Merge branch 'dr/ceiling'
[git/git.git] / Documentation / git.txt
1 git(1)
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 linkgit:gittutorial[7] 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 linkgit:gitcvs-migration[7]. See
27 the 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 linkgit: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:v1.5.6.2/git.html[documentation for release 1.5.6.2]
47
48 * release notes for
49 link:RelNotes-1.5.6.2.txt[1.5.6.2].
50 link:RelNotes-1.5.6.1.txt[1.5.6.1].
51 link:RelNotes-1.5.6.txt[1.5.6].
52
53 * link:v1.5.5.4/git.html[documentation for release 1.5.5.4]
54
55 * release notes for
56 link:RelNotes-1.5.5.4.txt[1.5.5.4],
57 link:RelNotes-1.5.5.3.txt[1.5.5.3],
58 link:RelNotes-1.5.5.2.txt[1.5.5.2],
59 link:RelNotes-1.5.5.1.txt[1.5.5.1],
60 link:RelNotes-1.5.5.txt[1.5.5].
61
62 * link:v1.5.4.5/git.html[documentation for release 1.5.4.5]
63
64 * release notes for
65 link:RelNotes-1.5.4.5.txt[1.5.4.5],
66 link:RelNotes-1.5.4.4.txt[1.5.4.4],
67 link:RelNotes-1.5.4.3.txt[1.5.4.3],
68 link:RelNotes-1.5.4.2.txt[1.5.4.2],
69 link:RelNotes-1.5.4.1.txt[1.5.4.1],
70 link:RelNotes-1.5.4.txt[1.5.4].
71
72 * link:v1.5.3.8/git.html[documentation for release 1.5.3.8]
73
74 * release notes for
75 link:RelNotes-1.5.3.8.txt[1.5.3.8],
76 link:RelNotes-1.5.3.7.txt[1.5.3.7],
77 link:RelNotes-1.5.3.6.txt[1.5.3.6],
78 link:RelNotes-1.5.3.5.txt[1.5.3.5],
79 link:RelNotes-1.5.3.4.txt[1.5.3.4],
80 link:RelNotes-1.5.3.3.txt[1.5.3.3],
81 link:RelNotes-1.5.3.2.txt[1.5.3.2],
82 link:RelNotes-1.5.3.1.txt[1.5.3.1],
83 link:RelNotes-1.5.3.txt[1.5.3].
84
85 * link:v1.5.2.5/git.html[documentation for release 1.5.2.5]
86
87 * release notes for
88 link:RelNotes-1.5.2.5.txt[1.5.2.5],
89 link:RelNotes-1.5.2.4.txt[1.5.2.4],
90 link:RelNotes-1.5.2.3.txt[1.5.2.3],
91 link:RelNotes-1.5.2.2.txt[1.5.2.2],
92 link:RelNotes-1.5.2.1.txt[1.5.2.1],
93 link:RelNotes-1.5.2.txt[1.5.2].
94
95 * link:v1.5.1.6/git.html[documentation for release 1.5.1.6]
96
97 * release notes for
98 link:RelNotes-1.5.1.6.txt[1.5.1.6],
99 link:RelNotes-1.5.1.5.txt[1.5.1.5],
100 link:RelNotes-1.5.1.4.txt[1.5.1.4],
101 link:RelNotes-1.5.1.3.txt[1.5.1.3],
102 link:RelNotes-1.5.1.2.txt[1.5.1.2],
103 link:RelNotes-1.5.1.1.txt[1.5.1.1],
104 link:RelNotes-1.5.1.txt[1.5.1].
105
106 * link:v1.5.0.7/git.html[documentation for release 1.5.0.7]
107
108 * release notes for
109 link:RelNotes-1.5.0.7.txt[1.5.0.7],
110 link:RelNotes-1.5.0.6.txt[1.5.0.6],
111 link:RelNotes-1.5.0.5.txt[1.5.0.5],
112 link:RelNotes-1.5.0.3.txt[1.5.0.3],
113 link:RelNotes-1.5.0.2.txt[1.5.0.2],
114 link:RelNotes-1.5.0.1.txt[1.5.0.1],
115 link:RelNotes-1.5.0.txt[1.5.0].
116
117 * documentation for release link:v1.4.4.4/git.html[1.4.4.4],
118 link:v1.3.3/git.html[1.3.3],
119 link:v1.2.6/git.html[1.2.6],
120 link:v1.0.13/git.html[1.0.13].
121
122 ============
123
124 endif::stalenotes[]
125
126 OPTIONS
127 -------
128 --version::
129 Prints the git suite version that the 'git' program came from.
130
131 --help::
132 Prints the synopsis and a list of the most commonly used
133 commands. If the option '--all' or '-a' is given then all
134 available commands are printed. If a git command is named this
135 option will bring up the manual page for that command.
136 +
137 Other options are available to control how the manual page is
138 displayed. See linkgit:git-help[1] for more information,
139 because `git --help ...` is converted internally into `git
140 help ...`.
141
142 --exec-path::
143 Path to wherever your core git programs are installed.
144 This can also be controlled by setting the GIT_EXEC_PATH
145 environment variable. If no path is given, 'git' will print
146 the current setting and then exit.
147
148 -p::
149 --paginate::
150 Pipe all output into 'less' (or if set, $PAGER).
151
152 --no-pager::
153 Do not pipe git output into a pager.
154
155 --git-dir=<path>::
156 Set the path to the repository. This can also be controlled by
157 setting the GIT_DIR environment variable. It can be an absolute
158 path or relative path to current working directory.
159
160 --work-tree=<path>::
161 Set the path to the working tree. The value will not be
162 used in combination with repositories found automatically in
163 a .git directory (i.e. $GIT_DIR is not set).
164 This can also be controlled by setting the GIT_WORK_TREE
165 environment variable and the core.worktree configuration
166 variable. It can be an absolute path or relative path to
167 the directory specified by --git-dir or GIT_DIR.
168 Note: If --git-dir or GIT_DIR are specified but none of
169 --work-tree, GIT_WORK_TREE and core.worktree is specified,
170 the current working directory is regarded as the top directory
171 of your working tree.
172
173 --bare::
174 Treat the repository as a bare repository. If GIT_DIR
175 environment is not set, it is set to the current working
176 directory.
177
178
179 FURTHER DOCUMENTATION
180 ---------------------
181
182 See the references above to get started using git. The following is
183 probably more detail than necessary for a first-time user.
184
185 The link:user-manual.html#git-concepts[git concepts chapter of the
186 user-manual] and linkgit:gitcore-tutorial[7] both provide
187 introductions to the underlying git architecture.
188
189 See also the link:howto-index.html[howto] documents for some useful
190 examples.
191
192 The internals are documented in the
193 link:technical/api-index.html[GIT API documentation].
194
195 GIT COMMANDS
196 ------------
197
198 We divide git into high level ("porcelain") commands and low level
199 ("plumbing") commands.
200
201 High-level commands (porcelain)
202 -------------------------------
203
204 We separate the porcelain commands into the main commands and some
205 ancillary user utilities.
206
207 Main porcelain commands
208 ~~~~~~~~~~~~~~~~~~~~~~~
209
210 include::cmds-mainporcelain.txt[]
211
212 Ancillary Commands
213 ~~~~~~~~~~~~~~~~~~
214 Manipulators:
215
216 include::cmds-ancillarymanipulators.txt[]
217
218 Interrogators:
219
220 include::cmds-ancillaryinterrogators.txt[]
221
222
223 Interacting with Others
224 ~~~~~~~~~~~~~~~~~~~~~~~
225
226 These commands are to interact with foreign SCM and with other
227 people via patch over e-mail.
228
229 include::cmds-foreignscminterface.txt[]
230
231
232 Low-level commands (plumbing)
233 -----------------------------
234
235 Although git includes its
236 own porcelain layer, its low-level commands are sufficient to support
237 development of alternative porcelains. Developers of such porcelains
238 might start by reading about linkgit:git-update-index[1] and
239 linkgit:git-read-tree[1].
240
241 The interface (input, output, set of options and the semantics)
242 to these low-level commands are meant to be a lot more stable
243 than Porcelain level commands, because these commands are
244 primarily for scripted use. The interface to Porcelain commands
245 on the other hand are subject to change in order to improve the
246 end user experience.
247
248 The following description divides
249 the low-level commands into commands that manipulate objects (in
250 the repository, index, and working tree), commands that interrogate and
251 compare objects, and commands that move objects and references between
252 repositories.
253
254
255 Manipulation commands
256 ~~~~~~~~~~~~~~~~~~~~~
257
258 include::cmds-plumbingmanipulators.txt[]
259
260
261 Interrogation commands
262 ~~~~~~~~~~~~~~~~~~~~~~
263
264 include::cmds-plumbinginterrogators.txt[]
265
266 In general, the interrogate commands do not touch the files in
267 the working tree.
268
269
270 Synching repositories
271 ~~~~~~~~~~~~~~~~~~~~~
272
273 include::cmds-synchingrepositories.txt[]
274
275 The following are helper programs used by the above; end users
276 typically do not use them directly.
277
278 include::cmds-synchelpers.txt[]
279
280
281 Internal helper commands
282 ~~~~~~~~~~~~~~~~~~~~~~~~
283
284 These are internal helper commands used by other commands; end
285 users typically do not use them directly.
286
287 include::cmds-purehelpers.txt[]
288
289
290 Configuration Mechanism
291 -----------------------
292
293 Starting from 0.99.9 (actually mid 0.99.8.GIT), `.git/config` file
294 is used to hold per-repository configuration options. It is a
295 simple text file modeled after `.ini` format familiar to some
296 people. Here is an example:
297
298 ------------
299 #
300 # A '#' or ';' character indicates a comment.
301 #
302
303 ; core variables
304 [core]
305 ; Don't trust file modes
306 filemode = false
307
308 ; user identity
309 [user]
310 name = "Junio C Hamano"
311 email = "junkio@twinsun.com"
312
313 ------------
314
315 Various commands read from the configuration file and adjust
316 their operation accordingly.
317
318
319 Identifier Terminology
320 ----------------------
321 <object>::
322 Indicates the object name for any type of object.
323
324 <blob>::
325 Indicates a blob object name.
326
327 <tree>::
328 Indicates a tree object name.
329
330 <commit>::
331 Indicates a commit object name.
332
333 <tree-ish>::
334 Indicates a tree, commit or tag object name. A
335 command that takes a <tree-ish> argument ultimately wants to
336 operate on a <tree> object but automatically dereferences
337 <commit> and <tag> objects that point at a <tree>.
338
339 <commit-ish>::
340 Indicates a commit or tag object name. A
341 command that takes a <commit-ish> argument ultimately wants to
342 operate on a <commit> object but automatically dereferences
343 <tag> objects that point at a <commit>.
344
345 <type>::
346 Indicates that an object type is required.
347 Currently one of: `blob`, `tree`, `commit`, or `tag`.
348
349 <file>::
350 Indicates a filename - almost always relative to the
351 root of the tree structure `GIT_INDEX_FILE` describes.
352
353 Symbolic Identifiers
354 --------------------
355 Any git command accepting any <object> can also use the following
356 symbolic notation:
357
358 HEAD::
359 indicates the head of the current branch (i.e. the
360 contents of `$GIT_DIR/HEAD`).
361
362 <tag>::
363 a valid tag 'name'
364 (i.e. the contents of `$GIT_DIR/refs/tags/<tag>`).
365
366 <head>::
367 a valid head 'name'
368 (i.e. the contents of `$GIT_DIR/refs/heads/<head>`).
369
370 For a more complete list of ways to spell object names, see
371 "SPECIFYING REVISIONS" section in linkgit:git-rev-parse[1].
372
373
374 File/Directory Structure
375 ------------------------
376
377 Please see the linkgit:gitrepository-layout[5] document.
378
379 Read linkgit:githooks[5] for more details about each hook.
380
381 Higher level SCMs may provide and manage additional information in the
382 `$GIT_DIR`.
383
384
385 Terminology
386 -----------
387 Please see linkgit:gitglossary[7].
388
389
390 Environment Variables
391 ---------------------
392 Various git commands use the following environment variables:
393
394 The git Repository
395 ~~~~~~~~~~~~~~~~~~
396 These environment variables apply to 'all' core git commands. Nb: it
397 is worth noting that they may be used/overridden by SCMS sitting above
398 git so take care if using Cogito etc.
399
400 'GIT_INDEX_FILE'::
401 This environment allows the specification of an alternate
402 index file. If not specified, the default of `$GIT_DIR/index`
403 is used.
404
405 'GIT_OBJECT_DIRECTORY'::
406 If the object storage directory is specified via this
407 environment variable then the sha1 directories are created
408 underneath - otherwise the default `$GIT_DIR/objects`
409 directory is used.
410
411 'GIT_ALTERNATE_OBJECT_DIRECTORIES'::
412 Due to the immutable nature of git objects, old objects can be
413 archived into shared, read-only directories. This variable
414 specifies a ":" separated (on Windows ";" separated) list
415 of git object directories which can be used to search for git
416 objects. New objects will not be written to these directories.
417
418 'GIT_DIR'::
419 If the 'GIT_DIR' environment variable is set then it
420 specifies a path to use instead of the default `.git`
421 for the base of the repository.
422
423 'GIT_WORK_TREE'::
424 Set the path to the working tree. The value will not be
425 used in combination with repositories found automatically in
426 a .git directory (i.e. $GIT_DIR is not set).
427 This can also be controlled by the '--work-tree' command line
428 option and the core.worktree configuration variable.
429
430 'GIT_CEILING_DIRECTORIES'::
431 This should be a colon-separated list of absolute paths.
432 If set, it is a list of directories that git should not chdir
433 up into while looking for a repository directory.
434 It will not exclude the current working directory or
435 a GIT_DIR set on the command line or in the environment.
436 (Useful for excluding slow-loading network directories.)
437
438 git Commits
439 ~~~~~~~~~~~
440 'GIT_AUTHOR_NAME'::
441 'GIT_AUTHOR_EMAIL'::
442 'GIT_AUTHOR_DATE'::
443 'GIT_COMMITTER_NAME'::
444 'GIT_COMMITTER_EMAIL'::
445 'GIT_COMMITTER_DATE'::
446 'EMAIL'::
447 see linkgit:git-commit-tree[1]
448
449 git Diffs
450 ~~~~~~~~~
451 'GIT_DIFF_OPTS'::
452 Only valid setting is "--unified=??" or "-u??" to set the
453 number of context lines shown when a unified diff is created.
454 This takes precedence over any "-U" or "--unified" option
455 value passed on the git diff command line.
456
457 'GIT_EXTERNAL_DIFF'::
458 When the environment variable 'GIT_EXTERNAL_DIFF' is set, the
459 program named by it is called, instead of the diff invocation
460 described above. For a path that is added, removed, or modified,
461 'GIT_EXTERNAL_DIFF' is called with 7 parameters:
462
463 path old-file old-hex old-mode new-file new-hex new-mode
464 +
465 where:
466
467 <old|new>-file:: are files GIT_EXTERNAL_DIFF can use to read the
468 contents of <old|new>,
469 <old|new>-hex:: are the 40-hexdigit SHA1 hashes,
470 <old|new>-mode:: are the octal representation of the file modes.
471
472 +
473 The file parameters can point at the user's working file
474 (e.g. `new-file` in "git-diff-files"), `/dev/null` (e.g. `old-file`
475 when a new file is added), or a temporary file (e.g. `old-file` in the
476 index). 'GIT_EXTERNAL_DIFF' should not worry about unlinking the
477 temporary file --- it is removed when 'GIT_EXTERNAL_DIFF' exits.
478 +
479 For a path that is unmerged, 'GIT_EXTERNAL_DIFF' is called with 1
480 parameter, <path>.
481
482 other
483 ~~~~~
484 'GIT_MERGE_VERBOSITY'::
485 A number controlling the amount of output shown by
486 the recursive merge strategy. Overrides merge.verbosity.
487 See linkgit:git-merge[1]
488
489 'GIT_PAGER'::
490 This environment variable overrides `$PAGER`. If it is set
491 to an empty string or to the value "cat", git will not launch
492 a pager.
493
494 'GIT_SSH'::
495 If this environment variable is set then 'git-fetch'
496 and 'git-push' will use this command instead
497 of 'ssh' when they need to connect to a remote system.
498 The '$GIT_SSH' command will be given exactly two arguments:
499 the 'username@host' (or just 'host') from the URL and the
500 shell command to execute on that remote system.
501 +
502 To pass options to the program that you want to list in GIT_SSH
503 you will need to wrap the program and options into a shell script,
504 then set GIT_SSH to refer to the shell script.
505 +
506 Usually it is easier to configure any desired options through your
507 personal `.ssh/config` file. Please consult your ssh documentation
508 for further details.
509
510 'GIT_FLUSH'::
511 If this environment variable is set to "1", then commands such
512 as 'git-blame' (in incremental mode), 'git-rev-list', 'git-log',
513 and 'git-whatchanged' will force a flush of the output stream
514 after each commit-oriented record have been flushed. If this
515 variable is set to "0", the output of these commands will be done
516 using completely buffered I/O. If this environment variable is
517 not set, git will choose buffered or record-oriented flushing
518 based on whether stdout appears to be redirected to a file or not.
519
520 'GIT_TRACE'::
521 If this variable is set to "1", "2" or "true" (comparison
522 is case insensitive), git will print `trace:` messages on
523 stderr telling about alias expansion, built-in command
524 execution and external command execution.
525 If this variable is set to an integer value greater than 1
526 and lower than 10 (strictly) then git will interpret this
527 value as an open file descriptor and will try to write the
528 trace messages into this file descriptor.
529 Alternatively, if this variable is set to an absolute path
530 (starting with a '/' character), git will interpret this
531 as a file path and will try to write the trace messages
532 into it.
533
534 Discussion[[Discussion]]
535 ------------------------
536
537 More detail on the following is available from the
538 link:user-manual.html#git-concepts[git concepts chapter of the
539 user-manual] and linkgit:gitcore-tutorial[7].
540
541 A git project normally consists of a working directory with a ".git"
542 subdirectory at the top level. The .git directory contains, among other
543 things, a compressed object database representing the complete history
544 of the project, an "index" file which links that history to the current
545 contents of the working tree, and named pointers into that history such
546 as tags and branch heads.
547
548 The object database contains objects of three main types: blobs, which
549 hold file data; trees, which point to blobs and other trees to build up
550 directory hierarchies; and commits, which each reference a single tree
551 and some number of parent commits.
552
553 The commit, equivalent to what other systems call a "changeset" or
554 "version", represents a step in the project's history, and each parent
555 represents an immediately preceding step. Commits with more than one
556 parent represent merges of independent lines of development.
557
558 All objects are named by the SHA1 hash of their contents, normally
559 written as a string of 40 hex digits. Such names are globally unique.
560 The entire history leading up to a commit can be vouched for by signing
561 just that commit. A fourth object type, the tag, is provided for this
562 purpose.
563
564 When first created, objects are stored in individual files, but for
565 efficiency may later be compressed together into "pack files".
566
567 Named pointers called refs mark interesting points in history. A ref
568 may contain the SHA1 name of an object or the name of another ref. Refs
569 with names beginning `ref/head/` contain the SHA1 name of the most
570 recent commit (or "head") of a branch under development. SHA1 names of
571 tags of interest are stored under `ref/tags/`. A special ref named
572 `HEAD` contains the name of the currently checked-out branch.
573
574 The index file is initialized with a list of all paths and, for each
575 path, a blob object and a set of attributes. The blob object represents
576 the contents of the file as of the head of the current branch. The
577 attributes (last modified time, size, etc.) are taken from the
578 corresponding file in the working tree. Subsequent changes to the
579 working tree can be found by comparing these attributes. The index may
580 be updated with new content, and new commits may be created from the
581 content stored in the index.
582
583 The index is also capable of storing multiple entries (called "stages")
584 for a given pathname. These stages are used to hold the various
585 unmerged version of a file when a merge is in progress.
586
587 Authors
588 -------
589 * git's founding father is Linus Torvalds <torvalds@osdl.org>.
590 * The current git nurse is Junio C Hamano <gitster@pobox.com>.
591 * The git potty was written by Andreas Ericsson <ae@op5.se>.
592 * General upbringing is handled by the git-list <git@vger.kernel.org>.
593
594 Documentation
595 --------------
596 The documentation for git suite was started by David Greaves
597 <david@dgreaves.com>, and later enhanced greatly by the
598 contributors on the git-list <git@vger.kernel.org>.
599
600 SEE ALSO
601 --------
602 linkgit:gittutorial[7], linkgit:gittutorial-2[7],
603 linkgit:giteveryday[7], linkgit:gitcvs-migration[7],
604 linkgit:gitglossary[7], linkgit:gitcore-tutorial[7],
605 linkgit:gitcli[7], link:user-manual.html[The Git User's Manual]
606
607 GIT
608 ---
609 Part of the linkgit:git[1] suite