git --bare cmd: do not unconditionally nuke GIT_DIR
[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:v1.5.2.5/git.html[documentation for release 1.5.2.5]
47
48 * release notes for
49 link:RelNotes-1.5.2.5.txt[1.5.2.5],
50 link:RelNotes-1.5.2.4.txt[1.5.2.4],
51 link:RelNotes-1.5.2.3.txt[1.5.2.3],
52 link:RelNotes-1.5.2.2.txt[1.5.2.2],
53 link:RelNotes-1.5.2.1.txt[1.5.2.1],
54 link:RelNotes-1.5.2.txt[1.5.2].
55
56 * link:v1.5.1.6/git.html[documentation for release 1.5.1.6]
57
58 * release notes for
59 link:RelNotes-1.5.1.6.txt[1.5.1.6],
60 link:RelNotes-1.5.1.5.txt[1.5.1.5],
61 link:RelNotes-1.5.1.4.txt[1.5.1.4],
62 link:RelNotes-1.5.1.3.txt[1.5.1.3],
63 link:RelNotes-1.5.1.2.txt[1.5.1.2],
64 link:RelNotes-1.5.1.1.txt[1.5.1.1],
65 link:RelNotes-1.5.1.txt[1.5.1].
66
67 * link:v1.5.0.7/git.html[documentation for release 1.5.0.7]
68
69 * release notes for
70 link:RelNotes-1.5.0.7.txt[1.5.0.7],
71 link:RelNotes-1.5.0.6.txt[1.5.0.6],
72 link:RelNotes-1.5.0.5.txt[1.5.0.5],
73 link:RelNotes-1.5.0.3.txt[1.5.0.3],
74 link:RelNotes-1.5.0.2.txt[1.5.0.2],
75 link:RelNotes-1.5.0.1.txt[1.5.0.1],
76 link:RelNotes-1.5.0.txt[1.5.0].
77
78 * documentation for release link:v1.4.4.4/git.html[1.4.4.4],
79 link:v1.3.3/git.html[1.3.3],
80 link:v1.2.6/git.html[1.2.6],
81 link:v1.0.13/git.html[1.0.13].
82
83 ============
84
85 endif::stalenotes[]
86
87 OPTIONS
88 -------
89 --version::
90 Prints the git suite version that the 'git' program came from.
91
92 --help::
93 Prints the synopsis and a list of the most commonly used
94 commands. If a git command is named this option will bring up
95 the man-page for that command. If the option '--all' or '-a' is
96 given then all available commands are printed.
97
98 --exec-path::
99 Path to wherever your core git programs are installed.
100 This can also be controlled by setting the GIT_EXEC_PATH
101 environment variable. If no path is given 'git' will print
102 the current setting and then exit.
103
104 -p|--paginate::
105 Pipe all output into 'less' (or if set, $PAGER).
106
107 --no-pager::
108 Do not pipe git output into a pager.
109
110 --git-dir=<path>::
111 Set the path to the repository. This can also be controlled by
112 setting the GIT_DIR environment variable.
113
114 --work-tree=<path>::
115 Set the path to the working tree. The value will not be
116 used in combination with repositories found automatically in
117 a .git directory (i.e. $GIT_DIR is not set).
118 This can also be controlled by setting the GIT_WORK_TREE
119 environment variable and the core.worktree configuration
120 variable.
121
122 --bare::
123 Treat the repository as a bare repository. If GIT_DIR
124 environment is not set, it is set to the current working
125 directory.
126
127
128 FURTHER DOCUMENTATION
129 ---------------------
130
131 See the references above to get started using git. The following is
132 probably more detail than necessary for a first-time user.
133
134 The <<Discussion,Discussion>> section below and the
135 link:core-tutorial.html[Core tutorial] both provide introductions to the
136 underlying git architecture.
137
138 See also the link:howto-index.html[howto] documents for some useful
139 examples.
140
141 GIT COMMANDS
142 ------------
143
144 We divide git into high level ("porcelain") commands and low level
145 ("plumbing") commands.
146
147 High-level commands (porcelain)
148 -------------------------------
149
150 We separate the porcelain commands into the main commands and some
151 ancillary user utilities.
152
153 Main porcelain commands
154 ~~~~~~~~~~~~~~~~~~~~~~~
155
156 include::cmds-mainporcelain.txt[]
157
158 Ancillary Commands
159 ~~~~~~~~~~~~~~~~~~
160 Manipulators:
161
162 include::cmds-ancillarymanipulators.txt[]
163
164 Interrogators:
165
166 include::cmds-ancillaryinterrogators.txt[]
167
168
169 Interacting with Others
170 ~~~~~~~~~~~~~~~~~~~~~~~
171
172 These commands are to interact with foreign SCM and with other
173 people via patch over e-mail.
174
175 include::cmds-foreignscminterface.txt[]
176
177
178 Low-level commands (plumbing)
179 -----------------------------
180
181 Although git includes its
182 own porcelain layer, its low-level commands are sufficient to support
183 development of alternative porcelains. Developers of such porcelains
184 might start by reading about gitlink:git-update-index[1] and
185 gitlink:git-read-tree[1].
186
187 The interface (input, output, set of options and the semantics)
188 to these low-level commands are meant to be a lot more stable
189 than Porcelain level commands, because these commands are
190 primarily for scripted use. The interface to Porcelain commands
191 on the other hand are subject to change in order to improve the
192 end user experience.
193
194 The following description divides
195 the low-level commands into commands that manipulate objects (in
196 the repository, index, and working tree), commands that interrogate and
197 compare objects, and commands that move objects and references between
198 repositories.
199
200
201 Manipulation commands
202 ~~~~~~~~~~~~~~~~~~~~~
203
204 include::cmds-plumbingmanipulators.txt[]
205
206
207 Interrogation commands
208 ~~~~~~~~~~~~~~~~~~~~~~
209
210 include::cmds-plumbinginterrogators.txt[]
211
212 In general, the interrogate commands do not touch the files in
213 the working tree.
214
215
216 Synching repositories
217 ~~~~~~~~~~~~~~~~~~~~~
218
219 include::cmds-synchingrepositories.txt[]
220
221 The following are helper programs used by the above; end users
222 typically do not use them directly.
223
224 include::cmds-synchelpers.txt[]
225
226
227 Internal helper commands
228 ~~~~~~~~~~~~~~~~~~~~~~~~
229
230 These are internal helper commands used by other commands; end
231 users typically do not use them directly.
232
233 include::cmds-purehelpers.txt[]
234
235
236 Configuration Mechanism
237 -----------------------
238
239 Starting from 0.99.9 (actually mid 0.99.8.GIT), `.git/config` file
240 is used to hold per-repository configuration options. It is a
241 simple text file modeled after `.ini` format familiar to some
242 people. Here is an example:
243
244 ------------
245 #
246 # A '#' or ';' character indicates a comment.
247 #
248
249 ; core variables
250 [core]
251 ; Don't trust file modes
252 filemode = false
253
254 ; user identity
255 [user]
256 name = "Junio C Hamano"
257 email = "junkio@twinsun.com"
258
259 ------------
260
261 Various commands read from the configuration file and adjust
262 their operation accordingly.
263
264
265 Identifier Terminology
266 ----------------------
267 <object>::
268 Indicates the object name for any type of object.
269
270 <blob>::
271 Indicates a blob object name.
272
273 <tree>::
274 Indicates a tree object name.
275
276 <commit>::
277 Indicates a commit object name.
278
279 <tree-ish>::
280 Indicates a tree, commit or tag object name. A
281 command that takes a <tree-ish> argument ultimately wants to
282 operate on a <tree> object but automatically dereferences
283 <commit> and <tag> objects that point at a <tree>.
284
285 <commit-ish>::
286 Indicates a commit or tag object name. A
287 command that takes a <commit-ish> argument ultimately wants to
288 operate on a <commit> object but automatically dereferences
289 <tag> objects that point at a <commit>.
290
291 <type>::
292 Indicates that an object type is required.
293 Currently one of: `blob`, `tree`, `commit`, or `tag`.
294
295 <file>::
296 Indicates a filename - almost always relative to the
297 root of the tree structure `GIT_INDEX_FILE` describes.
298
299 Symbolic Identifiers
300 --------------------
301 Any git command accepting any <object> can also use the following
302 symbolic notation:
303
304 HEAD::
305 indicates the head of the current branch (i.e. the
306 contents of `$GIT_DIR/HEAD`).
307
308 <tag>::
309 a valid tag 'name'
310 (i.e. the contents of `$GIT_DIR/refs/tags/<tag>`).
311
312 <head>::
313 a valid head 'name'
314 (i.e. the contents of `$GIT_DIR/refs/heads/<head>`).
315
316 For a more complete list of ways to spell object names, see
317 "SPECIFYING REVISIONS" section in gitlink:git-rev-parse[1].
318
319
320 File/Directory Structure
321 ------------------------
322
323 Please see link:repository-layout.html[repository layout] document.
324
325 Read link:hooks.html[hooks] for more details about each hook.
326
327 Higher level SCMs may provide and manage additional information in the
328 `$GIT_DIR`.
329
330
331 Terminology
332 -----------
333 Please see link:glossary.html[glossary] document.
334
335
336 Environment Variables
337 ---------------------
338 Various git commands use the following environment variables:
339
340 The git Repository
341 ~~~~~~~~~~~~~~~~~~
342 These environment variables apply to 'all' core git commands. Nb: it
343 is worth noting that they may be used/overridden by SCMS sitting above
344 git so take care if using Cogito etc.
345
346 'GIT_INDEX_FILE'::
347 This environment allows the specification of an alternate
348 index file. If not specified, the default of `$GIT_DIR/index`
349 is used.
350
351 'GIT_OBJECT_DIRECTORY'::
352 If the object storage directory is specified via this
353 environment variable then the sha1 directories are created
354 underneath - otherwise the default `$GIT_DIR/objects`
355 directory is used.
356
357 'GIT_ALTERNATE_OBJECT_DIRECTORIES'::
358 Due to the immutable nature of git objects, old objects can be
359 archived into shared, read-only directories. This variable
360 specifies a ":" separated list of git object directories which
361 can be used to search for git objects. New objects will not be
362 written to these directories.
363
364 'GIT_DIR'::
365 If the 'GIT_DIR' environment variable is set then it
366 specifies a path to use instead of the default `.git`
367 for the base of the repository.
368
369 'GIT_WORK_TREE'::
370 Set the path to the working tree. The value will not be
371 used in combination with repositories found automatically in
372 a .git directory (i.e. $GIT_DIR is not set).
373 This can also be controlled by the '--work-tree' command line
374 option and the core.worktree configuration variable.
375
376 git Commits
377 ~~~~~~~~~~~
378 'GIT_AUTHOR_NAME'::
379 'GIT_AUTHOR_EMAIL'::
380 'GIT_AUTHOR_DATE'::
381 'GIT_COMMITTER_NAME'::
382 'GIT_COMMITTER_EMAIL'::
383 'GIT_COMMITTER_DATE'::
384 'EMAIL'::
385 see gitlink:git-commit-tree[1]
386
387 git Diffs
388 ~~~~~~~~~
389 'GIT_DIFF_OPTS'::
390 Only valid setting is "--unified=??" or "-u??" to set the
391 number of context lines shown when a unified diff is created.
392 This takes precedence over any "-U" or "--unified" option
393 value passed on the git diff command line.
394
395 'GIT_EXTERNAL_DIFF'::
396 When the environment variable 'GIT_EXTERNAL_DIFF' is set, the
397 program named by it is called, instead of the diff invocation
398 described above. For a path that is added, removed, or modified,
399 'GIT_EXTERNAL_DIFF' is called with 7 parameters:
400
401 path old-file old-hex old-mode new-file new-hex new-mode
402 +
403 where:
404
405 <old|new>-file:: are files GIT_EXTERNAL_DIFF can use to read the
406 contents of <old|new>,
407 <old|new>-hex:: are the 40-hexdigit SHA1 hashes,
408 <old|new>-mode:: are the octal representation of the file modes.
409
410 +
411 The file parameters can point at the user's working file
412 (e.g. `new-file` in "git-diff-files"), `/dev/null` (e.g. `old-file`
413 when a new file is added), or a temporary file (e.g. `old-file` in the
414 index). 'GIT_EXTERNAL_DIFF' should not worry about unlinking the
415 temporary file --- it is removed when 'GIT_EXTERNAL_DIFF' exits.
416 +
417 For a path that is unmerged, 'GIT_EXTERNAL_DIFF' is called with 1
418 parameter, <path>.
419
420 other
421 ~~~~~
422 'GIT_MERGE_VERBOSITY'::
423 A number controlling the amount of output shown by
424 the recursive merge strategy. Overrides merge.verbosity.
425 See gitlink:git-merge[1]
426
427 'GIT_PAGER'::
428 This environment variable overrides `$PAGER`. If it is set
429 to an empty string or to the value "cat", git will not launch
430 a pager.
431
432 'GIT_SSH'::
433 If this environment variable is set then gitlink:git-fetch[1]
434 and gitlink:git-push[1] will use this command instead
435 of `ssh` when they need to connect to a remote system.
436 The 'GIT_SSH' command will be given exactly two arguments:
437 the 'username@host' (or just 'host') from the URL and the
438 shell command to execute on that remote system.
439 +
440 To pass options to the program that you want to list in GIT_SSH
441 you will need to wrap the program and options into a shell script,
442 then set GIT_SSH to refer to the shell script.
443 +
444 Usually it is easier to configure any desired options through your
445 personal `.ssh/config` file. Please consult your ssh documentation
446 for further details.
447
448 'GIT_FLUSH'::
449 If this environment variable is set to "1", then commands such
450 as git-blame (in incremental mode), git-rev-list, git-log,
451 git-whatchanged, etc., will force a flush of the output stream
452 after each commit-oriented record have been flushed. If this
453 variable is set to "0", the output of these commands will be done
454 using completely buffered I/O. If this environment variable is
455 not set, git will choose buffered or record-oriented flushing
456 based on whether stdout appears to be redirected to a file or not.
457
458 'GIT_TRACE'::
459 If this variable is set to "1", "2" or "true" (comparison
460 is case insensitive), git will print `trace:` messages on
461 stderr telling about alias expansion, built-in command
462 execution and external command execution.
463 If this variable is set to an integer value greater than 1
464 and lower than 10 (strictly) then git will interpret this
465 value as an open file descriptor and will try to write the
466 trace messages into this file descriptor.
467 Alternatively, if this variable is set to an absolute path
468 (starting with a '/' character), git will interpret this
469 as a file path and will try to write the trace messages
470 into it.
471
472 Discussion[[Discussion]]
473 ------------------------
474 include::core-intro.txt[]
475
476 Authors
477 -------
478 * git's founding father is Linus Torvalds <torvalds@osdl.org>.
479 * The current git nurse is Junio C Hamano <junkio@cox.net>.
480 * The git potty was written by Andres Ericsson <ae@op5.se>.
481 * General upbringing is handled by the git-list <git@vger.kernel.org>.
482
483 Documentation
484 --------------
485 The documentation for git suite was started by David Greaves
486 <david@dgreaves.com>, and later enhanced greatly by the
487 contributors on the git-list <git@vger.kernel.org>.
488
489 GIT
490 ---
491 Part of the gitlink:git[7] suite