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:v1.7.7.5/git.html[documentation for release 1.7.7.5]
50 link:RelNotes/1.7.7.5.txt[1.7.7.5],
51 link:RelNotes/1.7.7.4.txt[1.7.7.4],
52 link:RelNotes/1.7.7.3.txt[1.7.7.3],
53 link:RelNotes/1.7.7.2.txt[1.7.7.2],
54 link:RelNotes/1.7.7.1.txt[1.7.7.1],
55 link:RelNotes/1.7.7.txt[1.7.7].
57 * link:v1.7.6.6/git.html[documentation for release 1.7.6.6]
60 link:RelNotes/1.7.6.6.txt[1.7.6.6],
61 link:RelNotes/1.7.6.5.txt[1.7.6.5],
62 link:RelNotes/1.7.6.4.txt[1.7.6.4],
63 link:RelNotes/1.7.6.3.txt[1.7.6.3],
64 link:RelNotes/1.7.6.2.txt[1.7.6.2],
65 link:RelNotes/1.7.6.1.txt[1.7.6.1],
66 link:RelNotes/1.7.6.txt[1.7.6].
68 * link:v1.7.5.4/git.html[documentation for release 1.7.5.4]
71 link:RelNotes/1.7.5.4.txt[1.7.5.4],
72 link:RelNotes/1.7.5.3.txt[1.7.5.3],
73 link:RelNotes/1.7.5.2.txt[1.7.5.2],
74 link:RelNotes/1.7.5.1.txt[1.7.5.1],
75 link:RelNotes/1.7.5.txt[1.7.5].
77 * link:v1.7.4.5/git.html[documentation for release 1.7.4.5]
80 link:RelNotes/1.7.4.5.txt[1.7.4.5],
81 link:RelNotes/1.7.4.4.txt[1.7.4.4],
82 link:RelNotes/1.7.4.3.txt[1.7.4.3],
83 link:RelNotes/1.7.4.2.txt[1.7.4.2],
84 link:RelNotes/1.7.4.1.txt[1.7.4.1],
85 link:RelNotes/1.7.4.txt[1.7.4].
87 * link:v1.7.3.5/git.html[documentation for release 1.7.3.5]
90 link:RelNotes/1.7.3.5.txt[1.7.3.5],
91 link:RelNotes/1.7.3.4.txt[1.7.3.4],
92 link:RelNotes/1.7.3.3.txt[1.7.3.3],
93 link:RelNotes/1.7.3.2.txt[1.7.3.2],
94 link:RelNotes/1.7.3.1.txt[1.7.3.1],
95 link:RelNotes/1.7.3.txt[1.7.3].
97 * link:v1.7.2.5/git.html[documentation for release 1.7.2.5]
100 link:RelNotes/1.7.2.5.txt[1.7.2.5],
101 link:RelNotes/1.7.2.4.txt[1.7.2.4],
102 link:RelNotes/1.7.2.3.txt[1.7.2.3],
103 link:RelNotes/1.7.2.2.txt[1.7.2.2],
104 link:RelNotes/1.7.2.1.txt[1.7.2.1],
105 link:RelNotes/1.7.2.txt[1.7.2].
107 * link:v1.7.1.4/git.html[documentation for release 1.7.1.4]
110 link:RelNotes/1.7.1.4.txt[1.7.1.4],
111 link:RelNotes/1.7.1.3.txt[1.7.1.3],
112 link:RelNotes/1.7.1.2.txt[1.7.1.2],
113 link:RelNotes/1.7.1.1.txt[1.7.1.1],
114 link:RelNotes/1.7.1.txt[1.7.1].
116 * link:v1.7.0.9/git.html[documentation for release 1.7.0.9]
119 link:RelNotes/1.7.0.9.txt[1.7.0.9],
120 link:RelNotes/1.7.0.8.txt[1.7.0.8],
121 link:RelNotes/1.7.0.7.txt[1.7.0.7],
122 link:RelNotes/1.7.0.6.txt[1.7.0.6],
123 link:RelNotes/1.7.0.5.txt[1.7.0.5],
124 link:RelNotes/1.7.0.4.txt[1.7.0.4],
125 link:RelNotes/1.7.0.3.txt[1.7.0.3],
126 link:RelNotes/1.7.0.2.txt[1.7.0.2],
127 link:RelNotes/1.7.0.1.txt[1.7.0.1],
128 link:RelNotes/1.7.0.txt[1.7.0].
130 * link:v1.6.6.3/git.html[documentation for release 1.6.6.3]
133 link:RelNotes/1.6.6.3.txt[1.6.6.3],
134 link:RelNotes/1.6.6.2.txt[1.6.6.2],
135 link:RelNotes/1.6.6.1.txt[1.6.6.1],
136 link:RelNotes/1.6.6.txt[1.6.6].
138 * link:v1.6.5.9/git.html[documentation for release 1.6.5.9]
141 link:RelNotes/1.6.5.9.txt[1.6.5.9],
142 link:RelNotes/1.6.5.8.txt[1.6.5.8],
143 link:RelNotes/1.6.5.7.txt[1.6.5.7],
144 link:RelNotes/1.6.5.6.txt[1.6.5.6],
145 link:RelNotes/1.6.5.5.txt[1.6.5.5],
146 link:RelNotes/1.6.5.4.txt[1.6.5.4],
147 link:RelNotes/1.6.5.3.txt[1.6.5.3],
148 link:RelNotes/1.6.5.2.txt[1.6.5.2],
149 link:RelNotes/1.6.5.1.txt[1.6.5.1],
150 link:RelNotes/1.6.5.txt[1.6.5].
152 * link:v1.6.4.5/git.html[documentation for release 1.6.4.5]
155 link:RelNotes/1.6.4.5.txt[1.6.4.5],
156 link:RelNotes/1.6.4.4.txt[1.6.4.4],
157 link:RelNotes/1.6.4.3.txt[1.6.4.3],
158 link:RelNotes/1.6.4.2.txt[1.6.4.2],
159 link:RelNotes/1.6.4.1.txt[1.6.4.1],
160 link:RelNotes/1.6.4.txt[1.6.4].
162 * link:v1.6.3.4/git.html[documentation for release 1.6.3.4]
165 link:RelNotes/1.6.3.4.txt[1.6.3.4],
166 link:RelNotes/1.6.3.3.txt[1.6.3.3],
167 link:RelNotes/1.6.3.2.txt[1.6.3.2],
168 link:RelNotes/1.6.3.1.txt[1.6.3.1],
169 link:RelNotes/1.6.3.txt[1.6.3].
172 link:RelNotes/1.6.2.5.txt[1.6.2.5],
173 link:RelNotes/1.6.2.4.txt[1.6.2.4],
174 link:RelNotes/1.6.2.3.txt[1.6.2.3],
175 link:RelNotes/1.6.2.2.txt[1.6.2.2],
176 link:RelNotes/1.6.2.1.txt[1.6.2.1],
177 link:RelNotes/1.6.2.txt[1.6.2].
179 * link:v1.6.1.3/git.html[documentation for release 1.6.1.3]
182 link:RelNotes/1.6.1.3.txt[1.6.1.3],
183 link:RelNotes/1.6.1.2.txt[1.6.1.2],
184 link:RelNotes/1.6.1.1.txt[1.6.1.1],
185 link:RelNotes/1.6.1.txt[1.6.1].
187 * link:v1.6.0.6/git.html[documentation for release 1.6.0.6]
190 link:RelNotes/1.6.0.6.txt[1.6.0.6],
191 link:RelNotes/1.6.0.5.txt[1.6.0.5],
192 link:RelNotes/1.6.0.4.txt[1.6.0.4],
193 link:RelNotes/1.6.0.3.txt[1.6.0.3],
194 link:RelNotes/1.6.0.2.txt[1.6.0.2],
195 link:RelNotes/1.6.0.1.txt[1.6.0.1],
196 link:RelNotes/1.6.0.txt[1.6.0].
198 * link:v1.5.6.6/git.html[documentation for release 1.5.6.6]
201 link:RelNotes/1.5.6.6.txt[1.5.6.6],
202 link:RelNotes/1.5.6.5.txt[1.5.6.5],
203 link:RelNotes/1.5.6.4.txt[1.5.6.4],
204 link:RelNotes/1.5.6.3.txt[1.5.6.3],
205 link:RelNotes/1.5.6.2.txt[1.5.6.2],
206 link:RelNotes/1.5.6.1.txt[1.5.6.1],
207 link:RelNotes/1.5.6.txt[1.5.6].
209 * link:v1.5.5.6/git.html[documentation for release 1.5.5.6]
212 link:RelNotes/1.5.5.6.txt[1.5.5.6],
213 link:RelNotes/1.5.5.5.txt[1.5.5.5],
214 link:RelNotes/1.5.5.4.txt[1.5.5.4],
215 link:RelNotes/1.5.5.3.txt[1.5.5.3],
216 link:RelNotes/1.5.5.2.txt[1.5.5.2],
217 link:RelNotes/1.5.5.1.txt[1.5.5.1],
218 link:RelNotes/1.5.5.txt[1.5.5].
220 * link:v1.5.4.7/git.html[documentation for release 1.5.4.7]
223 link:RelNotes/1.5.4.7.txt[1.5.4.7],
224 link:RelNotes/1.5.4.6.txt[1.5.4.6],
225 link:RelNotes/1.5.4.5.txt[1.5.4.5],
226 link:RelNotes/1.5.4.4.txt[1.5.4.4],
227 link:RelNotes/1.5.4.3.txt[1.5.4.3],
228 link:RelNotes/1.5.4.2.txt[1.5.4.2],
229 link:RelNotes/1.5.4.1.txt[1.5.4.1],
230 link:RelNotes/1.5.4.txt[1.5.4].
232 * link:v1.5.3.8/git.html[documentation for release 1.5.3.8]
235 link:RelNotes/1.5.3.8.txt[1.5.3.8],
236 link:RelNotes/1.5.3.7.txt[1.5.3.7],
237 link:RelNotes/1.5.3.6.txt[1.5.3.6],
238 link:RelNotes/1.5.3.5.txt[1.5.3.5],
239 link:RelNotes/1.5.3.4.txt[1.5.3.4],
240 link:RelNotes/1.5.3.3.txt[1.5.3.3],
241 link:RelNotes/1.5.3.2.txt[1.5.3.2],
242 link:RelNotes/1.5.3.1.txt[1.5.3.1],
243 link:RelNotes/1.5.3.txt[1.5.3].
245 * link:v1.5.2.5/git.html[documentation for release 1.5.2.5]
248 link:RelNotes/1.5.2.5.txt[1.5.2.5],
249 link:RelNotes/1.5.2.4.txt[1.5.2.4],
250 link:RelNotes/1.5.2.3.txt[1.5.2.3],
251 link:RelNotes/1.5.2.2.txt[1.5.2.2],
252 link:RelNotes/1.5.2.1.txt[1.5.2.1],
253 link:RelNotes/1.5.2.txt[1.5.2].
255 * link:v1.5.1.6/git.html[documentation for release 1.5.1.6]
258 link:RelNotes/1.5.1.6.txt[1.5.1.6],
259 link:RelNotes/1.5.1.5.txt[1.5.1.5],
260 link:RelNotes/1.5.1.4.txt[1.5.1.4],
261 link:RelNotes/1.5.1.3.txt[1.5.1.3],
262 link:RelNotes/1.5.1.2.txt[1.5.1.2],
263 link:RelNotes/1.5.1.1.txt[1.5.1.1],
264 link:RelNotes/1.5.1.txt[1.5.1].
266 * link:v1.5.0.7/git.html[documentation for release 1.5.0.7]
269 link:RelNotes/1.5.0.7.txt[1.5.0.7],
270 link:RelNotes/1.5.0.6.txt[1.5.0.6],
271 link:RelNotes/1.5.0.5.txt[1.5.0.5],
272 link:RelNotes/1.5.0.3.txt[1.5.0.3],
273 link:RelNotes/1.5.0.2.txt[1.5.0.2],
274 link:RelNotes/1.5.0.1.txt[1.5.0.1],
275 link:RelNotes/1.5.0.txt[1.5.0].
277 * documentation for release link:v1.4.4.4/git.html[1.4.4.4],
278 link:v1.3.3/git.html[1.3.3],
279 link:v1.2.6/git.html[1.2.6],
280 link:v1.0.13/git.html[1.0.13].
289 Prints the git suite version that the 'git' program came from.
292 Prints the synopsis and a list of the most commonly used
293 commands. If the option '--all' or '-a' is given then all
294 available commands are printed. If a git command is named this
295 option will bring up the manual page for that command.
297 Other options are available to control how the manual page is
298 displayed. See linkgit:git-help[1] for more information,
299 because `git --help ...` is converted internally into `git
303 Pass a configuration parameter to the command. The value
304 given will override values from configuration files.
305 The <name> is expected in the same format as listed by
306 'git config' (subkeys separated by dots).
308 --exec-path[=<path>]::
309 Path to wherever your core git programs are installed.
310 This can also be controlled by setting the GIT_EXEC_PATH
311 environment variable. If no path is given, 'git' will print
312 the current setting and then exit.
315 Print the path, without trailing slash, where git's HTML
316 documentation is installed and exit.
319 Print the manpath (see `man(1)`) for the man pages for
320 this version of git and exit.
323 Print the path where the Info files documenting this
324 version of git are installed and exit.
328 Pipe all output into 'less' (or if set, $PAGER) if standard
329 output is a terminal. This overrides the `pager.<cmd>`
330 configuration options (see the "Configuration Mechanism" section
334 Do not pipe git output into a pager.
337 Set the path to the repository. This can also be controlled by
338 setting the GIT_DIR environment variable. It can be an absolute
339 path or relative path to current working directory.
342 Set the path to the working tree. It can be an absolute path
343 or a path relative to the current working directory.
344 This can also be controlled by setting the GIT_WORK_TREE
345 environment variable and the core.worktree configuration
346 variable (see core.worktree in linkgit:git-config[1] for a
347 more detailed discussion).
350 Set the git namespace. See linkgit:gitnamespaces[7] for more
351 details. Equivalent to setting the `GIT_NAMESPACE` environment
355 Treat the repository as a bare repository. If GIT_DIR
356 environment is not set, it is set to the current working
359 --no-replace-objects::
360 Do not use replacement refs to replace git objects. See
361 linkgit:git-replace[1] for more information.
364 FURTHER DOCUMENTATION
365 ---------------------
367 See the references above to get started using git. The following is
368 probably more detail than necessary for a first-time user.
370 The link:user-manual.html#git-concepts[git concepts chapter of the
371 user-manual] and linkgit:gitcore-tutorial[7] both provide
372 introductions to the underlying git architecture.
374 See linkgit:gitworkflows[7] for an overview of recommended workflows.
376 See also the link:howto-index.html[howto] documents for some useful
379 The internals are documented in the
380 link:technical/api-index.html[GIT API documentation].
385 We divide git into high level ("porcelain") commands and low level
386 ("plumbing") commands.
388 High-level commands (porcelain)
389 -------------------------------
391 We separate the porcelain commands into the main commands and some
392 ancillary user utilities.
394 Main porcelain commands
395 ~~~~~~~~~~~~~~~~~~~~~~~
397 include::cmds-mainporcelain.txt[]
403 include::cmds-ancillarymanipulators.txt[]
407 include::cmds-ancillaryinterrogators.txt[]
410 Interacting with Others
411 ~~~~~~~~~~~~~~~~~~~~~~~
413 These commands are to interact with foreign SCM and with other
414 people via patch over e-mail.
416 include::cmds-foreignscminterface.txt[]
419 Low-level commands (plumbing)
420 -----------------------------
422 Although git includes its
423 own porcelain layer, its low-level commands are sufficient to support
424 development of alternative porcelains. Developers of such porcelains
425 might start by reading about linkgit:git-update-index[1] and
426 linkgit:git-read-tree[1].
428 The interface (input, output, set of options and the semantics)
429 to these low-level commands are meant to be a lot more stable
430 than Porcelain level commands, because these commands are
431 primarily for scripted use. The interface to Porcelain commands
432 on the other hand are subject to change in order to improve the
435 The following description divides
436 the low-level commands into commands that manipulate objects (in
437 the repository, index, and working tree), commands that interrogate and
438 compare objects, and commands that move objects and references between
442 Manipulation commands
443 ~~~~~~~~~~~~~~~~~~~~~
445 include::cmds-plumbingmanipulators.txt[]
448 Interrogation commands
449 ~~~~~~~~~~~~~~~~~~~~~~
451 include::cmds-plumbinginterrogators.txt[]
453 In general, the interrogate commands do not touch the files in
457 Synching repositories
458 ~~~~~~~~~~~~~~~~~~~~~
460 include::cmds-synchingrepositories.txt[]
462 The following are helper commands used by the above; end users
463 typically do not use them directly.
465 include::cmds-synchelpers.txt[]
468 Internal helper commands
469 ~~~~~~~~~~~~~~~~~~~~~~~~
471 These are internal helper commands used by other commands; end
472 users typically do not use them directly.
474 include::cmds-purehelpers.txt[]
477 Configuration Mechanism
478 -----------------------
480 Starting from 0.99.9 (actually mid 0.99.8.GIT), `.git/config` file
481 is used to hold per-repository configuration options. It is a
482 simple text file modeled after `.ini` format familiar to some
483 people. Here is an example:
487 # A '#' or ';' character indicates a comment.
492 ; Don't trust file modes
497 name = "Junio C Hamano"
498 email = "junkio@twinsun.com"
502 Various commands read from the configuration file and adjust
503 their operation accordingly. See linkgit:git-config[1] for a
507 Identifier Terminology
508 ----------------------
510 Indicates the object name for any type of object.
513 Indicates a blob object name.
516 Indicates a tree object name.
519 Indicates a commit object name.
522 Indicates a tree, commit or tag object name. A
523 command that takes a <tree-ish> argument ultimately wants to
524 operate on a <tree> object but automatically dereferences
525 <commit> and <tag> objects that point at a <tree>.
528 Indicates a commit or tag object name. A
529 command that takes a <commit-ish> argument ultimately wants to
530 operate on a <commit> object but automatically dereferences
531 <tag> objects that point at a <commit>.
534 Indicates that an object type is required.
535 Currently one of: `blob`, `tree`, `commit`, or `tag`.
538 Indicates a filename - almost always relative to the
539 root of the tree structure `GIT_INDEX_FILE` describes.
543 Any git command accepting any <object> can also use the following
547 indicates the head of the current branch.
551 (i.e. a `refs/tags/<tag>` reference).
555 (i.e. a `refs/heads/<head>` reference).
557 For a more complete list of ways to spell object names, see
558 "SPECIFYING REVISIONS" section in linkgit:gitrevisions[7].
561 File/Directory Structure
562 ------------------------
564 Please see the linkgit:gitrepository-layout[5] document.
566 Read linkgit:githooks[5] for more details about each hook.
568 Higher level SCMs may provide and manage additional information in the
574 Please see linkgit:gitglossary[7].
577 Environment Variables
578 ---------------------
579 Various git commands use the following environment variables:
583 These environment variables apply to 'all' core git commands. Nb: it
584 is worth noting that they may be used/overridden by SCMS sitting above
585 git so take care if using Cogito etc.
588 This environment allows the specification of an alternate
589 index file. If not specified, the default of `$GIT_DIR/index`
592 'GIT_OBJECT_DIRECTORY'::
593 If the object storage directory is specified via this
594 environment variable then the sha1 directories are created
595 underneath - otherwise the default `$GIT_DIR/objects`
598 'GIT_ALTERNATE_OBJECT_DIRECTORIES'::
599 Due to the immutable nature of git objects, old objects can be
600 archived into shared, read-only directories. This variable
601 specifies a ":" separated (on Windows ";" separated) list
602 of git object directories which can be used to search for git
603 objects. New objects will not be written to these directories.
606 If the 'GIT_DIR' environment variable is set then it
607 specifies a path to use instead of the default `.git`
608 for the base of the repository.
611 Set the path to the working tree. The value will not be
612 used in combination with repositories found automatically in
613 a .git directory (i.e. $GIT_DIR is not set).
614 This can also be controlled by the '--work-tree' command line
615 option and the core.worktree configuration variable.
618 Set the git namespace; see linkgit:gitnamespaces[7] for details.
619 The '--namespace' command-line option also sets this value.
621 'GIT_CEILING_DIRECTORIES'::
622 This should be a colon-separated list of absolute paths.
623 If set, it is a list of directories that git should not chdir
624 up into while looking for a repository directory.
625 It will not exclude the current working directory or
626 a GIT_DIR set on the command line or in the environment.
627 (Useful for excluding slow-loading network directories.)
629 'GIT_DISCOVERY_ACROSS_FILESYSTEM'::
630 When run in a directory that does not have ".git" repository
631 directory, git tries to find such a directory in the parent
632 directories to find the top of the working tree, but by default it
633 does not cross filesystem boundaries. This environment variable
634 can be set to true to tell git not to stop at filesystem
635 boundaries. Like 'GIT_CEILING_DIRECTORIES', this will not affect
636 an explicit repository directory set via 'GIT_DIR' or on the
644 'GIT_COMMITTER_NAME'::
645 'GIT_COMMITTER_EMAIL'::
646 'GIT_COMMITTER_DATE'::
648 see linkgit:git-commit-tree[1]
653 Only valid setting is "--unified=??" or "-u??" to set the
654 number of context lines shown when a unified diff is created.
655 This takes precedence over any "-U" or "--unified" option
656 value passed on the git diff command line.
658 'GIT_EXTERNAL_DIFF'::
659 When the environment variable 'GIT_EXTERNAL_DIFF' is set, the
660 program named by it is called, instead of the diff invocation
661 described above. For a path that is added, removed, or modified,
662 'GIT_EXTERNAL_DIFF' is called with 7 parameters:
664 path old-file old-hex old-mode new-file new-hex new-mode
668 <old|new>-file:: are files GIT_EXTERNAL_DIFF can use to read the
669 contents of <old|new>,
670 <old|new>-hex:: are the 40-hexdigit SHA1 hashes,
671 <old|new>-mode:: are the octal representation of the file modes.
673 The file parameters can point at the user's working file
674 (e.g. `new-file` in "git-diff-files"), `/dev/null` (e.g. `old-file`
675 when a new file is added), or a temporary file (e.g. `old-file` in the
676 index). 'GIT_EXTERNAL_DIFF' should not worry about unlinking the
677 temporary file --- it is removed when 'GIT_EXTERNAL_DIFF' exits.
679 For a path that is unmerged, 'GIT_EXTERNAL_DIFF' is called with 1
684 'GIT_MERGE_VERBOSITY'::
685 A number controlling the amount of output shown by
686 the recursive merge strategy. Overrides merge.verbosity.
687 See linkgit:git-merge[1]
690 This environment variable overrides `$PAGER`. If it is set
691 to an empty string or to the value "cat", git will not launch
692 a pager. See also the `core.pager` option in
693 linkgit:git-config[1].
696 If this environment variable is set then 'git fetch'
697 and 'git push' will use this command instead
698 of 'ssh' when they need to connect to a remote system.
699 The '$GIT_SSH' command will be given exactly two arguments:
700 the 'username@host' (or just 'host') from the URL and the
701 shell command to execute on that remote system.
703 To pass options to the program that you want to list in GIT_SSH
704 you will need to wrap the program and options into a shell script,
705 then set GIT_SSH to refer to the shell script.
707 Usually it is easier to configure any desired options through your
708 personal `.ssh/config` file. Please consult your ssh documentation
712 If this environment variable is set, then git commands which need to
713 acquire passwords or passphrases (e.g. for HTTP or IMAP authentication)
714 will call this program with a suitable prompt as command line argument
715 and read the password from its STDOUT. See also the 'core.askpass'
716 option in linkgit:git-config[1].
719 If this environment variable is set to "1", then commands such
720 as 'git blame' (in incremental mode), 'git rev-list', 'git log',
721 and 'git whatchanged' will force a flush of the output stream
722 after each commit-oriented record have been flushed. If this
723 variable is set to "0", the output of these commands will be done
724 using completely buffered I/O. If this environment variable is
725 not set, git will choose buffered or record-oriented flushing
726 based on whether stdout appears to be redirected to a file or not.
729 If this variable is set to "1", "2" or "true" (comparison
730 is case insensitive), git will print `trace:` messages on
731 stderr telling about alias expansion, built-in command
732 execution and external command execution.
733 If this variable is set to an integer value greater than 1
734 and lower than 10 (strictly) then git will interpret this
735 value as an open file descriptor and will try to write the
736 trace messages into this file descriptor.
737 Alternatively, if this variable is set to an absolute path
738 (starting with a '/' character), git will interpret this
739 as a file path and will try to write the trace messages
742 Discussion[[Discussion]]
743 ------------------------
745 More detail on the following is available from the
746 link:user-manual.html#git-concepts[git concepts chapter of the
747 user-manual] and linkgit:gitcore-tutorial[7].
749 A git project normally consists of a working directory with a ".git"
750 subdirectory at the top level. The .git directory contains, among other
751 things, a compressed object database representing the complete history
752 of the project, an "index" file which links that history to the current
753 contents of the working tree, and named pointers into that history such
754 as tags and branch heads.
756 The object database contains objects of three main types: blobs, which
757 hold file data; trees, which point to blobs and other trees to build up
758 directory hierarchies; and commits, which each reference a single tree
759 and some number of parent commits.
761 The commit, equivalent to what other systems call a "changeset" or
762 "version", represents a step in the project's history, and each parent
763 represents an immediately preceding step. Commits with more than one
764 parent represent merges of independent lines of development.
766 All objects are named by the SHA1 hash of their contents, normally
767 written as a string of 40 hex digits. Such names are globally unique.
768 The entire history leading up to a commit can be vouched for by signing
769 just that commit. A fourth object type, the tag, is provided for this
772 When first created, objects are stored in individual files, but for
773 efficiency may later be compressed together into "pack files".
775 Named pointers called refs mark interesting points in history. A ref
776 may contain the SHA1 name of an object or the name of another ref. Refs
777 with names beginning `ref/head/` contain the SHA1 name of the most
778 recent commit (or "head") of a branch under development. SHA1 names of
779 tags of interest are stored under `ref/tags/`. A special ref named
780 `HEAD` contains the name of the currently checked-out branch.
782 The index file is initialized with a list of all paths and, for each
783 path, a blob object and a set of attributes. The blob object represents
784 the contents of the file as of the head of the current branch. The
785 attributes (last modified time, size, etc.) are taken from the
786 corresponding file in the working tree. Subsequent changes to the
787 working tree can be found by comparing these attributes. The index may
788 be updated with new content, and new commits may be created from the
789 content stored in the index.
791 The index is also capable of storing multiple entries (called "stages")
792 for a given pathname. These stages are used to hold the various
793 unmerged version of a file when a merge is in progress.
797 Git was started by Linus Torvalds, and is currently maintained by Junio
798 C Hamano. Numerous contributions have come from the git mailing list
799 <git@vger.kernel.org>. For a more complete list of contributors, see
800 http://git-scm.com/about. If you have a clone of git.git itself, the
801 output of linkgit:git-shortlog[1] and linkgit:git-blame[1] can show you
802 the authors for specific parts of the project.
807 Report bugs to the Git mailing list <git@vger.kernel.org> where the
808 development and maintenance is primarily done. You do not have to be
809 subscribed to the list to send a message there.
813 linkgit:gittutorial[7], linkgit:gittutorial-2[7],
814 link:everyday.html[Everyday Git], linkgit:gitcvs-migration[7],
815 linkgit:gitglossary[7], linkgit:gitcore-tutorial[7],
816 linkgit:gitcli[7], link:user-manual.html[The Git User's Manual],
817 linkgit:gitworkflows[7]
821 Part of the linkgit:git[1] suite