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[git/git.git] / Documentation / git.txt
1 git(7)
2 ======
3
4 NAME
5 ----
6 git - the stupid content tracker
7
8
9 SYNOPSIS
10 --------
11 [verse]
12 'git' [--version] [--exec-path[=GIT_EXEC_PATH]]
13 [-p|--paginate|--no-pager]
14 [--bare] [--git-dir=GIT_DIR] [--work-tree=GIT_WORK_TREE]
15 [--help] COMMAND [ARGS]
16
17 DESCRIPTION
18 -----------
19 Git is a fast, scalable, distributed revision control system with an
20 unusually rich command set that provides both high-level operations
21 and full access to internals.
22
23 See this link:tutorial.html[tutorial] to get started, then see
24 link:everyday.html[Everyday Git] for a useful minimum set of commands, and
25 "man git-commandname" for documentation of each command. CVS users may
26 also want to read link:cvs-migration.html[CVS migration]. See
27 link:user-manual.html[Git User's Manual] for a more in-depth
28 introduction.
29
30 The COMMAND is either a name of a Git command (see below) or an alias
31 as defined in the configuration file (see gitlink:git-config[1]).
32
33 Formatted and hyperlinked version of the latest git
34 documentation can be viewed at
35 `http://www.kernel.org/pub/software/scm/git/docs/`.
36
37 ifdef::stalenotes[]
38 [NOTE]
39 ============
40
41 You are reading the documentation for the latest (possibly
42 unreleased) version of git, that is available from 'master'
43 branch of the `git.git` repository.
44 Documentation for older releases are available here:
45
46 * link:v1.5.3/git.html[documentation for release 1.5.3]
47
48 * release notes for
49 link:RelNotes-1.5.3.7.txt[1.5.3.7],
50 link:RelNotes-1.5.3.6.txt[1.5.3.6],
51 link:RelNotes-1.5.3.5.txt[1.5.3.5],
52 link:RelNotes-1.5.3.4.txt[1.5.3.4],
53 link:RelNotes-1.5.3.3.txt[1.5.3.3],
54 link:RelNotes-1.5.3.2.txt[1.5.3.2],
55 link:RelNotes-1.5.3.1.txt[1.5.3.1],
56 link:RelNotes-1.5.3.txt[1.5.3].
57
58 * release notes for
59 link:RelNotes-1.5.2.5.txt[1.5.2.5],
60 link:RelNotes-1.5.2.4.txt[1.5.2.4],
61 link:RelNotes-1.5.2.3.txt[1.5.2.3],
62 link:RelNotes-1.5.2.2.txt[1.5.2.2],
63 link:RelNotes-1.5.2.1.txt[1.5.2.1],
64 link:RelNotes-1.5.2.txt[1.5.2].
65
66 * link:v1.5.1.6/git.html[documentation for release 1.5.1.6]
67
68 * release notes for
69 link:RelNotes-1.5.1.6.txt[1.5.1.6],
70 link:RelNotes-1.5.1.5.txt[1.5.1.5],
71 link:RelNotes-1.5.1.4.txt[1.5.1.4],
72 link:RelNotes-1.5.1.3.txt[1.5.1.3],
73 link:RelNotes-1.5.1.2.txt[1.5.1.2],
74 link:RelNotes-1.5.1.1.txt[1.5.1.1],
75 link:RelNotes-1.5.1.txt[1.5.1].
76
77 * link:v1.5.0.7/git.html[documentation for release 1.5.0.7]
78
79 * release notes for
80 link:RelNotes-1.5.0.7.txt[1.5.0.7],
81 link:RelNotes-1.5.0.6.txt[1.5.0.6],
82 link:RelNotes-1.5.0.5.txt[1.5.0.5],
83 link:RelNotes-1.5.0.3.txt[1.5.0.3],
84 link:RelNotes-1.5.0.2.txt[1.5.0.2],
85 link:RelNotes-1.5.0.1.txt[1.5.0.1],
86 link:RelNotes-1.5.0.txt[1.5.0].
87
88 * documentation for release link:v1.4.4.4/git.html[1.4.4.4],
89 link:v1.3.3/git.html[1.3.3],
90 link:v1.2.6/git.html[1.2.6],
91 link:v1.0.13/git.html[1.0.13].
92
93 ============
94
95 endif::stalenotes[]
96
97 OPTIONS
98 -------
99 --version::
100 Prints the git suite version that the 'git' program came from.
101
102 --help::
103 Prints the synopsis and a list of the most commonly used
104 commands. If the option '--all' or '-a' is given then all
105 available commands are printed. If a git command is named this
106 option will bring up the manual page for that command.
107 +
108 Other options are available to control how the manual page is
109 displayed. See gitlink:git-help[1] for more information,
110 because 'git --help ...' is converted internally into 'git
111 help ...'.
112
113 --exec-path::
114 Path to wherever your core git programs are installed.
115 This can also be controlled by setting the GIT_EXEC_PATH
116 environment variable. If no path is given 'git' will print
117 the current setting and then exit.
118
119 -p|--paginate::
120 Pipe all output into 'less' (or if set, $PAGER).
121
122 --no-pager::
123 Do not pipe git output into a pager.
124
125 --git-dir=<path>::
126 Set the path to the repository. This can also be controlled by
127 setting the GIT_DIR environment variable.
128
129 --work-tree=<path>::
130 Set the path to the working tree. The value will not be
131 used in combination with repositories found automatically in
132 a .git directory (i.e. $GIT_DIR is not set).
133 This can also be controlled by setting the GIT_WORK_TREE
134 environment variable and the core.worktree configuration
135 variable.
136
137 --bare::
138 Treat the repository as a bare repository. If GIT_DIR
139 environment is not set, it is set to the current working
140 directory.
141
142
143 FURTHER DOCUMENTATION
144 ---------------------
145
146 See the references above to get started using git. The following is
147 probably more detail than necessary for a first-time user.
148
149 The link:user-manual.html#git-concepts[git concepts chapter of the
150 user-manual] and the link:core-tutorial.html[Core tutorial] both provide
151 introductions to the underlying git architecture.
152
153 See also the link:howto-index.html[howto] documents for some useful
154 examples.
155
156 The internals are documented link:technical/api-index.html[here].
157
158 GIT COMMANDS
159 ------------
160
161 We divide git into high level ("porcelain") commands and low level
162 ("plumbing") commands.
163
164 High-level commands (porcelain)
165 -------------------------------
166
167 We separate the porcelain commands into the main commands and some
168 ancillary user utilities.
169
170 Main porcelain commands
171 ~~~~~~~~~~~~~~~~~~~~~~~
172
173 include::cmds-mainporcelain.txt[]
174
175 Ancillary Commands
176 ~~~~~~~~~~~~~~~~~~
177 Manipulators:
178
179 include::cmds-ancillarymanipulators.txt[]
180
181 Interrogators:
182
183 include::cmds-ancillaryinterrogators.txt[]
184
185
186 Interacting with Others
187 ~~~~~~~~~~~~~~~~~~~~~~~
188
189 These commands are to interact with foreign SCM and with other
190 people via patch over e-mail.
191
192 include::cmds-foreignscminterface.txt[]
193
194
195 Low-level commands (plumbing)
196 -----------------------------
197
198 Although git includes its
199 own porcelain layer, its low-level commands are sufficient to support
200 development of alternative porcelains. Developers of such porcelains
201 might start by reading about gitlink:git-update-index[1] and
202 gitlink:git-read-tree[1].
203
204 The interface (input, output, set of options and the semantics)
205 to these low-level commands are meant to be a lot more stable
206 than Porcelain level commands, because these commands are
207 primarily for scripted use. The interface to Porcelain commands
208 on the other hand are subject to change in order to improve the
209 end user experience.
210
211 The following description divides
212 the low-level commands into commands that manipulate objects (in
213 the repository, index, and working tree), commands that interrogate and
214 compare objects, and commands that move objects and references between
215 repositories.
216
217
218 Manipulation commands
219 ~~~~~~~~~~~~~~~~~~~~~
220
221 include::cmds-plumbingmanipulators.txt[]
222
223
224 Interrogation commands
225 ~~~~~~~~~~~~~~~~~~~~~~
226
227 include::cmds-plumbinginterrogators.txt[]
228
229 In general, the interrogate commands do not touch the files in
230 the working tree.
231
232
233 Synching repositories
234 ~~~~~~~~~~~~~~~~~~~~~
235
236 include::cmds-synchingrepositories.txt[]
237
238 The following are helper programs used by the above; end users
239 typically do not use them directly.
240
241 include::cmds-synchelpers.txt[]
242
243
244 Internal helper commands
245 ~~~~~~~~~~~~~~~~~~~~~~~~
246
247 These are internal helper commands used by other commands; end
248 users typically do not use them directly.
249
250 include::cmds-purehelpers.txt[]
251
252
253 Configuration Mechanism
254 -----------------------
255
256 Starting from 0.99.9 (actually mid 0.99.8.GIT), `.git/config` file
257 is used to hold per-repository configuration options. It is a
258 simple text file modeled after `.ini` format familiar to some
259 people. Here is an example:
260
261 ------------
262 #
263 # A '#' or ';' character indicates a comment.
264 #
265
266 ; core variables
267 [core]
268 ; Don't trust file modes
269 filemode = false
270
271 ; user identity
272 [user]
273 name = "Junio C Hamano"
274 email = "junkio@twinsun.com"
275
276 ------------
277
278 Various commands read from the configuration file and adjust
279 their operation accordingly.
280
281
282 Identifier Terminology
283 ----------------------
284 <object>::
285 Indicates the object name for any type of object.
286
287 <blob>::
288 Indicates a blob object name.
289
290 <tree>::
291 Indicates a tree object name.
292
293 <commit>::
294 Indicates a commit object name.
295
296 <tree-ish>::
297 Indicates a tree, commit or tag object name. A
298 command that takes a <tree-ish> argument ultimately wants to
299 operate on a <tree> object but automatically dereferences
300 <commit> and <tag> objects that point at a <tree>.
301
302 <commit-ish>::
303 Indicates a commit or tag object name. A
304 command that takes a <commit-ish> argument ultimately wants to
305 operate on a <commit> object but automatically dereferences
306 <tag> objects that point at a <commit>.
307
308 <type>::
309 Indicates that an object type is required.
310 Currently one of: `blob`, `tree`, `commit`, or `tag`.
311
312 <file>::
313 Indicates a filename - almost always relative to the
314 root of the tree structure `GIT_INDEX_FILE` describes.
315
316 Symbolic Identifiers
317 --------------------
318 Any git command accepting any <object> can also use the following
319 symbolic notation:
320
321 HEAD::
322 indicates the head of the current branch (i.e. the
323 contents of `$GIT_DIR/HEAD`).
324
325 <tag>::
326 a valid tag 'name'
327 (i.e. the contents of `$GIT_DIR/refs/tags/<tag>`).
328
329 <head>::
330 a valid head 'name'
331 (i.e. the contents of `$GIT_DIR/refs/heads/<head>`).
332
333 For a more complete list of ways to spell object names, see
334 "SPECIFYING REVISIONS" section in gitlink:git-rev-parse[1].
335
336
337 File/Directory Structure
338 ------------------------
339
340 Please see the link:repository-layout.html[repository layout] document.
341
342 Read link:hooks.html[hooks] for more details about each hook.
343
344 Higher level SCMs may provide and manage additional information in the
345 `$GIT_DIR`.
346
347
348 Terminology
349 -----------
350 Please see the link:glossary.html[glossary] document.
351
352
353 Environment Variables
354 ---------------------
355 Various git commands use the following environment variables:
356
357 The git Repository
358 ~~~~~~~~~~~~~~~~~~
359 These environment variables apply to 'all' core git commands. Nb: it
360 is worth noting that they may be used/overridden by SCMS sitting above
361 git so take care if using Cogito etc.
362
363 'GIT_INDEX_FILE'::
364 This environment allows the specification of an alternate
365 index file. If not specified, the default of `$GIT_DIR/index`
366 is used.
367
368 'GIT_OBJECT_DIRECTORY'::
369 If the object storage directory is specified via this
370 environment variable then the sha1 directories are created
371 underneath - otherwise the default `$GIT_DIR/objects`
372 directory is used.
373
374 'GIT_ALTERNATE_OBJECT_DIRECTORIES'::
375 Due to the immutable nature of git objects, old objects can be
376 archived into shared, read-only directories. This variable
377 specifies a ":" separated list of git object directories which
378 can be used to search for git objects. New objects will not be
379 written to these directories.
380
381 'GIT_DIR'::
382 If the 'GIT_DIR' environment variable is set then it
383 specifies a path to use instead of the default `.git`
384 for the base of the repository.
385
386 'GIT_WORK_TREE'::
387 Set the path to the working tree. The value will not be
388 used in combination with repositories found automatically in
389 a .git directory (i.e. $GIT_DIR is not set).
390 This can also be controlled by the '--work-tree' command line
391 option and the core.worktree configuration variable.
392
393 git Commits
394 ~~~~~~~~~~~
395 'GIT_AUTHOR_NAME'::
396 'GIT_AUTHOR_EMAIL'::
397 'GIT_AUTHOR_DATE'::
398 'GIT_COMMITTER_NAME'::
399 'GIT_COMMITTER_EMAIL'::
400 'GIT_COMMITTER_DATE'::
401 'EMAIL'::
402 see gitlink:git-commit-tree[1]
403
404 git Diffs
405 ~~~~~~~~~
406 'GIT_DIFF_OPTS'::
407 Only valid setting is "--unified=??" or "-u??" to set the
408 number of context lines shown when a unified diff is created.
409 This takes precedence over any "-U" or "--unified" option
410 value passed on the git diff command line.
411
412 'GIT_EXTERNAL_DIFF'::
413 When the environment variable 'GIT_EXTERNAL_DIFF' is set, the
414 program named by it is called, instead of the diff invocation
415 described above. For a path that is added, removed, or modified,
416 'GIT_EXTERNAL_DIFF' is called with 7 parameters:
417
418 path old-file old-hex old-mode new-file new-hex new-mode
419 +
420 where:
421
422 <old|new>-file:: are files GIT_EXTERNAL_DIFF can use to read the
423 contents of <old|new>,
424 <old|new>-hex:: are the 40-hexdigit SHA1 hashes,
425 <old|new>-mode:: are the octal representation of the file modes.
426
427 +
428 The file parameters can point at the user's working file
429 (e.g. `new-file` in "git-diff-files"), `/dev/null` (e.g. `old-file`
430 when a new file is added), or a temporary file (e.g. `old-file` in the
431 index). 'GIT_EXTERNAL_DIFF' should not worry about unlinking the
432 temporary file --- it is removed when 'GIT_EXTERNAL_DIFF' exits.
433 +
434 For a path that is unmerged, 'GIT_EXTERNAL_DIFF' is called with 1
435 parameter, <path>.
436
437 other
438 ~~~~~
439 'GIT_MERGE_VERBOSITY'::
440 A number controlling the amount of output shown by
441 the recursive merge strategy. Overrides merge.verbosity.
442 See gitlink:git-merge[1]
443
444 'GIT_PAGER'::
445 This environment variable overrides `$PAGER`. If it is set
446 to an empty string or to the value "cat", git will not launch
447 a pager.
448
449 'GIT_SSH'::
450 If this environment variable is set then gitlink:git-fetch[1]
451 and gitlink:git-push[1] will use this command instead
452 of `ssh` when they need to connect to a remote system.
453 The 'GIT_SSH' command will be given exactly two arguments:
454 the 'username@host' (or just 'host') from the URL and the
455 shell command to execute on that remote system.
456 +
457 To pass options to the program that you want to list in GIT_SSH
458 you will need to wrap the program and options into a shell script,
459 then set GIT_SSH to refer to the shell script.
460 +
461 Usually it is easier to configure any desired options through your
462 personal `.ssh/config` file. Please consult your ssh documentation
463 for further details.
464
465 'GIT_FLUSH'::
466 If this environment variable is set to "1", then commands such
467 as git-blame (in incremental mode), git-rev-list, git-log,
468 git-whatchanged, etc., will force a flush of the output stream
469 after each commit-oriented record have been flushed. If this
470 variable is set to "0", the output of these commands will be done
471 using completely buffered I/O. If this environment variable is
472 not set, git will choose buffered or record-oriented flushing
473 based on whether stdout appears to be redirected to a file or not.
474
475 'GIT_TRACE'::
476 If this variable is set to "1", "2" or "true" (comparison
477 is case insensitive), git will print `trace:` messages on
478 stderr telling about alias expansion, built-in command
479 execution and external command execution.
480 If this variable is set to an integer value greater than 1
481 and lower than 10 (strictly) then git will interpret this
482 value as an open file descriptor and will try to write the
483 trace messages into this file descriptor.
484 Alternatively, if this variable is set to an absolute path
485 (starting with a '/' character), git will interpret this
486 as a file path and will try to write the trace messages
487 into it.
488
489 Discussion[[Discussion]]
490 ------------------------
491
492 More detail on the following is available from the
493 link:user-manual.html#git-concepts[git concepts chapter of the
494 user-manual] and the link:core-tutorial.html[Core tutorial].
495
496 A git project normally consists of a working directory with a ".git"
497 subdirectory at the top level. The .git directory contains, among other
498 things, a compressed object database representing the complete history
499 of the project, an "index" file which links that history to the current
500 contents of the working tree, and named pointers into that history such
501 as tags and branch heads.
502
503 The object database contains objects of three main types: blobs, which
504 hold file data; trees, which point to blobs and other trees to build up
505 directory heirarchies; and commits, which each reference a single tree
506 and some number of parent commits.
507
508 The commit, equivalent to what other systems call a "changeset" or
509 "version", represents a step in the project's history, and each parent
510 represents an immediately preceding step. Commits with more than one
511 parent represent merges of independent lines of development.
512
513 All objects are named by the SHA1 hash of their contents, normally
514 written as a string of 40 hex digits. Such names are globally unique.
515 The entire history leading up to a commit can be vouched for by signing
516 just that commit. A fourth object type, the tag, is provided for this
517 purpose.
518
519 When first created, objects are stored in individual files, but for
520 efficiency may later be compressed together into "pack files".
521
522 Named pointers called refs mark interesting points in history. A ref
523 may contain the SHA1 name of an object or the name of another ref. Refs
524 with names beginning `ref/head/` contain the SHA1 name of the most
525 recent commit (or "head") of a branch under developement. SHA1 names of
526 tags of interest are stored under `ref/tags/`. A special ref named
527 `HEAD` contains the name of the currently checked-out branch.
528
529 The index file is initialized with a list of all paths and, for each
530 path, a blob object and a set of attributes. The blob object represents
531 the contents of the file as of the head of the current branch. The
532 attributes (last modified time, size, etc.) are taken from the
533 corresponding file in the working tree. Subsequent changes to the
534 working tree can be found by comparing these attributes. The index may
535 be updated with new content, and new commits may be created from the
536 content stored in the index.
537
538 The index is also capable of storing multiple entries (called "stages")
539 for a given pathname. These stages are used to hold the various
540 unmerged version of a file when a merge is in progress.
541
542 Authors
543 -------
544 * git's founding father is Linus Torvalds <torvalds@osdl.org>.
545 * The current git nurse is Junio C Hamano <gitster@pobox.com>.
546 * The git potty was written by Andreas Ericsson <ae@op5.se>.
547 * General upbringing is handled by the git-list <git@vger.kernel.org>.
548
549 Documentation
550 --------------
551 The documentation for git suite was started by David Greaves
552 <david@dgreaves.com>, and later enhanced greatly by the
553 contributors on the git-list <git@vger.kernel.org>.
554
555 GIT
556 ---
557 Part of the gitlink:git[7] suite