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:v1.7.6.2/git.html[documentation for release 1.7.6.2]
50 link:RelNotes/1.7.6.2.txt[1.7.6.2],
51 link:RelNotes/1.7.6.1.txt[1.7.6.1],
52 link:RelNotes/1.7.6.txt[1.7.6].
54 * link:v1.7.5.4/git.html[documentation for release 1.7.5.4]
57 link:RelNotes/1.7.5.4.txt[1.7.5.4],
58 link:RelNotes/1.7.5.3.txt[1.7.5.3],
59 link:RelNotes/1.7.5.2.txt[1.7.5.2],
60 link:RelNotes/1.7.5.1.txt[1.7.5.1],
61 link:RelNotes/1.7.5.txt[1.7.5].
63 * link:v1.7.4.5/git.html[documentation for release 1.7.4.5]
66 link:RelNotes/1.7.4.5.txt[1.7.4.5],
67 link:RelNotes/1.7.4.4.txt[1.7.4.4],
68 link:RelNotes/1.7.4.3.txt[1.7.4.3],
69 link:RelNotes/1.7.4.2.txt[1.7.4.2],
70 link:RelNotes/1.7.4.1.txt[1.7.4.1],
71 link:RelNotes/1.7.4.txt[1.7.4].
73 * link:v1.7.3.5/git.html[documentation for release 1.7.3.5]
76 link:RelNotes/1.7.3.5.txt[1.7.3.5],
77 link:RelNotes/1.7.3.4.txt[1.7.3.4],
78 link:RelNotes/1.7.3.3.txt[1.7.3.3],
79 link:RelNotes/1.7.3.2.txt[1.7.3.2],
80 link:RelNotes/1.7.3.1.txt[1.7.3.1],
81 link:RelNotes/1.7.3.txt[1.7.3].
83 * link:v1.7.2.5/git.html[documentation for release 1.7.2.5]
86 link:RelNotes/1.7.2.5.txt[1.7.2.5],
87 link:RelNotes/1.7.2.4.txt[1.7.2.4],
88 link:RelNotes/1.7.2.3.txt[1.7.2.3],
89 link:RelNotes/1.7.2.2.txt[1.7.2.2],
90 link:RelNotes/1.7.2.1.txt[1.7.2.1],
91 link:RelNotes/1.7.2.txt[1.7.2].
93 * link:v1.7.1.4/git.html[documentation for release 1.7.1.4]
96 link:RelNotes/1.7.1.4.txt[1.7.1.4],
97 link:RelNotes/1.7.1.3.txt[1.7.1.3],
98 link:RelNotes/1.7.1.2.txt[1.7.1.2],
99 link:RelNotes/1.7.1.1.txt[1.7.1.1],
100 link:RelNotes/1.7.1.txt[1.7.1].
102 * link:v1.7.0.9/git.html[documentation for release 1.7.0.9]
105 link:RelNotes/1.7.0.9.txt[1.7.0.9],
106 link:RelNotes/1.7.0.8.txt[1.7.0.8],
107 link:RelNotes/1.7.0.7.txt[1.7.0.7],
108 link:RelNotes/1.7.0.6.txt[1.7.0.6],
109 link:RelNotes/1.7.0.5.txt[1.7.0.5],
110 link:RelNotes/1.7.0.4.txt[1.7.0.4],
111 link:RelNotes/1.7.0.3.txt[1.7.0.3],
112 link:RelNotes/1.7.0.2.txt[1.7.0.2],
113 link:RelNotes/1.7.0.1.txt[1.7.0.1],
114 link:RelNotes/1.7.0.txt[1.7.0].
116 * link:v1.6.6.3/git.html[documentation for release 1.6.6.3]
119 link:RelNotes/1.6.6.3.txt[1.6.6.3],
120 link:RelNotes/1.6.6.2.txt[1.6.6.2],
121 link:RelNotes/1.6.6.1.txt[1.6.6.1],
122 link:RelNotes/1.6.6.txt[1.6.6].
124 * link:v1.6.5.9/git.html[documentation for release 1.6.5.9]
127 link:RelNotes/1.6.5.9.txt[1.6.5.9],
128 link:RelNotes/1.6.5.8.txt[1.6.5.8],
129 link:RelNotes/1.6.5.7.txt[1.6.5.7],
130 link:RelNotes/1.6.5.6.txt[1.6.5.6],
131 link:RelNotes/1.6.5.5.txt[1.6.5.5],
132 link:RelNotes/1.6.5.4.txt[1.6.5.4],
133 link:RelNotes/1.6.5.3.txt[1.6.5.3],
134 link:RelNotes/1.6.5.2.txt[1.6.5.2],
135 link:RelNotes/1.6.5.1.txt[1.6.5.1],
136 link:RelNotes/1.6.5.txt[1.6.5].
138 * link:v1.6.4.5/git.html[documentation for release 1.6.4.5]
141 link:RelNotes/1.6.4.5.txt[1.6.4.5],
142 link:RelNotes/1.6.4.4.txt[1.6.4.4],
143 link:RelNotes/1.6.4.3.txt[1.6.4.3],
144 link:RelNotes/1.6.4.2.txt[1.6.4.2],
145 link:RelNotes/1.6.4.1.txt[1.6.4.1],
146 link:RelNotes/1.6.4.txt[1.6.4].
148 * link:v1.6.3.4/git.html[documentation for release 1.6.3.4]
151 link:RelNotes/1.6.3.4.txt[1.6.3.4],
152 link:RelNotes/1.6.3.3.txt[1.6.3.3],
153 link:RelNotes/1.6.3.2.txt[1.6.3.2],
154 link:RelNotes/1.6.3.1.txt[1.6.3.1],
155 link:RelNotes/1.6.3.txt[1.6.3].
158 link:RelNotes/1.6.2.5.txt[1.6.2.5],
159 link:RelNotes/1.6.2.4.txt[1.6.2.4],
160 link:RelNotes/1.6.2.3.txt[1.6.2.3],
161 link:RelNotes/1.6.2.2.txt[1.6.2.2],
162 link:RelNotes/1.6.2.1.txt[1.6.2.1],
163 link:RelNotes/1.6.2.txt[1.6.2].
165 * link:v1.6.1.3/git.html[documentation for release 1.6.1.3]
168 link:RelNotes/1.6.1.3.txt[1.6.1.3],
169 link:RelNotes/1.6.1.2.txt[1.6.1.2],
170 link:RelNotes/1.6.1.1.txt[1.6.1.1],
171 link:RelNotes/1.6.1.txt[1.6.1].
173 * link:v1.6.0.6/git.html[documentation for release 1.6.0.6]
176 link:RelNotes/1.6.0.6.txt[1.6.0.6],
177 link:RelNotes/1.6.0.5.txt[1.6.0.5],
178 link:RelNotes/1.6.0.4.txt[1.6.0.4],
179 link:RelNotes/1.6.0.3.txt[1.6.0.3],
180 link:RelNotes/1.6.0.2.txt[1.6.0.2],
181 link:RelNotes/1.6.0.1.txt[1.6.0.1],
182 link:RelNotes/1.6.0.txt[1.6.0].
184 * link:v1.5.6.6/git.html[documentation for release 1.5.6.6]
187 link:RelNotes/1.5.6.6.txt[1.5.6.6],
188 link:RelNotes/1.5.6.5.txt[1.5.6.5],
189 link:RelNotes/1.5.6.4.txt[1.5.6.4],
190 link:RelNotes/1.5.6.3.txt[1.5.6.3],
191 link:RelNotes/1.5.6.2.txt[1.5.6.2],
192 link:RelNotes/1.5.6.1.txt[1.5.6.1],
193 link:RelNotes/1.5.6.txt[1.5.6].
195 * link:v1.5.5.6/git.html[documentation for release 1.5.5.6]
198 link:RelNotes/1.5.5.6.txt[1.5.5.6],
199 link:RelNotes/1.5.5.5.txt[1.5.5.5],
200 link:RelNotes/1.5.5.4.txt[1.5.5.4],
201 link:RelNotes/1.5.5.3.txt[1.5.5.3],
202 link:RelNotes/1.5.5.2.txt[1.5.5.2],
203 link:RelNotes/1.5.5.1.txt[1.5.5.1],
204 link:RelNotes/1.5.5.txt[1.5.5].
206 * link:v1.5.4.7/git.html[documentation for release 1.5.4.7]
209 link:RelNotes/1.5.4.7.txt[1.5.4.7],
210 link:RelNotes/1.5.4.6.txt[1.5.4.6],
211 link:RelNotes/1.5.4.5.txt[1.5.4.5],
212 link:RelNotes/1.5.4.4.txt[1.5.4.4],
213 link:RelNotes/1.5.4.3.txt[1.5.4.3],
214 link:RelNotes/1.5.4.2.txt[1.5.4.2],
215 link:RelNotes/1.5.4.1.txt[1.5.4.1],
216 link:RelNotes/1.5.4.txt[1.5.4].
218 * link:v1.5.3.8/git.html[documentation for release 1.5.3.8]
221 link:RelNotes/1.5.3.8.txt[1.5.3.8],
222 link:RelNotes/1.5.3.7.txt[1.5.3.7],
223 link:RelNotes/1.5.3.6.txt[1.5.3.6],
224 link:RelNotes/1.5.3.5.txt[1.5.3.5],
225 link:RelNotes/1.5.3.4.txt[1.5.3.4],
226 link:RelNotes/1.5.3.3.txt[1.5.3.3],
227 link:RelNotes/1.5.3.2.txt[1.5.3.2],
228 link:RelNotes/1.5.3.1.txt[1.5.3.1],
229 link:RelNotes/1.5.3.txt[1.5.3].
231 * link:v1.5.2.5/git.html[documentation for release 1.5.2.5]
234 link:RelNotes/1.5.2.5.txt[1.5.2.5],
235 link:RelNotes/1.5.2.4.txt[1.5.2.4],
236 link:RelNotes/1.5.2.3.txt[1.5.2.3],
237 link:RelNotes/1.5.2.2.txt[1.5.2.2],
238 link:RelNotes/1.5.2.1.txt[1.5.2.1],
239 link:RelNotes/1.5.2.txt[1.5.2].
241 * link:v1.5.1.6/git.html[documentation for release 1.5.1.6]
244 link:RelNotes/1.5.1.6.txt[1.5.1.6],
245 link:RelNotes/1.5.1.5.txt[1.5.1.5],
246 link:RelNotes/1.5.1.4.txt[1.5.1.4],
247 link:RelNotes/1.5.1.3.txt[1.5.1.3],
248 link:RelNotes/1.5.1.2.txt[1.5.1.2],
249 link:RelNotes/1.5.1.1.txt[1.5.1.1],
250 link:RelNotes/1.5.1.txt[1.5.1].
252 * link:v1.5.0.7/git.html[documentation for release 1.5.0.7]
255 link:RelNotes/1.5.0.7.txt[1.5.0.7],
256 link:RelNotes/1.5.0.6.txt[1.5.0.6],
257 link:RelNotes/1.5.0.5.txt[1.5.0.5],
258 link:RelNotes/1.5.0.3.txt[1.5.0.3],
259 link:RelNotes/1.5.0.2.txt[1.5.0.2],
260 link:RelNotes/1.5.0.1.txt[1.5.0.1],
261 link:RelNotes/1.5.0.txt[1.5.0].
263 * documentation for release link:v1.4.4.4/git.html[1.4.4.4],
264 link:v1.3.3/git.html[1.3.3],
265 link:v1.2.6/git.html[1.2.6],
266 link:v1.0.13/git.html[1.0.13].
275 Prints the git suite version that the 'git' program came from.
278 Prints the synopsis and a list of the most commonly used
279 commands. If the option '--all' or '-a' is given then all
280 available commands are printed. If a git command is named this
281 option will bring up the manual page for that command.
283 Other options are available to control how the manual page is
284 displayed. See linkgit:git-help[1] for more information,
285 because `git --help ...` is converted internally into `git
289 Pass a configuration parameter to the command. The value
290 given will override values from configuration files.
291 The <name> is expected in the same format as listed by
292 'git config' (subkeys separated by dots).
294 --exec-path[=<path>]::
295 Path to wherever your core git programs are installed.
296 This can also be controlled by setting the GIT_EXEC_PATH
297 environment variable. If no path is given, 'git' will print
298 the current setting and then exit.
301 Print the path, without trailing slash, where git's HTML
302 documentation is installed and exit.
305 Print the manpath (see `man(1)`) for the man pages for
306 this version of git and exit.
309 Print the path where the Info files documenting this
310 version of git are installed and exit.
314 Pipe all output into 'less' (or if set, $PAGER) if standard
315 output is a terminal. This overrides the `pager.<cmd>`
316 configuration options (see the "Configuration Mechanism" section
320 Do not pipe git output into a pager.
323 Set the path to the repository. This can also be controlled by
324 setting the GIT_DIR environment variable. It can be an absolute
325 path or relative path to current working directory.
328 Set the path to the working tree. It can be an absolute path
329 or a path relative to the current working directory.
330 This can also be controlled by setting the GIT_WORK_TREE
331 environment variable and the core.worktree configuration
332 variable (see core.worktree in linkgit:git-config[1] for a
333 more detailed discussion).
336 Set the git namespace. See linkgit:gitnamespaces[7] for more
337 details. Equivalent to setting the `GIT_NAMESPACE` environment
341 Treat the repository as a bare repository. If GIT_DIR
342 environment is not set, it is set to the current working
345 --no-replace-objects::
346 Do not use replacement refs to replace git objects. See
347 linkgit:git-replace[1] for more information.
350 FURTHER DOCUMENTATION
351 ---------------------
353 See the references above to get started using git. The following is
354 probably more detail than necessary for a first-time user.
356 The link:user-manual.html#git-concepts[git concepts chapter of the
357 user-manual] and linkgit:gitcore-tutorial[7] both provide
358 introductions to the underlying git architecture.
360 See linkgit:gitworkflows[7] for an overview of recommended workflows.
362 See also the link:howto-index.html[howto] documents for some useful
365 The internals are documented in the
366 link:technical/api-index.html[GIT API documentation].
371 We divide git into high level ("porcelain") commands and low level
372 ("plumbing") commands.
374 High-level commands (porcelain)
375 -------------------------------
377 We separate the porcelain commands into the main commands and some
378 ancillary user utilities.
380 Main porcelain commands
381 ~~~~~~~~~~~~~~~~~~~~~~~
383 include::cmds-mainporcelain.txt[]
389 include::cmds-ancillarymanipulators.txt[]
393 include::cmds-ancillaryinterrogators.txt[]
396 Interacting with Others
397 ~~~~~~~~~~~~~~~~~~~~~~~
399 These commands are to interact with foreign SCM and with other
400 people via patch over e-mail.
402 include::cmds-foreignscminterface.txt[]
405 Low-level commands (plumbing)
406 -----------------------------
408 Although git includes its
409 own porcelain layer, its low-level commands are sufficient to support
410 development of alternative porcelains. Developers of such porcelains
411 might start by reading about linkgit:git-update-index[1] and
412 linkgit:git-read-tree[1].
414 The interface (input, output, set of options and the semantics)
415 to these low-level commands are meant to be a lot more stable
416 than Porcelain level commands, because these commands are
417 primarily for scripted use. The interface to Porcelain commands
418 on the other hand are subject to change in order to improve the
421 The following description divides
422 the low-level commands into commands that manipulate objects (in
423 the repository, index, and working tree), commands that interrogate and
424 compare objects, and commands that move objects and references between
428 Manipulation commands
429 ~~~~~~~~~~~~~~~~~~~~~
431 include::cmds-plumbingmanipulators.txt[]
434 Interrogation commands
435 ~~~~~~~~~~~~~~~~~~~~~~
437 include::cmds-plumbinginterrogators.txt[]
439 In general, the interrogate commands do not touch the files in
443 Synching repositories
444 ~~~~~~~~~~~~~~~~~~~~~
446 include::cmds-synchingrepositories.txt[]
448 The following are helper commands used by the above; end users
449 typically do not use them directly.
451 include::cmds-synchelpers.txt[]
454 Internal helper commands
455 ~~~~~~~~~~~~~~~~~~~~~~~~
457 These are internal helper commands used by other commands; end
458 users typically do not use them directly.
460 include::cmds-purehelpers.txt[]
463 Configuration Mechanism
464 -----------------------
466 Starting from 0.99.9 (actually mid 0.99.8.GIT), `.git/config` file
467 is used to hold per-repository configuration options. It is a
468 simple text file modeled after `.ini` format familiar to some
469 people. Here is an example:
473 # A '#' or ';' character indicates a comment.
478 ; Don't trust file modes
483 name = "Junio C Hamano"
484 email = "junkio@twinsun.com"
488 Various commands read from the configuration file and adjust
489 their operation accordingly. See linkgit:git-config[1] for a
493 Identifier Terminology
494 ----------------------
496 Indicates the object name for any type of object.
499 Indicates a blob object name.
502 Indicates a tree object name.
505 Indicates a commit object name.
508 Indicates a tree, commit or tag object name. A
509 command that takes a <tree-ish> argument ultimately wants to
510 operate on a <tree> object but automatically dereferences
511 <commit> and <tag> objects that point at a <tree>.
514 Indicates a commit or tag object name. A
515 command that takes a <commit-ish> argument ultimately wants to
516 operate on a <commit> object but automatically dereferences
517 <tag> objects that point at a <commit>.
520 Indicates that an object type is required.
521 Currently one of: `blob`, `tree`, `commit`, or `tag`.
524 Indicates a filename - almost always relative to the
525 root of the tree structure `GIT_INDEX_FILE` describes.
529 Any git command accepting any <object> can also use the following
533 indicates the head of the current branch.
537 (i.e. a `refs/tags/<tag>` reference).
541 (i.e. a `refs/heads/<head>` reference).
543 For a more complete list of ways to spell object names, see
544 "SPECIFYING REVISIONS" section in linkgit:gitrevisions[7].
547 File/Directory Structure
548 ------------------------
550 Please see the linkgit:gitrepository-layout[5] document.
552 Read linkgit:githooks[5] for more details about each hook.
554 Higher level SCMs may provide and manage additional information in the
560 Please see linkgit:gitglossary[7].
563 Environment Variables
564 ---------------------
565 Various git commands use the following environment variables:
569 These environment variables apply to 'all' core git commands. Nb: it
570 is worth noting that they may be used/overridden by SCMS sitting above
571 git so take care if using Cogito etc.
574 This environment allows the specification of an alternate
575 index file. If not specified, the default of `$GIT_DIR/index`
578 'GIT_OBJECT_DIRECTORY'::
579 If the object storage directory is specified via this
580 environment variable then the sha1 directories are created
581 underneath - otherwise the default `$GIT_DIR/objects`
584 'GIT_ALTERNATE_OBJECT_DIRECTORIES'::
585 Due to the immutable nature of git objects, old objects can be
586 archived into shared, read-only directories. This variable
587 specifies a ":" separated (on Windows ";" separated) list
588 of git object directories which can be used to search for git
589 objects. New objects will not be written to these directories.
592 If the 'GIT_DIR' environment variable is set then it
593 specifies a path to use instead of the default `.git`
594 for the base of the repository.
597 Set the path to the working tree. The value will not be
598 used in combination with repositories found automatically in
599 a .git directory (i.e. $GIT_DIR is not set).
600 This can also be controlled by the '--work-tree' command line
601 option and the core.worktree configuration variable.
604 Set the git namespace; see linkgit:gitnamespaces[7] for details.
605 The '--namespace' command-line option also sets this value.
607 'GIT_CEILING_DIRECTORIES'::
608 This should be a colon-separated list of absolute paths.
609 If set, it is a list of directories that git should not chdir
610 up into while looking for a repository directory.
611 It will not exclude the current working directory or
612 a GIT_DIR set on the command line or in the environment.
613 (Useful for excluding slow-loading network directories.)
615 'GIT_DISCOVERY_ACROSS_FILESYSTEM'::
616 When run in a directory that does not have ".git" repository
617 directory, git tries to find such a directory in the parent
618 directories to find the top of the working tree, but by default it
619 does not cross filesystem boundaries. This environment variable
620 can be set to true to tell git not to stop at filesystem
621 boundaries. Like 'GIT_CEILING_DIRECTORIES', this will not affect
622 an explicit repository directory set via 'GIT_DIR' or on the
630 'GIT_COMMITTER_NAME'::
631 'GIT_COMMITTER_EMAIL'::
632 'GIT_COMMITTER_DATE'::
634 see linkgit:git-commit-tree[1]
639 Only valid setting is "--unified=??" or "-u??" to set the
640 number of context lines shown when a unified diff is created.
641 This takes precedence over any "-U" or "--unified" option
642 value passed on the git diff command line.
644 'GIT_EXTERNAL_DIFF'::
645 When the environment variable 'GIT_EXTERNAL_DIFF' is set, the
646 program named by it is called, instead of the diff invocation
647 described above. For a path that is added, removed, or modified,
648 'GIT_EXTERNAL_DIFF' is called with 7 parameters:
650 path old-file old-hex old-mode new-file new-hex new-mode
654 <old|new>-file:: are files GIT_EXTERNAL_DIFF can use to read the
655 contents of <old|new>,
656 <old|new>-hex:: are the 40-hexdigit SHA1 hashes,
657 <old|new>-mode:: are the octal representation of the file modes.
659 The file parameters can point at the user's working file
660 (e.g. `new-file` in "git-diff-files"), `/dev/null` (e.g. `old-file`
661 when a new file is added), or a temporary file (e.g. `old-file` in the
662 index). 'GIT_EXTERNAL_DIFF' should not worry about unlinking the
663 temporary file --- it is removed when 'GIT_EXTERNAL_DIFF' exits.
665 For a path that is unmerged, 'GIT_EXTERNAL_DIFF' is called with 1
670 'GIT_MERGE_VERBOSITY'::
671 A number controlling the amount of output shown by
672 the recursive merge strategy. Overrides merge.verbosity.
673 See linkgit:git-merge[1]
676 This environment variable overrides `$PAGER`. If it is set
677 to an empty string or to the value "cat", git will not launch
678 a pager. See also the `core.pager` option in
679 linkgit:git-config[1].
682 If this environment variable is set then 'git fetch'
683 and 'git push' will use this command instead
684 of 'ssh' when they need to connect to a remote system.
685 The '$GIT_SSH' command will be given exactly two arguments:
686 the 'username@host' (or just 'host') from the URL and the
687 shell command to execute on that remote system.
689 To pass options to the program that you want to list in GIT_SSH
690 you will need to wrap the program and options into a shell script,
691 then set GIT_SSH to refer to the shell script.
693 Usually it is easier to configure any desired options through your
694 personal `.ssh/config` file. Please consult your ssh documentation
698 If this environment variable is set, then git commands which need to
699 acquire passwords or passphrases (e.g. for HTTP or IMAP authentication)
700 will call this program with a suitable prompt as command line argument
701 and read the password from its STDOUT. See also the 'core.askpass'
702 option in linkgit:git-config[1].
705 If this environment variable is set to "1", then commands such
706 as 'git blame' (in incremental mode), 'git rev-list', 'git log',
707 and 'git whatchanged' will force a flush of the output stream
708 after each commit-oriented record have been flushed. If this
709 variable is set to "0", the output of these commands will be done
710 using completely buffered I/O. If this environment variable is
711 not set, git will choose buffered or record-oriented flushing
712 based on whether stdout appears to be redirected to a file or not.
715 If this variable is set to "1", "2" or "true" (comparison
716 is case insensitive), git will print `trace:` messages on
717 stderr telling about alias expansion, built-in command
718 execution and external command execution.
719 If this variable is set to an integer value greater than 1
720 and lower than 10 (strictly) then git will interpret this
721 value as an open file descriptor and will try to write the
722 trace messages into this file descriptor.
723 Alternatively, if this variable is set to an absolute path
724 (starting with a '/' character), git will interpret this
725 as a file path and will try to write the trace messages
728 Discussion[[Discussion]]
729 ------------------------
731 More detail on the following is available from the
732 link:user-manual.html#git-concepts[git concepts chapter of the
733 user-manual] and linkgit:gitcore-tutorial[7].
735 A git project normally consists of a working directory with a ".git"
736 subdirectory at the top level. The .git directory contains, among other
737 things, a compressed object database representing the complete history
738 of the project, an "index" file which links that history to the current
739 contents of the working tree, and named pointers into that history such
740 as tags and branch heads.
742 The object database contains objects of three main types: blobs, which
743 hold file data; trees, which point to blobs and other trees to build up
744 directory hierarchies; and commits, which each reference a single tree
745 and some number of parent commits.
747 The commit, equivalent to what other systems call a "changeset" or
748 "version", represents a step in the project's history, and each parent
749 represents an immediately preceding step. Commits with more than one
750 parent represent merges of independent lines of development.
752 All objects are named by the SHA1 hash of their contents, normally
753 written as a string of 40 hex digits. Such names are globally unique.
754 The entire history leading up to a commit can be vouched for by signing
755 just that commit. A fourth object type, the tag, is provided for this
758 When first created, objects are stored in individual files, but for
759 efficiency may later be compressed together into "pack files".
761 Named pointers called refs mark interesting points in history. A ref
762 may contain the SHA1 name of an object or the name of another ref. Refs
763 with names beginning `ref/head/` contain the SHA1 name of the most
764 recent commit (or "head") of a branch under development. SHA1 names of
765 tags of interest are stored under `ref/tags/`. A special ref named
766 `HEAD` contains the name of the currently checked-out branch.
768 The index file is initialized with a list of all paths and, for each
769 path, a blob object and a set of attributes. The blob object represents
770 the contents of the file as of the head of the current branch. The
771 attributes (last modified time, size, etc.) are taken from the
772 corresponding file in the working tree. Subsequent changes to the
773 working tree can be found by comparing these attributes. The index may
774 be updated with new content, and new commits may be created from the
775 content stored in the index.
777 The index is also capable of storing multiple entries (called "stages")
778 for a given pathname. These stages are used to hold the various
779 unmerged version of a file when a merge is in progress.
783 Git was started by Linus Torvalds, and is currently maintained by Junio
784 C Hamano. Numerous contributions have come from the git mailing list
785 <git@vger.kernel.org>. For a more complete list of contributors, see
786 http://git-scm.com/about. If you have a clone of git.git itself, the
787 output of linkgit:git-shortlog[1] and linkgit:git-blame[1] can show you
788 the authors for specific parts of the project.
793 Report bugs to the Git mailing list <git@vger.kernel.org> where the
794 development and maintenance is primarily done. You do not have to be
795 subscribed to the list to send a message there.
799 linkgit:gittutorial[7], linkgit:gittutorial-2[7],
800 link:everyday.html[Everyday Git], linkgit:gitcvs-migration[7],
801 linkgit:gitglossary[7], linkgit:gitcore-tutorial[7],
802 linkgit:gitcli[7], link:user-manual.html[The Git User's Manual],
803 linkgit:gitworkflows[7]
807 Part of the linkgit:git[1] suite