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