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] [--bare]
14 [--git-dir=<path>] [--work-tree=<path>] [--namespace=<name>]
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:v1.7.5.2/git.html[documentation for release 1.7.5.2]
50 link:RelNotes/1.7.5.2.txt[1.7.5.2],
51 link:RelNotes/1.7.5.1.txt[1.7.5.1],
52 link:RelNotes/1.7.5.txt[1.7.5].
54 * link:v1.7.4.5/git.html[documentation for release 1.7.4.5]
57 link:RelNotes/1.7.4.5.txt[1.7.4.5],
58 link:RelNotes/1.7.4.4.txt[1.7.4.4],
59 link:RelNotes/1.7.4.3.txt[1.7.4.3],
60 link:RelNotes/1.7.4.2.txt[1.7.4.2],
61 link:RelNotes/1.7.4.1.txt[1.7.4.1],
62 link:RelNotes/1.7.4.txt[1.7.4].
64 * link:v1.7.3.5/git.html[documentation for release 1.7.3.5]
67 link:RelNotes/1.7.3.5.txt[1.7.3.5],
68 link:RelNotes/1.7.3.4.txt[1.7.3.4],
69 link:RelNotes/1.7.3.3.txt[1.7.3.3],
70 link:RelNotes/1.7.3.2.txt[1.7.3.2],
71 link:RelNotes/1.7.3.1.txt[1.7.3.1],
72 link:RelNotes/1.7.3.txt[1.7.3].
74 * link:v1.7.2.5/git.html[documentation for release 1.7.2.5]
77 link:RelNotes/1.7.2.5.txt[1.7.2.5],
78 link:RelNotes/1.7.2.4.txt[1.7.2.4],
79 link:RelNotes/1.7.2.3.txt[1.7.2.3],
80 link:RelNotes/1.7.2.2.txt[1.7.2.2],
81 link:RelNotes/1.7.2.1.txt[1.7.2.1],
82 link:RelNotes/1.7.2.txt[1.7.2].
84 * link:v1.7.1.4/git.html[documentation for release 1.7.1.4]
87 link:RelNotes/1.7.1.4.txt[1.7.1.4],
88 link:RelNotes/1.7.1.3.txt[1.7.1.3],
89 link:RelNotes/1.7.1.2.txt[1.7.1.2],
90 link:RelNotes/1.7.1.1.txt[1.7.1.1],
91 link:RelNotes/1.7.1.txt[1.7.1].
93 * link:v1.7.0.9/git.html[documentation for release 1.7.0.9]
96 link:RelNotes/1.7.0.9.txt[1.7.0.9],
97 link:RelNotes/1.7.0.8.txt[1.7.0.8],
98 link:RelNotes/1.7.0.7.txt[1.7.0.7],
99 link:RelNotes/1.7.0.6.txt[1.7.0.6],
100 link:RelNotes/1.7.0.5.txt[1.7.0.5],
101 link:RelNotes/1.7.0.4.txt[1.7.0.4],
102 link:RelNotes/1.7.0.3.txt[1.7.0.3],
103 link:RelNotes/1.7.0.2.txt[1.7.0.2],
104 link:RelNotes/1.7.0.1.txt[1.7.0.1],
105 link:RelNotes/1.7.0.txt[1.7.0].
107 * link:v1.6.6.3/git.html[documentation for release 1.6.6.3]
110 link:RelNotes/1.6.6.3.txt[1.6.6.3],
111 link:RelNotes/1.6.6.2.txt[1.6.6.2],
112 link:RelNotes/1.6.6.1.txt[1.6.6.1],
113 link:RelNotes/1.6.6.txt[1.6.6].
115 * link:v1.6.5.9/git.html[documentation for release 1.6.5.9]
118 link:RelNotes/1.6.5.9.txt[1.6.5.9],
119 link:RelNotes/1.6.5.8.txt[1.6.5.8],
120 link:RelNotes/1.6.5.7.txt[1.6.5.7],
121 link:RelNotes/1.6.5.6.txt[1.6.5.6],
122 link:RelNotes/1.6.5.5.txt[1.6.5.5],
123 link:RelNotes/1.6.5.4.txt[1.6.5.4],
124 link:RelNotes/1.6.5.3.txt[1.6.5.3],
125 link:RelNotes/1.6.5.2.txt[1.6.5.2],
126 link:RelNotes/1.6.5.1.txt[1.6.5.1],
127 link:RelNotes/1.6.5.txt[1.6.5].
129 * link:v1.6.4.5/git.html[documentation for release 1.6.4.5]
132 link:RelNotes/1.6.4.5.txt[1.6.4.5],
133 link:RelNotes/1.6.4.4.txt[1.6.4.4],
134 link:RelNotes/1.6.4.3.txt[1.6.4.3],
135 link:RelNotes/1.6.4.2.txt[1.6.4.2],
136 link:RelNotes/1.6.4.1.txt[1.6.4.1],
137 link:RelNotes/1.6.4.txt[1.6.4].
139 * link:v1.6.3.4/git.html[documentation for release 1.6.3.4]
142 link:RelNotes/1.6.3.4.txt[1.6.3.4],
143 link:RelNotes/1.6.3.3.txt[1.6.3.3],
144 link:RelNotes/1.6.3.2.txt[1.6.3.2],
145 link:RelNotes/1.6.3.1.txt[1.6.3.1],
146 link:RelNotes/1.6.3.txt[1.6.3].
149 link:RelNotes/1.6.2.5.txt[1.6.2.5],
150 link:RelNotes/1.6.2.4.txt[1.6.2.4],
151 link:RelNotes/1.6.2.3.txt[1.6.2.3],
152 link:RelNotes/1.6.2.2.txt[1.6.2.2],
153 link:RelNotes/1.6.2.1.txt[1.6.2.1],
154 link:RelNotes/1.6.2.txt[1.6.2].
156 * link:v1.6.1.3/git.html[documentation for release 1.6.1.3]
159 link:RelNotes/1.6.1.3.txt[1.6.1.3],
160 link:RelNotes/1.6.1.2.txt[1.6.1.2],
161 link:RelNotes/1.6.1.1.txt[1.6.1.1],
162 link:RelNotes/1.6.1.txt[1.6.1].
164 * link:v1.6.0.6/git.html[documentation for release 1.6.0.6]
167 link:RelNotes/1.6.0.6.txt[1.6.0.6],
168 link:RelNotes/1.6.0.5.txt[1.6.0.5],
169 link:RelNotes/1.6.0.4.txt[1.6.0.4],
170 link:RelNotes/1.6.0.3.txt[1.6.0.3],
171 link:RelNotes/1.6.0.2.txt[1.6.0.2],
172 link:RelNotes/1.6.0.1.txt[1.6.0.1],
173 link:RelNotes/1.6.0.txt[1.6.0].
175 * link:v1.5.6.6/git.html[documentation for release 1.5.6.6]
178 link:RelNotes/1.5.6.6.txt[1.5.6.6],
179 link:RelNotes/1.5.6.5.txt[1.5.6.5],
180 link:RelNotes/1.5.6.4.txt[1.5.6.4],
181 link:RelNotes/1.5.6.3.txt[1.5.6.3],
182 link:RelNotes/1.5.6.2.txt[1.5.6.2],
183 link:RelNotes/1.5.6.1.txt[1.5.6.1],
184 link:RelNotes/1.5.6.txt[1.5.6].
186 * link:v1.5.5.6/git.html[documentation for release 1.5.5.6]
189 link:RelNotes/1.5.5.6.txt[1.5.5.6],
190 link:RelNotes/1.5.5.5.txt[1.5.5.5],
191 link:RelNotes/1.5.5.4.txt[1.5.5.4],
192 link:RelNotes/1.5.5.3.txt[1.5.5.3],
193 link:RelNotes/1.5.5.2.txt[1.5.5.2],
194 link:RelNotes/1.5.5.1.txt[1.5.5.1],
195 link:RelNotes/1.5.5.txt[1.5.5].
197 * link:v1.5.4.7/git.html[documentation for release 1.5.4.7]
200 link:RelNotes/1.5.4.7.txt[1.5.4.7],
201 link:RelNotes/1.5.4.6.txt[1.5.4.6],
202 link:RelNotes/1.5.4.5.txt[1.5.4.5],
203 link:RelNotes/1.5.4.4.txt[1.5.4.4],
204 link:RelNotes/1.5.4.3.txt[1.5.4.3],
205 link:RelNotes/1.5.4.2.txt[1.5.4.2],
206 link:RelNotes/1.5.4.1.txt[1.5.4.1],
207 link:RelNotes/1.5.4.txt[1.5.4].
209 * link:v1.5.3.8/git.html[documentation for release 1.5.3.8]
212 link:RelNotes/1.5.3.8.txt[1.5.3.8],
213 link:RelNotes/1.5.3.7.txt[1.5.3.7],
214 link:RelNotes/1.5.3.6.txt[1.5.3.6],
215 link:RelNotes/1.5.3.5.txt[1.5.3.5],
216 link:RelNotes/1.5.3.4.txt[1.5.3.4],
217 link:RelNotes/1.5.3.3.txt[1.5.3.3],
218 link:RelNotes/1.5.3.2.txt[1.5.3.2],
219 link:RelNotes/1.5.3.1.txt[1.5.3.1],
220 link:RelNotes/1.5.3.txt[1.5.3].
222 * link:v1.5.2.5/git.html[documentation for release 1.5.2.5]
225 link:RelNotes/1.5.2.5.txt[1.5.2.5],
226 link:RelNotes/1.5.2.4.txt[1.5.2.4],
227 link:RelNotes/1.5.2.3.txt[1.5.2.3],
228 link:RelNotes/1.5.2.2.txt[1.5.2.2],
229 link:RelNotes/1.5.2.1.txt[1.5.2.1],
230 link:RelNotes/1.5.2.txt[1.5.2].
232 * link:v1.5.1.6/git.html[documentation for release 1.5.1.6]
235 link:RelNotes/1.5.1.6.txt[1.5.1.6],
236 link:RelNotes/1.5.1.5.txt[1.5.1.5],
237 link:RelNotes/1.5.1.4.txt[1.5.1.4],
238 link:RelNotes/1.5.1.3.txt[1.5.1.3],
239 link:RelNotes/1.5.1.2.txt[1.5.1.2],
240 link:RelNotes/1.5.1.1.txt[1.5.1.1],
241 link:RelNotes/1.5.1.txt[1.5.1].
243 * link:v1.5.0.7/git.html[documentation for release 1.5.0.7]
246 link:RelNotes/1.5.0.7.txt[1.5.0.7],
247 link:RelNotes/1.5.0.6.txt[1.5.0.6],
248 link:RelNotes/1.5.0.5.txt[1.5.0.5],
249 link:RelNotes/1.5.0.3.txt[1.5.0.3],
250 link:RelNotes/1.5.0.2.txt[1.5.0.2],
251 link:RelNotes/1.5.0.1.txt[1.5.0.1],
252 link:RelNotes/1.5.0.txt[1.5.0].
254 * documentation for release link:v1.4.4.4/git.html[1.4.4.4],
255 link:v1.3.3/git.html[1.3.3],
256 link:v1.2.6/git.html[1.2.6],
257 link:v1.0.13/git.html[1.0.13].
266 Prints the git suite version that the 'git' program came from.
269 Prints the synopsis and a list of the most commonly used
270 commands. If the option '--all' or '-a' is given then all
271 available commands are printed. If a git command is named this
272 option will bring up the manual page for that command.
274 Other options are available to control how the manual page is
275 displayed. See linkgit:git-help[1] for more information,
276 because `git --help ...` is converted internally into `git
280 Pass a configuration parameter to the command. The value
281 given will override values from configuration files.
282 The <name> is expected in the same format as listed by
283 'git config' (subkeys separated by dots).
285 --exec-path[=<path>]::
286 Path to wherever your core git programs are installed.
287 This can also be controlled by setting the GIT_EXEC_PATH
288 environment variable. If no path is given, 'git' will print
289 the current setting and then exit.
292 Print the path, without trailing slash, where git's HTML
293 documentation is installed and exit.
296 Print the manpath (see `man(1)`) for the man pages for
297 this version of git and exit.
300 Print the path where the Info files documenting this
301 version of git are installed and exit.
305 Pipe all output into 'less' (or if set, $PAGER) if standard
306 output is a terminal. This overrides the `pager.<cmd>`
307 configuration options (see the "Configuration Mechanism" section
311 Do not pipe git output into a pager.
314 Set the path to the repository. This can also be controlled by
315 setting the GIT_DIR environment variable. It can be an absolute
316 path or relative path to current working directory.
319 Set the path to the working tree. It can be an absolute path
320 or a path relative to the current working directory.
321 This can also be controlled by setting the GIT_WORK_TREE
322 environment variable and the core.worktree configuration
323 variable (see core.worktree in linkgit:git-config[1] for a
324 more detailed discussion).
327 Set the git namespace. See linkgit:gitnamespaces[7] for more
328 details. Equivalent to setting the `GIT_NAMESPACE` environment
332 Treat the repository as a bare repository. If GIT_DIR
333 environment is not set, it is set to the current working
336 --no-replace-objects::
337 Do not use replacement refs to replace git objects. See
338 linkgit:git-replace[1] for more information.
341 FURTHER DOCUMENTATION
342 ---------------------
344 See the references above to get started using git. The following is
345 probably more detail than necessary for a first-time user.
347 The link:user-manual.html#git-concepts[git concepts chapter of the
348 user-manual] and linkgit:gitcore-tutorial[7] both provide
349 introductions to the underlying git architecture.
351 See linkgit:gitworkflows[7] for an overview of recommended workflows.
353 See also the link:howto-index.html[howto] documents for some useful
356 The internals are documented in the
357 link:technical/api-index.html[GIT API documentation].
362 We divide git into high level ("porcelain") commands and low level
363 ("plumbing") commands.
365 High-level commands (porcelain)
366 -------------------------------
368 We separate the porcelain commands into the main commands and some
369 ancillary user utilities.
371 Main porcelain commands
372 ~~~~~~~~~~~~~~~~~~~~~~~
374 include::cmds-mainporcelain.txt[]
380 include::cmds-ancillarymanipulators.txt[]
384 include::cmds-ancillaryinterrogators.txt[]
387 Interacting with Others
388 ~~~~~~~~~~~~~~~~~~~~~~~
390 These commands are to interact with foreign SCM and with other
391 people via patch over e-mail.
393 include::cmds-foreignscminterface.txt[]
396 Low-level commands (plumbing)
397 -----------------------------
399 Although git includes its
400 own porcelain layer, its low-level commands are sufficient to support
401 development of alternative porcelains. Developers of such porcelains
402 might start by reading about linkgit:git-update-index[1] and
403 linkgit:git-read-tree[1].
405 The interface (input, output, set of options and the semantics)
406 to these low-level commands are meant to be a lot more stable
407 than Porcelain level commands, because these commands are
408 primarily for scripted use. The interface to Porcelain commands
409 on the other hand are subject to change in order to improve the
412 The following description divides
413 the low-level commands into commands that manipulate objects (in
414 the repository, index, and working tree), commands that interrogate and
415 compare objects, and commands that move objects and references between
419 Manipulation commands
420 ~~~~~~~~~~~~~~~~~~~~~
422 include::cmds-plumbingmanipulators.txt[]
425 Interrogation commands
426 ~~~~~~~~~~~~~~~~~~~~~~
428 include::cmds-plumbinginterrogators.txt[]
430 In general, the interrogate commands do not touch the files in
434 Synching repositories
435 ~~~~~~~~~~~~~~~~~~~~~
437 include::cmds-synchingrepositories.txt[]
439 The following are helper commands used by the above; end users
440 typically do not use them directly.
442 include::cmds-synchelpers.txt[]
445 Internal helper commands
446 ~~~~~~~~~~~~~~~~~~~~~~~~
448 These are internal helper commands used by other commands; end
449 users typically do not use them directly.
451 include::cmds-purehelpers.txt[]
454 Configuration Mechanism
455 -----------------------
457 Starting from 0.99.9 (actually mid 0.99.8.GIT), `.git/config` file
458 is used to hold per-repository configuration options. It is a
459 simple text file modeled after `.ini` format familiar to some
460 people. Here is an example:
464 # A '#' or ';' character indicates a comment.
469 ; Don't trust file modes
474 name = "Junio C Hamano"
475 email = "junkio@twinsun.com"
479 Various commands read from the configuration file and adjust
480 their operation accordingly. See linkgit:git-config[1] for a
484 Identifier Terminology
485 ----------------------
487 Indicates the object name for any type of object.
490 Indicates a blob object name.
493 Indicates a tree object name.
496 Indicates a commit object name.
499 Indicates a tree, commit or tag object name. A
500 command that takes a <tree-ish> argument ultimately wants to
501 operate on a <tree> object but automatically dereferences
502 <commit> and <tag> objects that point at a <tree>.
505 Indicates a commit or tag object name. A
506 command that takes a <commit-ish> argument ultimately wants to
507 operate on a <commit> object but automatically dereferences
508 <tag> objects that point at a <commit>.
511 Indicates that an object type is required.
512 Currently one of: `blob`, `tree`, `commit`, or `tag`.
515 Indicates a filename - almost always relative to the
516 root of the tree structure `GIT_INDEX_FILE` describes.
520 Any git command accepting any <object> can also use the following
524 indicates the head of the current branch (i.e. the
525 contents of `$GIT_DIR/HEAD`).
529 (i.e. the contents of `$GIT_DIR/refs/tags/<tag>`).
533 (i.e. the contents of `$GIT_DIR/refs/heads/<head>`).
535 For a more complete list of ways to spell object names, see
536 "SPECIFYING REVISIONS" section in linkgit:gitrevisions[7].
539 File/Directory Structure
540 ------------------------
542 Please see the linkgit:gitrepository-layout[5] document.
544 Read linkgit:githooks[5] for more details about each hook.
546 Higher level SCMs may provide and manage additional information in the
552 Please see linkgit:gitglossary[7].
555 Environment Variables
556 ---------------------
557 Various git commands use the following environment variables:
561 These environment variables apply to 'all' core git commands. Nb: it
562 is worth noting that they may be used/overridden by SCMS sitting above
563 git so take care if using Cogito etc.
566 This environment allows the specification of an alternate
567 index file. If not specified, the default of `$GIT_DIR/index`
570 'GIT_OBJECT_DIRECTORY'::
571 If the object storage directory is specified via this
572 environment variable then the sha1 directories are created
573 underneath - otherwise the default `$GIT_DIR/objects`
576 'GIT_ALTERNATE_OBJECT_DIRECTORIES'::
577 Due to the immutable nature of git objects, old objects can be
578 archived into shared, read-only directories. This variable
579 specifies a ":" separated (on Windows ";" separated) list
580 of git object directories which can be used to search for git
581 objects. New objects will not be written to these directories.
584 If the 'GIT_DIR' environment variable is set then it
585 specifies a path to use instead of the default `.git`
586 for the base of the repository.
589 Set the path to the working tree. The value will not be
590 used in combination with repositories found automatically in
591 a .git directory (i.e. $GIT_DIR is not set).
592 This can also be controlled by the '--work-tree' command line
593 option and the core.worktree configuration variable.
596 Set the git namespace; see linkgit:gitnamespaces[7] for details.
597 The '--namespace' command-line option also sets this value.
599 'GIT_CEILING_DIRECTORIES'::
600 This should be a colon-separated list of absolute paths.
601 If set, it is a list of directories that git should not chdir
602 up into while looking for a repository directory.
603 It will not exclude the current working directory or
604 a GIT_DIR set on the command line or in the environment.
605 (Useful for excluding slow-loading network directories.)
607 'GIT_DISCOVERY_ACROSS_FILESYSTEM'::
608 When run in a directory that does not have ".git" repository
609 directory, git tries to find such a directory in the parent
610 directories to find the top of the working tree, but by default it
611 does not cross filesystem boundaries. This environment variable
612 can be set to true to tell git not to stop at filesystem
613 boundaries. Like 'GIT_CEILING_DIRECTORIES', this will not affect
614 an explicit repository directory set via 'GIT_DIR' or on the
622 'GIT_COMMITTER_NAME'::
623 'GIT_COMMITTER_EMAIL'::
624 'GIT_COMMITTER_DATE'::
626 see linkgit:git-commit-tree[1]
631 Only valid setting is "--unified=??" or "-u??" to set the
632 number of context lines shown when a unified diff is created.
633 This takes precedence over any "-U" or "--unified" option
634 value passed on the git diff command line.
636 'GIT_EXTERNAL_DIFF'::
637 When the environment variable 'GIT_EXTERNAL_DIFF' is set, the
638 program named by it is called, instead of the diff invocation
639 described above. For a path that is added, removed, or modified,
640 'GIT_EXTERNAL_DIFF' is called with 7 parameters:
642 path old-file old-hex old-mode new-file new-hex new-mode
646 <old|new>-file:: are files GIT_EXTERNAL_DIFF can use to read the
647 contents of <old|new>,
648 <old|new>-hex:: are the 40-hexdigit SHA1 hashes,
649 <old|new>-mode:: are the octal representation of the file modes.
651 The file parameters can point at the user's working file
652 (e.g. `new-file` in "git-diff-files"), `/dev/null` (e.g. `old-file`
653 when a new file is added), or a temporary file (e.g. `old-file` in the
654 index). 'GIT_EXTERNAL_DIFF' should not worry about unlinking the
655 temporary file --- it is removed when 'GIT_EXTERNAL_DIFF' exits.
657 For a path that is unmerged, 'GIT_EXTERNAL_DIFF' is called with 1
662 'GIT_MERGE_VERBOSITY'::
663 A number controlling the amount of output shown by
664 the recursive merge strategy. Overrides merge.verbosity.
665 See linkgit:git-merge[1]
668 This environment variable overrides `$PAGER`. If it is set
669 to an empty string or to the value "cat", git will not launch
670 a pager. See also the `core.pager` option in
671 linkgit:git-config[1].
674 If this environment variable is set then 'git fetch'
675 and 'git push' will use this command instead
676 of 'ssh' when they need to connect to a remote system.
677 The '$GIT_SSH' command will be given exactly two arguments:
678 the 'username@host' (or just 'host') from the URL and the
679 shell command to execute on that remote system.
681 To pass options to the program that you want to list in GIT_SSH
682 you will need to wrap the program and options into a shell script,
683 then set GIT_SSH to refer to the shell script.
685 Usually it is easier to configure any desired options through your
686 personal `.ssh/config` file. Please consult your ssh documentation
690 If this environment variable is set, then git commands which need to
691 acquire passwords or passphrases (e.g. for HTTP or IMAP authentication)
692 will call this program with a suitable prompt as command line argument
693 and read the password from its STDOUT. See also the 'core.askpass'
694 option in linkgit:git-config[1].
697 If this environment variable is set to "1", then commands such
698 as 'git blame' (in incremental mode), 'git rev-list', 'git log',
699 and 'git whatchanged' will force a flush of the output stream
700 after each commit-oriented record have been flushed. If this
701 variable is set to "0", the output of these commands will be done
702 using completely buffered I/O. If this environment variable is
703 not set, git will choose buffered or record-oriented flushing
704 based on whether stdout appears to be redirected to a file or not.
707 If this variable is set to "1", "2" or "true" (comparison
708 is case insensitive), git will print `trace:` messages on
709 stderr telling about alias expansion, built-in command
710 execution and external command execution.
711 If this variable is set to an integer value greater than 1
712 and lower than 10 (strictly) then git will interpret this
713 value as an open file descriptor and will try to write the
714 trace messages into this file descriptor.
715 Alternatively, if this variable is set to an absolute path
716 (starting with a '/' character), git will interpret this
717 as a file path and will try to write the trace messages
720 Discussion[[Discussion]]
721 ------------------------
723 More detail on the following is available from the
724 link:user-manual.html#git-concepts[git concepts chapter of the
725 user-manual] and linkgit:gitcore-tutorial[7].
727 A git project normally consists of a working directory with a ".git"
728 subdirectory at the top level. The .git directory contains, among other
729 things, a compressed object database representing the complete history
730 of the project, an "index" file which links that history to the current
731 contents of the working tree, and named pointers into that history such
732 as tags and branch heads.
734 The object database contains objects of three main types: blobs, which
735 hold file data; trees, which point to blobs and other trees to build up
736 directory hierarchies; and commits, which each reference a single tree
737 and some number of parent commits.
739 The commit, equivalent to what other systems call a "changeset" or
740 "version", represents a step in the project's history, and each parent
741 represents an immediately preceding step. Commits with more than one
742 parent represent merges of independent lines of development.
744 All objects are named by the SHA1 hash of their contents, normally
745 written as a string of 40 hex digits. Such names are globally unique.
746 The entire history leading up to a commit can be vouched for by signing
747 just that commit. A fourth object type, the tag, is provided for this
750 When first created, objects are stored in individual files, but for
751 efficiency may later be compressed together into "pack files".
753 Named pointers called refs mark interesting points in history. A ref
754 may contain the SHA1 name of an object or the name of another ref. Refs
755 with names beginning `ref/head/` contain the SHA1 name of the most
756 recent commit (or "head") of a branch under development. SHA1 names of
757 tags of interest are stored under `ref/tags/`. A special ref named
758 `HEAD` contains the name of the currently checked-out branch.
760 The index file is initialized with a list of all paths and, for each
761 path, a blob object and a set of attributes. The blob object represents
762 the contents of the file as of the head of the current branch. The
763 attributes (last modified time, size, etc.) are taken from the
764 corresponding file in the working tree. Subsequent changes to the
765 working tree can be found by comparing these attributes. The index may
766 be updated with new content, and new commits may be created from the
767 content stored in the index.
769 The index is also capable of storing multiple entries (called "stages")
770 for a given pathname. These stages are used to hold the various
771 unmerged version of a file when a merge is in progress.
775 Git was started by Linus Torvalds, and is currently maintained by Junio
776 C Hamano. Numerous contributions have come from the git mailing list
777 <git@vger.kernel.org>. For a more complete list of contributors, see
778 http://git-scm.com/about. If you have a clone of git.git itself, the
779 output of linkgit:git-shortlog[1] and linkgit:git-blame[1] can show you
780 the authors for specific parts of the project.
785 Report bugs to the Git mailing list <git@vger.kernel.org> where the
786 development and maintenance is primarily done. You do not have to be
787 subscribed to the list to send a message there.
791 linkgit:gittutorial[7], linkgit:gittutorial-2[7],
792 link:everyday.html[Everyday Git], linkgit:gitcvs-migration[7],
793 linkgit:gitglossary[7], linkgit:gitcore-tutorial[7],
794 linkgit:gitcli[7], link:user-manual.html[The Git User's Manual],
795 linkgit:gitworkflows[7]
799 Part of the linkgit:git[1] suite