Sync with 1.7.3.4
[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[=<path>]] [--html-path]
13 [-p|--paginate|--no-pager] [--no-replace-objects]
14 [--bare] [--git-dir=<path>] [--work-tree=<path>]
15 [-c <name>=<value>]
16 [--help] <command> [<args>]
17
18 DESCRIPTION
19 -----------
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.
23
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
29 introduction.
30
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]).
33
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/`.
37
38 ifdef::stalenotes[]
39 [NOTE]
40 ============
41
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:
46
47 * link:v1.7.3.4/git.html[documentation for release 1.7.3.4]
48
49 * release notes for
50 link:RelNotes/1.7.3.4.txt[1.7.3.4],
51 link:RelNotes/1.7.3.3.txt[1.7.3.3],
52 link:RelNotes/1.7.3.2.txt[1.7.3.2],
53 link:RelNotes/1.7.3.1.txt[1.7.3.1],
54 link:RelNotes/1.7.3.txt[1.7.3].
55
56 * link:v1.7.2.4/git.html[documentation for release 1.7.2.4]
57
58 * release notes for
59 link:RelNotes/1.7.2.4.txt[1.7.2.4],
60 link:RelNotes/1.7.2.3.txt[1.7.2.3],
61 link:RelNotes/1.7.2.2.txt[1.7.2.2],
62 link:RelNotes/1.7.2.1.txt[1.7.2.1],
63 link:RelNotes/1.7.2.txt[1.7.2].
64
65 * link:v1.7.1.3/git.html[documentation for release 1.7.1.3]
66
67 * release notes for
68 link:RelNotes/1.7.1.3.txt[1.7.1.3],
69 link:RelNotes/1.7.1.2.txt[1.7.1.2],
70 link:RelNotes/1.7.1.1.txt[1.7.1.1],
71 link:RelNotes/1.7.1.txt[1.7.1].
72
73 * link:v1.7.0.8/git.html[documentation for release 1.7.0.8]
74
75 * release notes for
76 link:RelNotes/1.7.0.8.txt[1.7.0.8],
77 link:RelNotes/1.7.0.7.txt[1.7.0.7],
78 link:RelNotes/1.7.0.6.txt[1.7.0.6],
79 link:RelNotes/1.7.0.5.txt[1.7.0.5],
80 link:RelNotes/1.7.0.4.txt[1.7.0.4],
81 link:RelNotes/1.7.0.3.txt[1.7.0.3],
82 link:RelNotes/1.7.0.2.txt[1.7.0.2],
83 link:RelNotes/1.7.0.1.txt[1.7.0.1],
84 link:RelNotes/1.7.0.txt[1.7.0].
85
86 * link:v1.6.6.2/git.html[documentation for release 1.6.6.2]
87
88 * release notes for
89 link:RelNotes/1.6.6.2.txt[1.6.6.2],
90 link:RelNotes/1.6.6.1.txt[1.6.6.1],
91 link:RelNotes/1.6.6.txt[1.6.6].
92
93 * link:v1.6.5.8/git.html[documentation for release 1.6.5.8]
94
95 * release notes for
96 link:RelNotes/1.6.5.8.txt[1.6.5.8],
97 link:RelNotes/1.6.5.7.txt[1.6.5.7],
98 link:RelNotes/1.6.5.6.txt[1.6.5.6],
99 link:RelNotes/1.6.5.5.txt[1.6.5.5],
100 link:RelNotes/1.6.5.4.txt[1.6.5.4],
101 link:RelNotes/1.6.5.3.txt[1.6.5.3],
102 link:RelNotes/1.6.5.2.txt[1.6.5.2],
103 link:RelNotes/1.6.5.1.txt[1.6.5.1],
104 link:RelNotes/1.6.5.txt[1.6.5].
105
106 * link:v1.6.4.4/git.html[documentation for release 1.6.4.4]
107
108 * release notes for
109 link:RelNotes/1.6.4.4.txt[1.6.4.4],
110 link:RelNotes/1.6.4.3.txt[1.6.4.3],
111 link:RelNotes/1.6.4.2.txt[1.6.4.2],
112 link:RelNotes/1.6.4.1.txt[1.6.4.1],
113 link:RelNotes/1.6.4.txt[1.6.4].
114
115 * link:v1.6.3.4/git.html[documentation for release 1.6.3.4]
116
117 * release notes for
118 link:RelNotes/1.6.3.4.txt[1.6.3.4],
119 link:RelNotes/1.6.3.3.txt[1.6.3.3],
120 link:RelNotes/1.6.3.2.txt[1.6.3.2],
121 link:RelNotes/1.6.3.1.txt[1.6.3.1],
122 link:RelNotes/1.6.3.txt[1.6.3].
123
124 * release notes for
125 link:RelNotes/1.6.2.5.txt[1.6.2.5],
126 link:RelNotes/1.6.2.4.txt[1.6.2.4],
127 link:RelNotes/1.6.2.3.txt[1.6.2.3],
128 link:RelNotes/1.6.2.2.txt[1.6.2.2],
129 link:RelNotes/1.6.2.1.txt[1.6.2.1],
130 link:RelNotes/1.6.2.txt[1.6.2].
131
132 * link:v1.6.1.3/git.html[documentation for release 1.6.1.3]
133
134 * release notes for
135 link:RelNotes/1.6.1.3.txt[1.6.1.3],
136 link:RelNotes/1.6.1.2.txt[1.6.1.2],
137 link:RelNotes/1.6.1.1.txt[1.6.1.1],
138 link:RelNotes/1.6.1.txt[1.6.1].
139
140 * link:v1.6.0.6/git.html[documentation for release 1.6.0.6]
141
142 * release notes for
143 link:RelNotes/1.6.0.6.txt[1.6.0.6],
144 link:RelNotes/1.6.0.5.txt[1.6.0.5],
145 link:RelNotes/1.6.0.4.txt[1.6.0.4],
146 link:RelNotes/1.6.0.3.txt[1.6.0.3],
147 link:RelNotes/1.6.0.2.txt[1.6.0.2],
148 link:RelNotes/1.6.0.1.txt[1.6.0.1],
149 link:RelNotes/1.6.0.txt[1.6.0].
150
151 * link:v1.5.6.6/git.html[documentation for release 1.5.6.6]
152
153 * release notes for
154 link:RelNotes/1.5.6.6.txt[1.5.6.6],
155 link:RelNotes/1.5.6.5.txt[1.5.6.5],
156 link:RelNotes/1.5.6.4.txt[1.5.6.4],
157 link:RelNotes/1.5.6.3.txt[1.5.6.3],
158 link:RelNotes/1.5.6.2.txt[1.5.6.2],
159 link:RelNotes/1.5.6.1.txt[1.5.6.1],
160 link:RelNotes/1.5.6.txt[1.5.6].
161
162 * link:v1.5.5.6/git.html[documentation for release 1.5.5.6]
163
164 * release notes for
165 link:RelNotes/1.5.5.6.txt[1.5.5.6],
166 link:RelNotes/1.5.5.5.txt[1.5.5.5],
167 link:RelNotes/1.5.5.4.txt[1.5.5.4],
168 link:RelNotes/1.5.5.3.txt[1.5.5.3],
169 link:RelNotes/1.5.5.2.txt[1.5.5.2],
170 link:RelNotes/1.5.5.1.txt[1.5.5.1],
171 link:RelNotes/1.5.5.txt[1.5.5].
172
173 * link:v1.5.4.7/git.html[documentation for release 1.5.4.7]
174
175 * release notes for
176 link:RelNotes/1.5.4.7.txt[1.5.4.7],
177 link:RelNotes/1.5.4.6.txt[1.5.4.6],
178 link:RelNotes/1.5.4.5.txt[1.5.4.5],
179 link:RelNotes/1.5.4.4.txt[1.5.4.4],
180 link:RelNotes/1.5.4.3.txt[1.5.4.3],
181 link:RelNotes/1.5.4.2.txt[1.5.4.2],
182 link:RelNotes/1.5.4.1.txt[1.5.4.1],
183 link:RelNotes/1.5.4.txt[1.5.4].
184
185 * link:v1.5.3.8/git.html[documentation for release 1.5.3.8]
186
187 * release notes for
188 link:RelNotes/1.5.3.8.txt[1.5.3.8],
189 link:RelNotes/1.5.3.7.txt[1.5.3.7],
190 link:RelNotes/1.5.3.6.txt[1.5.3.6],
191 link:RelNotes/1.5.3.5.txt[1.5.3.5],
192 link:RelNotes/1.5.3.4.txt[1.5.3.4],
193 link:RelNotes/1.5.3.3.txt[1.5.3.3],
194 link:RelNotes/1.5.3.2.txt[1.5.3.2],
195 link:RelNotes/1.5.3.1.txt[1.5.3.1],
196 link:RelNotes/1.5.3.txt[1.5.3].
197
198 * link:v1.5.2.5/git.html[documentation for release 1.5.2.5]
199
200 * release notes for
201 link:RelNotes/1.5.2.5.txt[1.5.2.5],
202 link:RelNotes/1.5.2.4.txt[1.5.2.4],
203 link:RelNotes/1.5.2.3.txt[1.5.2.3],
204 link:RelNotes/1.5.2.2.txt[1.5.2.2],
205 link:RelNotes/1.5.2.1.txt[1.5.2.1],
206 link:RelNotes/1.5.2.txt[1.5.2].
207
208 * link:v1.5.1.6/git.html[documentation for release 1.5.1.6]
209
210 * release notes for
211 link:RelNotes/1.5.1.6.txt[1.5.1.6],
212 link:RelNotes/1.5.1.5.txt[1.5.1.5],
213 link:RelNotes/1.5.1.4.txt[1.5.1.4],
214 link:RelNotes/1.5.1.3.txt[1.5.1.3],
215 link:RelNotes/1.5.1.2.txt[1.5.1.2],
216 link:RelNotes/1.5.1.1.txt[1.5.1.1],
217 link:RelNotes/1.5.1.txt[1.5.1].
218
219 * link:v1.5.0.7/git.html[documentation for release 1.5.0.7]
220
221 * release notes for
222 link:RelNotes/1.5.0.7.txt[1.5.0.7],
223 link:RelNotes/1.5.0.6.txt[1.5.0.6],
224 link:RelNotes/1.5.0.5.txt[1.5.0.5],
225 link:RelNotes/1.5.0.3.txt[1.5.0.3],
226 link:RelNotes/1.5.0.2.txt[1.5.0.2],
227 link:RelNotes/1.5.0.1.txt[1.5.0.1],
228 link:RelNotes/1.5.0.txt[1.5.0].
229
230 * documentation for release link:v1.4.4.4/git.html[1.4.4.4],
231 link:v1.3.3/git.html[1.3.3],
232 link:v1.2.6/git.html[1.2.6],
233 link:v1.0.13/git.html[1.0.13].
234
235 ============
236
237 endif::stalenotes[]
238
239 OPTIONS
240 -------
241 --version::
242 Prints the git suite version that the 'git' program came from.
243
244 --help::
245 Prints the synopsis and a list of the most commonly used
246 commands. If the option '--all' or '-a' is given then all
247 available commands are printed. If a git command is named this
248 option will bring up the manual page for that command.
249 +
250 Other options are available to control how the manual page is
251 displayed. See linkgit:git-help[1] for more information,
252 because `git --help ...` is converted internally into `git
253 help ...`.
254
255 -c <name>=<value>::
256 Pass a configuration parameter to the command. The value
257 given will override values from configuration files.
258 The <name> is expected in the same format as listed by
259 'git config' (subkeys separated by dots).
260
261 --exec-path[=<path>]::
262 Path to wherever your core git programs are installed.
263 This can also be controlled by setting the GIT_EXEC_PATH
264 environment variable. If no path is given, 'git' will print
265 the current setting and then exit.
266
267 --html-path::
268 Print the path to wherever your git HTML documentation is installed
269 and exit.
270
271 -p::
272 --paginate::
273 Pipe all output into 'less' (or if set, $PAGER) if standard
274 output is a terminal. This overrides the `pager.<cmd>`
275 configuration options (see the "Configuration Mechanism" section
276 below).
277
278 --no-pager::
279 Do not pipe git output into a pager.
280
281 --git-dir=<path>::
282 Set the path to the repository. This can also be controlled by
283 setting the GIT_DIR environment variable. It can be an absolute
284 path or relative path to current working directory.
285
286 --work-tree=<path>::
287 Set the path to the working tree. The value will not be
288 used in combination with repositories found automatically in
289 a .git directory (i.e. $GIT_DIR is not set).
290 This can also be controlled by setting the GIT_WORK_TREE
291 environment variable and the core.worktree configuration
292 variable. It can be an absolute path or relative path to
293 the directory specified by --git-dir or GIT_DIR.
294 Note: If --git-dir or GIT_DIR are specified but none of
295 --work-tree, GIT_WORK_TREE and core.worktree is specified,
296 the current working directory is regarded as the top directory
297 of your working tree.
298
299 --bare::
300 Treat the repository as a bare repository. If GIT_DIR
301 environment is not set, it is set to the current working
302 directory.
303
304 --no-replace-objects::
305 Do not use replacement refs to replace git objects. See
306 linkgit:git-replace[1] for more information.
307
308
309 FURTHER DOCUMENTATION
310 ---------------------
311
312 See the references above to get started using git. The following is
313 probably more detail than necessary for a first-time user.
314
315 The link:user-manual.html#git-concepts[git concepts chapter of the
316 user-manual] and linkgit:gitcore-tutorial[7] both provide
317 introductions to the underlying git architecture.
318
319 See linkgit:gitworkflows[7] for an overview of recommended workflows.
320
321 See also the link:howto-index.html[howto] documents for some useful
322 examples.
323
324 The internals are documented in the
325 link:technical/api-index.html[GIT API documentation].
326
327 GIT COMMANDS
328 ------------
329
330 We divide git into high level ("porcelain") commands and low level
331 ("plumbing") commands.
332
333 High-level commands (porcelain)
334 -------------------------------
335
336 We separate the porcelain commands into the main commands and some
337 ancillary user utilities.
338
339 Main porcelain commands
340 ~~~~~~~~~~~~~~~~~~~~~~~
341
342 include::cmds-mainporcelain.txt[]
343
344 Ancillary Commands
345 ~~~~~~~~~~~~~~~~~~
346 Manipulators:
347
348 include::cmds-ancillarymanipulators.txt[]
349
350 Interrogators:
351
352 include::cmds-ancillaryinterrogators.txt[]
353
354
355 Interacting with Others
356 ~~~~~~~~~~~~~~~~~~~~~~~
357
358 These commands are to interact with foreign SCM and with other
359 people via patch over e-mail.
360
361 include::cmds-foreignscminterface.txt[]
362
363
364 Low-level commands (plumbing)
365 -----------------------------
366
367 Although git includes its
368 own porcelain layer, its low-level commands are sufficient to support
369 development of alternative porcelains. Developers of such porcelains
370 might start by reading about linkgit:git-update-index[1] and
371 linkgit:git-read-tree[1].
372
373 The interface (input, output, set of options and the semantics)
374 to these low-level commands are meant to be a lot more stable
375 than Porcelain level commands, because these commands are
376 primarily for scripted use. The interface to Porcelain commands
377 on the other hand are subject to change in order to improve the
378 end user experience.
379
380 The following description divides
381 the low-level commands into commands that manipulate objects (in
382 the repository, index, and working tree), commands that interrogate and
383 compare objects, and commands that move objects and references between
384 repositories.
385
386
387 Manipulation commands
388 ~~~~~~~~~~~~~~~~~~~~~
389
390 include::cmds-plumbingmanipulators.txt[]
391
392
393 Interrogation commands
394 ~~~~~~~~~~~~~~~~~~~~~~
395
396 include::cmds-plumbinginterrogators.txt[]
397
398 In general, the interrogate commands do not touch the files in
399 the working tree.
400
401
402 Synching repositories
403 ~~~~~~~~~~~~~~~~~~~~~
404
405 include::cmds-synchingrepositories.txt[]
406
407 The following are helper commands used by the above; end users
408 typically do not use them directly.
409
410 include::cmds-synchelpers.txt[]
411
412
413 Internal helper commands
414 ~~~~~~~~~~~~~~~~~~~~~~~~
415
416 These are internal helper commands used by other commands; end
417 users typically do not use them directly.
418
419 include::cmds-purehelpers.txt[]
420
421
422 Configuration Mechanism
423 -----------------------
424
425 Starting from 0.99.9 (actually mid 0.99.8.GIT), `.git/config` file
426 is used to hold per-repository configuration options. It is a
427 simple text file modeled after `.ini` format familiar to some
428 people. Here is an example:
429
430 ------------
431 #
432 # A '#' or ';' character indicates a comment.
433 #
434
435 ; core variables
436 [core]
437 ; Don't trust file modes
438 filemode = false
439
440 ; user identity
441 [user]
442 name = "Junio C Hamano"
443 email = "junkio@twinsun.com"
444
445 ------------
446
447 Various commands read from the configuration file and adjust
448 their operation accordingly. See linkgit:git-config[1] for a
449 list.
450
451
452 Identifier Terminology
453 ----------------------
454 <object>::
455 Indicates the object name for any type of object.
456
457 <blob>::
458 Indicates a blob object name.
459
460 <tree>::
461 Indicates a tree object name.
462
463 <commit>::
464 Indicates a commit object name.
465
466 <tree-ish>::
467 Indicates a tree, commit or tag object name. A
468 command that takes a <tree-ish> argument ultimately wants to
469 operate on a <tree> object but automatically dereferences
470 <commit> and <tag> objects that point at a <tree>.
471
472 <commit-ish>::
473 Indicates a commit or tag object name. A
474 command that takes a <commit-ish> argument ultimately wants to
475 operate on a <commit> object but automatically dereferences
476 <tag> objects that point at a <commit>.
477
478 <type>::
479 Indicates that an object type is required.
480 Currently one of: `blob`, `tree`, `commit`, or `tag`.
481
482 <file>::
483 Indicates a filename - almost always relative to the
484 root of the tree structure `GIT_INDEX_FILE` describes.
485
486 Symbolic Identifiers
487 --------------------
488 Any git command accepting any <object> can also use the following
489 symbolic notation:
490
491 HEAD::
492 indicates the head of the current branch (i.e. the
493 contents of `$GIT_DIR/HEAD`).
494
495 <tag>::
496 a valid tag 'name'
497 (i.e. the contents of `$GIT_DIR/refs/tags/<tag>`).
498
499 <head>::
500 a valid head 'name'
501 (i.e. the contents of `$GIT_DIR/refs/heads/<head>`).
502
503 For a more complete list of ways to spell object names, see
504 "SPECIFYING REVISIONS" section in linkgit:gitrevisions[7].
505
506
507 File/Directory Structure
508 ------------------------
509
510 Please see the linkgit:gitrepository-layout[5] document.
511
512 Read linkgit:githooks[5] for more details about each hook.
513
514 Higher level SCMs may provide and manage additional information in the
515 `$GIT_DIR`.
516
517
518 Terminology
519 -----------
520 Please see linkgit:gitglossary[7].
521
522
523 Environment Variables
524 ---------------------
525 Various git commands use the following environment variables:
526
527 The git Repository
528 ~~~~~~~~~~~~~~~~~~
529 These environment variables apply to 'all' core git commands. Nb: it
530 is worth noting that they may be used/overridden by SCMS sitting above
531 git so take care if using Cogito etc.
532
533 'GIT_INDEX_FILE'::
534 This environment allows the specification of an alternate
535 index file. If not specified, the default of `$GIT_DIR/index`
536 is used.
537
538 'GIT_OBJECT_DIRECTORY'::
539 If the object storage directory is specified via this
540 environment variable then the sha1 directories are created
541 underneath - otherwise the default `$GIT_DIR/objects`
542 directory is used.
543
544 'GIT_ALTERNATE_OBJECT_DIRECTORIES'::
545 Due to the immutable nature of git objects, old objects can be
546 archived into shared, read-only directories. This variable
547 specifies a ":" separated (on Windows ";" separated) list
548 of git object directories which can be used to search for git
549 objects. New objects will not be written to these directories.
550
551 'GIT_DIR'::
552 If the 'GIT_DIR' environment variable is set then it
553 specifies a path to use instead of the default `.git`
554 for the base of the repository.
555
556 'GIT_WORK_TREE'::
557 Set the path to the working tree. The value will not be
558 used in combination with repositories found automatically in
559 a .git directory (i.e. $GIT_DIR is not set).
560 This can also be controlled by the '--work-tree' command line
561 option and the core.worktree configuration variable.
562
563 'GIT_CEILING_DIRECTORIES'::
564 This should be a colon-separated list of absolute paths.
565 If set, it is a list of directories that git should not chdir
566 up into while looking for a repository directory.
567 It will not exclude the current working directory or
568 a GIT_DIR set on the command line or in the environment.
569 (Useful for excluding slow-loading network directories.)
570
571 'GIT_DISCOVERY_ACROSS_FILESYSTEM'::
572 When run in a directory that does not have ".git" repository
573 directory, git tries to find such a directory in the parent
574 directories to find the top of the working tree, but by default it
575 does not cross filesystem boundaries. This environment variable
576 can be set to true to tell git not to stop at filesystem
577 boundaries. Like 'GIT_CEILING_DIRECTORIES', this will not affect
578 an explicit repository directory set via 'GIT_DIR' or on the
579 command line.
580
581 git Commits
582 ~~~~~~~~~~~
583 'GIT_AUTHOR_NAME'::
584 'GIT_AUTHOR_EMAIL'::
585 'GIT_AUTHOR_DATE'::
586 'GIT_COMMITTER_NAME'::
587 'GIT_COMMITTER_EMAIL'::
588 'GIT_COMMITTER_DATE'::
589 'EMAIL'::
590 see linkgit:git-commit-tree[1]
591
592 git Diffs
593 ~~~~~~~~~
594 'GIT_DIFF_OPTS'::
595 Only valid setting is "--unified=??" or "-u??" to set the
596 number of context lines shown when a unified diff is created.
597 This takes precedence over any "-U" or "--unified" option
598 value passed on the git diff command line.
599
600 'GIT_EXTERNAL_DIFF'::
601 When the environment variable 'GIT_EXTERNAL_DIFF' is set, the
602 program named by it is called, instead of the diff invocation
603 described above. For a path that is added, removed, or modified,
604 'GIT_EXTERNAL_DIFF' is called with 7 parameters:
605
606 path old-file old-hex old-mode new-file new-hex new-mode
607 +
608 where:
609
610 <old|new>-file:: are files GIT_EXTERNAL_DIFF can use to read the
611 contents of <old|new>,
612 <old|new>-hex:: are the 40-hexdigit SHA1 hashes,
613 <old|new>-mode:: are the octal representation of the file modes.
614
615 +
616 The file parameters can point at the user's working file
617 (e.g. `new-file` in "git-diff-files"), `/dev/null` (e.g. `old-file`
618 when a new file is added), or a temporary file (e.g. `old-file` in the
619 index). 'GIT_EXTERNAL_DIFF' should not worry about unlinking the
620 temporary file --- it is removed when 'GIT_EXTERNAL_DIFF' exits.
621 +
622 For a path that is unmerged, 'GIT_EXTERNAL_DIFF' is called with 1
623 parameter, <path>.
624
625 other
626 ~~~~~
627 'GIT_MERGE_VERBOSITY'::
628 A number controlling the amount of output shown by
629 the recursive merge strategy. Overrides merge.verbosity.
630 See linkgit:git-merge[1]
631
632 'GIT_PAGER'::
633 This environment variable overrides `$PAGER`. If it is set
634 to an empty string or to the value "cat", git will not launch
635 a pager. See also the `core.pager` option in
636 linkgit:git-config[1].
637
638 'GIT_SSH'::
639 If this environment variable is set then 'git fetch'
640 and 'git push' will use this command instead
641 of 'ssh' when they need to connect to a remote system.
642 The '$GIT_SSH' command will be given exactly two arguments:
643 the 'username@host' (or just 'host') from the URL and the
644 shell command to execute on that remote system.
645 +
646 To pass options to the program that you want to list in GIT_SSH
647 you will need to wrap the program and options into a shell script,
648 then set GIT_SSH to refer to the shell script.
649 +
650 Usually it is easier to configure any desired options through your
651 personal `.ssh/config` file. Please consult your ssh documentation
652 for further details.
653
654 'GIT_ASKPASS'::
655 If this environment variable is set, then git commands which need to
656 acquire passwords or passphrases (e.g. for HTTP or IMAP authentication)
657 will call this program with a suitable prompt as command line argument
658 and read the password from its STDOUT. See also the 'core.askpass'
659 option in linkgit:git-config[1].
660
661 'GIT_FLUSH'::
662 If this environment variable is set to "1", then commands such
663 as 'git blame' (in incremental mode), 'git rev-list', 'git log',
664 and 'git whatchanged' will force a flush of the output stream
665 after each commit-oriented record have been flushed. If this
666 variable is set to "0", the output of these commands will be done
667 using completely buffered I/O. If this environment variable is
668 not set, git will choose buffered or record-oriented flushing
669 based on whether stdout appears to be redirected to a file or not.
670
671 'GIT_TRACE'::
672 If this variable is set to "1", "2" or "true" (comparison
673 is case insensitive), git will print `trace:` messages on
674 stderr telling about alias expansion, built-in command
675 execution and external command execution.
676 If this variable is set to an integer value greater than 1
677 and lower than 10 (strictly) then git will interpret this
678 value as an open file descriptor and will try to write the
679 trace messages into this file descriptor.
680 Alternatively, if this variable is set to an absolute path
681 (starting with a '/' character), git will interpret this
682 as a file path and will try to write the trace messages
683 into it.
684
685 Discussion[[Discussion]]
686 ------------------------
687
688 More detail on the following is available from the
689 link:user-manual.html#git-concepts[git concepts chapter of the
690 user-manual] and linkgit:gitcore-tutorial[7].
691
692 A git project normally consists of a working directory with a ".git"
693 subdirectory at the top level. The .git directory contains, among other
694 things, a compressed object database representing the complete history
695 of the project, an "index" file which links that history to the current
696 contents of the working tree, and named pointers into that history such
697 as tags and branch heads.
698
699 The object database contains objects of three main types: blobs, which
700 hold file data; trees, which point to blobs and other trees to build up
701 directory hierarchies; and commits, which each reference a single tree
702 and some number of parent commits.
703
704 The commit, equivalent to what other systems call a "changeset" or
705 "version", represents a step in the project's history, and each parent
706 represents an immediately preceding step. Commits with more than one
707 parent represent merges of independent lines of development.
708
709 All objects are named by the SHA1 hash of their contents, normally
710 written as a string of 40 hex digits. Such names are globally unique.
711 The entire history leading up to a commit can be vouched for by signing
712 just that commit. A fourth object type, the tag, is provided for this
713 purpose.
714
715 When first created, objects are stored in individual files, but for
716 efficiency may later be compressed together into "pack files".
717
718 Named pointers called refs mark interesting points in history. A ref
719 may contain the SHA1 name of an object or the name of another ref. Refs
720 with names beginning `ref/head/` contain the SHA1 name of the most
721 recent commit (or "head") of a branch under development. SHA1 names of
722 tags of interest are stored under `ref/tags/`. A special ref named
723 `HEAD` contains the name of the currently checked-out branch.
724
725 The index file is initialized with a list of all paths and, for each
726 path, a blob object and a set of attributes. The blob object represents
727 the contents of the file as of the head of the current branch. The
728 attributes (last modified time, size, etc.) are taken from the
729 corresponding file in the working tree. Subsequent changes to the
730 working tree can be found by comparing these attributes. The index may
731 be updated with new content, and new commits may be created from the
732 content stored in the index.
733
734 The index is also capable of storing multiple entries (called "stages")
735 for a given pathname. These stages are used to hold the various
736 unmerged version of a file when a merge is in progress.
737
738 Authors
739 -------
740 * git's founding father is Linus Torvalds <torvalds@osdl.org>.
741 * The current git nurse is Junio C Hamano <gitster@pobox.com>.
742 * The git potty was written by Andreas Ericsson <ae@op5.se>.
743 * General upbringing is handled by the git-list <git@vger.kernel.org>.
744
745 Documentation
746 --------------
747 The documentation for git suite was started by David Greaves
748 <david@dgreaves.com>, and later enhanced greatly by the
749 contributors on the git-list <git@vger.kernel.org>.
750
751 Reporting Bugs
752 --------------
753
754 Report bugs to the Git mailing list <git@vger.kernel.org> where the
755 development and maintenance is primarily done. You do not have to be
756 subscribed to the list to send a message there.
757
758 SEE ALSO
759 --------
760 linkgit:gittutorial[7], linkgit:gittutorial-2[7],
761 link:everyday.html[Everyday Git], linkgit:gitcvs-migration[7],
762 linkgit:gitglossary[7], linkgit:gitcore-tutorial[7],
763 linkgit:gitcli[7], link:user-manual.html[The Git User's Manual],
764 linkgit:gitworkflows[7]
765
766 GIT
767 ---
768 Part of the linkgit:git[1] suite