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:v1.7.7.1/git.html[documentation for release 1.7.7.1]
50 link:RelNotes/1.7.7.1.txt[1.7.7.1],
51 link:RelNotes/1.7.7.txt[1.7.7].
53 * link:v1.7.6.4/git.html[documentation for release 1.7.6.4]
56 link:RelNotes/1.7.6.4.txt[1.7.6.4],
57 link:RelNotes/1.7.6.3.txt[1.7.6.3],
58 link:RelNotes/1.7.6.2.txt[1.7.6.2],
59 link:RelNotes/1.7.6.1.txt[1.7.6.1],
60 link:RelNotes/1.7.6.txt[1.7.6].
62 * link:v1.7.5.4/git.html[documentation for release 1.7.5.4]
65 link:RelNotes/1.7.5.4.txt[1.7.5.4],
66 link:RelNotes/1.7.5.3.txt[1.7.5.3],
67 link:RelNotes/1.7.5.2.txt[1.7.5.2],
68 link:RelNotes/1.7.5.1.txt[1.7.5.1],
69 link:RelNotes/1.7.5.txt[1.7.5].
71 * link:v1.7.4.5/git.html[documentation for release 1.7.4.5]
74 link:RelNotes/1.7.4.5.txt[1.7.4.5],
75 link:RelNotes/1.7.4.4.txt[1.7.4.4],
76 link:RelNotes/1.7.4.3.txt[1.7.4.3],
77 link:RelNotes/1.7.4.2.txt[1.7.4.2],
78 link:RelNotes/1.7.4.1.txt[1.7.4.1],
79 link:RelNotes/1.7.4.txt[1.7.4].
81 * link:v1.7.3.5/git.html[documentation for release 1.7.3.5]
84 link:RelNotes/1.7.3.5.txt[1.7.3.5],
85 link:RelNotes/1.7.3.4.txt[1.7.3.4],
86 link:RelNotes/1.7.3.3.txt[1.7.3.3],
87 link:RelNotes/1.7.3.2.txt[1.7.3.2],
88 link:RelNotes/1.7.3.1.txt[1.7.3.1],
89 link:RelNotes/1.7.3.txt[1.7.3].
91 * link:v1.7.2.5/git.html[documentation for release 1.7.2.5]
94 link:RelNotes/1.7.2.5.txt[1.7.2.5],
95 link:RelNotes/1.7.2.4.txt[1.7.2.4],
96 link:RelNotes/1.7.2.3.txt[1.7.2.3],
97 link:RelNotes/1.7.2.2.txt[1.7.2.2],
98 link:RelNotes/1.7.2.1.txt[1.7.2.1],
99 link:RelNotes/1.7.2.txt[1.7.2].
101 * link:v1.7.1.4/git.html[documentation for release 1.7.1.4]
104 link:RelNotes/1.7.1.4.txt[1.7.1.4],
105 link:RelNotes/1.7.1.3.txt[1.7.1.3],
106 link:RelNotes/1.7.1.2.txt[1.7.1.2],
107 link:RelNotes/1.7.1.1.txt[1.7.1.1],
108 link:RelNotes/1.7.1.txt[1.7.1].
110 * link:v1.7.0.9/git.html[documentation for release 1.7.0.9]
113 link:RelNotes/1.7.0.9.txt[1.7.0.9],
114 link:RelNotes/1.7.0.8.txt[1.7.0.8],
115 link:RelNotes/1.7.0.7.txt[1.7.0.7],
116 link:RelNotes/1.7.0.6.txt[1.7.0.6],
117 link:RelNotes/1.7.0.5.txt[1.7.0.5],
118 link:RelNotes/1.7.0.4.txt[1.7.0.4],
119 link:RelNotes/1.7.0.3.txt[1.7.0.3],
120 link:RelNotes/1.7.0.2.txt[1.7.0.2],
121 link:RelNotes/1.7.0.1.txt[1.7.0.1],
122 link:RelNotes/1.7.0.txt[1.7.0].
124 * link:v1.6.6.3/git.html[documentation for release 1.6.6.3]
127 link:RelNotes/1.6.6.3.txt[1.6.6.3],
128 link:RelNotes/1.6.6.2.txt[1.6.6.2],
129 link:RelNotes/1.6.6.1.txt[1.6.6.1],
130 link:RelNotes/1.6.6.txt[1.6.6].
132 * link:v1.6.5.9/git.html[documentation for release 1.6.5.9]
135 link:RelNotes/1.6.5.9.txt[1.6.5.9],
136 link:RelNotes/1.6.5.8.txt[1.6.5.8],
137 link:RelNotes/1.6.5.7.txt[1.6.5.7],
138 link:RelNotes/1.6.5.6.txt[1.6.5.6],
139 link:RelNotes/1.6.5.5.txt[1.6.5.5],
140 link:RelNotes/1.6.5.4.txt[1.6.5.4],
141 link:RelNotes/1.6.5.3.txt[1.6.5.3],
142 link:RelNotes/1.6.5.2.txt[1.6.5.2],
143 link:RelNotes/1.6.5.1.txt[1.6.5.1],
144 link:RelNotes/1.6.5.txt[1.6.5].
146 * link:v1.6.4.5/git.html[documentation for release 1.6.4.5]
149 link:RelNotes/1.6.4.5.txt[1.6.4.5],
150 link:RelNotes/1.6.4.4.txt[1.6.4.4],
151 link:RelNotes/1.6.4.3.txt[1.6.4.3],
152 link:RelNotes/1.6.4.2.txt[1.6.4.2],
153 link:RelNotes/1.6.4.1.txt[1.6.4.1],
154 link:RelNotes/1.6.4.txt[1.6.4].
156 * link:v1.6.3.4/git.html[documentation for release 1.6.3.4]
159 link:RelNotes/1.6.3.4.txt[1.6.3.4],
160 link:RelNotes/1.6.3.3.txt[1.6.3.3],
161 link:RelNotes/1.6.3.2.txt[1.6.3.2],
162 link:RelNotes/1.6.3.1.txt[1.6.3.1],
163 link:RelNotes/1.6.3.txt[1.6.3].
166 link:RelNotes/1.6.2.5.txt[1.6.2.5],
167 link:RelNotes/1.6.2.4.txt[1.6.2.4],
168 link:RelNotes/1.6.2.3.txt[1.6.2.3],
169 link:RelNotes/1.6.2.2.txt[1.6.2.2],
170 link:RelNotes/1.6.2.1.txt[1.6.2.1],
171 link:RelNotes/1.6.2.txt[1.6.2].
173 * link:v1.6.1.3/git.html[documentation for release 1.6.1.3]
176 link:RelNotes/1.6.1.3.txt[1.6.1.3],
177 link:RelNotes/1.6.1.2.txt[1.6.1.2],
178 link:RelNotes/1.6.1.1.txt[1.6.1.1],
179 link:RelNotes/1.6.1.txt[1.6.1].
181 * link:v1.6.0.6/git.html[documentation for release 1.6.0.6]
184 link:RelNotes/1.6.0.6.txt[1.6.0.6],
185 link:RelNotes/1.6.0.5.txt[1.6.0.5],
186 link:RelNotes/1.6.0.4.txt[1.6.0.4],
187 link:RelNotes/1.6.0.3.txt[1.6.0.3],
188 link:RelNotes/1.6.0.2.txt[1.6.0.2],
189 link:RelNotes/1.6.0.1.txt[1.6.0.1],
190 link:RelNotes/1.6.0.txt[1.6.0].
192 * link:v1.5.6.6/git.html[documentation for release 1.5.6.6]
195 link:RelNotes/1.5.6.6.txt[1.5.6.6],
196 link:RelNotes/1.5.6.5.txt[1.5.6.5],
197 link:RelNotes/1.5.6.4.txt[1.5.6.4],
198 link:RelNotes/1.5.6.3.txt[1.5.6.3],
199 link:RelNotes/1.5.6.2.txt[1.5.6.2],
200 link:RelNotes/1.5.6.1.txt[1.5.6.1],
201 link:RelNotes/1.5.6.txt[1.5.6].
203 * link:v1.5.5.6/git.html[documentation for release 1.5.5.6]
206 link:RelNotes/1.5.5.6.txt[1.5.5.6],
207 link:RelNotes/1.5.5.5.txt[1.5.5.5],
208 link:RelNotes/1.5.5.4.txt[1.5.5.4],
209 link:RelNotes/1.5.5.3.txt[1.5.5.3],
210 link:RelNotes/1.5.5.2.txt[1.5.5.2],
211 link:RelNotes/1.5.5.1.txt[1.5.5.1],
212 link:RelNotes/1.5.5.txt[1.5.5].
214 * link:v1.5.4.7/git.html[documentation for release 1.5.4.7]
217 link:RelNotes/1.5.4.7.txt[1.5.4.7],
218 link:RelNotes/1.5.4.6.txt[1.5.4.6],
219 link:RelNotes/1.5.4.5.txt[1.5.4.5],
220 link:RelNotes/1.5.4.4.txt[1.5.4.4],
221 link:RelNotes/1.5.4.3.txt[1.5.4.3],
222 link:RelNotes/1.5.4.2.txt[1.5.4.2],
223 link:RelNotes/1.5.4.1.txt[1.5.4.1],
224 link:RelNotes/1.5.4.txt[1.5.4].
226 * link:v1.5.3.8/git.html[documentation for release 1.5.3.8]
229 link:RelNotes/1.5.3.8.txt[1.5.3.8],
230 link:RelNotes/1.5.3.7.txt[1.5.3.7],
231 link:RelNotes/1.5.3.6.txt[1.5.3.6],
232 link:RelNotes/1.5.3.5.txt[1.5.3.5],
233 link:RelNotes/1.5.3.4.txt[1.5.3.4],
234 link:RelNotes/1.5.3.3.txt[1.5.3.3],
235 link:RelNotes/1.5.3.2.txt[1.5.3.2],
236 link:RelNotes/1.5.3.1.txt[1.5.3.1],
237 link:RelNotes/1.5.3.txt[1.5.3].
239 * link:v1.5.2.5/git.html[documentation for release 1.5.2.5]
242 link:RelNotes/1.5.2.5.txt[1.5.2.5],
243 link:RelNotes/1.5.2.4.txt[1.5.2.4],
244 link:RelNotes/1.5.2.3.txt[1.5.2.3],
245 link:RelNotes/1.5.2.2.txt[1.5.2.2],
246 link:RelNotes/1.5.2.1.txt[1.5.2.1],
247 link:RelNotes/1.5.2.txt[1.5.2].
249 * link:v1.5.1.6/git.html[documentation for release 1.5.1.6]
252 link:RelNotes/1.5.1.6.txt[1.5.1.6],
253 link:RelNotes/1.5.1.5.txt[1.5.1.5],
254 link:RelNotes/1.5.1.4.txt[1.5.1.4],
255 link:RelNotes/1.5.1.3.txt[1.5.1.3],
256 link:RelNotes/1.5.1.2.txt[1.5.1.2],
257 link:RelNotes/1.5.1.1.txt[1.5.1.1],
258 link:RelNotes/1.5.1.txt[1.5.1].
260 * link:v1.5.0.7/git.html[documentation for release 1.5.0.7]
263 link:RelNotes/1.5.0.7.txt[1.5.0.7],
264 link:RelNotes/1.5.0.6.txt[1.5.0.6],
265 link:RelNotes/1.5.0.5.txt[1.5.0.5],
266 link:RelNotes/1.5.0.3.txt[1.5.0.3],
267 link:RelNotes/1.5.0.2.txt[1.5.0.2],
268 link:RelNotes/1.5.0.1.txt[1.5.0.1],
269 link:RelNotes/1.5.0.txt[1.5.0].
271 * documentation for release link:v1.4.4.4/git.html[1.4.4.4],
272 link:v1.3.3/git.html[1.3.3],
273 link:v1.2.6/git.html[1.2.6],
274 link:v1.0.13/git.html[1.0.13].
283 Prints the git suite version that the 'git' program came from.
286 Prints the synopsis and a list of the most commonly used
287 commands. If the option '--all' or '-a' is given then all
288 available commands are printed. If a git command is named this
289 option will bring up the manual page for that command.
291 Other options are available to control how the manual page is
292 displayed. See linkgit:git-help[1] for more information,
293 because `git --help ...` is converted internally into `git
297 Pass a configuration parameter to the command. The value
298 given will override values from configuration files.
299 The <name> is expected in the same format as listed by
300 'git config' (subkeys separated by dots).
302 --exec-path[=<path>]::
303 Path to wherever your core git programs are installed.
304 This can also be controlled by setting the GIT_EXEC_PATH
305 environment variable. If no path is given, 'git' will print
306 the current setting and then exit.
309 Print the path, without trailing slash, where git's HTML
310 documentation is installed and exit.
313 Print the manpath (see `man(1)`) for the man pages for
314 this version of git and exit.
317 Print the path where the Info files documenting this
318 version of git are installed and exit.
322 Pipe all output into 'less' (or if set, $PAGER) if standard
323 output is a terminal. This overrides the `pager.<cmd>`
324 configuration options (see the "Configuration Mechanism" section
328 Do not pipe git output into a pager.
331 Set the path to the repository. This can also be controlled by
332 setting the GIT_DIR environment variable. It can be an absolute
333 path or relative path to current working directory.
336 Set the path to the working tree. It can be an absolute path
337 or a path relative to the current working directory.
338 This can also be controlled by setting the GIT_WORK_TREE
339 environment variable and the core.worktree configuration
340 variable (see core.worktree in linkgit:git-config[1] for a
341 more detailed discussion).
344 Set the git namespace. See linkgit:gitnamespaces[7] for more
345 details. Equivalent to setting the `GIT_NAMESPACE` environment
349 Treat the repository as a bare repository. If GIT_DIR
350 environment is not set, it is set to the current working
353 --no-replace-objects::
354 Do not use replacement refs to replace git objects. See
355 linkgit:git-replace[1] for more information.
358 FURTHER DOCUMENTATION
359 ---------------------
361 See the references above to get started using git. The following is
362 probably more detail than necessary for a first-time user.
364 The link:user-manual.html#git-concepts[git concepts chapter of the
365 user-manual] and linkgit:gitcore-tutorial[7] both provide
366 introductions to the underlying git architecture.
368 See linkgit:gitworkflows[7] for an overview of recommended workflows.
370 See also the link:howto-index.html[howto] documents for some useful
373 The internals are documented in the
374 link:technical/api-index.html[GIT API documentation].
379 We divide git into high level ("porcelain") commands and low level
380 ("plumbing") commands.
382 High-level commands (porcelain)
383 -------------------------------
385 We separate the porcelain commands into the main commands and some
386 ancillary user utilities.
388 Main porcelain commands
389 ~~~~~~~~~~~~~~~~~~~~~~~
391 include::cmds-mainporcelain.txt[]
397 include::cmds-ancillarymanipulators.txt[]
401 include::cmds-ancillaryinterrogators.txt[]
404 Interacting with Others
405 ~~~~~~~~~~~~~~~~~~~~~~~
407 These commands are to interact with foreign SCM and with other
408 people via patch over e-mail.
410 include::cmds-foreignscminterface.txt[]
413 Low-level commands (plumbing)
414 -----------------------------
416 Although git includes its
417 own porcelain layer, its low-level commands are sufficient to support
418 development of alternative porcelains. Developers of such porcelains
419 might start by reading about linkgit:git-update-index[1] and
420 linkgit:git-read-tree[1].
422 The interface (input, output, set of options and the semantics)
423 to these low-level commands are meant to be a lot more stable
424 than Porcelain level commands, because these commands are
425 primarily for scripted use. The interface to Porcelain commands
426 on the other hand are subject to change in order to improve the
429 The following description divides
430 the low-level commands into commands that manipulate objects (in
431 the repository, index, and working tree), commands that interrogate and
432 compare objects, and commands that move objects and references between
436 Manipulation commands
437 ~~~~~~~~~~~~~~~~~~~~~
439 include::cmds-plumbingmanipulators.txt[]
442 Interrogation commands
443 ~~~~~~~~~~~~~~~~~~~~~~
445 include::cmds-plumbinginterrogators.txt[]
447 In general, the interrogate commands do not touch the files in
451 Synching repositories
452 ~~~~~~~~~~~~~~~~~~~~~
454 include::cmds-synchingrepositories.txt[]
456 The following are helper commands used by the above; end users
457 typically do not use them directly.
459 include::cmds-synchelpers.txt[]
462 Internal helper commands
463 ~~~~~~~~~~~~~~~~~~~~~~~~
465 These are internal helper commands used by other commands; end
466 users typically do not use them directly.
468 include::cmds-purehelpers.txt[]
471 Configuration Mechanism
472 -----------------------
474 Starting from 0.99.9 (actually mid 0.99.8.GIT), `.git/config` file
475 is used to hold per-repository configuration options. It is a
476 simple text file modeled after `.ini` format familiar to some
477 people. Here is an example:
481 # A '#' or ';' character indicates a comment.
486 ; Don't trust file modes
491 name = "Junio C Hamano"
492 email = "junkio@twinsun.com"
496 Various commands read from the configuration file and adjust
497 their operation accordingly. See linkgit:git-config[1] for a
501 Identifier Terminology
502 ----------------------
504 Indicates the object name for any type of object.
507 Indicates a blob object name.
510 Indicates a tree object name.
513 Indicates a commit object name.
516 Indicates a tree, commit or tag object name. A
517 command that takes a <tree-ish> argument ultimately wants to
518 operate on a <tree> object but automatically dereferences
519 <commit> and <tag> objects that point at a <tree>.
522 Indicates a commit or tag object name. A
523 command that takes a <commit-ish> argument ultimately wants to
524 operate on a <commit> object but automatically dereferences
525 <tag> objects that point at a <commit>.
528 Indicates that an object type is required.
529 Currently one of: `blob`, `tree`, `commit`, or `tag`.
532 Indicates a filename - almost always relative to the
533 root of the tree structure `GIT_INDEX_FILE` describes.
537 Any git command accepting any <object> can also use the following
541 indicates the head of the current branch.
545 (i.e. a `refs/tags/<tag>` reference).
549 (i.e. a `refs/heads/<head>` reference).
551 For a more complete list of ways to spell object names, see
552 "SPECIFYING REVISIONS" section in linkgit:gitrevisions[7].
555 File/Directory Structure
556 ------------------------
558 Please see the linkgit:gitrepository-layout[5] document.
560 Read linkgit:githooks[5] for more details about each hook.
562 Higher level SCMs may provide and manage additional information in the
568 Please see linkgit:gitglossary[7].
571 Environment Variables
572 ---------------------
573 Various git commands use the following environment variables:
577 These environment variables apply to 'all' core git commands. Nb: it
578 is worth noting that they may be used/overridden by SCMS sitting above
579 git so take care if using Cogito etc.
582 This environment allows the specification of an alternate
583 index file. If not specified, the default of `$GIT_DIR/index`
586 'GIT_OBJECT_DIRECTORY'::
587 If the object storage directory is specified via this
588 environment variable then the sha1 directories are created
589 underneath - otherwise the default `$GIT_DIR/objects`
592 'GIT_ALTERNATE_OBJECT_DIRECTORIES'::
593 Due to the immutable nature of git objects, old objects can be
594 archived into shared, read-only directories. This variable
595 specifies a ":" separated (on Windows ";" separated) list
596 of git object directories which can be used to search for git
597 objects. New objects will not be written to these directories.
600 If the 'GIT_DIR' environment variable is set then it
601 specifies a path to use instead of the default `.git`
602 for the base of the repository.
605 Set the path to the working tree. The value will not be
606 used in combination with repositories found automatically in
607 a .git directory (i.e. $GIT_DIR is not set).
608 This can also be controlled by the '--work-tree' command line
609 option and the core.worktree configuration variable.
612 Set the git namespace; see linkgit:gitnamespaces[7] for details.
613 The '--namespace' command-line option also sets this value.
615 'GIT_CEILING_DIRECTORIES'::
616 This should be a colon-separated list of absolute paths.
617 If set, it is a list of directories that git should not chdir
618 up into while looking for a repository directory.
619 It will not exclude the current working directory or
620 a GIT_DIR set on the command line or in the environment.
621 (Useful for excluding slow-loading network directories.)
623 'GIT_DISCOVERY_ACROSS_FILESYSTEM'::
624 When run in a directory that does not have ".git" repository
625 directory, git tries to find such a directory in the parent
626 directories to find the top of the working tree, but by default it
627 does not cross filesystem boundaries. This environment variable
628 can be set to true to tell git not to stop at filesystem
629 boundaries. Like 'GIT_CEILING_DIRECTORIES', this will not affect
630 an explicit repository directory set via 'GIT_DIR' or on the
638 'GIT_COMMITTER_NAME'::
639 'GIT_COMMITTER_EMAIL'::
640 'GIT_COMMITTER_DATE'::
642 see linkgit:git-commit-tree[1]
647 Only valid setting is "--unified=??" or "-u??" to set the
648 number of context lines shown when a unified diff is created.
649 This takes precedence over any "-U" or "--unified" option
650 value passed on the git diff command line.
652 'GIT_EXTERNAL_DIFF'::
653 When the environment variable 'GIT_EXTERNAL_DIFF' is set, the
654 program named by it is called, instead of the diff invocation
655 described above. For a path that is added, removed, or modified,
656 'GIT_EXTERNAL_DIFF' is called with 7 parameters:
658 path old-file old-hex old-mode new-file new-hex new-mode
662 <old|new>-file:: are files GIT_EXTERNAL_DIFF can use to read the
663 contents of <old|new>,
664 <old|new>-hex:: are the 40-hexdigit SHA1 hashes,
665 <old|new>-mode:: are the octal representation of the file modes.
667 The file parameters can point at the user's working file
668 (e.g. `new-file` in "git-diff-files"), `/dev/null` (e.g. `old-file`
669 when a new file is added), or a temporary file (e.g. `old-file` in the
670 index). 'GIT_EXTERNAL_DIFF' should not worry about unlinking the
671 temporary file --- it is removed when 'GIT_EXTERNAL_DIFF' exits.
673 For a path that is unmerged, 'GIT_EXTERNAL_DIFF' is called with 1
678 'GIT_MERGE_VERBOSITY'::
679 A number controlling the amount of output shown by
680 the recursive merge strategy. Overrides merge.verbosity.
681 See linkgit:git-merge[1]
684 This environment variable overrides `$PAGER`. If it is set
685 to an empty string or to the value "cat", git will not launch
686 a pager. See also the `core.pager` option in
687 linkgit:git-config[1].
690 If this environment variable is set then 'git fetch'
691 and 'git push' will use this command instead
692 of 'ssh' when they need to connect to a remote system.
693 The '$GIT_SSH' command will be given exactly two arguments:
694 the 'username@host' (or just 'host') from the URL and the
695 shell command to execute on that remote system.
697 To pass options to the program that you want to list in GIT_SSH
698 you will need to wrap the program and options into a shell script,
699 then set GIT_SSH to refer to the shell script.
701 Usually it is easier to configure any desired options through your
702 personal `.ssh/config` file. Please consult your ssh documentation
706 If this environment variable is set, then git commands which need to
707 acquire passwords or passphrases (e.g. for HTTP or IMAP authentication)
708 will call this program with a suitable prompt as command line argument
709 and read the password from its STDOUT. See also the 'core.askpass'
710 option in linkgit:git-config[1].
713 If this environment variable is set to "1", then commands such
714 as 'git blame' (in incremental mode), 'git rev-list', 'git log',
715 and 'git whatchanged' will force a flush of the output stream
716 after each commit-oriented record have been flushed. If this
717 variable is set to "0", the output of these commands will be done
718 using completely buffered I/O. If this environment variable is
719 not set, git will choose buffered or record-oriented flushing
720 based on whether stdout appears to be redirected to a file or not.
723 If this variable is set to "1", "2" or "true" (comparison
724 is case insensitive), git will print `trace:` messages on
725 stderr telling about alias expansion, built-in command
726 execution and external command execution.
727 If this variable is set to an integer value greater than 1
728 and lower than 10 (strictly) then git will interpret this
729 value as an open file descriptor and will try to write the
730 trace messages into this file descriptor.
731 Alternatively, if this variable is set to an absolute path
732 (starting with a '/' character), git will interpret this
733 as a file path and will try to write the trace messages
736 Discussion[[Discussion]]
737 ------------------------
739 More detail on the following is available from the
740 link:user-manual.html#git-concepts[git concepts chapter of the
741 user-manual] and linkgit:gitcore-tutorial[7].
743 A git project normally consists of a working directory with a ".git"
744 subdirectory at the top level. The .git directory contains, among other
745 things, a compressed object database representing the complete history
746 of the project, an "index" file which links that history to the current
747 contents of the working tree, and named pointers into that history such
748 as tags and branch heads.
750 The object database contains objects of three main types: blobs, which
751 hold file data; trees, which point to blobs and other trees to build up
752 directory hierarchies; and commits, which each reference a single tree
753 and some number of parent commits.
755 The commit, equivalent to what other systems call a "changeset" or
756 "version", represents a step in the project's history, and each parent
757 represents an immediately preceding step. Commits with more than one
758 parent represent merges of independent lines of development.
760 All objects are named by the SHA1 hash of their contents, normally
761 written as a string of 40 hex digits. Such names are globally unique.
762 The entire history leading up to a commit can be vouched for by signing
763 just that commit. A fourth object type, the tag, is provided for this
766 When first created, objects are stored in individual files, but for
767 efficiency may later be compressed together into "pack files".
769 Named pointers called refs mark interesting points in history. A ref
770 may contain the SHA1 name of an object or the name of another ref. Refs
771 with names beginning `ref/head/` contain the SHA1 name of the most
772 recent commit (or "head") of a branch under development. SHA1 names of
773 tags of interest are stored under `ref/tags/`. A special ref named
774 `HEAD` contains the name of the currently checked-out branch.
776 The index file is initialized with a list of all paths and, for each
777 path, a blob object and a set of attributes. The blob object represents
778 the contents of the file as of the head of the current branch. The
779 attributes (last modified time, size, etc.) are taken from the
780 corresponding file in the working tree. Subsequent changes to the
781 working tree can be found by comparing these attributes. The index may
782 be updated with new content, and new commits may be created from the
783 content stored in the index.
785 The index is also capable of storing multiple entries (called "stages")
786 for a given pathname. These stages are used to hold the various
787 unmerged version of a file when a merge is in progress.
791 Git was started by Linus Torvalds, and is currently maintained by Junio
792 C Hamano. Numerous contributions have come from the git mailing list
793 <git@vger.kernel.org>. For a more complete list of contributors, see
794 http://git-scm.com/about. If you have a clone of git.git itself, the
795 output of linkgit:git-shortlog[1] and linkgit:git-blame[1] can show you
796 the authors for specific parts of the project.
801 Report bugs to the Git mailing list <git@vger.kernel.org> where the
802 development and maintenance is primarily done. You do not have to be
803 subscribed to the list to send a message there.
807 linkgit:gittutorial[7], linkgit:gittutorial-2[7],
808 link:everyday.html[Everyday Git], linkgit:gitcvs-migration[7],
809 linkgit:gitglossary[7], linkgit:gitcore-tutorial[7],
810 linkgit:gitcli[7], link:user-manual.html[The Git User's Manual],
811 linkgit:gitworkflows[7]
815 Part of the linkgit:git[1] suite