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/git.html[documentation for release 1.7.7]
50 link:RelNotes/1.7.7.txt[1.7.7].
52 * link:v1.7.6.4/git.html[documentation for release 1.7.6.4]
55 link:RelNotes/1.7.6.4.txt[1.7.6.4],
56 link:RelNotes/1.7.6.3.txt[1.7.6.3],
57 link:RelNotes/1.7.6.2.txt[1.7.6.2],
58 link:RelNotes/1.7.6.1.txt[1.7.6.1],
59 link:RelNotes/1.7.6.txt[1.7.6].
61 * link:v1.7.5.4/git.html[documentation for release 1.7.5.4]
64 link:RelNotes/1.7.5.4.txt[1.7.5.4],
65 link:RelNotes/1.7.5.3.txt[1.7.5.3],
66 link:RelNotes/1.7.5.2.txt[1.7.5.2],
67 link:RelNotes/1.7.5.1.txt[1.7.5.1],
68 link:RelNotes/1.7.5.txt[1.7.5].
70 * link:v1.7.4.5/git.html[documentation for release 1.7.4.5]
73 link:RelNotes/1.7.4.5.txt[1.7.4.5],
74 link:RelNotes/1.7.4.4.txt[1.7.4.4],
75 link:RelNotes/1.7.4.3.txt[1.7.4.3],
76 link:RelNotes/1.7.4.2.txt[1.7.4.2],
77 link:RelNotes/1.7.4.1.txt[1.7.4.1],
78 link:RelNotes/1.7.4.txt[1.7.4].
80 * link:v1.7.3.5/git.html[documentation for release 1.7.3.5]
83 link:RelNotes/1.7.3.5.txt[1.7.3.5],
84 link:RelNotes/1.7.3.4.txt[1.7.3.4],
85 link:RelNotes/1.7.3.3.txt[1.7.3.3],
86 link:RelNotes/1.7.3.2.txt[1.7.3.2],
87 link:RelNotes/1.7.3.1.txt[1.7.3.1],
88 link:RelNotes/1.7.3.txt[1.7.3].
90 * link:v1.7.2.5/git.html[documentation for release 1.7.2.5]
93 link:RelNotes/1.7.2.5.txt[1.7.2.5],
94 link:RelNotes/1.7.2.4.txt[1.7.2.4],
95 link:RelNotes/1.7.2.3.txt[1.7.2.3],
96 link:RelNotes/1.7.2.2.txt[1.7.2.2],
97 link:RelNotes/1.7.2.1.txt[1.7.2.1],
98 link:RelNotes/1.7.2.txt[1.7.2].
100 * link:v1.7.1.4/git.html[documentation for release 1.7.1.4]
103 link:RelNotes/1.7.1.4.txt[1.7.1.4],
104 link:RelNotes/1.7.1.3.txt[1.7.1.3],
105 link:RelNotes/1.7.1.2.txt[1.7.1.2],
106 link:RelNotes/1.7.1.1.txt[1.7.1.1],
107 link:RelNotes/1.7.1.txt[1.7.1].
109 * link:v1.7.0.9/git.html[documentation for release 1.7.0.9]
112 link:RelNotes/1.7.0.9.txt[1.7.0.9],
113 link:RelNotes/1.7.0.8.txt[1.7.0.8],
114 link:RelNotes/1.7.0.7.txt[1.7.0.7],
115 link:RelNotes/1.7.0.6.txt[1.7.0.6],
116 link:RelNotes/1.7.0.5.txt[1.7.0.5],
117 link:RelNotes/1.7.0.4.txt[1.7.0.4],
118 link:RelNotes/1.7.0.3.txt[1.7.0.3],
119 link:RelNotes/1.7.0.2.txt[1.7.0.2],
120 link:RelNotes/1.7.0.1.txt[1.7.0.1],
121 link:RelNotes/1.7.0.txt[1.7.0].
123 * link:v1.6.6.3/git.html[documentation for release 1.6.6.3]
126 link:RelNotes/1.6.6.3.txt[1.6.6.3],
127 link:RelNotes/1.6.6.2.txt[1.6.6.2],
128 link:RelNotes/1.6.6.1.txt[1.6.6.1],
129 link:RelNotes/1.6.6.txt[1.6.6].
131 * link:v1.6.5.9/git.html[documentation for release 1.6.5.9]
134 link:RelNotes/1.6.5.9.txt[1.6.5.9],
135 link:RelNotes/1.6.5.8.txt[1.6.5.8],
136 link:RelNotes/1.6.5.7.txt[1.6.5.7],
137 link:RelNotes/1.6.5.6.txt[1.6.5.6],
138 link:RelNotes/1.6.5.5.txt[1.6.5.5],
139 link:RelNotes/1.6.5.4.txt[1.6.5.4],
140 link:RelNotes/1.6.5.3.txt[1.6.5.3],
141 link:RelNotes/1.6.5.2.txt[1.6.5.2],
142 link:RelNotes/1.6.5.1.txt[1.6.5.1],
143 link:RelNotes/1.6.5.txt[1.6.5].
145 * link:v1.6.4.5/git.html[documentation for release 1.6.4.5]
148 link:RelNotes/1.6.4.5.txt[1.6.4.5],
149 link:RelNotes/1.6.4.4.txt[1.6.4.4],
150 link:RelNotes/1.6.4.3.txt[1.6.4.3],
151 link:RelNotes/1.6.4.2.txt[1.6.4.2],
152 link:RelNotes/1.6.4.1.txt[1.6.4.1],
153 link:RelNotes/1.6.4.txt[1.6.4].
155 * link:v1.6.3.4/git.html[documentation for release 1.6.3.4]
158 link:RelNotes/1.6.3.4.txt[1.6.3.4],
159 link:RelNotes/1.6.3.3.txt[1.6.3.3],
160 link:RelNotes/1.6.3.2.txt[1.6.3.2],
161 link:RelNotes/1.6.3.1.txt[1.6.3.1],
162 link:RelNotes/1.6.3.txt[1.6.3].
165 link:RelNotes/1.6.2.5.txt[1.6.2.5],
166 link:RelNotes/1.6.2.4.txt[1.6.2.4],
167 link:RelNotes/1.6.2.3.txt[1.6.2.3],
168 link:RelNotes/1.6.2.2.txt[1.6.2.2],
169 link:RelNotes/1.6.2.1.txt[1.6.2.1],
170 link:RelNotes/1.6.2.txt[1.6.2].
172 * link:v1.6.1.3/git.html[documentation for release 1.6.1.3]
175 link:RelNotes/1.6.1.3.txt[1.6.1.3],
176 link:RelNotes/1.6.1.2.txt[1.6.1.2],
177 link:RelNotes/1.6.1.1.txt[1.6.1.1],
178 link:RelNotes/1.6.1.txt[1.6.1].
180 * link:v1.6.0.6/git.html[documentation for release 1.6.0.6]
183 link:RelNotes/1.6.0.6.txt[1.6.0.6],
184 link:RelNotes/1.6.0.5.txt[1.6.0.5],
185 link:RelNotes/1.6.0.4.txt[1.6.0.4],
186 link:RelNotes/1.6.0.3.txt[1.6.0.3],
187 link:RelNotes/1.6.0.2.txt[1.6.0.2],
188 link:RelNotes/1.6.0.1.txt[1.6.0.1],
189 link:RelNotes/1.6.0.txt[1.6.0].
191 * link:v1.5.6.6/git.html[documentation for release 1.5.6.6]
194 link:RelNotes/1.5.6.6.txt[1.5.6.6],
195 link:RelNotes/1.5.6.5.txt[1.5.6.5],
196 link:RelNotes/1.5.6.4.txt[1.5.6.4],
197 link:RelNotes/1.5.6.3.txt[1.5.6.3],
198 link:RelNotes/1.5.6.2.txt[1.5.6.2],
199 link:RelNotes/1.5.6.1.txt[1.5.6.1],
200 link:RelNotes/1.5.6.txt[1.5.6].
202 * link:v1.5.5.6/git.html[documentation for release 1.5.5.6]
205 link:RelNotes/1.5.5.6.txt[1.5.5.6],
206 link:RelNotes/1.5.5.5.txt[1.5.5.5],
207 link:RelNotes/1.5.5.4.txt[1.5.5.4],
208 link:RelNotes/1.5.5.3.txt[1.5.5.3],
209 link:RelNotes/1.5.5.2.txt[1.5.5.2],
210 link:RelNotes/1.5.5.1.txt[1.5.5.1],
211 link:RelNotes/1.5.5.txt[1.5.5].
213 * link:v1.5.4.7/git.html[documentation for release 1.5.4.7]
216 link:RelNotes/1.5.4.7.txt[1.5.4.7],
217 link:RelNotes/1.5.4.6.txt[1.5.4.6],
218 link:RelNotes/1.5.4.5.txt[1.5.4.5],
219 link:RelNotes/1.5.4.4.txt[1.5.4.4],
220 link:RelNotes/1.5.4.3.txt[1.5.4.3],
221 link:RelNotes/1.5.4.2.txt[1.5.4.2],
222 link:RelNotes/1.5.4.1.txt[1.5.4.1],
223 link:RelNotes/1.5.4.txt[1.5.4].
225 * link:v1.5.3.8/git.html[documentation for release 1.5.3.8]
228 link:RelNotes/1.5.3.8.txt[1.5.3.8],
229 link:RelNotes/1.5.3.7.txt[1.5.3.7],
230 link:RelNotes/1.5.3.6.txt[1.5.3.6],
231 link:RelNotes/1.5.3.5.txt[1.5.3.5],
232 link:RelNotes/1.5.3.4.txt[1.5.3.4],
233 link:RelNotes/1.5.3.3.txt[1.5.3.3],
234 link:RelNotes/1.5.3.2.txt[1.5.3.2],
235 link:RelNotes/1.5.3.1.txt[1.5.3.1],
236 link:RelNotes/1.5.3.txt[1.5.3].
238 * link:v1.5.2.5/git.html[documentation for release 1.5.2.5]
241 link:RelNotes/1.5.2.5.txt[1.5.2.5],
242 link:RelNotes/1.5.2.4.txt[1.5.2.4],
243 link:RelNotes/1.5.2.3.txt[1.5.2.3],
244 link:RelNotes/1.5.2.2.txt[1.5.2.2],
245 link:RelNotes/1.5.2.1.txt[1.5.2.1],
246 link:RelNotes/1.5.2.txt[1.5.2].
248 * link:v1.5.1.6/git.html[documentation for release 1.5.1.6]
251 link:RelNotes/1.5.1.6.txt[1.5.1.6],
252 link:RelNotes/1.5.1.5.txt[1.5.1.5],
253 link:RelNotes/1.5.1.4.txt[1.5.1.4],
254 link:RelNotes/1.5.1.3.txt[1.5.1.3],
255 link:RelNotes/1.5.1.2.txt[1.5.1.2],
256 link:RelNotes/1.5.1.1.txt[1.5.1.1],
257 link:RelNotes/1.5.1.txt[1.5.1].
259 * link:v1.5.0.7/git.html[documentation for release 1.5.0.7]
262 link:RelNotes/1.5.0.7.txt[1.5.0.7],
263 link:RelNotes/1.5.0.6.txt[1.5.0.6],
264 link:RelNotes/1.5.0.5.txt[1.5.0.5],
265 link:RelNotes/1.5.0.3.txt[1.5.0.3],
266 link:RelNotes/1.5.0.2.txt[1.5.0.2],
267 link:RelNotes/1.5.0.1.txt[1.5.0.1],
268 link:RelNotes/1.5.0.txt[1.5.0].
270 * documentation for release link:v1.4.4.4/git.html[1.4.4.4],
271 link:v1.3.3/git.html[1.3.3],
272 link:v1.2.6/git.html[1.2.6],
273 link:v1.0.13/git.html[1.0.13].
282 Prints the git suite version that the 'git' program came from.
285 Prints the synopsis and a list of the most commonly used
286 commands. If the option '--all' or '-a' is given then all
287 available commands are printed. If a git command is named this
288 option will bring up the manual page for that command.
290 Other options are available to control how the manual page is
291 displayed. See linkgit:git-help[1] for more information,
292 because `git --help ...` is converted internally into `git
296 Pass a configuration parameter to the command. The value
297 given will override values from configuration files.
298 The <name> is expected in the same format as listed by
299 'git config' (subkeys separated by dots).
301 --exec-path[=<path>]::
302 Path to wherever your core git programs are installed.
303 This can also be controlled by setting the GIT_EXEC_PATH
304 environment variable. If no path is given, 'git' will print
305 the current setting and then exit.
308 Print the path, without trailing slash, where git's HTML
309 documentation is installed and exit.
312 Print the manpath (see `man(1)`) for the man pages for
313 this version of git and exit.
316 Print the path where the Info files documenting this
317 version of git are installed and exit.
321 Pipe all output into 'less' (or if set, $PAGER) if standard
322 output is a terminal. This overrides the `pager.<cmd>`
323 configuration options (see the "Configuration Mechanism" section
327 Do not pipe git output into a pager.
330 Set the path to the repository. This can also be controlled by
331 setting the GIT_DIR environment variable. It can be an absolute
332 path or relative path to current working directory.
335 Set the path to the working tree. It can be an absolute path
336 or a path relative to the current working directory.
337 This can also be controlled by setting the GIT_WORK_TREE
338 environment variable and the core.worktree configuration
339 variable (see core.worktree in linkgit:git-config[1] for a
340 more detailed discussion).
343 Set the git namespace. See linkgit:gitnamespaces[7] for more
344 details. Equivalent to setting the `GIT_NAMESPACE` environment
348 Treat the repository as a bare repository. If GIT_DIR
349 environment is not set, it is set to the current working
352 --no-replace-objects::
353 Do not use replacement refs to replace git objects. See
354 linkgit:git-replace[1] for more information.
357 FURTHER DOCUMENTATION
358 ---------------------
360 See the references above to get started using git. The following is
361 probably more detail than necessary for a first-time user.
363 The link:user-manual.html#git-concepts[git concepts chapter of the
364 user-manual] and linkgit:gitcore-tutorial[7] both provide
365 introductions to the underlying git architecture.
367 See linkgit:gitworkflows[7] for an overview of recommended workflows.
369 See also the link:howto-index.html[howto] documents for some useful
372 The internals are documented in the
373 link:technical/api-index.html[GIT API documentation].
378 We divide git into high level ("porcelain") commands and low level
379 ("plumbing") commands.
381 High-level commands (porcelain)
382 -------------------------------
384 We separate the porcelain commands into the main commands and some
385 ancillary user utilities.
387 Main porcelain commands
388 ~~~~~~~~~~~~~~~~~~~~~~~
390 include::cmds-mainporcelain.txt[]
396 include::cmds-ancillarymanipulators.txt[]
400 include::cmds-ancillaryinterrogators.txt[]
403 Interacting with Others
404 ~~~~~~~~~~~~~~~~~~~~~~~
406 These commands are to interact with foreign SCM and with other
407 people via patch over e-mail.
409 include::cmds-foreignscminterface.txt[]
412 Low-level commands (plumbing)
413 -----------------------------
415 Although git includes its
416 own porcelain layer, its low-level commands are sufficient to support
417 development of alternative porcelains. Developers of such porcelains
418 might start by reading about linkgit:git-update-index[1] and
419 linkgit:git-read-tree[1].
421 The interface (input, output, set of options and the semantics)
422 to these low-level commands are meant to be a lot more stable
423 than Porcelain level commands, because these commands are
424 primarily for scripted use. The interface to Porcelain commands
425 on the other hand are subject to change in order to improve the
428 The following description divides
429 the low-level commands into commands that manipulate objects (in
430 the repository, index, and working tree), commands that interrogate and
431 compare objects, and commands that move objects and references between
435 Manipulation commands
436 ~~~~~~~~~~~~~~~~~~~~~
438 include::cmds-plumbingmanipulators.txt[]
441 Interrogation commands
442 ~~~~~~~~~~~~~~~~~~~~~~
444 include::cmds-plumbinginterrogators.txt[]
446 In general, the interrogate commands do not touch the files in
450 Synching repositories
451 ~~~~~~~~~~~~~~~~~~~~~
453 include::cmds-synchingrepositories.txt[]
455 The following are helper commands used by the above; end users
456 typically do not use them directly.
458 include::cmds-synchelpers.txt[]
461 Internal helper commands
462 ~~~~~~~~~~~~~~~~~~~~~~~~
464 These are internal helper commands used by other commands; end
465 users typically do not use them directly.
467 include::cmds-purehelpers.txt[]
470 Configuration Mechanism
471 -----------------------
473 Starting from 0.99.9 (actually mid 0.99.8.GIT), `.git/config` file
474 is used to hold per-repository configuration options. It is a
475 simple text file modeled after `.ini` format familiar to some
476 people. Here is an example:
480 # A '#' or ';' character indicates a comment.
485 ; Don't trust file modes
490 name = "Junio C Hamano"
491 email = "junkio@twinsun.com"
495 Various commands read from the configuration file and adjust
496 their operation accordingly. See linkgit:git-config[1] for a
500 Identifier Terminology
501 ----------------------
503 Indicates the object name for any type of object.
506 Indicates a blob object name.
509 Indicates a tree object name.
512 Indicates a commit object name.
515 Indicates a tree, commit or tag object name. A
516 command that takes a <tree-ish> argument ultimately wants to
517 operate on a <tree> object but automatically dereferences
518 <commit> and <tag> objects that point at a <tree>.
521 Indicates a commit or tag object name. A
522 command that takes a <commit-ish> argument ultimately wants to
523 operate on a <commit> object but automatically dereferences
524 <tag> objects that point at a <commit>.
527 Indicates that an object type is required.
528 Currently one of: `blob`, `tree`, `commit`, or `tag`.
531 Indicates a filename - almost always relative to the
532 root of the tree structure `GIT_INDEX_FILE` describes.
536 Any git command accepting any <object> can also use the following
540 indicates the head of the current branch.
544 (i.e. a `refs/tags/<tag>` reference).
548 (i.e. a `refs/heads/<head>` reference).
550 For a more complete list of ways to spell object names, see
551 "SPECIFYING REVISIONS" section in linkgit:gitrevisions[7].
554 File/Directory Structure
555 ------------------------
557 Please see the linkgit:gitrepository-layout[5] document.
559 Read linkgit:githooks[5] for more details about each hook.
561 Higher level SCMs may provide and manage additional information in the
567 Please see linkgit:gitglossary[7].
570 Environment Variables
571 ---------------------
572 Various git commands use the following environment variables:
576 These environment variables apply to 'all' core git commands. Nb: it
577 is worth noting that they may be used/overridden by SCMS sitting above
578 git so take care if using Cogito etc.
581 This environment allows the specification of an alternate
582 index file. If not specified, the default of `$GIT_DIR/index`
585 'GIT_OBJECT_DIRECTORY'::
586 If the object storage directory is specified via this
587 environment variable then the sha1 directories are created
588 underneath - otherwise the default `$GIT_DIR/objects`
591 'GIT_ALTERNATE_OBJECT_DIRECTORIES'::
592 Due to the immutable nature of git objects, old objects can be
593 archived into shared, read-only directories. This variable
594 specifies a ":" separated (on Windows ";" separated) list
595 of git object directories which can be used to search for git
596 objects. New objects will not be written to these directories.
599 If the 'GIT_DIR' environment variable is set then it
600 specifies a path to use instead of the default `.git`
601 for the base of the repository.
604 Set the path to the working tree. The value will not be
605 used in combination with repositories found automatically in
606 a .git directory (i.e. $GIT_DIR is not set).
607 This can also be controlled by the '--work-tree' command line
608 option and the core.worktree configuration variable.
611 Set the git namespace; see linkgit:gitnamespaces[7] for details.
612 The '--namespace' command-line option also sets this value.
614 'GIT_CEILING_DIRECTORIES'::
615 This should be a colon-separated list of absolute paths.
616 If set, it is a list of directories that git should not chdir
617 up into while looking for a repository directory.
618 It will not exclude the current working directory or
619 a GIT_DIR set on the command line or in the environment.
620 (Useful for excluding slow-loading network directories.)
622 'GIT_DISCOVERY_ACROSS_FILESYSTEM'::
623 When run in a directory that does not have ".git" repository
624 directory, git tries to find such a directory in the parent
625 directories to find the top of the working tree, but by default it
626 does not cross filesystem boundaries. This environment variable
627 can be set to true to tell git not to stop at filesystem
628 boundaries. Like 'GIT_CEILING_DIRECTORIES', this will not affect
629 an explicit repository directory set via 'GIT_DIR' or on the
637 'GIT_COMMITTER_NAME'::
638 'GIT_COMMITTER_EMAIL'::
639 'GIT_COMMITTER_DATE'::
641 see linkgit:git-commit-tree[1]
646 Only valid setting is "--unified=??" or "-u??" to set the
647 number of context lines shown when a unified diff is created.
648 This takes precedence over any "-U" or "--unified" option
649 value passed on the git diff command line.
651 'GIT_EXTERNAL_DIFF'::
652 When the environment variable 'GIT_EXTERNAL_DIFF' is set, the
653 program named by it is called, instead of the diff invocation
654 described above. For a path that is added, removed, or modified,
655 'GIT_EXTERNAL_DIFF' is called with 7 parameters:
657 path old-file old-hex old-mode new-file new-hex new-mode
661 <old|new>-file:: are files GIT_EXTERNAL_DIFF can use to read the
662 contents of <old|new>,
663 <old|new>-hex:: are the 40-hexdigit SHA1 hashes,
664 <old|new>-mode:: are the octal representation of the file modes.
666 The file parameters can point at the user's working file
667 (e.g. `new-file` in "git-diff-files"), `/dev/null` (e.g. `old-file`
668 when a new file is added), or a temporary file (e.g. `old-file` in the
669 index). 'GIT_EXTERNAL_DIFF' should not worry about unlinking the
670 temporary file --- it is removed when 'GIT_EXTERNAL_DIFF' exits.
672 For a path that is unmerged, 'GIT_EXTERNAL_DIFF' is called with 1
677 'GIT_MERGE_VERBOSITY'::
678 A number controlling the amount of output shown by
679 the recursive merge strategy. Overrides merge.verbosity.
680 See linkgit:git-merge[1]
683 This environment variable overrides `$PAGER`. If it is set
684 to an empty string or to the value "cat", git will not launch
685 a pager. See also the `core.pager` option in
686 linkgit:git-config[1].
689 If this environment variable is set then 'git fetch'
690 and 'git push' will use this command instead
691 of 'ssh' when they need to connect to a remote system.
692 The '$GIT_SSH' command will be given exactly two arguments:
693 the 'username@host' (or just 'host') from the URL and the
694 shell command to execute on that remote system.
696 To pass options to the program that you want to list in GIT_SSH
697 you will need to wrap the program and options into a shell script,
698 then set GIT_SSH to refer to the shell script.
700 Usually it is easier to configure any desired options through your
701 personal `.ssh/config` file. Please consult your ssh documentation
705 If this environment variable is set, then git commands which need to
706 acquire passwords or passphrases (e.g. for HTTP or IMAP authentication)
707 will call this program with a suitable prompt as command line argument
708 and read the password from its STDOUT. See also the 'core.askpass'
709 option in linkgit:git-config[1].
712 If this environment variable is set to "1", then commands such
713 as 'git blame' (in incremental mode), 'git rev-list', 'git log',
714 and 'git whatchanged' will force a flush of the output stream
715 after each commit-oriented record have been flushed. If this
716 variable is set to "0", the output of these commands will be done
717 using completely buffered I/O. If this environment variable is
718 not set, git will choose buffered or record-oriented flushing
719 based on whether stdout appears to be redirected to a file or not.
722 If this variable is set to "1", "2" or "true" (comparison
723 is case insensitive), git will print `trace:` messages on
724 stderr telling about alias expansion, built-in command
725 execution and external command execution.
726 If this variable is set to an integer value greater than 1
727 and lower than 10 (strictly) then git will interpret this
728 value as an open file descriptor and will try to write the
729 trace messages into this file descriptor.
730 Alternatively, if this variable is set to an absolute path
731 (starting with a '/' character), git will interpret this
732 as a file path and will try to write the trace messages
735 Discussion[[Discussion]]
736 ------------------------
738 More detail on the following is available from the
739 link:user-manual.html#git-concepts[git concepts chapter of the
740 user-manual] and linkgit:gitcore-tutorial[7].
742 A git project normally consists of a working directory with a ".git"
743 subdirectory at the top level. The .git directory contains, among other
744 things, a compressed object database representing the complete history
745 of the project, an "index" file which links that history to the current
746 contents of the working tree, and named pointers into that history such
747 as tags and branch heads.
749 The object database contains objects of three main types: blobs, which
750 hold file data; trees, which point to blobs and other trees to build up
751 directory hierarchies; and commits, which each reference a single tree
752 and some number of parent commits.
754 The commit, equivalent to what other systems call a "changeset" or
755 "version", represents a step in the project's history, and each parent
756 represents an immediately preceding step. Commits with more than one
757 parent represent merges of independent lines of development.
759 All objects are named by the SHA1 hash of their contents, normally
760 written as a string of 40 hex digits. Such names are globally unique.
761 The entire history leading up to a commit can be vouched for by signing
762 just that commit. A fourth object type, the tag, is provided for this
765 When first created, objects are stored in individual files, but for
766 efficiency may later be compressed together into "pack files".
768 Named pointers called refs mark interesting points in history. A ref
769 may contain the SHA1 name of an object or the name of another ref. Refs
770 with names beginning `ref/head/` contain the SHA1 name of the most
771 recent commit (or "head") of a branch under development. SHA1 names of
772 tags of interest are stored under `ref/tags/`. A special ref named
773 `HEAD` contains the name of the currently checked-out branch.
775 The index file is initialized with a list of all paths and, for each
776 path, a blob object and a set of attributes. The blob object represents
777 the contents of the file as of the head of the current branch. The
778 attributes (last modified time, size, etc.) are taken from the
779 corresponding file in the working tree. Subsequent changes to the
780 working tree can be found by comparing these attributes. The index may
781 be updated with new content, and new commits may be created from the
782 content stored in the index.
784 The index is also capable of storing multiple entries (called "stages")
785 for a given pathname. These stages are used to hold the various
786 unmerged version of a file when a merge is in progress.
790 Git was started by Linus Torvalds, and is currently maintained by Junio
791 C Hamano. Numerous contributions have come from the git mailing list
792 <git@vger.kernel.org>. For a more complete list of contributors, see
793 http://git-scm.com/about. If you have a clone of git.git itself, the
794 output of linkgit:git-shortlog[1] and linkgit:git-blame[1] can show you
795 the authors for specific parts of the project.
800 Report bugs to the Git mailing list <git@vger.kernel.org> where the
801 development and maintenance is primarily done. You do not have to be
802 subscribed to the list to send a message there.
806 linkgit:gittutorial[7], linkgit:gittutorial-2[7],
807 link:everyday.html[Everyday Git], linkgit:gitcvs-migration[7],
808 linkgit:gitglossary[7], linkgit:gitcore-tutorial[7],
809 linkgit:gitcli[7], link:user-manual.html[The Git User's Manual],
810 linkgit:gitworkflows[7]
814 Part of the linkgit:git[1] suite