Make git-add behave more sensibly in a case-insensitive environment
[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 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:v1.5.5/git.html[documentation for release 1.5.5]
47
48 * release notes for
49 link:RelNotes-1.5.5.txt[1.5.5].
50
51 * link:v1.5.4.5/git.html[documentation for release 1.5.4.5]
52
53 * release notes for
54 link:RelNotes-1.5.4.5.txt[1.5.4.5],
55 link:RelNotes-1.5.4.4.txt[1.5.4.4],
56 link:RelNotes-1.5.4.3.txt[1.5.4.3],
57 link:RelNotes-1.5.4.2.txt[1.5.4.2],
58 link:RelNotes-1.5.4.1.txt[1.5.4.1],
59 link:RelNotes-1.5.4.txt[1.5.4].
60
61 * link:v1.5.3.8/git.html[documentation for release 1.5.3.8]
62
63 * release notes for
64 link:RelNotes-1.5.3.8.txt[1.5.3.8],
65 link:RelNotes-1.5.3.7.txt[1.5.3.7],
66 link:RelNotes-1.5.3.6.txt[1.5.3.6],
67 link:RelNotes-1.5.3.5.txt[1.5.3.5],
68 link:RelNotes-1.5.3.4.txt[1.5.3.4],
69 link:RelNotes-1.5.3.3.txt[1.5.3.3],
70 link:RelNotes-1.5.3.2.txt[1.5.3.2],
71 link:RelNotes-1.5.3.1.txt[1.5.3.1],
72 link:RelNotes-1.5.3.txt[1.5.3].
73
74 * release notes for
75 link:RelNotes-1.5.2.5.txt[1.5.2.5],
76 link:RelNotes-1.5.2.4.txt[1.5.2.4],
77 link:RelNotes-1.5.2.3.txt[1.5.2.3],
78 link:RelNotes-1.5.2.2.txt[1.5.2.2],
79 link:RelNotes-1.5.2.1.txt[1.5.2.1],
80 link:RelNotes-1.5.2.txt[1.5.2].
81
82 * link:v1.5.1.6/git.html[documentation for release 1.5.1.6]
83
84 * release notes for
85 link:RelNotes-1.5.1.6.txt[1.5.1.6],
86 link:RelNotes-1.5.1.5.txt[1.5.1.5],
87 link:RelNotes-1.5.1.4.txt[1.5.1.4],
88 link:RelNotes-1.5.1.3.txt[1.5.1.3],
89 link:RelNotes-1.5.1.2.txt[1.5.1.2],
90 link:RelNotes-1.5.1.1.txt[1.5.1.1],
91 link:RelNotes-1.5.1.txt[1.5.1].
92
93 * link:v1.5.0.7/git.html[documentation for release 1.5.0.7]
94
95 * release notes for
96 link:RelNotes-1.5.0.7.txt[1.5.0.7],
97 link:RelNotes-1.5.0.6.txt[1.5.0.6],
98 link:RelNotes-1.5.0.5.txt[1.5.0.5],
99 link:RelNotes-1.5.0.3.txt[1.5.0.3],
100 link:RelNotes-1.5.0.2.txt[1.5.0.2],
101 link:RelNotes-1.5.0.1.txt[1.5.0.1],
102 link:RelNotes-1.5.0.txt[1.5.0].
103
104 * documentation for release link:v1.4.4.4/git.html[1.4.4.4],
105 link:v1.3.3/git.html[1.3.3],
106 link:v1.2.6/git.html[1.2.6],
107 link:v1.0.13/git.html[1.0.13].
108
109 ============
110
111 endif::stalenotes[]
112
113 OPTIONS
114 -------
115 --version::
116 Prints the git suite version that the 'git' program came from.
117
118 --help::
119 Prints the synopsis and a list of the most commonly used
120 commands. If the option '--all' or '-a' is given then all
121 available commands are printed. If a git command is named this
122 option will bring up the manual page for that command.
123 +
124 Other options are available to control how the manual page is
125 displayed. See linkgit:git-help[1] for more information,
126 because 'git --help ...' is converted internally into 'git
127 help ...'.
128
129 --exec-path::
130 Path to wherever your core git programs are installed.
131 This can also be controlled by setting the GIT_EXEC_PATH
132 environment variable. If no path is given 'git' will print
133 the current setting and then exit.
134
135 -p|--paginate::
136 Pipe all output into 'less' (or if set, $PAGER).
137
138 --no-pager::
139 Do not pipe git output into a pager.
140
141 --git-dir=<path>::
142 Set the path to the repository. This can also be controlled by
143 setting the GIT_DIR environment variable.
144
145 --work-tree=<path>::
146 Set the path to the working tree. The value will not be
147 used in combination with repositories found automatically in
148 a .git directory (i.e. $GIT_DIR is not set).
149 This can also be controlled by setting the GIT_WORK_TREE
150 environment variable and the core.worktree configuration
151 variable.
152
153 --bare::
154 Treat the repository as a bare repository. If GIT_DIR
155 environment is not set, it is set to the current working
156 directory.
157
158
159 FURTHER DOCUMENTATION
160 ---------------------
161
162 See the references above to get started using git. The following is
163 probably more detail than necessary for a first-time user.
164
165 The link:user-manual.html#git-concepts[git concepts chapter of the
166 user-manual] and the link:core-tutorial.html[Core tutorial] both provide
167 introductions to the underlying git architecture.
168
169 See also the link:howto-index.html[howto] documents for some useful
170 examples.
171
172 The internals are documented link:technical/api-index.html[here].
173
174 GIT COMMANDS
175 ------------
176
177 We divide git into high level ("porcelain") commands and low level
178 ("plumbing") commands.
179
180 High-level commands (porcelain)
181 -------------------------------
182
183 We separate the porcelain commands into the main commands and some
184 ancillary user utilities.
185
186 Main porcelain commands
187 ~~~~~~~~~~~~~~~~~~~~~~~
188
189 include::cmds-mainporcelain.txt[]
190
191 Ancillary Commands
192 ~~~~~~~~~~~~~~~~~~
193 Manipulators:
194
195 include::cmds-ancillarymanipulators.txt[]
196
197 Interrogators:
198
199 include::cmds-ancillaryinterrogators.txt[]
200
201
202 Interacting with Others
203 ~~~~~~~~~~~~~~~~~~~~~~~
204
205 These commands are to interact with foreign SCM and with other
206 people via patch over e-mail.
207
208 include::cmds-foreignscminterface.txt[]
209
210
211 Low-level commands (plumbing)
212 -----------------------------
213
214 Although git includes its
215 own porcelain layer, its low-level commands are sufficient to support
216 development of alternative porcelains. Developers of such porcelains
217 might start by reading about linkgit:git-update-index[1] and
218 linkgit:git-read-tree[1].
219
220 The interface (input, output, set of options and the semantics)
221 to these low-level commands are meant to be a lot more stable
222 than Porcelain level commands, because these commands are
223 primarily for scripted use. The interface to Porcelain commands
224 on the other hand are subject to change in order to improve the
225 end user experience.
226
227 The following description divides
228 the low-level commands into commands that manipulate objects (in
229 the repository, index, and working tree), commands that interrogate and
230 compare objects, and commands that move objects and references between
231 repositories.
232
233
234 Manipulation commands
235 ~~~~~~~~~~~~~~~~~~~~~
236
237 include::cmds-plumbingmanipulators.txt[]
238
239
240 Interrogation commands
241 ~~~~~~~~~~~~~~~~~~~~~~
242
243 include::cmds-plumbinginterrogators.txt[]
244
245 In general, the interrogate commands do not touch the files in
246 the working tree.
247
248
249 Synching repositories
250 ~~~~~~~~~~~~~~~~~~~~~
251
252 include::cmds-synchingrepositories.txt[]
253
254 The following are helper programs used by the above; end users
255 typically do not use them directly.
256
257 include::cmds-synchelpers.txt[]
258
259
260 Internal helper commands
261 ~~~~~~~~~~~~~~~~~~~~~~~~
262
263 These are internal helper commands used by other commands; end
264 users typically do not use them directly.
265
266 include::cmds-purehelpers.txt[]
267
268
269 Configuration Mechanism
270 -----------------------
271
272 Starting from 0.99.9 (actually mid 0.99.8.GIT), `.git/config` file
273 is used to hold per-repository configuration options. It is a
274 simple text file modeled after `.ini` format familiar to some
275 people. Here is an example:
276
277 ------------
278 #
279 # A '#' or ';' character indicates a comment.
280 #
281
282 ; core variables
283 [core]
284 ; Don't trust file modes
285 filemode = false
286
287 ; user identity
288 [user]
289 name = "Junio C Hamano"
290 email = "junkio@twinsun.com"
291
292 ------------
293
294 Various commands read from the configuration file and adjust
295 their operation accordingly.
296
297
298 Identifier Terminology
299 ----------------------
300 <object>::
301 Indicates the object name for any type of object.
302
303 <blob>::
304 Indicates a blob object name.
305
306 <tree>::
307 Indicates a tree object name.
308
309 <commit>::
310 Indicates a commit object name.
311
312 <tree-ish>::
313 Indicates a tree, commit or tag object name. A
314 command that takes a <tree-ish> argument ultimately wants to
315 operate on a <tree> object but automatically dereferences
316 <commit> and <tag> objects that point at a <tree>.
317
318 <commit-ish>::
319 Indicates a commit or tag object name. A
320 command that takes a <commit-ish> argument ultimately wants to
321 operate on a <commit> object but automatically dereferences
322 <tag> objects that point at a <commit>.
323
324 <type>::
325 Indicates that an object type is required.
326 Currently one of: `blob`, `tree`, `commit`, or `tag`.
327
328 <file>::
329 Indicates a filename - almost always relative to the
330 root of the tree structure `GIT_INDEX_FILE` describes.
331
332 Symbolic Identifiers
333 --------------------
334 Any git command accepting any <object> can also use the following
335 symbolic notation:
336
337 HEAD::
338 indicates the head of the current branch (i.e. the
339 contents of `$GIT_DIR/HEAD`).
340
341 <tag>::
342 a valid tag 'name'
343 (i.e. the contents of `$GIT_DIR/refs/tags/<tag>`).
344
345 <head>::
346 a valid head 'name'
347 (i.e. the contents of `$GIT_DIR/refs/heads/<head>`).
348
349 For a more complete list of ways to spell object names, see
350 "SPECIFYING REVISIONS" section in linkgit:git-rev-parse[1].
351
352
353 File/Directory Structure
354 ------------------------
355
356 Please see the link:repository-layout.html[repository layout] document.
357
358 Read link:hooks.html[hooks] for more details about each hook.
359
360 Higher level SCMs may provide and manage additional information in the
361 `$GIT_DIR`.
362
363
364 Terminology
365 -----------
366 Please see the link:glossary.html[glossary] document.
367
368
369 Environment Variables
370 ---------------------
371 Various git commands use the following environment variables:
372
373 The git Repository
374 ~~~~~~~~~~~~~~~~~~
375 These environment variables apply to 'all' core git commands. Nb: it
376 is worth noting that they may be used/overridden by SCMS sitting above
377 git so take care if using Cogito etc.
378
379 'GIT_INDEX_FILE'::
380 This environment allows the specification of an alternate
381 index file. If not specified, the default of `$GIT_DIR/index`
382 is used.
383
384 'GIT_OBJECT_DIRECTORY'::
385 If the object storage directory is specified via this
386 environment variable then the sha1 directories are created
387 underneath - otherwise the default `$GIT_DIR/objects`
388 directory is used.
389
390 'GIT_ALTERNATE_OBJECT_DIRECTORIES'::
391 Due to the immutable nature of git objects, old objects can be
392 archived into shared, read-only directories. This variable
393 specifies a ":" separated list of git object directories which
394 can be used to search for git objects. New objects will not be
395 written to these directories.
396
397 'GIT_DIR'::
398 If the 'GIT_DIR' environment variable is set then it
399 specifies a path to use instead of the default `.git`
400 for the base of the repository.
401
402 'GIT_WORK_TREE'::
403 Set the path to the working tree. The value will not be
404 used in combination with repositories found automatically in
405 a .git directory (i.e. $GIT_DIR is not set).
406 This can also be controlled by the '--work-tree' command line
407 option and the core.worktree configuration variable.
408
409 git Commits
410 ~~~~~~~~~~~
411 'GIT_AUTHOR_NAME'::
412 'GIT_AUTHOR_EMAIL'::
413 'GIT_AUTHOR_DATE'::
414 'GIT_COMMITTER_NAME'::
415 'GIT_COMMITTER_EMAIL'::
416 'GIT_COMMITTER_DATE'::
417 'EMAIL'::
418 see linkgit:git-commit-tree[1]
419
420 git Diffs
421 ~~~~~~~~~
422 'GIT_DIFF_OPTS'::
423 Only valid setting is "--unified=??" or "-u??" to set the
424 number of context lines shown when a unified diff is created.
425 This takes precedence over any "-U" or "--unified" option
426 value passed on the git diff command line.
427
428 'GIT_EXTERNAL_DIFF'::
429 When the environment variable 'GIT_EXTERNAL_DIFF' is set, the
430 program named by it is called, instead of the diff invocation
431 described above. For a path that is added, removed, or modified,
432 'GIT_EXTERNAL_DIFF' is called with 7 parameters:
433
434 path old-file old-hex old-mode new-file new-hex new-mode
435 +
436 where:
437
438 <old|new>-file:: are files GIT_EXTERNAL_DIFF can use to read the
439 contents of <old|new>,
440 <old|new>-hex:: are the 40-hexdigit SHA1 hashes,
441 <old|new>-mode:: are the octal representation of the file modes.
442
443 +
444 The file parameters can point at the user's working file
445 (e.g. `new-file` in "git-diff-files"), `/dev/null` (e.g. `old-file`
446 when a new file is added), or a temporary file (e.g. `old-file` in the
447 index). 'GIT_EXTERNAL_DIFF' should not worry about unlinking the
448 temporary file --- it is removed when 'GIT_EXTERNAL_DIFF' exits.
449 +
450 For a path that is unmerged, 'GIT_EXTERNAL_DIFF' is called with 1
451 parameter, <path>.
452
453 other
454 ~~~~~
455 'GIT_MERGE_VERBOSITY'::
456 A number controlling the amount of output shown by
457 the recursive merge strategy. Overrides merge.verbosity.
458 See linkgit:git-merge[1]
459
460 'GIT_PAGER'::
461 This environment variable overrides `$PAGER`. If it is set
462 to an empty string or to the value "cat", git will not launch
463 a pager.
464
465 'GIT_SSH'::
466 If this environment variable is set then linkgit:git-fetch[1]
467 and linkgit:git-push[1] will use this command instead
468 of `ssh` when they need to connect to a remote system.
469 The 'GIT_SSH' command will be given exactly two arguments:
470 the 'username@host' (or just 'host') from the URL and the
471 shell command to execute on that remote system.
472 +
473 To pass options to the program that you want to list in GIT_SSH
474 you will need to wrap the program and options into a shell script,
475 then set GIT_SSH to refer to the shell script.
476 +
477 Usually it is easier to configure any desired options through your
478 personal `.ssh/config` file. Please consult your ssh documentation
479 for further details.
480
481 'GIT_FLUSH'::
482 If this environment variable is set to "1", then commands such
483 as git-blame (in incremental mode), git-rev-list, git-log,
484 git-whatchanged, etc., will force a flush of the output stream
485 after each commit-oriented record have been flushed. If this
486 variable is set to "0", the output of these commands will be done
487 using completely buffered I/O. If this environment variable is
488 not set, git will choose buffered or record-oriented flushing
489 based on whether stdout appears to be redirected to a file or not.
490
491 'GIT_TRACE'::
492 If this variable is set to "1", "2" or "true" (comparison
493 is case insensitive), git will print `trace:` messages on
494 stderr telling about alias expansion, built-in command
495 execution and external command execution.
496 If this variable is set to an integer value greater than 1
497 and lower than 10 (strictly) then git will interpret this
498 value as an open file descriptor and will try to write the
499 trace messages into this file descriptor.
500 Alternatively, if this variable is set to an absolute path
501 (starting with a '/' character), git will interpret this
502 as a file path and will try to write the trace messages
503 into it.
504
505 Discussion[[Discussion]]
506 ------------------------
507
508 More detail on the following is available from the
509 link:user-manual.html#git-concepts[git concepts chapter of the
510 user-manual] and the link:core-tutorial.html[Core tutorial].
511
512 A git project normally consists of a working directory with a ".git"
513 subdirectory at the top level. The .git directory contains, among other
514 things, a compressed object database representing the complete history
515 of the project, an "index" file which links that history to the current
516 contents of the working tree, and named pointers into that history such
517 as tags and branch heads.
518
519 The object database contains objects of three main types: blobs, which
520 hold file data; trees, which point to blobs and other trees to build up
521 directory hierarchies; and commits, which each reference a single tree
522 and some number of parent commits.
523
524 The commit, equivalent to what other systems call a "changeset" or
525 "version", represents a step in the project's history, and each parent
526 represents an immediately preceding step. Commits with more than one
527 parent represent merges of independent lines of development.
528
529 All objects are named by the SHA1 hash of their contents, normally
530 written as a string of 40 hex digits. Such names are globally unique.
531 The entire history leading up to a commit can be vouched for by signing
532 just that commit. A fourth object type, the tag, is provided for this
533 purpose.
534
535 When first created, objects are stored in individual files, but for
536 efficiency may later be compressed together into "pack files".
537
538 Named pointers called refs mark interesting points in history. A ref
539 may contain the SHA1 name of an object or the name of another ref. Refs
540 with names beginning `ref/head/` contain the SHA1 name of the most
541 recent commit (or "head") of a branch under development. SHA1 names of
542 tags of interest are stored under `ref/tags/`. A special ref named
543 `HEAD` contains the name of the currently checked-out branch.
544
545 The index file is initialized with a list of all paths and, for each
546 path, a blob object and a set of attributes. The blob object represents
547 the contents of the file as of the head of the current branch. The
548 attributes (last modified time, size, etc.) are taken from the
549 corresponding file in the working tree. Subsequent changes to the
550 working tree can be found by comparing these attributes. The index may
551 be updated with new content, and new commits may be created from the
552 content stored in the index.
553
554 The index is also capable of storing multiple entries (called "stages")
555 for a given pathname. These stages are used to hold the various
556 unmerged version of a file when a merge is in progress.
557
558 Authors
559 -------
560 * git's founding father is Linus Torvalds <torvalds@osdl.org>.
561 * The current git nurse is Junio C Hamano <gitster@pobox.com>.
562 * The git potty was written by Andreas Ericsson <ae@op5.se>.
563 * General upbringing is handled by the git-list <git@vger.kernel.org>.
564
565 Documentation
566 --------------
567 The documentation for git suite was started by David Greaves
568 <david@dgreaves.com>, and later enhanced greatly by the
569 contributors on the git-list <git@vger.kernel.org>.
570
571 GIT
572 ---
573 Part of the linkgit:git[7] suite