6 git - the stupid content tracker
12 'git' [--version] [--exec-path[=<path>]] [--html-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:v1.7.5.2/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 to wherever your git HTML documentation is installed
297 Pipe all output into 'less' (or if set, $PAGER) if standard
298 output is a terminal. This overrides the `pager.<cmd>`
299 configuration options (see the "Configuration Mechanism" section
303 Do not pipe git output into a pager.
306 Set the path to the repository. This can also be controlled by
307 setting the GIT_DIR environment variable. It can be an absolute
308 path or relative path to current working directory.
311 Set the path to the working tree. It can be an absolute path
312 or a path relative to the current working directory.
313 This can also be controlled by setting the GIT_WORK_TREE
314 environment variable and the core.worktree configuration
315 variable (see core.worktree in linkgit:git-config[1] for a
316 more detailed discussion).
319 Treat the repository as a bare repository. If GIT_DIR
320 environment is not set, it is set to the current working
323 --no-replace-objects::
324 Do not use replacement refs to replace git objects. See
325 linkgit:git-replace[1] for more information.
328 FURTHER DOCUMENTATION
329 ---------------------
331 See the references above to get started using git. The following is
332 probably more detail than necessary for a first-time user.
334 The link:user-manual.html#git-concepts[git concepts chapter of the
335 user-manual] and linkgit:gitcore-tutorial[7] both provide
336 introductions to the underlying git architecture.
338 See linkgit:gitworkflows[7] for an overview of recommended workflows.
340 See also the link:howto-index.html[howto] documents for some useful
343 The internals are documented in the
344 link:technical/api-index.html[GIT API documentation].
349 We divide git into high level ("porcelain") commands and low level
350 ("plumbing") commands.
352 High-level commands (porcelain)
353 -------------------------------
355 We separate the porcelain commands into the main commands and some
356 ancillary user utilities.
358 Main porcelain commands
359 ~~~~~~~~~~~~~~~~~~~~~~~
361 include::cmds-mainporcelain.txt[]
367 include::cmds-ancillarymanipulators.txt[]
371 include::cmds-ancillaryinterrogators.txt[]
374 Interacting with Others
375 ~~~~~~~~~~~~~~~~~~~~~~~
377 These commands are to interact with foreign SCM and with other
378 people via patch over e-mail.
380 include::cmds-foreignscminterface.txt[]
383 Low-level commands (plumbing)
384 -----------------------------
386 Although git includes its
387 own porcelain layer, its low-level commands are sufficient to support
388 development of alternative porcelains. Developers of such porcelains
389 might start by reading about linkgit:git-update-index[1] and
390 linkgit:git-read-tree[1].
392 The interface (input, output, set of options and the semantics)
393 to these low-level commands are meant to be a lot more stable
394 than Porcelain level commands, because these commands are
395 primarily for scripted use. The interface to Porcelain commands
396 on the other hand are subject to change in order to improve the
399 The following description divides
400 the low-level commands into commands that manipulate objects (in
401 the repository, index, and working tree), commands that interrogate and
402 compare objects, and commands that move objects and references between
406 Manipulation commands
407 ~~~~~~~~~~~~~~~~~~~~~
409 include::cmds-plumbingmanipulators.txt[]
412 Interrogation commands
413 ~~~~~~~~~~~~~~~~~~~~~~
415 include::cmds-plumbinginterrogators.txt[]
417 In general, the interrogate commands do not touch the files in
421 Synching repositories
422 ~~~~~~~~~~~~~~~~~~~~~
424 include::cmds-synchingrepositories.txt[]
426 The following are helper commands used by the above; end users
427 typically do not use them directly.
429 include::cmds-synchelpers.txt[]
432 Internal helper commands
433 ~~~~~~~~~~~~~~~~~~~~~~~~
435 These are internal helper commands used by other commands; end
436 users typically do not use them directly.
438 include::cmds-purehelpers.txt[]
441 Configuration Mechanism
442 -----------------------
444 Starting from 0.99.9 (actually mid 0.99.8.GIT), `.git/config` file
445 is used to hold per-repository configuration options. It is a
446 simple text file modeled after `.ini` format familiar to some
447 people. Here is an example:
451 # A '#' or ';' character indicates a comment.
456 ; Don't trust file modes
461 name = "Junio C Hamano"
462 email = "junkio@twinsun.com"
466 Various commands read from the configuration file and adjust
467 their operation accordingly. See linkgit:git-config[1] for a
471 Identifier Terminology
472 ----------------------
474 Indicates the object name for any type of object.
477 Indicates a blob object name.
480 Indicates a tree object name.
483 Indicates a commit object name.
486 Indicates a tree, commit or tag object name. A
487 command that takes a <tree-ish> argument ultimately wants to
488 operate on a <tree> object but automatically dereferences
489 <commit> and <tag> objects that point at a <tree>.
492 Indicates a commit or tag object name. A
493 command that takes a <commit-ish> argument ultimately wants to
494 operate on a <commit> object but automatically dereferences
495 <tag> objects that point at a <commit>.
498 Indicates that an object type is required.
499 Currently one of: `blob`, `tree`, `commit`, or `tag`.
502 Indicates a filename - almost always relative to the
503 root of the tree structure `GIT_INDEX_FILE` describes.
507 Any git command accepting any <object> can also use the following
511 indicates the head of the current branch (i.e. the
512 contents of `$GIT_DIR/HEAD`).
516 (i.e. the contents of `$GIT_DIR/refs/tags/<tag>`).
520 (i.e. the contents of `$GIT_DIR/refs/heads/<head>`).
522 For a more complete list of ways to spell object names, see
523 "SPECIFYING REVISIONS" section in linkgit:gitrevisions[7].
526 File/Directory Structure
527 ------------------------
529 Please see the linkgit:gitrepository-layout[5] document.
531 Read linkgit:githooks[5] for more details about each hook.
533 Higher level SCMs may provide and manage additional information in the
539 Please see linkgit:gitglossary[7].
542 Environment Variables
543 ---------------------
544 Various git commands use the following environment variables:
548 These environment variables apply to 'all' core git commands. Nb: it
549 is worth noting that they may be used/overridden by SCMS sitting above
550 git so take care if using Cogito etc.
553 This environment allows the specification of an alternate
554 index file. If not specified, the default of `$GIT_DIR/index`
557 'GIT_OBJECT_DIRECTORY'::
558 If the object storage directory is specified via this
559 environment variable then the sha1 directories are created
560 underneath - otherwise the default `$GIT_DIR/objects`
563 'GIT_ALTERNATE_OBJECT_DIRECTORIES'::
564 Due to the immutable nature of git objects, old objects can be
565 archived into shared, read-only directories. This variable
566 specifies a ":" separated (on Windows ";" separated) list
567 of git object directories which can be used to search for git
568 objects. New objects will not be written to these directories.
571 If the 'GIT_DIR' environment variable is set then it
572 specifies a path to use instead of the default `.git`
573 for the base of the repository.
576 Set the path to the working tree. The value will not be
577 used in combination with repositories found automatically in
578 a .git directory (i.e. $GIT_DIR is not set).
579 This can also be controlled by the '--work-tree' command line
580 option and the core.worktree configuration variable.
582 'GIT_CEILING_DIRECTORIES'::
583 This should be a colon-separated list of absolute paths.
584 If set, it is a list of directories that git should not chdir
585 up into while looking for a repository directory.
586 It will not exclude the current working directory or
587 a GIT_DIR set on the command line or in the environment.
588 (Useful for excluding slow-loading network directories.)
590 'GIT_DISCOVERY_ACROSS_FILESYSTEM'::
591 When run in a directory that does not have ".git" repository
592 directory, git tries to find such a directory in the parent
593 directories to find the top of the working tree, but by default it
594 does not cross filesystem boundaries. This environment variable
595 can be set to true to tell git not to stop at filesystem
596 boundaries. Like 'GIT_CEILING_DIRECTORIES', this will not affect
597 an explicit repository directory set via 'GIT_DIR' or on the
605 'GIT_COMMITTER_NAME'::
606 'GIT_COMMITTER_EMAIL'::
607 'GIT_COMMITTER_DATE'::
609 see linkgit:git-commit-tree[1]
614 Only valid setting is "--unified=??" or "-u??" to set the
615 number of context lines shown when a unified diff is created.
616 This takes precedence over any "-U" or "--unified" option
617 value passed on the git diff command line.
619 'GIT_EXTERNAL_DIFF'::
620 When the environment variable 'GIT_EXTERNAL_DIFF' is set, the
621 program named by it is called, instead of the diff invocation
622 described above. For a path that is added, removed, or modified,
623 'GIT_EXTERNAL_DIFF' is called with 7 parameters:
625 path old-file old-hex old-mode new-file new-hex new-mode
629 <old|new>-file:: are files GIT_EXTERNAL_DIFF can use to read the
630 contents of <old|new>,
631 <old|new>-hex:: are the 40-hexdigit SHA1 hashes,
632 <old|new>-mode:: are the octal representation of the file modes.
634 The file parameters can point at the user's working file
635 (e.g. `new-file` in "git-diff-files"), `/dev/null` (e.g. `old-file`
636 when a new file is added), or a temporary file (e.g. `old-file` in the
637 index). 'GIT_EXTERNAL_DIFF' should not worry about unlinking the
638 temporary file --- it is removed when 'GIT_EXTERNAL_DIFF' exits.
640 For a path that is unmerged, 'GIT_EXTERNAL_DIFF' is called with 1
645 'GIT_MERGE_VERBOSITY'::
646 A number controlling the amount of output shown by
647 the recursive merge strategy. Overrides merge.verbosity.
648 See linkgit:git-merge[1]
651 This environment variable overrides `$PAGER`. If it is set
652 to an empty string or to the value "cat", git will not launch
653 a pager. See also the `core.pager` option in
654 linkgit:git-config[1].
657 If this environment variable is set then 'git fetch'
658 and 'git push' will use this command instead
659 of 'ssh' when they need to connect to a remote system.
660 The '$GIT_SSH' command will be given exactly two arguments:
661 the 'username@host' (or just 'host') from the URL and the
662 shell command to execute on that remote system.
664 To pass options to the program that you want to list in GIT_SSH
665 you will need to wrap the program and options into a shell script,
666 then set GIT_SSH to refer to the shell script.
668 Usually it is easier to configure any desired options through your
669 personal `.ssh/config` file. Please consult your ssh documentation
673 If this environment variable is set, then git commands which need to
674 acquire passwords or passphrases (e.g. for HTTP or IMAP authentication)
675 will call this program with a suitable prompt as command line argument
676 and read the password from its STDOUT. See also the 'core.askpass'
677 option in linkgit:git-config[1].
680 If this environment variable is set to "1", then commands such
681 as 'git blame' (in incremental mode), 'git rev-list', 'git log',
682 and 'git whatchanged' will force a flush of the output stream
683 after each commit-oriented record have been flushed. If this
684 variable is set to "0", the output of these commands will be done
685 using completely buffered I/O. If this environment variable is
686 not set, git will choose buffered or record-oriented flushing
687 based on whether stdout appears to be redirected to a file or not.
690 If this variable is set to "1", "2" or "true" (comparison
691 is case insensitive), git will print `trace:` messages on
692 stderr telling about alias expansion, built-in command
693 execution and external command execution.
694 If this variable is set to an integer value greater than 1
695 and lower than 10 (strictly) then git will interpret this
696 value as an open file descriptor and will try to write the
697 trace messages into this file descriptor.
698 Alternatively, if this variable is set to an absolute path
699 (starting with a '/' character), git will interpret this
700 as a file path and will try to write the trace messages
703 Discussion[[Discussion]]
704 ------------------------
706 More detail on the following is available from the
707 link:user-manual.html#git-concepts[git concepts chapter of the
708 user-manual] and linkgit:gitcore-tutorial[7].
710 A git project normally consists of a working directory with a ".git"
711 subdirectory at the top level. The .git directory contains, among other
712 things, a compressed object database representing the complete history
713 of the project, an "index" file which links that history to the current
714 contents of the working tree, and named pointers into that history such
715 as tags and branch heads.
717 The object database contains objects of three main types: blobs, which
718 hold file data; trees, which point to blobs and other trees to build up
719 directory hierarchies; and commits, which each reference a single tree
720 and some number of parent commits.
722 The commit, equivalent to what other systems call a "changeset" or
723 "version", represents a step in the project's history, and each parent
724 represents an immediately preceding step. Commits with more than one
725 parent represent merges of independent lines of development.
727 All objects are named by the SHA1 hash of their contents, normally
728 written as a string of 40 hex digits. Such names are globally unique.
729 The entire history leading up to a commit can be vouched for by signing
730 just that commit. A fourth object type, the tag, is provided for this
733 When first created, objects are stored in individual files, but for
734 efficiency may later be compressed together into "pack files".
736 Named pointers called refs mark interesting points in history. A ref
737 may contain the SHA1 name of an object or the name of another ref. Refs
738 with names beginning `ref/head/` contain the SHA1 name of the most
739 recent commit (or "head") of a branch under development. SHA1 names of
740 tags of interest are stored under `ref/tags/`. A special ref named
741 `HEAD` contains the name of the currently checked-out branch.
743 The index file is initialized with a list of all paths and, for each
744 path, a blob object and a set of attributes. The blob object represents
745 the contents of the file as of the head of the current branch. The
746 attributes (last modified time, size, etc.) are taken from the
747 corresponding file in the working tree. Subsequent changes to the
748 working tree can be found by comparing these attributes. The index may
749 be updated with new content, and new commits may be created from the
750 content stored in the index.
752 The index is also capable of storing multiple entries (called "stages")
753 for a given pathname. These stages are used to hold the various
754 unmerged version of a file when a merge is in progress.
758 Git was started by Linus Torvalds, and is currently maintained by Junio
759 C Hamano. Numerous contributions have come from the git mailing list
760 <git@vger.kernel.org>. For a more complete list of contributors, see
761 http://git-scm.com/about. If you have a clone of git.git itself, the
762 output of linkgit:git-shortlog[1] and linkgit:git-blame[1] can show you
763 the authors for specific parts of the project.
768 Report bugs to the Git mailing list <git@vger.kernel.org> where the
769 development and maintenance is primarily done. You do not have to be
770 subscribed to the list to send a message there.
774 linkgit:gittutorial[7], linkgit:gittutorial-2[7],
775 link:everyday.html[Everyday Git], linkgit:gitcvs-migration[7],
776 linkgit:gitglossary[7], linkgit:gitcore-tutorial[7],
777 linkgit:gitcli[7], link:user-manual.html[The Git User's Manual],
778 linkgit:gitworkflows[7]
782 Part of the linkgit:git[1] suite