6 git - the stupid content tracker
12 'git' [--version] [--exec-path[=<path>]] [--html-path] [--man-path] [--info-path]
13 [-p|--paginate|--no-pager] [--no-replace-objects]
14 [--bare] [--git-dir=<path>] [--work-tree=<path>]
16 [--help] <command> [<args>]
20 Git is a fast, scalable, distributed revision control system with an
21 unusually rich command set that provides both high-level operations
22 and full access to internals.
24 See linkgit:gittutorial[7] to get started, then see
25 link:everyday.html[Everyday Git] for a useful minimum set of commands, and
26 "man git-commandname" for documentation of each command. CVS users may
27 also want to read linkgit:gitcvs-migration[7]. See
28 the link:user-manual.html[Git User's Manual] for a more in-depth
31 The '<command>' is either a name of a Git command (see below) or an alias
32 as defined in the configuration file (see linkgit:git-config[1]).
34 Formatted and hyperlinked version of the latest git
35 documentation can be viewed at
36 `http://www.kernel.org/pub/software/scm/git/docs/`.
42 You are reading the documentation for the latest (possibly
43 unreleased) version of git, that is available from 'master'
44 branch of the `git.git` repository.
45 Documentation for older releases are available here:
47 * link:v1.7.6.6/git.html[documentation for release 1.7.6.6]
50 link:RelNotes/1.7.6.6.txt[1.7.6.6],
51 link:RelNotes/1.7.6.5.txt[1.7.6.5],
52 link:RelNotes/1.7.6.4.txt[1.7.6.4],
53 link:RelNotes/1.7.6.3.txt[1.7.6.3],
54 link:RelNotes/1.7.6.2.txt[1.7.6.2],
55 link:RelNotes/1.7.6.1.txt[1.7.6.1],
56 link:RelNotes/1.7.6.txt[1.7.6].
58 * link:v1.7.5.4/git.html[documentation for release 1.7.5.4]
61 link:RelNotes/1.7.5.4.txt[1.7.5.4],
62 link:RelNotes/1.7.5.3.txt[1.7.5.3],
63 link:RelNotes/1.7.5.2.txt[1.7.5.2],
64 link:RelNotes/1.7.5.1.txt[1.7.5.1],
65 link:RelNotes/1.7.5.txt[1.7.5].
67 * link:v1.7.4.5/git.html[documentation for release 1.7.4.5]
70 link:RelNotes/1.7.4.5.txt[1.7.4.5],
71 link:RelNotes/1.7.4.4.txt[1.7.4.4],
72 link:RelNotes/1.7.4.3.txt[1.7.4.3],
73 link:RelNotes/1.7.4.2.txt[1.7.4.2],
74 link:RelNotes/1.7.4.1.txt[1.7.4.1],
75 link:RelNotes/1.7.4.txt[1.7.4].
77 * link:v1.7.3.5/git.html[documentation for release 1.7.3.5]
80 link:RelNotes/1.7.3.5.txt[1.7.3.5],
81 link:RelNotes/1.7.3.4.txt[1.7.3.4],
82 link:RelNotes/1.7.3.3.txt[1.7.3.3],
83 link:RelNotes/1.7.3.2.txt[1.7.3.2],
84 link:RelNotes/1.7.3.1.txt[1.7.3.1],
85 link:RelNotes/1.7.3.txt[1.7.3].
87 * link:v1.7.2.5/git.html[documentation for release 1.7.2.5]
90 link:RelNotes/1.7.2.5.txt[1.7.2.5],
91 link:RelNotes/1.7.2.4.txt[1.7.2.4],
92 link:RelNotes/1.7.2.3.txt[1.7.2.3],
93 link:RelNotes/1.7.2.2.txt[1.7.2.2],
94 link:RelNotes/1.7.2.1.txt[1.7.2.1],
95 link:RelNotes/1.7.2.txt[1.7.2].
97 * link:v1.7.1.4/git.html[documentation for release 1.7.1.4]
100 link:RelNotes/1.7.1.4.txt[1.7.1.4],
101 link:RelNotes/1.7.1.3.txt[1.7.1.3],
102 link:RelNotes/1.7.1.2.txt[1.7.1.2],
103 link:RelNotes/1.7.1.1.txt[1.7.1.1],
104 link:RelNotes/1.7.1.txt[1.7.1].
106 * link:v1.7.0.9/git.html[documentation for release 1.7.0.9]
109 link:RelNotes/1.7.0.9.txt[1.7.0.9],
110 link:RelNotes/1.7.0.8.txt[1.7.0.8],
111 link:RelNotes/1.7.0.7.txt[1.7.0.7],
112 link:RelNotes/1.7.0.6.txt[1.7.0.6],
113 link:RelNotes/1.7.0.5.txt[1.7.0.5],
114 link:RelNotes/1.7.0.4.txt[1.7.0.4],
115 link:RelNotes/1.7.0.3.txt[1.7.0.3],
116 link:RelNotes/1.7.0.2.txt[1.7.0.2],
117 link:RelNotes/1.7.0.1.txt[1.7.0.1],
118 link:RelNotes/1.7.0.txt[1.7.0].
120 * link:v1.6.6.3/git.html[documentation for release 1.6.6.3]
123 link:RelNotes/1.6.6.3.txt[1.6.6.3],
124 link:RelNotes/1.6.6.2.txt[1.6.6.2],
125 link:RelNotes/1.6.6.1.txt[1.6.6.1],
126 link:RelNotes/1.6.6.txt[1.6.6].
128 * link:v1.6.5.9/git.html[documentation for release 1.6.5.9]
131 link:RelNotes/1.6.5.9.txt[1.6.5.9],
132 link:RelNotes/1.6.5.8.txt[1.6.5.8],
133 link:RelNotes/1.6.5.7.txt[1.6.5.7],
134 link:RelNotes/1.6.5.6.txt[1.6.5.6],
135 link:RelNotes/1.6.5.5.txt[1.6.5.5],
136 link:RelNotes/1.6.5.4.txt[1.6.5.4],
137 link:RelNotes/1.6.5.3.txt[1.6.5.3],
138 link:RelNotes/1.6.5.2.txt[1.6.5.2],
139 link:RelNotes/1.6.5.1.txt[1.6.5.1],
140 link:RelNotes/1.6.5.txt[1.6.5].
142 * link:v1.6.4.5/git.html[documentation for release 1.6.4.5]
145 link:RelNotes/1.6.4.5.txt[1.6.4.5],
146 link:RelNotes/1.6.4.4.txt[1.6.4.4],
147 link:RelNotes/1.6.4.3.txt[1.6.4.3],
148 link:RelNotes/1.6.4.2.txt[1.6.4.2],
149 link:RelNotes/1.6.4.1.txt[1.6.4.1],
150 link:RelNotes/1.6.4.txt[1.6.4].
152 * link:v1.6.3.4/git.html[documentation for release 1.6.3.4]
155 link:RelNotes/1.6.3.4.txt[1.6.3.4],
156 link:RelNotes/1.6.3.3.txt[1.6.3.3],
157 link:RelNotes/1.6.3.2.txt[1.6.3.2],
158 link:RelNotes/1.6.3.1.txt[1.6.3.1],
159 link:RelNotes/1.6.3.txt[1.6.3].
162 link:RelNotes/1.6.2.5.txt[1.6.2.5],
163 link:RelNotes/1.6.2.4.txt[1.6.2.4],
164 link:RelNotes/1.6.2.3.txt[1.6.2.3],
165 link:RelNotes/1.6.2.2.txt[1.6.2.2],
166 link:RelNotes/1.6.2.1.txt[1.6.2.1],
167 link:RelNotes/1.6.2.txt[1.6.2].
169 * link:v1.6.1.3/git.html[documentation for release 1.6.1.3]
172 link:RelNotes/1.6.1.3.txt[1.6.1.3],
173 link:RelNotes/1.6.1.2.txt[1.6.1.2],
174 link:RelNotes/1.6.1.1.txt[1.6.1.1],
175 link:RelNotes/1.6.1.txt[1.6.1].
177 * link:v1.6.0.6/git.html[documentation for release 1.6.0.6]
180 link:RelNotes/1.6.0.6.txt[1.6.0.6],
181 link:RelNotes/1.6.0.5.txt[1.6.0.5],
182 link:RelNotes/1.6.0.4.txt[1.6.0.4],
183 link:RelNotes/1.6.0.3.txt[1.6.0.3],
184 link:RelNotes/1.6.0.2.txt[1.6.0.2],
185 link:RelNotes/1.6.0.1.txt[1.6.0.1],
186 link:RelNotes/1.6.0.txt[1.6.0].
188 * link:v1.5.6.6/git.html[documentation for release 1.5.6.6]
191 link:RelNotes/1.5.6.6.txt[1.5.6.6],
192 link:RelNotes/1.5.6.5.txt[1.5.6.5],
193 link:RelNotes/1.5.6.4.txt[1.5.6.4],
194 link:RelNotes/1.5.6.3.txt[1.5.6.3],
195 link:RelNotes/1.5.6.2.txt[1.5.6.2],
196 link:RelNotes/1.5.6.1.txt[1.5.6.1],
197 link:RelNotes/1.5.6.txt[1.5.6].
199 * link:v1.5.5.6/git.html[documentation for release 1.5.5.6]
202 link:RelNotes/1.5.5.6.txt[1.5.5.6],
203 link:RelNotes/1.5.5.5.txt[1.5.5.5],
204 link:RelNotes/1.5.5.4.txt[1.5.5.4],
205 link:RelNotes/1.5.5.3.txt[1.5.5.3],
206 link:RelNotes/1.5.5.2.txt[1.5.5.2],
207 link:RelNotes/1.5.5.1.txt[1.5.5.1],
208 link:RelNotes/1.5.5.txt[1.5.5].
210 * link:v1.5.4.7/git.html[documentation for release 1.5.4.7]
213 link:RelNotes/1.5.4.7.txt[1.5.4.7],
214 link:RelNotes/1.5.4.6.txt[1.5.4.6],
215 link:RelNotes/1.5.4.5.txt[1.5.4.5],
216 link:RelNotes/1.5.4.4.txt[1.5.4.4],
217 link:RelNotes/1.5.4.3.txt[1.5.4.3],
218 link:RelNotes/1.5.4.2.txt[1.5.4.2],
219 link:RelNotes/1.5.4.1.txt[1.5.4.1],
220 link:RelNotes/1.5.4.txt[1.5.4].
222 * link:v1.5.3.8/git.html[documentation for release 1.5.3.8]
225 link:RelNotes/1.5.3.8.txt[1.5.3.8],
226 link:RelNotes/1.5.3.7.txt[1.5.3.7],
227 link:RelNotes/1.5.3.6.txt[1.5.3.6],
228 link:RelNotes/1.5.3.5.txt[1.5.3.5],
229 link:RelNotes/1.5.3.4.txt[1.5.3.4],
230 link:RelNotes/1.5.3.3.txt[1.5.3.3],
231 link:RelNotes/1.5.3.2.txt[1.5.3.2],
232 link:RelNotes/1.5.3.1.txt[1.5.3.1],
233 link:RelNotes/1.5.3.txt[1.5.3].
235 * link:v1.5.2.5/git.html[documentation for release 1.5.2.5]
238 link:RelNotes/1.5.2.5.txt[1.5.2.5],
239 link:RelNotes/1.5.2.4.txt[1.5.2.4],
240 link:RelNotes/1.5.2.3.txt[1.5.2.3],
241 link:RelNotes/1.5.2.2.txt[1.5.2.2],
242 link:RelNotes/1.5.2.1.txt[1.5.2.1],
243 link:RelNotes/1.5.2.txt[1.5.2].
245 * link:v1.5.1.6/git.html[documentation for release 1.5.1.6]
248 link:RelNotes/1.5.1.6.txt[1.5.1.6],
249 link:RelNotes/1.5.1.5.txt[1.5.1.5],
250 link:RelNotes/1.5.1.4.txt[1.5.1.4],
251 link:RelNotes/1.5.1.3.txt[1.5.1.3],
252 link:RelNotes/1.5.1.2.txt[1.5.1.2],
253 link:RelNotes/1.5.1.1.txt[1.5.1.1],
254 link:RelNotes/1.5.1.txt[1.5.1].
256 * link:v1.5.0.7/git.html[documentation for release 1.5.0.7]
259 link:RelNotes/1.5.0.7.txt[1.5.0.7],
260 link:RelNotes/1.5.0.6.txt[1.5.0.6],
261 link:RelNotes/1.5.0.5.txt[1.5.0.5],
262 link:RelNotes/1.5.0.3.txt[1.5.0.3],
263 link:RelNotes/1.5.0.2.txt[1.5.0.2],
264 link:RelNotes/1.5.0.1.txt[1.5.0.1],
265 link:RelNotes/1.5.0.txt[1.5.0].
267 * documentation for release link:v1.4.4.4/git.html[1.4.4.4],
268 link:v1.3.3/git.html[1.3.3],
269 link:v1.2.6/git.html[1.2.6],
270 link:v1.0.13/git.html[1.0.13].
279 Prints the git suite version that the 'git' program came from.
282 Prints the synopsis and a list of the most commonly used
283 commands. If the option '--all' or '-a' is given then all
284 available commands are printed. If a git command is named this
285 option will bring up the manual page for that command.
287 Other options are available to control how the manual page is
288 displayed. See linkgit:git-help[1] for more information,
289 because `git --help ...` is converted internally into `git
293 Pass a configuration parameter to the command. The value
294 given will override values from configuration files.
295 The <name> is expected in the same format as listed by
296 'git config' (subkeys separated by dots).
298 --exec-path[=<path>]::
299 Path to wherever your core git programs are installed.
300 This can also be controlled by setting the GIT_EXEC_PATH
301 environment variable. If no path is given, 'git' will print
302 the current setting and then exit.
305 Print the path, without trailing slash, where git's HTML
306 documentation is installed and exit.
309 Print the manpath (see `man(1)`) for the man pages for
310 this version of git and exit.
313 Print the path where the Info files documenting this
314 version of git are installed and exit.
318 Pipe all output into 'less' (or if set, $PAGER) if standard
319 output is a terminal. This overrides the `pager.<cmd>`
320 configuration options (see the "Configuration Mechanism" section
324 Do not pipe git output into a pager.
327 Set the path to the repository. This can also be controlled by
328 setting the GIT_DIR environment variable. It can be an absolute
329 path or relative path to current working directory.
332 Set the path to the working tree. It can be an absolute path
333 or a path relative to the current working directory.
334 This can also be controlled by setting the GIT_WORK_TREE
335 environment variable and the core.worktree configuration
336 variable (see core.worktree in linkgit:git-config[1] for a
337 more detailed discussion).
340 Treat the repository as a bare repository. If GIT_DIR
341 environment is not set, it is set to the current working
344 --no-replace-objects::
345 Do not use replacement refs to replace git objects. See
346 linkgit:git-replace[1] for more information.
349 FURTHER DOCUMENTATION
350 ---------------------
352 See the references above to get started using git. The following is
353 probably more detail than necessary for a first-time user.
355 The link:user-manual.html#git-concepts[git concepts chapter of the
356 user-manual] and linkgit:gitcore-tutorial[7] both provide
357 introductions to the underlying git architecture.
359 See linkgit:gitworkflows[7] for an overview of recommended workflows.
361 See also the link:howto-index.html[howto] documents for some useful
364 The internals are documented in the
365 link:technical/api-index.html[GIT API documentation].
370 We divide git into high level ("porcelain") commands and low level
371 ("plumbing") commands.
373 High-level commands (porcelain)
374 -------------------------------
376 We separate the porcelain commands into the main commands and some
377 ancillary user utilities.
379 Main porcelain commands
380 ~~~~~~~~~~~~~~~~~~~~~~~
382 include::cmds-mainporcelain.txt[]
388 include::cmds-ancillarymanipulators.txt[]
392 include::cmds-ancillaryinterrogators.txt[]
395 Interacting with Others
396 ~~~~~~~~~~~~~~~~~~~~~~~
398 These commands are to interact with foreign SCM and with other
399 people via patch over e-mail.
401 include::cmds-foreignscminterface.txt[]
404 Low-level commands (plumbing)
405 -----------------------------
407 Although git includes its
408 own porcelain layer, its low-level commands are sufficient to support
409 development of alternative porcelains. Developers of such porcelains
410 might start by reading about linkgit:git-update-index[1] and
411 linkgit:git-read-tree[1].
413 The interface (input, output, set of options and the semantics)
414 to these low-level commands are meant to be a lot more stable
415 than Porcelain level commands, because these commands are
416 primarily for scripted use. The interface to Porcelain commands
417 on the other hand are subject to change in order to improve the
420 The following description divides
421 the low-level commands into commands that manipulate objects (in
422 the repository, index, and working tree), commands that interrogate and
423 compare objects, and commands that move objects and references between
427 Manipulation commands
428 ~~~~~~~~~~~~~~~~~~~~~
430 include::cmds-plumbingmanipulators.txt[]
433 Interrogation commands
434 ~~~~~~~~~~~~~~~~~~~~~~
436 include::cmds-plumbinginterrogators.txt[]
438 In general, the interrogate commands do not touch the files in
442 Synching repositories
443 ~~~~~~~~~~~~~~~~~~~~~
445 include::cmds-synchingrepositories.txt[]
447 The following are helper commands used by the above; end users
448 typically do not use them directly.
450 include::cmds-synchelpers.txt[]
453 Internal helper commands
454 ~~~~~~~~~~~~~~~~~~~~~~~~
456 These are internal helper commands used by other commands; end
457 users typically do not use them directly.
459 include::cmds-purehelpers.txt[]
462 Configuration Mechanism
463 -----------------------
465 Starting from 0.99.9 (actually mid 0.99.8.GIT), `.git/config` file
466 is used to hold per-repository configuration options. It is a
467 simple text file modeled after `.ini` format familiar to some
468 people. Here is an example:
472 # A '#' or ';' character indicates a comment.
477 ; Don't trust file modes
482 name = "Junio C Hamano"
483 email = "junkio@twinsun.com"
487 Various commands read from the configuration file and adjust
488 their operation accordingly. See linkgit:git-config[1] for a
492 Identifier Terminology
493 ----------------------
495 Indicates the object name for any type of object.
498 Indicates a blob object name.
501 Indicates a tree object name.
504 Indicates a commit object name.
507 Indicates a tree, commit or tag object name. A
508 command that takes a <tree-ish> argument ultimately wants to
509 operate on a <tree> object but automatically dereferences
510 <commit> and <tag> objects that point at a <tree>.
513 Indicates a commit or tag object name. A
514 command that takes a <commit-ish> argument ultimately wants to
515 operate on a <commit> object but automatically dereferences
516 <tag> objects that point at a <commit>.
519 Indicates that an object type is required.
520 Currently one of: `blob`, `tree`, `commit`, or `tag`.
523 Indicates a filename - almost always relative to the
524 root of the tree structure `GIT_INDEX_FILE` describes.
528 Any git command accepting any <object> can also use the following
532 indicates the head of the current branch.
536 (i.e. a `refs/tags/<tag>` reference).
540 (i.e. a `refs/heads/<head>` reference).
542 For a more complete list of ways to spell object names, see
543 "SPECIFYING REVISIONS" section in linkgit:gitrevisions[7].
546 File/Directory Structure
547 ------------------------
549 Please see the linkgit:gitrepository-layout[5] document.
551 Read linkgit:githooks[5] for more details about each hook.
553 Higher level SCMs may provide and manage additional information in the
559 Please see linkgit:gitglossary[7].
562 Environment Variables
563 ---------------------
564 Various git commands use the following environment variables:
568 These environment variables apply to 'all' core git commands. Nb: it
569 is worth noting that they may be used/overridden by SCMS sitting above
570 git so take care if using Cogito etc.
573 This environment allows the specification of an alternate
574 index file. If not specified, the default of `$GIT_DIR/index`
577 'GIT_OBJECT_DIRECTORY'::
578 If the object storage directory is specified via this
579 environment variable then the sha1 directories are created
580 underneath - otherwise the default `$GIT_DIR/objects`
583 'GIT_ALTERNATE_OBJECT_DIRECTORIES'::
584 Due to the immutable nature of git objects, old objects can be
585 archived into shared, read-only directories. This variable
586 specifies a ":" separated (on Windows ";" separated) list
587 of git object directories which can be used to search for git
588 objects. New objects will not be written to these directories.
591 If the 'GIT_DIR' environment variable is set then it
592 specifies a path to use instead of the default `.git`
593 for the base of the repository.
596 Set the path to the working tree. The value will not be
597 used in combination with repositories found automatically in
598 a .git directory (i.e. $GIT_DIR is not set).
599 This can also be controlled by the '--work-tree' command line
600 option and the core.worktree configuration variable.
602 'GIT_CEILING_DIRECTORIES'::
603 This should be a colon-separated list of absolute paths.
604 If set, it is a list of directories that git should not chdir
605 up into while looking for a repository directory.
606 It will not exclude the current working directory or
607 a GIT_DIR set on the command line or in the environment.
608 (Useful for excluding slow-loading network directories.)
610 'GIT_DISCOVERY_ACROSS_FILESYSTEM'::
611 When run in a directory that does not have ".git" repository
612 directory, git tries to find such a directory in the parent
613 directories to find the top of the working tree, but by default it
614 does not cross filesystem boundaries. This environment variable
615 can be set to true to tell git not to stop at filesystem
616 boundaries. Like 'GIT_CEILING_DIRECTORIES', this will not affect
617 an explicit repository directory set via 'GIT_DIR' or on the
625 'GIT_COMMITTER_NAME'::
626 'GIT_COMMITTER_EMAIL'::
627 'GIT_COMMITTER_DATE'::
629 see linkgit:git-commit-tree[1]
634 Only valid setting is "--unified=??" or "-u??" to set the
635 number of context lines shown when a unified diff is created.
636 This takes precedence over any "-U" or "--unified" option
637 value passed on the git diff command line.
639 'GIT_EXTERNAL_DIFF'::
640 When the environment variable 'GIT_EXTERNAL_DIFF' is set, the
641 program named by it is called, instead of the diff invocation
642 described above. For a path that is added, removed, or modified,
643 'GIT_EXTERNAL_DIFF' is called with 7 parameters:
645 path old-file old-hex old-mode new-file new-hex new-mode
649 <old|new>-file:: are files GIT_EXTERNAL_DIFF can use to read the
650 contents of <old|new>,
651 <old|new>-hex:: are the 40-hexdigit SHA1 hashes,
652 <old|new>-mode:: are the octal representation of the file modes.
654 The file parameters can point at the user's working file
655 (e.g. `new-file` in "git-diff-files"), `/dev/null` (e.g. `old-file`
656 when a new file is added), or a temporary file (e.g. `old-file` in the
657 index). 'GIT_EXTERNAL_DIFF' should not worry about unlinking the
658 temporary file --- it is removed when 'GIT_EXTERNAL_DIFF' exits.
660 For a path that is unmerged, 'GIT_EXTERNAL_DIFF' is called with 1
665 'GIT_MERGE_VERBOSITY'::
666 A number controlling the amount of output shown by
667 the recursive merge strategy. Overrides merge.verbosity.
668 See linkgit:git-merge[1]
671 This environment variable overrides `$PAGER`. If it is set
672 to an empty string or to the value "cat", git will not launch
673 a pager. See also the `core.pager` option in
674 linkgit:git-config[1].
677 If this environment variable is set then 'git fetch'
678 and 'git push' will use this command instead
679 of 'ssh' when they need to connect to a remote system.
680 The '$GIT_SSH' command will be given exactly two arguments:
681 the 'username@host' (or just 'host') from the URL and the
682 shell command to execute on that remote system.
684 To pass options to the program that you want to list in GIT_SSH
685 you will need to wrap the program and options into a shell script,
686 then set GIT_SSH to refer to the shell script.
688 Usually it is easier to configure any desired options through your
689 personal `.ssh/config` file. Please consult your ssh documentation
693 If this environment variable is set, then git commands which need to
694 acquire passwords or passphrases (e.g. for HTTP or IMAP authentication)
695 will call this program with a suitable prompt as command line argument
696 and read the password from its STDOUT. See also the 'core.askpass'
697 option in linkgit:git-config[1].
700 If this environment variable is set to "1", then commands such
701 as 'git blame' (in incremental mode), 'git rev-list', 'git log',
702 and 'git whatchanged' will force a flush of the output stream
703 after each commit-oriented record have been flushed. If this
704 variable is set to "0", the output of these commands will be done
705 using completely buffered I/O. If this environment variable is
706 not set, git will choose buffered or record-oriented flushing
707 based on whether stdout appears to be redirected to a file or not.
710 If this variable is set to "1", "2" or "true" (comparison
711 is case insensitive), git will print `trace:` messages on
712 stderr telling about alias expansion, built-in command
713 execution and external command execution.
714 If this variable is set to an integer value greater than 1
715 and lower than 10 (strictly) then git will interpret this
716 value as an open file descriptor and will try to write the
717 trace messages into this file descriptor.
718 Alternatively, if this variable is set to an absolute path
719 (starting with a '/' character), git will interpret this
720 as a file path and will try to write the trace messages
723 Discussion[[Discussion]]
724 ------------------------
726 More detail on the following is available from the
727 link:user-manual.html#git-concepts[git concepts chapter of the
728 user-manual] and linkgit:gitcore-tutorial[7].
730 A git project normally consists of a working directory with a ".git"
731 subdirectory at the top level. The .git directory contains, among other
732 things, a compressed object database representing the complete history
733 of the project, an "index" file which links that history to the current
734 contents of the working tree, and named pointers into that history such
735 as tags and branch heads.
737 The object database contains objects of three main types: blobs, which
738 hold file data; trees, which point to blobs and other trees to build up
739 directory hierarchies; and commits, which each reference a single tree
740 and some number of parent commits.
742 The commit, equivalent to what other systems call a "changeset" or
743 "version", represents a step in the project's history, and each parent
744 represents an immediately preceding step. Commits with more than one
745 parent represent merges of independent lines of development.
747 All objects are named by the SHA1 hash of their contents, normally
748 written as a string of 40 hex digits. Such names are globally unique.
749 The entire history leading up to a commit can be vouched for by signing
750 just that commit. A fourth object type, the tag, is provided for this
753 When first created, objects are stored in individual files, but for
754 efficiency may later be compressed together into "pack files".
756 Named pointers called refs mark interesting points in history. A ref
757 may contain the SHA1 name of an object or the name of another ref. Refs
758 with names beginning `ref/head/` contain the SHA1 name of the most
759 recent commit (or "head") of a branch under development. SHA1 names of
760 tags of interest are stored under `ref/tags/`. A special ref named
761 `HEAD` contains the name of the currently checked-out branch.
763 The index file is initialized with a list of all paths and, for each
764 path, a blob object and a set of attributes. The blob object represents
765 the contents of the file as of the head of the current branch. The
766 attributes (last modified time, size, etc.) are taken from the
767 corresponding file in the working tree. Subsequent changes to the
768 working tree can be found by comparing these attributes. The index may
769 be updated with new content, and new commits may be created from the
770 content stored in the index.
772 The index is also capable of storing multiple entries (called "stages")
773 for a given pathname. These stages are used to hold the various
774 unmerged version of a file when a merge is in progress.
778 Git was started by Linus Torvalds, and is currently maintained by Junio
779 C Hamano. Numerous contributions have come from the git mailing list
780 <git@vger.kernel.org>. For a more complete list of contributors, see
781 http://git-scm.com/about. If you have a clone of git.git itself, the
782 output of linkgit:git-shortlog[1] and linkgit:git-blame[1] can show you
783 the authors for specific parts of the project.
788 Report bugs to the Git mailing list <git@vger.kernel.org> where the
789 development and maintenance is primarily done. You do not have to be
790 subscribed to the list to send a message there.
794 linkgit:gittutorial[7], linkgit:gittutorial-2[7],
795 link:everyday.html[Everyday Git], linkgit:gitcvs-migration[7],
796 linkgit:gitglossary[7], linkgit:gitcore-tutorial[7],
797 linkgit:gitcli[7], link:user-manual.html[The Git User's Manual],
798 linkgit:gitworkflows[7]
802 Part of the linkgit:git[1] suite