repository, index, and working tree), commands that interrogate and
417 compare objects, and commands that move objects and references between
421 Manipulation commands
422 ~~~~~~~~~~~~~~~~~~~~~
424 include::cmds-plumbingmanipulators.txt[]
427 Interrogation commands
428 ~~~~~~~~~~~~~~~~~~~~~~
430 include::cmds-plumbinginterrogators.txt[]
432 In general, the interrogate commands do not touch the files in
436 Synching repositories
437 ~~~~~~~~~~~~~~~~~~~~~
439 include::cmds-synchingrepositories.txt[]
441 The following are helper commands used by the above; end users
442 typically do not use them directly.
444 include::cmds-synchelpers.txt[]
447 Internal helper commands
448 ~~~~~~~~~~~~~~~~~~~~~~~~
450 These are internal helper commands used by other commands; end
451 users typically do not use them directly.
453 include::cmds-purehelpers.txt[]
456 Configuration Mechanism
457 -----------------------
459 Starting from 0.99.9 (actually mid 0.99.8.GIT), `.git/config` file
460 is used to hold per-repository configuration options. It is a
461 simple text file modeled after `.ini` format familiar to some
462 people. Here is an example:
466 # A '#' or ';' character indicates a comment.
471 ; Don't trust file modes
476 name = "Junio C Hamano"
477 email = "junkio@twinsun.com"
481 Various commands read from the configuration file and adjust
482 their operation accordingly. See linkgit:git-config[1] for a
486 Identifier Terminology
487 ----------------------
489 Indicates the object name for any type of object.
492 Indicates a blob object name.
495 Indicates a tree object name.
498 Indicates a commit object name.
501 Indicates a tree, commit or tag object name. A
502 command that takes a <tree-ish> argument ultimately wants to
503 operate on a <tree> object but automatically dereferences
504 <commit> and <tag> objects that point at a <tree>.
507 Indicates a commit or tag object name. A
508 command that takes a <commit-ish> argument ultimately wants to
509 operate on a <commit> object but automatically dereferences
510 <tag> objects that point at a <commit>.
513 Indicates that an object type is required.
514 Currently one of: `blob`, `tree`, `commit`, or `tag`.
517 Indicates a filename - almost always relative to the
518 root of the tree structure `GIT_INDEX_FILE` describes.
522 Any git command accepting any <object> can also use the following
526 indicates the head of the current branch.
530 (i.e. a `refs/tags/<tag>` reference).
534 (i.e. a `refs/heads/<head>` reference).
536 For a more complete list of ways to spell object names, see
537 "SPECIFYING REVISIONS" section in linkgit:gitrevisions[7].
540 File/Directory Structure
541 ------------------------
543 Please see the linkgit:gitrepository-layout[5] document.
545 Read linkgit:githooks[5] for more details about each hook.
547 Higher level SCMs may provide and manage additional information in the
553 Please see linkgit:gitglossary[7].
556 Environment Variables
557 ---------------------
558 Various git commands use the following environment variables:
562 These environment variables apply to 'all' core git commands. Nb: it
563 is worth noting that they may be used/overridden by SCMS sitting above
564 git so take care if using Cogito etc.
567 This environment allows the specification of an alternate
568 index file. If not specified, the default of `$GIT_DIR/index`
571 'GIT_OBJECT_DIRECTORY'::
572 If the object storage directory is specified via this
573 environment variable then the sha1 directories are created
574 underneath - otherwise the default `$GIT_DIR/objects`
577 'GIT_ALTERNATE_OBJECT_DIRECTORIES'::
578 Due to the immutable nature of git objects, old objects can be
579 archived into shared, read-only directories. This variable
580 specifies a ":" separated (on Windows ";" separated) list
581 of git object directories which can be used to search for git
582 objects. New objects will not be written to these directories.
585 If the 'GIT_DIR' environment variable is set then it
586 specifies a path to use instead of the default `.git`
587 for the base of the repository.
590 Set the path to the working tree. The value will not be
591 used in combination with repositories found automatically in
592 a .git directory (i.e. $GIT_DIR is not set).
593 This can also be controlled by the '--work-tree' command line
594 option and the core.worktree configuration variable.
596 'GIT_CEILING_DIRECTORIES'::
597 This should be a colon-separated list of absolute paths.
598 If set, it is a list of directories that git should not chdir
599 up into while looking for a repository directory.
600 It will not exclude the current working directory or
601 a GIT_DIR set on the command line or in the environment.
602 (Useful for excluding slow-loading network directories.)
604 'GIT_DISCOVERY_ACROSS_FILESYSTEM'::
605 When run in a directory that does not have ".git" repository
606 directory, git tries to find such a directory in the parent
607 directories to find the top of the working tree, but by default it
608 does not cross filesystem boundaries. This environment variable
609 can be set to true to tell git not to stop at filesystem
610 boundaries. Like 'GIT_CEILING_DIRECTORIES', this will not affect
611 an explicit repository directory set via 'GIT_DIR' or on the
619 'GIT_COMMITTER_NAME'::
620 'GIT_COMMITTER_EMAIL'::
621 'GIT_COMMITTER_DATE'::
623 see linkgit:git-commit-tree[1]
628 Only valid setting is "--unified=??" or "-u??" to set the
629 number of context lines shown when a unified diff is created.
630 This takes precedence over any "-U" or "--unified" option
631 value passed on the git diff command line.
633 'GIT_EXTERNAL_DIFF'::
634 When the environment variable 'GIT_EXTERNAL_DIFF' is set, the
635 program named by it is called, instead of the diff invocation
636 described above. For a path that is added, removed, or modified,
637 'GIT_EXTERNAL_DIFF' is called with 7 parameters:
639 path old-file old-hex old-mode new-file new-hex new-mode
643 <old|new>-file:: are files GIT_EXTERNAL_DIFF can use to read the
644 contents of <old|new>,
645 <old|new>-hex:: are the 40-hexdigit SHA1 hashes,
646 <old|new>-mode:: are the octal representation of the file modes.
648 The file parameters can point at the user's working file
649 (e.g. `new-file` in "git-diff-files"), `/dev/null` (e.g. `old-file`
650 when a new file is added), or a temporary file (e.g. `old-file` in the
651 index). 'GIT_EXTERNAL_DIFF' should not worry about unlinking the
652 temporary file --- it is removed when 'GIT_EXTERNAL_DIFF' exits.
654 For a path that is unmerged, 'GIT_EXTERNAL_DIFF' is called with 1
659 'GIT_MERGE_VERBOSITY'::
660 A number controlling the amount of output shown by
661 the recursive merge strategy. Overrides merge.verbosity.
662 See linkgit:git-merge[1]
665 This environment variable overrides `$PAGER`. If it is set
666 to an empty string or to the value "cat", git will not launch
667 a pager. See also the `core.pager` option in
668 linkgit:git-config[1].
671 If this environment variable is set then 'git fetch'
672 and 'git push' will use this command instead
673 of 'ssh' when they need to connect to a remote system.
674 The '$GIT_SSH' command will be given exactly two arguments:
675 the 'username@host' (or just 'host') from the URL and the
676 shell command to execute on that remote system.
678 To pass options to the program that you want to list in GIT_SSH
679 you will need to wrap the program and options into a shell script,
680 then set GIT_SSH to refer to the shell script.
682 Usually it is easier to configure any desired options through your
683 personal `.ssh/config` file. Please consult your ssh documentation
687 If this environment variable is set, then git commands which need to
688 acquire passwords or passphrases (e.g. for HTTP or IMAP authentication)
689 will call this program with a suitable prompt as command line argument
690 and read the password from its STDOUT. See also the 'core.askpass'
691 option in linkgit:git-config[1].
694 If this environment variable is set to "1", then commands such
695 as 'git blame' (in incremental mode), 'git rev-list', 'git log',
696 and 'git whatchanged' will force a flush of the output stream
697 after each commit-oriented record have been flushed. If this
698 variable is set to "0", the output of these commands will be done
699 using completely buffered I/O. If this environment variable is
700 not set, git will choose buffered or record-oriented flushing
701 based on whether stdout appears to be redirected to a file or not.
704 If this variable is set to "1", "2" or "true" (comparison
705 is case insensitive), git will print `trace:` messages on
706 stderr telling about alias expansion, built-in command
707 execution and external command execution.
708 If this variable is set to an integer value greater than 1
709 and lower than 10 (strictly) then git will interpret this
710 value as an open file descriptor and will try to write the
711 trace messages into this file descriptor.
712 Alternatively, if this variable is set to an absolute path
713 (starting with a '/' character), git will interpret this
714 as a file path and will try to write the trace messages
717 Discussion[[Discussion]]
718 ------------------------
720 More detail on the following is available from the
721 link:user-manual.html#git-concepts[git concepts chapter of the
722 user-manual] and linkgit:gitcore-tutorial[7].
724 A git project normally consists of a working directory with a ".git"
725 subdirectory at the top level. The .git directory contains, among other
726 things, a compressed object database representing the complete history
727 of the project, an "index" file which links that history to the current
728 contents of the working tree, and named pointers into that history such
729 as tags and branch heads.
731 The object database contains objects of three main types: blobs, which
732 hold file data; trees, which point to blobs and other trees to build up
733 directory hierarchies; and commits, which each reference a single tree
734 and some number of parent commits.
736 The commit, equivalent to what other systems call a "changeset" or
737 "version", represents a step in the project's history, and each parent
738 represents an immediately preceding step. Commits with more than one
739 parent represent merges of independent lines of development.
741 All objects are named by the SHA1 hash of their contents, normally
742 written as a string of 40 hex digits. Such names are globally unique.
743 The entire history leading up to a commit can be vouched for by signing
744 just that commit. A fourth object type, the tag, is provided for this
747 When first created, objects are stored in individual files, but for
748 efficiency may later be compressed together into "pack files".
750 Named pointers called refs mark interesting points in history. A ref
751 may contain the SHA1 name of an object or the name of another ref. Refs
752 with names beginning `ref/head/` contain the SHA1 name of the most
753 recent commit (or "head") of a branch under development. SHA1 names of
754 tags of interest are stored under `ref/tags/`. A special ref named
755 `HEAD` contains the name of the currently checked-out branch.
757 The index file is initialized with a list of all paths and, for each
758 path, a blob object and a set of attributes. The blob object represents
759 the contents of the file as of the head of the current branch. The
760 attributes (last modified time, size, etc.) are taken from the
761 corresponding file in the working tree. Subsequent changes to the
762 working tree can be found by comparing these attributes. The index may
763 be updated with new content, and new commits may be created from the
764 content stored in the index.
766 The index is also capable of storing multiple entries (called "stages")
767 for a given pathname. These stages are used to hold the various
768 unmerged version of a file when a merge is in progress.
772 Git was started by Linus Torvalds, and is currently maintained by Junio
773 C Hamano. Numerous contributions have come from the git mailing list
774 <git@vger.kernel.org>. For a more complete list of contributors, see
775 http://git-scm.com/about. If you have a clone of git.git itself, the
776 output of linkgit:git-shortlog[1] and linkgit:git-blame[1] can show you
777 the authors for specific parts of the project.
782 Report bugs to the Git mailing list <git@vger.kernel.org> where the
783 development and maintenance is primarily done. You do not have to be
784 subscribed to the list to send a message there.
788 linkgit:gittutorial[7], linkgit:gittutorial-2[7],
789 link:everyday.html[Everyday Git], linkgit:gitcvs-migration[7],
790 linkgit:gitglossary[7], linkgit:gitcore-tutorial[7],
791 linkgit:gitcli[7], link:user-manual.html[The Git User's Manual],
792 linkgit:gitworkflows[7]
796 Part of the linkgit:git[1] suite