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9e1f0a85 1git(1)
2cf565c5 2======
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3
4NAME
5----
6git - the stupid content tracker
7
8
9SYNOPSIS
10--------
8b70004b 11[verse]
89a56bfb 12'git' [--version] [--exec-path[=GIT_EXEC_PATH]] [--html-path]
b0fa7ab5 13 [-p|--paginate|--no-pager] [--no-replace-objects]
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14 [--bare] [--git-dir=GIT_DIR] [--work-tree=GIT_WORK_TREE]
15 [--help] COMMAND [ARGS]
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16
17DESCRIPTION
18-----------
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19Git is a fast, scalable, distributed revision control system with an
20unusually rich command set that provides both high-level operations
21and full access to internals.
22
6998e4db 23See linkgit:gittutorial[7] to get started, then see
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24link:everyday.html[Everyday Git] for a useful minimum set of commands, and
25"man git-commandname" for documentation of each command. CVS users may
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26also want to read linkgit:gitcvs-migration[7]. See
27the link:user-manual.html[Git User's Manual] for a more in-depth
a1dc34fa 28introduction.
cb22bc44 29
4514ad4f 30The COMMAND is either a name of a Git command (see below) or an alias
5162e697 31as defined in the configuration file (see linkgit:git-config[1]).
4514ad4f 32
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33Formatted and hyperlinked version of the latest git
34documentation can be viewed at
35`http://www.kernel.org/pub/software/scm/git/docs/`.
36
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37ifdef::stalenotes[]
38[NOTE]
39============
26cfcfbf 40
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41You are reading the documentation for the latest (possibly
42unreleased) version of git, that is available from 'master'
43branch of the `git.git` repository.
44Documentation for older releases are available here:
43a8e4fe 45
527b9d70 46* link:v1.6.5.7/git.html[documentation for release 1.6.5.7]
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47
48* release notes for
527b9d70 49 link:RelNotes-1.6.5.7.txt[1.6.5.7],
9861b644 50 link:RelNotes-1.6.5.6.txt[1.6.5.6],
aa031314 51 link:RelNotes-1.6.5.5.txt[1.6.5.5],
eefe19fb 52 link:RelNotes-1.6.5.4.txt[1.6.5.4],
080cbc12 53 link:RelNotes-1.6.5.3.txt[1.6.5.3],
6c0efa2a 54 link:RelNotes-1.6.5.2.txt[1.6.5.2],
b142da2a 55 link:RelNotes-1.6.5.1.txt[1.6.5.1],
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56 link:RelNotes-1.6.5.txt[1.6.5].
57
cb572206 58* link:v1.6.4.4/git.html[documentation for release 1.6.4.4]
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59
60* release notes for
cb572206 61 link:RelNotes-1.6.4.4.txt[1.6.4.4],
7fb6bcff 62 link:RelNotes-1.6.4.3.txt[1.6.4.3],
82c3e210 63 link:RelNotes-1.6.4.2.txt[1.6.4.2],
d9b9784f 64 link:RelNotes-1.6.4.1.txt[1.6.4.1],
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65 link:RelNotes-1.6.4.txt[1.6.4].
66
441b40d8 67* link:v1.6.3.4/git.html[documentation for release 1.6.3.4]
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68
69* release notes for
441b40d8 70 link:RelNotes-1.6.3.4.txt[1.6.3.4],
e16a4779 71 link:RelNotes-1.6.3.3.txt[1.6.3.3],
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72 link:RelNotes-1.6.3.2.txt[1.6.3.2],
73 link:RelNotes-1.6.3.1.txt[1.6.3.1],
74 link:RelNotes-1.6.3.txt[1.6.3].
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75
76* release notes for
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77 link:RelNotes-1.6.2.5.txt[1.6.2.5],
78 link:RelNotes-1.6.2.4.txt[1.6.2.4],
c965c029 79 link:RelNotes-1.6.2.3.txt[1.6.2.3],
54a47493 80 link:RelNotes-1.6.2.2.txt[1.6.2.2],
de769780 81 link:RelNotes-1.6.2.1.txt[1.6.2.1],
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82 link:RelNotes-1.6.2.txt[1.6.2].
83
621f1b4b 84* link:v1.6.1.3/git.html[documentation for release 1.6.1.3]
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85
86* release notes for
621f1b4b
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87 link:RelNotes-1.6.1.3.txt[1.6.1.3],
88 link:RelNotes-1.6.1.2.txt[1.6.1.2],
c42b1ad9 89 link:RelNotes-1.6.1.1.txt[1.6.1.1],
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90 link:RelNotes-1.6.1.txt[1.6.1].
91
efe05b01 92* link:v1.6.0.6/git.html[documentation for release 1.6.0.6]
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93
94* release notes for
efe05b01 95 link:RelNotes-1.6.0.6.txt[1.6.0.6],
f371d3ea 96 link:RelNotes-1.6.0.5.txt[1.6.0.5],
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97 link:RelNotes-1.6.0.4.txt[1.6.0.4],
98 link:RelNotes-1.6.0.3.txt[1.6.0.3],
97a7a82f
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99 link:RelNotes-1.6.0.2.txt[1.6.0.2],
100 link:RelNotes-1.6.0.1.txt[1.6.0.1],
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101 link:RelNotes-1.6.0.txt[1.6.0].
102
efe05b01 103* link:v1.5.6.6/git.html[documentation for release 1.5.6.6]
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104
105* release notes for
efe05b01 106 link:RelNotes-1.5.6.6.txt[1.5.6.6],
781c1834 107 link:RelNotes-1.5.6.5.txt[1.5.6.5],
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108 link:RelNotes-1.5.6.4.txt[1.5.6.4],
109 link:RelNotes-1.5.6.3.txt[1.5.6.3],
110 link:RelNotes-1.5.6.2.txt[1.5.6.2],
111 link:RelNotes-1.5.6.1.txt[1.5.6.1],
e636106c 112 link:RelNotes-1.5.6.txt[1.5.6].
e449f105 113
efe05b01 114* link:v1.5.5.6/git.html[documentation for release 1.5.5.6]
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115
116* release notes for
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117 link:RelNotes-1.5.5.6.txt[1.5.5.6],
118 link:RelNotes-1.5.5.5.txt[1.5.5.5],
7064ca51 119 link:RelNotes-1.5.5.4.txt[1.5.5.4],
28bc3022 120 link:RelNotes-1.5.5.3.txt[1.5.5.3],
2d3922dc 121 link:RelNotes-1.5.5.2.txt[1.5.5.2],
66aaa2fc 122 link:RelNotes-1.5.5.1.txt[1.5.5.1],
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123 link:RelNotes-1.5.5.txt[1.5.5].
124
efe05b01 125* link:v1.5.4.7/git.html[documentation for release 1.5.4.7]
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126
127* release notes for
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128 link:RelNotes-1.5.4.7.txt[1.5.4.7],
129 link:RelNotes-1.5.4.6.txt[1.5.4.6],
803d5158 130 link:RelNotes-1.5.4.5.txt[1.5.4.5],
ad416ed4 131 link:RelNotes-1.5.4.4.txt[1.5.4.4],
923d44ae 132 link:RelNotes-1.5.4.3.txt[1.5.4.3],
cf5c51ef 133 link:RelNotes-1.5.4.2.txt[1.5.4.2],
ecb879f8 134 link:RelNotes-1.5.4.1.txt[1.5.4.1],
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135 link:RelNotes-1.5.4.txt[1.5.4].
136
e708af6e 137* link:v1.5.3.8/git.html[documentation for release 1.5.3.8]
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138
139* release notes for
e708af6e 140 link:RelNotes-1.5.3.8.txt[1.5.3.8],
b52e985a 141 link:RelNotes-1.5.3.7.txt[1.5.3.7],
4a44b9ea 142 link:RelNotes-1.5.3.6.txt[1.5.3.6],
afc05f9f 143 link:RelNotes-1.5.3.5.txt[1.5.3.5],
58ba4f6a 144 link:RelNotes-1.5.3.4.txt[1.5.3.4],
326df26d 145 link:RelNotes-1.5.3.3.txt[1.5.3.3],
077d6f72 146 link:RelNotes-1.5.3.2.txt[1.5.3.2],
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147 link:RelNotes-1.5.3.1.txt[1.5.3.1],
148 link:RelNotes-1.5.3.txt[1.5.3].
b6e4db6a 149
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150* link:v1.5.2.5/git.html[documentation for release 1.5.2.5]
151
aba170cd 152* release notes for
da899deb 153 link:RelNotes-1.5.2.5.txt[1.5.2.5],
baafd6e7 154 link:RelNotes-1.5.2.4.txt[1.5.2.4],
444649e5 155 link:RelNotes-1.5.2.3.txt[1.5.2.3],
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156 link:RelNotes-1.5.2.2.txt[1.5.2.2],
157 link:RelNotes-1.5.2.1.txt[1.5.2.1],
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158 link:RelNotes-1.5.2.txt[1.5.2].
159
160* link:v1.5.1.6/git.html[documentation for release 1.5.1.6]
161
162* release notes for
163 link:RelNotes-1.5.1.6.txt[1.5.1.6],
164 link:RelNotes-1.5.1.5.txt[1.5.1.5],
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165 link:RelNotes-1.5.1.4.txt[1.5.1.4],
166 link:RelNotes-1.5.1.3.txt[1.5.1.3],
167 link:RelNotes-1.5.1.2.txt[1.5.1.2],
168 link:RelNotes-1.5.1.1.txt[1.5.1.1],
169 link:RelNotes-1.5.1.txt[1.5.1].
170
171* link:v1.5.0.7/git.html[documentation for release 1.5.0.7]
172
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173* release notes for
174 link:RelNotes-1.5.0.7.txt[1.5.0.7],
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175 link:RelNotes-1.5.0.6.txt[1.5.0.6],
176 link:RelNotes-1.5.0.5.txt[1.5.0.5],
177 link:RelNotes-1.5.0.3.txt[1.5.0.3],
178 link:RelNotes-1.5.0.2.txt[1.5.0.2],
179 link:RelNotes-1.5.0.1.txt[1.5.0.1],
180 link:RelNotes-1.5.0.txt[1.5.0].
181
182* documentation for release link:v1.4.4.4/git.html[1.4.4.4],
183 link:v1.3.3/git.html[1.3.3],
184 link:v1.2.6/git.html[1.2.6],
185 link:v1.0.13/git.html[1.0.13].
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186
187============
188
189endif::stalenotes[]
190
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191OPTIONS
192-------
193--version::
a87cd02c 194 Prints the git suite version that the 'git' program came from.
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195
196--help::
a87cd02c 197 Prints the synopsis and a list of the most commonly used
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198 commands. If the option '--all' or '-a' is given then all
199 available commands are printed. If a git command is named this
200 option will bring up the manual page for that command.
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201+
202Other options are available to control how the manual page is
5162e697 203displayed. See linkgit:git-help[1] for more information,
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204because `git --help ...` is converted internally into `git
205help ...`.
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206
207--exec-path::
a87cd02c 208 Path to wherever your core git programs are installed.
cb22bc44 209 This can also be controlled by setting the GIT_EXEC_PATH
56992f76 210 environment variable. If no path is given, 'git' will print
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211 the current setting and then exit.
212
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213--html-path::
214 Print the path to wherever your git HTML documentation is installed
215 and exit.
216
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217-p::
218--paginate::
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219 Pipe all output into 'less' (or if set, $PAGER).
220
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221--no-pager::
222 Do not pipe git output into a pager.
223
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224--git-dir=<path>::
225 Set the path to the repository. This can also be controlled by
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226 setting the GIT_DIR environment variable. It can be an absolute
227 path or relative path to current working directory.
6acbcb92 228
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229--work-tree=<path>::
230 Set the path to the working tree. The value will not be
231 used in combination with repositories found automatically in
232 a .git directory (i.e. $GIT_DIR is not set).
233 This can also be controlled by setting the GIT_WORK_TREE
234 environment variable and the core.worktree configuration
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235 variable. It can be an absolute path or relative path to
236 the directory specified by --git-dir or GIT_DIR.
237 Note: If --git-dir or GIT_DIR are specified but none of
238 --work-tree, GIT_WORK_TREE and core.worktree is specified,
239 the current working directory is regarded as the top directory
240 of your working tree.
892c41b9 241
6acbcb92 242--bare::
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243 Treat the repository as a bare repository. If GIT_DIR
244 environment is not set, it is set to the current working
245 directory.
246
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247--no-replace-objects::
248 Do not use replacement refs to replace git objects. See
249 linkgit:git-replace[1] for more information.
250
9755afbd 251
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252FURTHER DOCUMENTATION
253---------------------
9755afbd 254
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255See the references above to get started using git. The following is
256probably more detail than necessary for a first-time user.
8db9307c 257
40dac517 258The link:user-manual.html#git-concepts[git concepts chapter of the
6998e4db 259user-manual] and linkgit:gitcore-tutorial[7] both provide
40dac517 260introductions to the underlying git architecture.
e6fc2346 261
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262See linkgit:gitworkflows[7] for an overview of recommended workflows.
263
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264See also the link:howto-index.html[howto] documents for some useful
265examples.
9755afbd 266
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267The internals are documented in the
268link:technical/api-index.html[GIT API documentation].
530e741c 269
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270GIT COMMANDS
271------------
9755afbd 272
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273We divide git into high level ("porcelain") commands and low level
274("plumbing") commands.
8b15e2fb 275
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276High-level commands (porcelain)
277-------------------------------
278
279We separate the porcelain commands into the main commands and some
280ancillary user utilities.
281
282Main porcelain commands
283~~~~~~~~~~~~~~~~~~~~~~~
905197de 284
377e8139 285include::cmds-mainporcelain.txt[]
e31bb3bb 286
90933efb 287Ancillary Commands
23091e95 288~~~~~~~~~~~~~~~~~~
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289Manipulators:
290
377e8139 291include::cmds-ancillarymanipulators.txt[]
204ee6a9 292
90933efb 293Interrogators:
204ee6a9 294
377e8139 295include::cmds-ancillaryinterrogators.txt[]
7fc9d69f 296
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297
298Interacting with Others
299~~~~~~~~~~~~~~~~~~~~~~~
300
301These commands are to interact with foreign SCM and with other
302people via patch over e-mail.
303
304include::cmds-foreignscminterface.txt[]
305
306
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307Low-level commands (plumbing)
308-----------------------------
309
310Although git includes its
311own porcelain layer, its low-level commands are sufficient to support
312development of alternative porcelains. Developers of such porcelains
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313might start by reading about linkgit:git-update-index[1] and
314linkgit:git-read-tree[1].
b1f33d62 315
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316The interface (input, output, set of options and the semantics)
317to these low-level commands are meant to be a lot more stable
318than Porcelain level commands, because these commands are
319primarily for scripted use. The interface to Porcelain commands
320on the other hand are subject to change in order to improve the
321end user experience.
322
323The following description divides
324the low-level commands into commands that manipulate objects (in
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325the repository, index, and working tree), commands that interrogate and
326compare objects, and commands that move objects and references between
327repositories.
328
89bf2077 329
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330Manipulation commands
331~~~~~~~~~~~~~~~~~~~~~
b1f33d62 332
377e8139 333include::cmds-plumbingmanipulators.txt[]
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334
335
336Interrogation commands
337~~~~~~~~~~~~~~~~~~~~~~
338
377e8139 339include::cmds-plumbinginterrogators.txt[]
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340
341In general, the interrogate commands do not touch the files in
342the working tree.
343
344
345Synching repositories
346~~~~~~~~~~~~~~~~~~~~~
347
377e8139 348include::cmds-synchingrepositories.txt[]
b1f33d62 349
57f6ec02 350The following are helper commands used by the above; end users
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351typically do not use them directly.
352
353include::cmds-synchelpers.txt[]
354
355
356Internal helper commands
357~~~~~~~~~~~~~~~~~~~~~~~~
358
359These are internal helper commands used by other commands; end
360users typically do not use them directly.
361
362include::cmds-purehelpers.txt[]
363
b1f33d62 364
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365Configuration Mechanism
366-----------------------
367
2fa090b6 368Starting from 0.99.9 (actually mid 0.99.8.GIT), `.git/config` file
5773c9f2 369is used to hold per-repository configuration options. It is a
addf88e4 370simple text file modeled after `.ini` format familiar to some
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371people. Here is an example:
372
373------------
374#
2fa090b6 375# A '#' or ';' character indicates a comment.
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376#
377
378; core variables
379[core]
380 ; Don't trust file modes
381 filemode = false
382
383; user identity
384[user]
385 name = "Junio C Hamano"
386 email = "junkio@twinsun.com"
387
388------------
389
390Various commands read from the configuration file and adjust
391their operation accordingly.
392
393
6c84e2e0 394Identifier Terminology
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395----------------------
396<object>::
2fa090b6 397 Indicates the object name for any type of object.
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398
399<blob>::
2fa090b6 400 Indicates a blob object name.
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401
402<tree>::
2fa090b6 403 Indicates a tree object name.
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404
405<commit>::
2fa090b6 406 Indicates a commit object name.
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407
408<tree-ish>::
2fa090b6 409 Indicates a tree, commit or tag object name. A
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410 command that takes a <tree-ish> argument ultimately wants to
411 operate on a <tree> object but automatically dereferences
412 <commit> and <tag> objects that point at a <tree>.
2cf565c5 413
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414<commit-ish>::
415 Indicates a commit or tag object name. A
416 command that takes a <commit-ish> argument ultimately wants to
417 operate on a <commit> object but automatically dereferences
418 <tag> objects that point at a <commit>.
419
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420<type>::
421 Indicates that an object type is required.
2fa090b6 422 Currently one of: `blob`, `tree`, `commit`, or `tag`.
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423
424<file>::
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425 Indicates a filename - almost always relative to the
426 root of the tree structure `GIT_INDEX_FILE` describes.
2cf565c5 427
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428Symbolic Identifiers
429--------------------
90933efb 430Any git command accepting any <object> can also use the following
6c84e2e0 431symbolic notation:
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432
433HEAD::
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434 indicates the head of the current branch (i.e. the
435 contents of `$GIT_DIR/HEAD`).
436
c1bdacf9 437<tag>::
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438 a valid tag 'name'
439 (i.e. the contents of `$GIT_DIR/refs/tags/<tag>`).
440
c1bdacf9 441<head>::
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442 a valid head 'name'
443 (i.e. the contents of `$GIT_DIR/refs/heads/<head>`).
444
d47107d8 445For a more complete list of ways to spell object names, see
5162e697 446"SPECIFYING REVISIONS" section in linkgit:git-rev-parse[1].
d47107d8 447
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448
449File/Directory Structure
450------------------------
c1bdacf9 451
6998e4db 452Please see the linkgit:gitrepository-layout[5] document.
c1bdacf9 453
6998e4db 454Read linkgit:githooks[5] for more details about each hook.
6250ad1e 455
c1bdacf9 456Higher level SCMs may provide and manage additional information in the
2fa090b6 457`$GIT_DIR`.
c1bdacf9 458
a1d4aa74 459
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460Terminology
461-----------
6998e4db 462Please see linkgit:gitglossary[7].
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463
464
465Environment Variables
466---------------------
467Various git commands use the following environment variables:
468
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469The git Repository
470~~~~~~~~~~~~~~~~~~
471These environment variables apply to 'all' core git commands. Nb: it
472is worth noting that they may be used/overridden by SCMS sitting above
2fa090b6 473git so take care if using Cogito etc.
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474
475'GIT_INDEX_FILE'::
476 This environment allows the specification of an alternate
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477 index file. If not specified, the default of `$GIT_DIR/index`
478 is used.
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479
480'GIT_OBJECT_DIRECTORY'::
481 If the object storage directory is specified via this
482 environment variable then the sha1 directories are created
483 underneath - otherwise the default `$GIT_DIR/objects`
484 directory is used.
485
486'GIT_ALTERNATE_OBJECT_DIRECTORIES'::
487 Due to the immutable nature of git objects, old objects can be
488 archived into shared, read-only directories. This variable
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489 specifies a ":" separated (on Windows ";" separated) list
490 of git object directories which can be used to search for git
491 objects. New objects will not be written to these directories.
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492
493'GIT_DIR'::
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494 If the 'GIT_DIR' environment variable is set then it
495 specifies a path to use instead of the default `.git`
496 for the base of the repository.
c1bdacf9 497
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498'GIT_WORK_TREE'::
499 Set the path to the working tree. The value will not be
500 used in combination with repositories found automatically in
501 a .git directory (i.e. $GIT_DIR is not set).
502 This can also be controlled by the '--work-tree' command line
503 option and the core.worktree configuration variable.
504
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505'GIT_CEILING_DIRECTORIES'::
506 This should be a colon-separated list of absolute paths.
507 If set, it is a list of directories that git should not chdir
508 up into while looking for a repository directory.
509 It will not exclude the current working directory or
510 a GIT_DIR set on the command line or in the environment.
511 (Useful for excluding slow-loading network directories.)
512
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513git Commits
514~~~~~~~~~~~
515'GIT_AUTHOR_NAME'::
516'GIT_AUTHOR_EMAIL'::
517'GIT_AUTHOR_DATE'::
518'GIT_COMMITTER_NAME'::
519'GIT_COMMITTER_EMAIL'::
4e58bf97 520'GIT_COMMITTER_DATE'::
28a94f88 521'EMAIL'::
5162e697 522 see linkgit:git-commit-tree[1]
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523
524git Diffs
525~~~~~~~~~
d81ed1b5 526'GIT_DIFF_OPTS'::
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527 Only valid setting is "--unified=??" or "-u??" to set the
528 number of context lines shown when a unified diff is created.
529 This takes precedence over any "-U" or "--unified" option
530 value passed on the git diff command line.
531
d81ed1b5 532'GIT_EXTERNAL_DIFF'::
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533 When the environment variable 'GIT_EXTERNAL_DIFF' is set, the
534 program named by it is called, instead of the diff invocation
535 described above. For a path that is added, removed, or modified,
536 'GIT_EXTERNAL_DIFF' is called with 7 parameters:
537
538 path old-file old-hex old-mode new-file new-hex new-mode
539+
540where:
541
542 <old|new>-file:: are files GIT_EXTERNAL_DIFF can use to read the
543 contents of <old|new>,
544 <old|new>-hex:: are the 40-hexdigit SHA1 hashes,
545 <old|new>-mode:: are the octal representation of the file modes.
546
547+
548The file parameters can point at the user's working file
549(e.g. `new-file` in "git-diff-files"), `/dev/null` (e.g. `old-file`
550when a new file is added), or a temporary file (e.g. `old-file` in the
551index). 'GIT_EXTERNAL_DIFF' should not worry about unlinking the
552temporary file --- it is removed when 'GIT_EXTERNAL_DIFF' exits.
553+
554For a path that is unmerged, 'GIT_EXTERNAL_DIFF' is called with 1
555parameter, <path>.
2cf565c5 556
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557other
558~~~~~
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559'GIT_MERGE_VERBOSITY'::
560 A number controlling the amount of output shown by
561 the recursive merge strategy. Overrides merge.verbosity.
5162e697 562 See linkgit:git-merge[1]
dbddb714 563
c27d205a 564'GIT_PAGER'::
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565 This environment variable overrides `$PAGER`. If it is set
566 to an empty string or to the value "cat", git will not launch
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567 a pager. See also the `core.pager` option in
568 linkgit:git-config[1].
c27d205a 569
d5538b41 570'GIT_SSH'::
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571 If this environment variable is set then 'git-fetch'
572 and 'git-push' will use this command instead
2fd02c92 573 of 'ssh' when they need to connect to a remote system.
483bc4f0 574 The '$GIT_SSH' command will be given exactly two arguments:
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575 the 'username@host' (or just 'host') from the URL and the
576 shell command to execute on that remote system.
577+
578To pass options to the program that you want to list in GIT_SSH
579you will need to wrap the program and options into a shell script,
580then set GIT_SSH to refer to the shell script.
581+
582Usually it is easier to configure any desired options through your
583personal `.ssh/config` file. Please consult your ssh documentation
584for further details.
585
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586'GIT_FLUSH'::
587 If this environment variable is set to "1", then commands such
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588 as 'git-blame' (in incremental mode), 'git-rev-list', 'git-log',
589 and 'git-whatchanged' will force a flush of the output stream
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590 after each commit-oriented record have been flushed. If this
591 variable is set to "0", the output of these commands will be done
592 using completely buffered I/O. If this environment variable is
593 not set, git will choose buffered or record-oriented flushing
594 based on whether stdout appears to be redirected to a file or not.
595
575ba9d6 596'GIT_TRACE'::
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597 If this variable is set to "1", "2" or "true" (comparison
598 is case insensitive), git will print `trace:` messages on
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599 stderr telling about alias expansion, built-in command
600 execution and external command execution.
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601 If this variable is set to an integer value greater than 1
602 and lower than 10 (strictly) then git will interpret this
603 value as an open file descriptor and will try to write the
604 trace messages into this file descriptor.
605 Alternatively, if this variable is set to an absolute path
606 (starting with a '/' character), git will interpret this
607 as a file path and will try to write the trace messages
608 into it.
575ba9d6 609
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610Discussion[[Discussion]]
611------------------------
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612
613More detail on the following is available from the
614link:user-manual.html#git-concepts[git concepts chapter of the
6998e4db 615user-manual] and linkgit:gitcore-tutorial[7].
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616
617A git project normally consists of a working directory with a ".git"
618subdirectory at the top level. The .git directory contains, among other
619things, a compressed object database representing the complete history
620of the project, an "index" file which links that history to the current
621contents of the working tree, and named pointers into that history such
622as tags and branch heads.
623
624The object database contains objects of three main types: blobs, which
625hold file data; trees, which point to blobs and other trees to build up
02ff6250 626directory hierarchies; and commits, which each reference a single tree
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627and some number of parent commits.
628
629The commit, equivalent to what other systems call a "changeset" or
630"version", represents a step in the project's history, and each parent
631represents an immediately preceding step. Commits with more than one
632parent represent merges of independent lines of development.
633
634All objects are named by the SHA1 hash of their contents, normally
635written as a string of 40 hex digits. Such names are globally unique.
636The entire history leading up to a commit can be vouched for by signing
637just that commit. A fourth object type, the tag, is provided for this
638purpose.
639
640When first created, objects are stored in individual files, but for
641efficiency may later be compressed together into "pack files".
642
643Named pointers called refs mark interesting points in history. A ref
644may contain the SHA1 name of an object or the name of another ref. Refs
645with names beginning `ref/head/` contain the SHA1 name of the most
02ff6250 646recent commit (or "head") of a branch under development. SHA1 names of
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647tags of interest are stored under `ref/tags/`. A special ref named
648`HEAD` contains the name of the currently checked-out branch.
649
650The index file is initialized with a list of all paths and, for each
651path, a blob object and a set of attributes. The blob object represents
652the contents of the file as of the head of the current branch. The
653attributes (last modified time, size, etc.) are taken from the
654corresponding file in the working tree. Subsequent changes to the
655working tree can be found by comparing these attributes. The index may
656be updated with new content, and new commits may be created from the
657content stored in the index.
658
659The index is also capable of storing multiple entries (called "stages")
660for a given pathname. These stages are used to hold the various
661unmerged version of a file when a merge is in progress.
6c84e2e0 662
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663Authors
664-------
9755afbd 665* git's founding father is Linus Torvalds <torvalds@osdl.org>.
947ad2e1 666* The current git nurse is Junio C Hamano <gitster@pobox.com>.
0240e21a 667* The git potty was written by Andreas Ericsson <ae@op5.se>.
9755afbd 668* General upbringing is handled by the git-list <git@vger.kernel.org>.
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669
670Documentation
671--------------
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672The documentation for git suite was started by David Greaves
673<david@dgreaves.com>, and later enhanced greatly by the
674contributors on the git-list <git@vger.kernel.org>.
2cf565c5 675
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676SEE ALSO
677--------
678linkgit:gittutorial[7], linkgit:gittutorial-2[7],
5cbef01a 679link:everyday.html[Everyday Git], linkgit:gitcvs-migration[7],
497c8331 680linkgit:gitglossary[7], linkgit:gitcore-tutorial[7],
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681linkgit:gitcli[7], link:user-manual.html[The Git User's Manual],
682linkgit:gitworkflows[7]
497c8331 683
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684GIT
685---
9e1f0a85 686Part of the linkgit:git[1] suite