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:v1.7.4.5/git.html[documentation for release 1.7.4.5]
50 link:RelNotes/1.7.4.5.txt[1.7.4.5],
51 link:RelNotes/1.7.4.4.txt[1.7.4.4],
52 link:RelNotes/1.7.4.3.txt[1.7.4.3],
53 link:RelNotes/1.7.4.2.txt[1.7.4.2],
54 link:RelNotes/1.7.4.1.txt[1.7.4.1],
55 link:RelNotes/1.7.4.txt[1.7.4].
57 * link:v1.7.3.5/git.html[documentation for release 1.7.3.5]
60 link:RelNotes/1.7.3.5.txt[1.7.3.5],
61 link:RelNotes/1.7.3.4.txt[1.7.3.4],
62 link:RelNotes/1.7.3.3.txt[1.7.3.3],
63 link:RelNotes/1.7.3.2.txt[1.7.3.2],
64 link:RelNotes/1.7.3.1.txt[1.7.3.1],
65 link:RelNotes/1.7.3.txt[1.7.3].
67 * link:v1.7.2.5/git.html[documentation for release 1.7.2.5]
70 link:RelNotes/1.7.2.5.txt[1.7.2.5],
71 link:RelNotes/1.7.2.4.txt[1.7.2.4],
72 link:RelNotes/1.7.2.3.txt[1.7.2.3],
73 link:RelNotes/1.7.2.2.txt[1.7.2.2],
74 link:RelNotes/1.7.2.1.txt[1.7.2.1],
75 link:RelNotes/1.7.2.txt[1.7.2].
77 * link:v1.7.1.4/git.html[documentation for release 1.7.1.4]
80 link:RelNotes/1.7.1.4.txt[1.7.1.4],
81 link:RelNotes/1.7.1.3.txt[1.7.1.3],
82 link:RelNotes/1.7.1.2.txt[1.7.1.2],
83 link:RelNotes/1.7.1.1.txt[1.7.1.1],
84 link:RelNotes/1.7.1.txt[1.7.1].
86 * link:v1.7.0.9/git.html[documentation for release 1.7.0.9]
89 link:RelNotes/1.7.0.9.txt[1.7.0.9],
90 link:RelNotes/1.7.0.8.txt[1.7.0.8],
91 link:RelNotes/1.7.0.7.txt[1.7.0.7],
92 link:RelNotes/1.7.0.6.txt[1.7.0.6],
93 link:RelNotes/1.7.0.5.txt[1.7.0.5],
94 link:RelNotes/1.7.0.4.txt[1.7.0.4],
95 link:RelNotes/1.7.0.3.txt[1.7.0.3],
96 link:RelNotes/1.7.0.2.txt[1.7.0.2],
97 link:RelNotes/1.7.0.1.txt[1.7.0.1],
98 link:RelNotes/1.7.0.txt[1.7.0].
100 * link:v1.6.6.3/git.html[documentation for release 1.6.6.3]
103 link:RelNotes/1.6.6.3.txt[1.6.6.3],
104 link:RelNotes/1.6.6.2.txt[1.6.6.2],
105 link:RelNotes/1.6.6.1.txt[1.6.6.1],
106 link:RelNotes/1.6.6.txt[1.6.6].
108 * link:v1.6.5.9/git.html[documentation for release 1.6.5.9]
111 link:RelNotes/1.6.5.9.txt[1.6.5.9],
112 link:RelNotes/1.6.5.8.txt[1.6.5.8],
113 link:RelNotes/1.6.5.7.txt[1.6.5.7],
114 link:RelNotes/1.6.5.6.txt[1.6.5.6],
115 link:RelNotes/1.6.5.5.txt[1.6.5.5],
116 link:RelNotes/1.6.5.4.txt[1.6.5.4],
117 link:RelNotes/1.6.5.3.txt[1.6.5.3],
118 link:RelNotes/1.6.5.2.txt[1.6.5.2],
119 link:RelNotes/1.6.5.1.txt[1.6.5.1],
120 link:RelNotes/1.6.5.txt[1.6.5].
122 * link:v1.6.4.5/git.html[documentation for release 1.6.4.5]
125 link:RelNotes/1.6.4.5.txt[1.6.4.5],
126 link:RelNotes/1.6.4.4.txt[1.6.4.4],
127 link:RelNotes/1.6.4.3.txt[1.6.4.3],
128 link:RelNotes/1.6.4.2.txt[1.6.4.2],
129 link:RelNotes/1.6.4.1.txt[1.6.4.1],
130 link:RelNotes/1.6.4.txt[1.6.4].
132 * link:v1.6.3.4/git.html[documentation for release 1.6.3.4]
135 link:RelNotes/1.6.3.4.txt[1.6.3.4],
136 link:RelNotes/1.6.3.3.txt[1.6.3.3],
137 link:RelNotes/1.6.3.2.txt[1.6.3.2],
138 link:RelNotes/1.6.3.1.txt[1.6.3.1],
139 link:RelNotes/1.6.3.txt[1.6.3].
142 link:RelNotes/1.6.2.5.txt[1.6.2.5],
143 link:RelNotes/1.6.2.4.txt[1.6.2.4],
144 link:RelNotes/1.6.2.3.txt[1.6.2.3],
145 link:RelNotes/1.6.2.2.txt[1.6.2.2],
146 link:RelNotes/1.6.2.1.txt[1.6.2.1],
147 link:RelNotes/1.6.2.txt[1.6.2].
149 * link:v1.6.1.3/git.html[documentation for release 1.6.1.3]
152 link:RelNotes/1.6.1.3.txt[1.6.1.3],
153 link:RelNotes/1.6.1.2.txt[1.6.1.2],
154 link:RelNotes/1.6.1.1.txt[1.6.1.1],
155 link:RelNotes/1.6.1.txt[1.6.1].
157 * link:v1.6.0.6/git.html[documentation for release 1.6.0.6]
160 link:RelNotes/1.6.0.6.txt[1.6.0.6],
161 link:RelNotes/1.6.0.5.txt[1.6.0.5],
162 link:RelNotes/1.6.0.4.txt[1.6.0.4],
163 link:RelNotes/1.6.0.3.txt[1.6.0.3],
164 link:RelNotes/1.6.0.2.txt[1.6.0.2],
165 link:RelNotes/1.6.0.1.txt[1.6.0.1],
166 link:RelNotes/1.6.0.txt[1.6.0].
168 * link:v1.5.6.6/git.html[documentation for release 1.5.6.6]
171 link:RelNotes/1.5.6.6.txt[1.5.6.6],
172 link:RelNotes/1.5.6.5.txt[1.5.6.5],
173 link:RelNotes/1.5.6.4.txt[1.5.6.4],
174 link:RelNotes/1.5.6.3.txt[1.5.6.3],
175 link:RelNotes/1.5.6.2.txt[1.5.6.2],
176 link:RelNotes/1.5.6.1.txt[1.5.6.1],
177 link:RelNotes/1.5.6.txt[1.5.6].
179 * link:v1.5.5.6/git.html[documentation for release 1.5.5.6]
182 link:RelNotes/1.5.5.6.txt[1.5.5.6],
183 link:RelNotes/1.5.5.5.txt[1.5.5.5],
184 link:RelNotes/1.5.5.4.txt[1.5.5.4],
185 link:RelNotes/1.5.5.3.txt[1.5.5.3],
186 link:RelNotes/1.5.5.2.txt[1.5.5.2],
187 link:RelNotes/1.5.5.1.txt[1.5.5.1],
188 link:RelNotes/1.5.5.txt[1.5.5].
190 * link:v1.5.4.7/git.html[documentation for release 1.5.4.7]
193 link:RelNotes/1.5.4.7.txt[1.5.4.7],
194 link:RelNotes/1.5.4.6.txt[1.5.4.6],
195 link:RelNotes/1.5.4.5.txt[1.5.4.5],
196 link:RelNotes/1.5.4.4.txt[1.5.4.4],
197 link:RelNotes/1.5.4.3.txt[1.5.4.3],
198 link:RelNotes/1.5.4.2.txt[1.5.4.2],
199 link:RelNotes/1.5.4.1.txt[1.5.4.1],
200 link:RelNotes/1.5.4.txt[1.5.4].
202 * link:v1.5.3.8/git.html[documentation for release 1.5.3.8]
205 link:RelNotes/1.5.3.8.txt[1.5.3.8],
206 link:RelNotes/1.5.3.7.txt[1.5.3.7],
207 link:RelNotes/1.5.3.6.txt[1.5.3.6],
208 link:RelNotes/1.5.3.5.txt[1.5.3.5],
209 link:RelNotes/1.5.3.4.txt[1.5.3.4],
210 link:RelNotes/1.5.3.3.txt[1.5.3.3],
211 link:RelNotes/1.5.3.2.txt[1.5.3.2],
212 link:RelNotes/1.5.3.1.txt[1.5.3.1],
213 link:RelNotes/1.5.3.txt[1.5.3].
215 * link:v1.5.2.5/git.html[documentation for release 1.5.2.5]
218 link:RelNotes/1.5.2.5.txt[1.5.2.5],
219 link:RelNotes/1.5.2.4.txt[1.5.2.4],
220 link:RelNotes/1.5.2.3.txt[1.5.2.3],
221 link:RelNotes/1.5.2.2.txt[1.5.2.2],
222 link:RelNotes/1.5.2.1.txt[1.5.2.1],
223 link:RelNotes/1.5.2.txt[1.5.2].
225 * link:v1.5.1.6/git.html[documentation for release 1.5.1.6]
228 link:RelNotes/1.5.1.6.txt[1.5.1.6],
229 link:RelNotes/1.5.1.5.txt[1.5.1.5],
230 link:RelNotes/1.5.1.4.txt[1.5.1.4],
231 link:RelNotes/1.5.1.3.txt[1.5.1.3],
232 link:RelNotes/1.5.1.2.txt[1.5.1.2],
233 link:RelNotes/1.5.1.1.txt[1.5.1.1],
234 link:RelNotes/1.5.1.txt[1.5.1].
236 * link:v1.5.0.7/git.html[documentation for release 1.5.0.7]
239 link:RelNotes/1.5.0.7.txt[1.5.0.7],
240 link:RelNotes/1.5.0.6.txt[1.5.0.6],
241 link:RelNotes/1.5.0.5.txt[1.5.0.5],
242 link:RelNotes/1.5.0.3.txt[1.5.0.3],
243 link:RelNotes/1.5.0.2.txt[1.5.0.2],
244 link:RelNotes/1.5.0.1.txt[1.5.0.1],
245 link:RelNotes/1.5.0.txt[1.5.0].
247 * documentation for release link:v1.4.4.4/git.html[1.4.4.4],
248 link:v1.3.3/git.html[1.3.3],
249 link:v1.2.6/git.html[1.2.6],
250 link:v1.0.13/git.html[1.0.13].
259 Prints the git suite version that the 'git' program came from.
262 Prints the synopsis and a list of the most commonly used
263 commands. If the option '--all' or '-a' is given then all
264 available commands are printed. If a git command is named this
265 option will bring up the manual page for that command.
267 Other options are available to control how the manual page is
268 displayed. See linkgit:git-help[1] for more information,
269 because `git --help ...` is converted internally into `git
273 Pass a configuration parameter to the command. The value
274 given will override values from configuration files.
275 The <name> is expected in the same format as listed by
276 'git config' (subkeys separated by dots).
278 --exec-path[=<path>]::
279 Path to wherever your core git programs are installed.
280 This can also be controlled by setting the GIT_EXEC_PATH
281 environment variable. If no path is given, 'git' will print
282 the current setting and then exit.
285 Print the path to wherever your git HTML documentation is installed
290 Pipe all output into 'less' (or if set, $PAGER) if standard
291 output is a terminal. This overrides the `pager.<cmd>`
292 configuration options (see the "Configuration Mechanism" section
296 Do not pipe git output into a pager.
299 Set the path to the repository. This can also be controlled by
300 setting the GIT_DIR environment variable. It can be an absolute
301 path or relative path to current working directory.
304 Set the path to the working tree. It can be an absolute path
305 or a path relative to the current working directory.
306 This can also be controlled by setting the GIT_WORK_TREE
307 environment variable and the core.worktree configuration
308 variable (see core.worktree in linkgit:git-config[1] for a
309 more detailed discussion).
312 Treat the repository as a bare repository. If GIT_DIR
313 environment is not set, it is set to the current working
316 --no-replace-objects::
317 Do not use replacement refs to replace git objects. See
318 linkgit:git-replace[1] for more information.
321 FURTHER DOCUMENTATION
322 ---------------------
324 See the references above to get started using git. The following is
325 probably more detail than necessary for a first-time user.
327 The link:user-manual.html#git-concepts[git concepts chapter of the
328 user-manual] and linkgit:gitcore-tutorial[7] both provide
329 introductions to the underlying git architecture.
331 See linkgit:gitworkflows[7] for an overview of recommended workflows.
333 See also the link:howto-index.html[howto] documents for some useful
336 The internals are documented in the
337 link:technical/api-index.html[GIT API documentation].
342 We divide git into high level ("porcelain") commands and low level
343 ("plumbing") commands.
345 High-level commands (porcelain)
346 -------------------------------
348 We separate the porcelain commands into the main commands and some
349 ancillary user utilities.
351 Main porcelain commands
352 ~~~~~~~~~~~~~~~~~~~~~~~
354 include::cmds-mainporcelain.txt[]
360 include::cmds-ancillarymanipulators.txt[]
364 include::cmds-ancillaryinterrogators.txt[]
367 Interacting with Others
368 ~~~~~~~~~~~~~~~~~~~~~~~
370 These commands are to interact with foreign SCM and with other
371 people via patch over e-mail.
373 include::cmds-foreignscminterface.txt[]
376 Low-level commands (plumbing)
377 -----------------------------
379 Although git includes its
380 own porcelain layer, its low-level commands are sufficient to support
381 development of alternative porcelains. Developers of such porcelains
382 might start by reading about linkgit:git-update-index[1] and
383 linkgit:git-read-tree[1].
385 The interface (input, output, set of options and the semantics)
386 to these low-level commands are meant to be a lot more stable
387 than Porcelain level commands, because these commands are
388 primarily for scripted use. The interface to Porcelain commands
389 on the other hand are subject to change in order to improve the
392 The following description divides
393 the low-level commands into commands that manipulate objects (in
394 the repository, index, and working tree), commands that interrogate and
395 compare objects, and commands that move objects and references between
399 Manipulation commands
400 ~~~~~~~~~~~~~~~~~~~~~
402 include::cmds-plumbingmanipulators.txt[]
405 Interrogation commands
406 ~~~~~~~~~~~~~~~~~~~~~~
408 include::cmds-plumbinginterrogators.txt[]
410 In general, the interrogate commands do not touch the files in
414 Synching repositories
415 ~~~~~~~~~~~~~~~~~~~~~
417 include::cmds-synchingrepositories.txt[]
419 The following are helper commands used by the above; end users
420 typically do not use them directly.
422 include::cmds-synchelpers.txt[]
425 Internal helper commands
426 ~~~~~~~~~~~~~~~~~~~~~~~~
428 These are internal helper commands used by other commands; end
429 users typically do not use them directly.
431 include::cmds-purehelpers.txt[]
434 Configuration Mechanism
435 -----------------------
437 Starting from 0.99.9 (actually mid 0.99.8.GIT), `.git/config` file
438 is used to hold per-repository configuration options. It is a
439 simple text file modeled after `.ini` format familiar to some
440 people. Here is an example:
444 # A '#' or ';' character indicates a comment.
449 ; Don't trust file modes
454 name = "Junio C Hamano"
455 email = "junkio@twinsun.com"
459 Various commands read from the configuration file and adjust
460 their operation accordingly. See linkgit:git-config[1] for a
464 Identifier Terminology
465 ----------------------
467 Indicates the object name for any type of object.
470 Indicates a blob object name.
473 Indicates a tree object name.
476 Indicates a commit object name.
479 Indicates a tree, commit or tag object name. A
480 command that takes a <tree-ish> argument ultimately wants to
481 operate on a <tree> object but automatically dereferences
482 <commit> and <tag> objects that point at a <tree>.
485 Indicates a commit or tag object name. A
486 command that takes a <commit-ish> argument ultimately wants to
487 operate on a <commit> object but automatically dereferences
488 <tag> objects that point at a <commit>.
491 Indicates that an object type is required.
492 Currently one of: `blob`, `tree`, `commit`, or `tag`.
495 Indicates a filename - almost always relative to the
496 root of the tree structure `GIT_INDEX_FILE` describes.
500 Any git command accepting any <object> can also use the following
504 indicates the head of the current branch (i.e. the
505 contents of `$GIT_DIR/HEAD`).
509 (i.e. the contents of `$GIT_DIR/refs/tags/<tag>`).
513 (i.e. the contents of `$GIT_DIR/refs/heads/<head>`).
515 For a more complete list of ways to spell object names, see
516 "SPECIFYING REVISIONS" section in linkgit:gitrevisions[7].
519 File/Directory Structure
520 ------------------------
522 Please see the linkgit:gitrepository-layout[5] document.
524 Read linkgit:githooks[5] for more details about each hook.
526 Higher level SCMs may provide and manage additional information in the
532 Please see linkgit:gitglossary[7].
535 Environment Variables
536 ---------------------
537 Various git commands use the following environment variables:
541 These environment variables apply to 'all' core git commands. Nb: it
542 is worth noting that they may be used/overridden by SCMS sitting above
543 git so take care if using Cogito etc.
546 This environment allows the specification of an alternate
547 index file. If not specified, the default of `$GIT_DIR/index`
550 'GIT_OBJECT_DIRECTORY'::
551 If the object storage directory is specified via this
552 environment variable then the sha1 directories are created
553 underneath - otherwise the default `$GIT_DIR/objects`
556 'GIT_ALTERNATE_OBJECT_DIRECTORIES'::
557 Due to the immutable nature of git objects, old objects can be
558 archived into shared, read-only directories. This variable
559 specifies a ":" separated (on Windows ";" separated) list
560 of git object directories which can be used to search for git
561 objects. New objects will not be written to these directories.
564 If the 'GIT_DIR' environment variable is set then it
565 specifies a path to use instead of the default `.git`
566 for the base of the repository.
569 Set the path to the working tree. The value will not be
570 used in combination with repositories found automatically in
571 a .git directory (i.e. $GIT_DIR is not set).
572 This can also be controlled by the '--work-tree' command line
573 option and the core.worktree configuration variable.
575 'GIT_CEILING_DIRECTORIES'::
576 This should be a colon-separated list of absolute paths.
577 If set, it is a list of directories that git should not chdir
578 up into while looking for a repository directory.
579 It will not exclude the current working directory or
580 a GIT_DIR set on the command line or in the environment.
581 (Useful for excluding slow-loading network directories.)
583 'GIT_DISCOVERY_ACROSS_FILESYSTEM'::
584 When run in a directory that does not have ".git" repository
585 directory, git tries to find such a directory in the parent
586 directories to find the top of the working tree, but by default it
587 does not cross filesystem boundaries. This environment variable
588 can be set to true to tell git not to stop at filesystem
589 boundaries. Like 'GIT_CEILING_DIRECTORIES', this will not affect
590 an explicit repository directory set via 'GIT_DIR' or on the
598 'GIT_COMMITTER_NAME'::
599 'GIT_COMMITTER_EMAIL'::
600 'GIT_COMMITTER_DATE'::
602 see linkgit:git-commit-tree[1]
607 Only valid setting is "--unified=??" or "-u??" to set the
608 number of context lines shown when a unified diff is created.
609 This takes precedence over any "-U" or "--unified" option
610 value passed on the git diff command line.
612 'GIT_EXTERNAL_DIFF'::
613 When the environment variable 'GIT_EXTERNAL_DIFF' is set, the
614 program named by it is called, instead of the diff invocation
615 described above. For a path that is added, removed, or modified,
616 'GIT_EXTERNAL_DIFF' is called with 7 parameters:
618 path old-file old-hex old-mode new-file new-hex new-mode
622 <old|new>-file:: are files GIT_EXTERNAL_DIFF can use to read the
623 contents of <old|new>,
624 <old|new>-hex:: are the 40-hexdigit SHA1 hashes,
625 <old|new>-mode:: are the octal representation of the file modes.
627 The file parameters can point at the user's working file
628 (e.g. `new-file` in "git-diff-files"), `/dev/null` (e.g. `old-file`
629 when a new file is added), or a temporary file (e.g. `old-file` in the
630 index). 'GIT_EXTERNAL_DIFF' should not worry about unlinking the
631 temporary file --- it is removed when 'GIT_EXTERNAL_DIFF' exits.
633 For a path that is unmerged, 'GIT_EXTERNAL_DIFF' is called with 1
638 'GIT_MERGE_VERBOSITY'::
639 A number controlling the amount of output shown by
640 the recursive merge strategy. Overrides merge.verbosity.
641 See linkgit:git-merge[1]
644 This environment variable overrides `$PAGER`. If it is set
645 to an empty string or to the value "cat", git will not launch
646 a pager. See also the `core.pager` option in
647 linkgit:git-config[1].
650 If this environment variable is set then 'git fetch'
651 and 'git push' will use this command instead
652 of 'ssh' when they need to connect to a remote system.
653 The '$GIT_SSH' command will be given exactly two arguments:
654 the 'username@host' (or just 'host') from the URL and the
655 shell command to execute on that remote system.
657 To pass options to the program that you want to list in GIT_SSH
658 you will need to wrap the program and options into a shell script,
659 then set GIT_SSH to refer to the shell script.
661 Usually it is easier to configure any desired options through your
662 personal `.ssh/config` file. Please consult your ssh documentation
666 If this environment variable is set, then git commands which need to
667 acquire passwords or passphrases (e.g. for HTTP or IMAP authentication)
668 will call this program with a suitable prompt as command line argument
669 and read the password from its STDOUT. See also the 'core.askpass'
670 option in linkgit:git-config[1].
673 If this environment variable is set to "1", then commands such
674 as 'git blame' (in incremental mode), 'git rev-list', 'git log',
675 and 'git whatchanged' will force a flush of the output stream
676 after each commit-oriented record have been flushed. If this
677 variable is set to "0", the output of these commands will be done
678 using completely buffered I/O. If this environment variable is
679 not set, git will choose buffered or record-oriented flushing
680 based on whether stdout appears to be redirected to a file or not.
683 If this variable is set to "1", "2" or "true" (comparison
684 is case insensitive), git will print `trace:` messages on
685 stderr telling about alias expansion, built-in command
686 execution and external command execution.
687 If this variable is set to an integer value greater than 1
688 and lower than 10 (strictly) then git will interpret this
689 value as an open file descriptor and will try to write the
690 trace messages into this file descriptor.
691 Alternatively, if this variable is set to an absolute path
692 (starting with a '/' character), git will interpret this
693 as a file path and will try to write the trace messages
696 Discussion[[Discussion]]
697 ------------------------
699 More detail on the following is available from the
700 link:user-manual.html#git-concepts[git concepts chapter of the
701 user-manual] and linkgit:gitcore-tutorial[7].
703 A git project normally consists of a working directory with a ".git"
704 subdirectory at the top level. The .git directory contains, among other
705 things, a compressed object database representing the complete history
706 of the project, an "index" file which links that history to the current
707 contents of the working tree, and named pointers into that history such
708 as tags and branch heads.
710 The object database contains objects of three main types: blobs, which
711 hold file data; trees, which point to blobs and other trees to build up
712 directory hierarchies; and commits, which each reference a single tree
713 and some number of parent commits.
715 The commit, equivalent to what other systems call a "changeset" or
716 "version", represents a step in the project's history, and each parent
717 represents an immediately preceding step. Commits with more than one
718 parent represent merges of independent lines of development.
720 All objects are named by the SHA1 hash of their contents, normally
721 written as a string of 40 hex digits. Such names are globally unique.
722 The entire history leading up to a commit can be vouched for by signing
723 just that commit. A fourth object type, the tag, is provided for this
726 When first created, objects are stored in individual files, but for
727 efficiency may later be compressed together into "pack files".
729 Named pointers called refs mark interesting points in history. A ref
730 may contain the SHA1 name of an object or the name of another ref. Refs
731 with names beginning `ref/head/` contain the SHA1 name of the most
732 recent commit (or "head") of a branch under development. SHA1 names of
733 tags of interest are stored under `ref/tags/`. A special ref named
734 `HEAD` contains the name of the currently checked-out branch.
736 The index file is initialized with a list of all paths and, for each
737 path, a blob object and a set of attributes. The blob object represents
738 the contents of the file as of the head of the current branch. The
739 attributes (last modified time, size, etc.) are taken from the
740 corresponding file in the working tree. Subsequent changes to the
741 working tree can be found by comparing these attributes. The index may
742 be updated with new content, and new commits may be created from the
743 content stored in the index.
745 The index is also capable of storing multiple entries (called "stages")
746 for a given pathname. These stages are used to hold the various
747 unmerged version of a file when a merge is in progress.
751 Git was started by Linus Torvalds, and is currently maintained by Junio
752 C Hamano. Numerous contributions have come from the git mailing list
753 <git@vger.kernel.org>. For a more complete list of contributors, see
754 http://git-scm.com/about. If you have a clone of git.git itself, the
755 output of linkgit:git-shortlog[1] and linkgit:git-blame[1] can show you
756 the authors for specific parts of the project.
761 Report bugs to the Git mailing list <git@vger.kernel.org> where the
762 development and maintenance is primarily done. You do not have to be
763 subscribed to the list to send a message there.
767 linkgit:gittutorial[7], linkgit:gittutorial-2[7],
768 link:everyday.html[Everyday Git], linkgit:gitcvs-migration[7],
769 linkgit:gitglossary[7], linkgit:gitcore-tutorial[7],
770 linkgit:gitcli[7], link:user-manual.html[The Git User's Manual],
771 linkgit:gitworkflows[7]
775 Part of the linkgit:git[1] suite