Documentation / git.txton commit doc: generate a list of valid merge tools (f35ec54)
   1git(1)
   2======
   3
   4NAME
   5----
   6git - the stupid content tracker
   7
   8
   9SYNOPSIS
  10--------
  11[verse]
  12'git' [--version] [--help] [-c <name>=<value>]
  13    [--exec-path[=<path>]] [--html-path] [--man-path] [--info-path]
  14    [-p|--paginate|--no-pager] [--no-replace-objects] [--bare]
  15    [--git-dir=<path>] [--work-tree=<path>] [--namespace=<name>]
  16    <command> [<args>]
  17
  18DESCRIPTION
  19-----------
  20Git is a fast, scalable, distributed revision control system with an
  21unusually rich command set that provides both high-level operations
  22and full access to internals.
  23
  24See linkgit:gittutorial[7] to get started, then see
  25link:everyday.html[Everyday Git] for a useful minimum set of
  26commands.  The link:user-manual.html[Git User's Manual] has a more
  27in-depth introduction.
  28
  29After you mastered the basic concepts, you can come back to this
  30page to learn what commands git offers.  You can learn more about
  31individual git commands with "git help command".  linkgit:gitcli[7]
  32manual page gives you an overview of the command line command syntax.
  33
  34Formatted and hyperlinked version of the latest git documentation
  35can be viewed at `http://git-htmldocs.googlecode.com/git/git.html`.
  36
  37ifdef::stalenotes[]
  38[NOTE]
  39============
  40
  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:
  45
  46* link:v1.8.0/git.html[documentation for release 1.8.0]
  47
  48* release notes for
  49  link:RelNotes/1.8.0.txt[1.8.0],
  50
  51* link:v1.7.12.4/git.html[documentation for release 1.7.12.4]
  52
  53* release notes for
  54  link:RelNotes/1.7.12.4.txt[1.7.12.4],
  55  link:RelNotes/1.7.12.3.txt[1.7.12.3],
  56  link:RelNotes/1.7.12.2.txt[1.7.12.2],
  57  link:RelNotes/1.7.12.1.txt[1.7.12.1],
  58  link:RelNotes/1.7.12.txt[1.7.12].
  59
  60* link:v1.7.11.7/git.html[documentation for release 1.7.11.7]
  61
  62* release notes for
  63  link:RelNotes/1.7.11.7.txt[1.7.11.7],
  64  link:RelNotes/1.7.11.6.txt[1.7.11.6],
  65  link:RelNotes/1.7.11.5.txt[1.7.11.5],
  66  link:RelNotes/1.7.11.4.txt[1.7.11.4],
  67  link:RelNotes/1.7.11.3.txt[1.7.11.3],
  68  link:RelNotes/1.7.11.2.txt[1.7.11.2],
  69  link:RelNotes/1.7.11.1.txt[1.7.11.1],
  70  link:RelNotes/1.7.11.txt[1.7.11].
  71
  72* link:v1.7.10.5/git.html[documentation for release 1.7.10.5]
  73
  74* release notes for
  75  link:RelNotes/1.7.10.5.txt[1.7.10.5],
  76  link:RelNotes/1.7.10.4.txt[1.7.10.4],
  77  link:RelNotes/1.7.10.3.txt[1.7.10.3],
  78  link:RelNotes/1.7.10.2.txt[1.7.10.2],
  79  link:RelNotes/1.7.10.1.txt[1.7.10.1],
  80  link:RelNotes/1.7.10.txt[1.7.10].
  81
  82* link:v1.7.9.7/git.html[documentation for release 1.7.9.7]
  83
  84* release notes for
  85  link:RelNotes/1.7.9.7.txt[1.7.9.7],
  86  link:RelNotes/1.7.9.6.txt[1.7.9.6],
  87  link:RelNotes/1.7.9.5.txt[1.7.9.5],
  88  link:RelNotes/1.7.9.4.txt[1.7.9.4],
  89  link:RelNotes/1.7.9.3.txt[1.7.9.3],
  90  link:RelNotes/1.7.9.2.txt[1.7.9.2],
  91  link:RelNotes/1.7.9.1.txt[1.7.9.1],
  92  link:RelNotes/1.7.9.txt[1.7.9].
  93
  94* link:v1.7.8.6/git.html[documentation for release 1.7.8.6]
  95
  96* release notes for
  97  link:RelNotes/1.7.8.6.txt[1.7.8.6],
  98  link:RelNotes/1.7.8.5.txt[1.7.8.5],
  99  link:RelNotes/1.7.8.4.txt[1.7.8.4],
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 101  link:RelNotes/1.7.8.2.txt[1.7.8.2],
 102  link:RelNotes/1.7.8.1.txt[1.7.8.1],
 103  link:RelNotes/1.7.8.txt[1.7.8].
 104
 105* link:v1.7.7.7/git.html[documentation for release 1.7.7.7]
 106
 107* release notes for
 108  link:RelNotes/1.7.7.7.txt[1.7.7.7],
 109  link:RelNotes/1.7.7.6.txt[1.7.7.6],
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 111  link:RelNotes/1.7.7.4.txt[1.7.7.4],
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 115  link:RelNotes/1.7.7.txt[1.7.7].
 116
 117* link:v1.7.6.6/git.html[documentation for release 1.7.6.6]
 118
 119* release notes for
 120  link:RelNotes/1.7.6.6.txt[1.7.6.6],
 121  link:RelNotes/1.7.6.5.txt[1.7.6.5],
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 123  link:RelNotes/1.7.6.3.txt[1.7.6.3],
 124  link:RelNotes/1.7.6.2.txt[1.7.6.2],
 125  link:RelNotes/1.7.6.1.txt[1.7.6.1],
 126  link:RelNotes/1.7.6.txt[1.7.6].
 127
 128* link:v1.7.5.4/git.html[documentation for release 1.7.5.4]
 129
 130* release notes for
 131  link:RelNotes/1.7.5.4.txt[1.7.5.4],
 132  link:RelNotes/1.7.5.3.txt[1.7.5.3],
 133  link:RelNotes/1.7.5.2.txt[1.7.5.2],
 134  link:RelNotes/1.7.5.1.txt[1.7.5.1],
 135  link:RelNotes/1.7.5.txt[1.7.5].
 136
 137* link:v1.7.4.5/git.html[documentation for release 1.7.4.5]
 138
 139* release notes for
 140  link:RelNotes/1.7.4.5.txt[1.7.4.5],
 141  link:RelNotes/1.7.4.4.txt[1.7.4.4],
 142  link:RelNotes/1.7.4.3.txt[1.7.4.3],
 143  link:RelNotes/1.7.4.2.txt[1.7.4.2],
 144  link:RelNotes/1.7.4.1.txt[1.7.4.1],
 145  link:RelNotes/1.7.4.txt[1.7.4].
 146
 147* link:v1.7.3.5/git.html[documentation for release 1.7.3.5]
 148
 149* release notes for
 150  link:RelNotes/1.7.3.5.txt[1.7.3.5],
 151  link:RelNotes/1.7.3.4.txt[1.7.3.4],
 152  link:RelNotes/1.7.3.3.txt[1.7.3.3],
 153  link:RelNotes/1.7.3.2.txt[1.7.3.2],
 154  link:RelNotes/1.7.3.1.txt[1.7.3.1],
 155  link:RelNotes/1.7.3.txt[1.7.3].
 156
 157* link:v1.7.2.5/git.html[documentation for release 1.7.2.5]
 158
 159* release notes for
 160  link:RelNotes/1.7.2.5.txt[1.7.2.5],
 161  link:RelNotes/1.7.2.4.txt[1.7.2.4],
 162  link:RelNotes/1.7.2.3.txt[1.7.2.3],
 163  link:RelNotes/1.7.2.2.txt[1.7.2.2],
 164  link:RelNotes/1.7.2.1.txt[1.7.2.1],
 165  link:RelNotes/1.7.2.txt[1.7.2].
 166
 167* link:v1.7.1.4/git.html[documentation for release 1.7.1.4]
 168
 169* release notes for
 170  link:RelNotes/1.7.1.4.txt[1.7.1.4],
 171  link:RelNotes/1.7.1.3.txt[1.7.1.3],
 172  link:RelNotes/1.7.1.2.txt[1.7.1.2],
 173  link:RelNotes/1.7.1.1.txt[1.7.1.1],
 174  link:RelNotes/1.7.1.txt[1.7.1].
 175
 176* link:v1.7.0.9/git.html[documentation for release 1.7.0.9]
 177
 178* release notes for
 179  link:RelNotes/1.7.0.9.txt[1.7.0.9],
 180  link:RelNotes/1.7.0.8.txt[1.7.0.8],
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 187  link:RelNotes/1.7.0.1.txt[1.7.0.1],
 188  link:RelNotes/1.7.0.txt[1.7.0].
 189
 190* link:v1.6.6.3/git.html[documentation for release 1.6.6.3]
 191
 192* release notes for
 193  link:RelNotes/1.6.6.3.txt[1.6.6.3],
 194  link:RelNotes/1.6.6.2.txt[1.6.6.2],
 195  link:RelNotes/1.6.6.1.txt[1.6.6.1],
 196  link:RelNotes/1.6.6.txt[1.6.6].
 197
 198* link:v1.6.5.9/git.html[documentation for release 1.6.5.9]
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 210  link:RelNotes/1.6.5.txt[1.6.5].
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 212* link:v1.6.4.5/git.html[documentation for release 1.6.4.5]
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 216  link:RelNotes/1.6.4.4.txt[1.6.4.4],
 217  link:RelNotes/1.6.4.3.txt[1.6.4.3],
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 220  link:RelNotes/1.6.4.txt[1.6.4].
 221
 222* link:v1.6.3.4/git.html[documentation for release 1.6.3.4]
 223
 224* release notes for
 225  link:RelNotes/1.6.3.4.txt[1.6.3.4],
 226  link:RelNotes/1.6.3.3.txt[1.6.3.3],
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 228  link:RelNotes/1.6.3.1.txt[1.6.3.1],
 229  link:RelNotes/1.6.3.txt[1.6.3].
 230
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 232  link:RelNotes/1.6.2.5.txt[1.6.2.5],
 233  link:RelNotes/1.6.2.4.txt[1.6.2.4],
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 235  link:RelNotes/1.6.2.2.txt[1.6.2.2],
 236  link:RelNotes/1.6.2.1.txt[1.6.2.1],
 237  link:RelNotes/1.6.2.txt[1.6.2].
 238
 239* link:v1.6.1.3/git.html[documentation for release 1.6.1.3]
 240
 241* release notes for
 242  link:RelNotes/1.6.1.3.txt[1.6.1.3],
 243  link:RelNotes/1.6.1.2.txt[1.6.1.2],
 244  link:RelNotes/1.6.1.1.txt[1.6.1.1],
 245  link:RelNotes/1.6.1.txt[1.6.1].
 246
 247* link:v1.6.0.6/git.html[documentation for release 1.6.0.6]
 248
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 250  link:RelNotes/1.6.0.6.txt[1.6.0.6],
 251  link:RelNotes/1.6.0.5.txt[1.6.0.5],
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 256  link:RelNotes/1.6.0.txt[1.6.0].
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 258* link:v1.5.6.6/git.html[documentation for release 1.5.6.6]
 259
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 261  link:RelNotes/1.5.6.6.txt[1.5.6.6],
 262  link:RelNotes/1.5.6.5.txt[1.5.6.5],
 263  link:RelNotes/1.5.6.4.txt[1.5.6.4],
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 267  link:RelNotes/1.5.6.txt[1.5.6].
 268
 269* link:v1.5.5.6/git.html[documentation for release 1.5.5.6]
 270
 271* release notes for
 272  link:RelNotes/1.5.5.6.txt[1.5.5.6],
 273  link:RelNotes/1.5.5.5.txt[1.5.5.5],
 274  link:RelNotes/1.5.5.4.txt[1.5.5.4],
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 278  link:RelNotes/1.5.5.txt[1.5.5].
 279
 280* link:v1.5.4.7/git.html[documentation for release 1.5.4.7]
 281
 282* release notes for
 283  link:RelNotes/1.5.4.7.txt[1.5.4.7],
 284  link:RelNotes/1.5.4.6.txt[1.5.4.6],
 285  link:RelNotes/1.5.4.5.txt[1.5.4.5],
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 287  link:RelNotes/1.5.4.3.txt[1.5.4.3],
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 289  link:RelNotes/1.5.4.1.txt[1.5.4.1],
 290  link:RelNotes/1.5.4.txt[1.5.4].
 291
 292* link:v1.5.3.8/git.html[documentation for release 1.5.3.8]
 293
 294* release notes for
 295  link:RelNotes/1.5.3.8.txt[1.5.3.8],
 296  link:RelNotes/1.5.3.7.txt[1.5.3.7],
 297  link:RelNotes/1.5.3.6.txt[1.5.3.6],
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 303  link:RelNotes/1.5.3.txt[1.5.3].
 304
 305* link:v1.5.2.5/git.html[documentation for release 1.5.2.5]
 306
 307* release notes for
 308  link:RelNotes/1.5.2.5.txt[1.5.2.5],
 309  link:RelNotes/1.5.2.4.txt[1.5.2.4],
 310  link:RelNotes/1.5.2.3.txt[1.5.2.3],
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 312  link:RelNotes/1.5.2.1.txt[1.5.2.1],
 313  link:RelNotes/1.5.2.txt[1.5.2].
 314
 315* link:v1.5.1.6/git.html[documentation for release 1.5.1.6]
 316
 317* release notes for
 318  link:RelNotes/1.5.1.6.txt[1.5.1.6],
 319  link:RelNotes/1.5.1.5.txt[1.5.1.5],
 320  link:RelNotes/1.5.1.4.txt[1.5.1.4],
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 325
 326* link:v1.5.0.7/git.html[documentation for release 1.5.0.7]
 327
 328* release notes for
 329  link:RelNotes/1.5.0.7.txt[1.5.0.7],
 330  link:RelNotes/1.5.0.6.txt[1.5.0.6],
 331  link:RelNotes/1.5.0.5.txt[1.5.0.5],
 332  link:RelNotes/1.5.0.3.txt[1.5.0.3],
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 334  link:RelNotes/1.5.0.1.txt[1.5.0.1],
 335  link:RelNotes/1.5.0.txt[1.5.0].
 336
 337* documentation for release link:v1.4.4.4/git.html[1.4.4.4],
 338  link:v1.3.3/git.html[1.3.3],
 339  link:v1.2.6/git.html[1.2.6],
 340  link:v1.0.13/git.html[1.0.13].
 341
 342============
 343
 344endif::stalenotes[]
 345
 346OPTIONS
 347-------
 348--version::
 349        Prints the git suite version that the 'git' program came from.
 350
 351--help::
 352        Prints the synopsis and a list of the most commonly used
 353        commands. If the option '--all' or '-a' is given then all
 354        available commands are printed. If a git command is named this
 355        option will bring up the manual page for that command.
 356+
 357Other options are available to control how the manual page is
 358displayed. See linkgit:git-help[1] for more information,
 359because `git --help ...` is converted internally into `git
 360help ...`.
 361
 362-c <name>=<value>::
 363        Pass a configuration parameter to the command. The value
 364        given will override values from configuration files.
 365        The <name> is expected in the same format as listed by
 366        'git config' (subkeys separated by dots).
 367
 368--exec-path[=<path>]::
 369        Path to wherever your core git programs are installed.
 370        This can also be controlled by setting the GIT_EXEC_PATH
 371        environment variable. If no path is given, 'git' will print
 372        the current setting and then exit.
 373
 374--html-path::
 375        Print the path, without trailing slash, where git's HTML
 376        documentation is installed and exit.
 377
 378--man-path::
 379        Print the manpath (see `man(1)`) for the man pages for
 380        this version of git and exit.
 381
 382--info-path::
 383        Print the path where the Info files documenting this
 384        version of git are installed and exit.
 385
 386-p::
 387--paginate::
 388        Pipe all output into 'less' (or if set, $PAGER) if standard
 389        output is a terminal.  This overrides the `pager.<cmd>`
 390        configuration options (see the "Configuration Mechanism" section
 391        below).
 392
 393--no-pager::
 394        Do not pipe git output into a pager.
 395
 396--git-dir=<path>::
 397        Set the path to the repository. This can also be controlled by
 398        setting the GIT_DIR environment variable. It can be an absolute
 399        path or relative path to current working directory.
 400
 401--work-tree=<path>::
 402        Set the path to the working tree. It can be an absolute path
 403        or a path relative to the current working directory.
 404        This can also be controlled by setting the GIT_WORK_TREE
 405        environment variable and the core.worktree configuration
 406        variable (see core.worktree in linkgit:git-config[1] for a
 407        more detailed discussion).
 408
 409--namespace=<path>::
 410        Set the git namespace.  See linkgit:gitnamespaces[7] for more
 411        details.  Equivalent to setting the `GIT_NAMESPACE` environment
 412        variable.
 413
 414--bare::
 415        Treat the repository as a bare repository.  If GIT_DIR
 416        environment is not set, it is set to the current working
 417        directory.
 418
 419--no-replace-objects::
 420        Do not use replacement refs to replace git objects. See
 421        linkgit:git-replace[1] for more information.
 422
 423
 424GIT COMMANDS
 425------------
 426
 427We divide git into high level ("porcelain") commands and low level
 428("plumbing") commands.
 429
 430High-level commands (porcelain)
 431-------------------------------
 432
 433We separate the porcelain commands into the main commands and some
 434ancillary user utilities.
 435
 436Main porcelain commands
 437~~~~~~~~~~~~~~~~~~~~~~~
 438
 439include::cmds-mainporcelain.txt[]
 440
 441Ancillary Commands
 442~~~~~~~~~~~~~~~~~~
 443Manipulators:
 444
 445include::cmds-ancillarymanipulators.txt[]
 446
 447Interrogators:
 448
 449include::cmds-ancillaryinterrogators.txt[]
 450
 451
 452Interacting with Others
 453~~~~~~~~~~~~~~~~~~~~~~~
 454
 455These commands are to interact with foreign SCM and with other
 456people via patch over e-mail.
 457
 458include::cmds-foreignscminterface.txt[]
 459
 460
 461Low-level commands (plumbing)
 462-----------------------------
 463
 464Although git includes its
 465own porcelain layer, its low-level commands are sufficient to support
 466development of alternative porcelains.  Developers of such porcelains
 467might start by reading about linkgit:git-update-index[1] and
 468linkgit:git-read-tree[1].
 469
 470The interface (input, output, set of options and the semantics)
 471to these low-level commands are meant to be a lot more stable
 472than Porcelain level commands, because these commands are
 473primarily for scripted use.  The interface to Porcelain commands
 474on the other hand are subject to change in order to improve the
 475end user experience.
 476
 477The following description divides
 478the low-level commands into commands that manipulate objects (in
 479the repository, index, and working tree), commands that interrogate and
 480compare objects, and commands that move objects and references between
 481repositories.
 482
 483
 484Manipulation commands
 485~~~~~~~~~~~~~~~~~~~~~
 486
 487include::cmds-plumbingmanipulators.txt[]
 488
 489
 490Interrogation commands
 491~~~~~~~~~~~~~~~~~~~~~~
 492
 493include::cmds-plumbinginterrogators.txt[]
 494
 495In general, the interrogate commands do not touch the files in
 496the working tree.
 497
 498
 499Synching repositories
 500~~~~~~~~~~~~~~~~~~~~~
 501
 502include::cmds-synchingrepositories.txt[]
 503
 504The following are helper commands used by the above; end users
 505typically do not use them directly.
 506
 507include::cmds-synchelpers.txt[]
 508
 509
 510Internal helper commands
 511~~~~~~~~~~~~~~~~~~~~~~~~
 512
 513These are internal helper commands used by other commands; end
 514users typically do not use them directly.
 515
 516include::cmds-purehelpers.txt[]
 517
 518
 519Configuration Mechanism
 520-----------------------
 521
 522Starting from 0.99.9 (actually mid 0.99.8.GIT), `.git/config` file
 523is used to hold per-repository configuration options.  It is a
 524simple text file modeled after `.ini` format familiar to some
 525people.  Here is an example:
 526
 527------------
 528#
 529# A '#' or ';' character indicates a comment.
 530#
 531
 532; core variables
 533[core]
 534        ; Don't trust file modes
 535        filemode = false
 536
 537; user identity
 538[user]
 539        name = "Junio C Hamano"
 540        email = "junkio@twinsun.com"
 541
 542------------
 543
 544Various commands read from the configuration file and adjust
 545their operation accordingly.  See linkgit:git-config[1] for a
 546list.
 547
 548
 549Identifier Terminology
 550----------------------
 551<object>::
 552        Indicates the object name for any type of object.
 553
 554<blob>::
 555        Indicates a blob object name.
 556
 557<tree>::
 558        Indicates a tree object name.
 559
 560<commit>::
 561        Indicates a commit object name.
 562
 563<tree-ish>::
 564        Indicates a tree, commit or tag object name.  A
 565        command that takes a <tree-ish> argument ultimately wants to
 566        operate on a <tree> object but automatically dereferences
 567        <commit> and <tag> objects that point at a <tree>.
 568
 569<commit-ish>::
 570        Indicates a commit or tag object name.  A
 571        command that takes a <commit-ish> argument ultimately wants to
 572        operate on a <commit> object but automatically dereferences
 573        <tag> objects that point at a <commit>.
 574
 575<type>::
 576        Indicates that an object type is required.
 577        Currently one of: `blob`, `tree`, `commit`, or `tag`.
 578
 579<file>::
 580        Indicates a filename - almost always relative to the
 581        root of the tree structure `GIT_INDEX_FILE` describes.
 582
 583Symbolic Identifiers
 584--------------------
 585Any git command accepting any <object> can also use the following
 586symbolic notation:
 587
 588HEAD::
 589        indicates the head of the current branch.
 590
 591<tag>::
 592        a valid tag 'name'
 593        (i.e. a `refs/tags/<tag>` reference).
 594
 595<head>::
 596        a valid head 'name'
 597        (i.e. a `refs/heads/<head>` reference).
 598
 599For a more complete list of ways to spell object names, see
 600"SPECIFYING REVISIONS" section in linkgit:gitrevisions[7].
 601
 602
 603File/Directory Structure
 604------------------------
 605
 606Please see the linkgit:gitrepository-layout[5] document.
 607
 608Read linkgit:githooks[5] for more details about each hook.
 609
 610Higher level SCMs may provide and manage additional information in the
 611`$GIT_DIR`.
 612
 613
 614Terminology
 615-----------
 616Please see linkgit:gitglossary[7].
 617
 618
 619Environment Variables
 620---------------------
 621Various git commands use the following environment variables:
 622
 623The git Repository
 624~~~~~~~~~~~~~~~~~~
 625These environment variables apply to 'all' core git commands. Nb: it
 626is worth noting that they may be used/overridden by SCMS sitting above
 627git so take care if using Cogito etc.
 628
 629'GIT_INDEX_FILE'::
 630        This environment allows the specification of an alternate
 631        index file. If not specified, the default of `$GIT_DIR/index`
 632        is used.
 633
 634'GIT_OBJECT_DIRECTORY'::
 635        If the object storage directory is specified via this
 636        environment variable then the sha1 directories are created
 637        underneath - otherwise the default `$GIT_DIR/objects`
 638        directory is used.
 639
 640'GIT_ALTERNATE_OBJECT_DIRECTORIES'::
 641        Due to the immutable nature of git objects, old objects can be
 642        archived into shared, read-only directories. This variable
 643        specifies a ":" separated (on Windows ";" separated) list
 644        of git object directories which can be used to search for git
 645        objects. New objects will not be written to these directories.
 646
 647'GIT_DIR'::
 648        If the 'GIT_DIR' environment variable is set then it
 649        specifies a path to use instead of the default `.git`
 650        for the base of the repository.
 651
 652'GIT_WORK_TREE'::
 653        Set the path to the working tree.  The value will not be
 654        used in combination with repositories found automatically in
 655        a .git directory (i.e. $GIT_DIR is not set).
 656        This can also be controlled by the '--work-tree' command line
 657        option and the core.worktree configuration variable.
 658
 659'GIT_NAMESPACE'::
 660        Set the git namespace; see linkgit:gitnamespaces[7] for details.
 661        The '--namespace' command-line option also sets this value.
 662
 663'GIT_CEILING_DIRECTORIES'::
 664        This should be a colon-separated list of absolute paths.
 665        If set, it is a list of directories that git should not chdir
 666        up into while looking for a repository directory.
 667        It will not exclude the current working directory or
 668        a GIT_DIR set on the command line or in the environment.
 669        (Useful for excluding slow-loading network directories.)
 670
 671'GIT_DISCOVERY_ACROSS_FILESYSTEM'::
 672        When run in a directory that does not have ".git" repository
 673        directory, git tries to find such a directory in the parent
 674        directories to find the top of the working tree, but by default it
 675        does not cross filesystem boundaries.  This environment variable
 676        can be set to true to tell git not to stop at filesystem
 677        boundaries.  Like 'GIT_CEILING_DIRECTORIES', this will not affect
 678        an explicit repository directory set via 'GIT_DIR' or on the
 679        command line.
 680
 681git Commits
 682~~~~~~~~~~~
 683'GIT_AUTHOR_NAME'::
 684'GIT_AUTHOR_EMAIL'::
 685'GIT_AUTHOR_DATE'::
 686'GIT_COMMITTER_NAME'::
 687'GIT_COMMITTER_EMAIL'::
 688'GIT_COMMITTER_DATE'::
 689'EMAIL'::
 690        see linkgit:git-commit-tree[1]
 691
 692git Diffs
 693~~~~~~~~~
 694'GIT_DIFF_OPTS'::
 695        Only valid setting is "--unified=??" or "-u??" to set the
 696        number of context lines shown when a unified diff is created.
 697        This takes precedence over any "-U" or "--unified" option
 698        value passed on the git diff command line.
 699
 700'GIT_EXTERNAL_DIFF'::
 701        When the environment variable 'GIT_EXTERNAL_DIFF' is set, the
 702        program named by it is called, instead of the diff invocation
 703        described above.  For a path that is added, removed, or modified,
 704        'GIT_EXTERNAL_DIFF' is called with 7 parameters:
 705
 706        path old-file old-hex old-mode new-file new-hex new-mode
 707+
 708where:
 709
 710        <old|new>-file:: are files GIT_EXTERNAL_DIFF can use to read the
 711                         contents of <old|new>,
 712        <old|new>-hex:: are the 40-hexdigit SHA1 hashes,
 713        <old|new>-mode:: are the octal representation of the file modes.
 714+
 715The file parameters can point at the user's working file
 716(e.g. `new-file` in "git-diff-files"), `/dev/null` (e.g. `old-file`
 717when a new file is added), or a temporary file (e.g. `old-file` in the
 718index).  'GIT_EXTERNAL_DIFF' should not worry about unlinking the
 719temporary file --- it is removed when 'GIT_EXTERNAL_DIFF' exits.
 720+
 721For a path that is unmerged, 'GIT_EXTERNAL_DIFF' is called with 1
 722parameter, <path>.
 723
 724other
 725~~~~~
 726'GIT_MERGE_VERBOSITY'::
 727        A number controlling the amount of output shown by
 728        the recursive merge strategy.  Overrides merge.verbosity.
 729        See linkgit:git-merge[1]
 730
 731'GIT_PAGER'::
 732        This environment variable overrides `$PAGER`. If it is set
 733        to an empty string or to the value "cat", git will not launch
 734        a pager.  See also the `core.pager` option in
 735        linkgit:git-config[1].
 736
 737'GIT_EDITOR'::
 738        This environment variable overrides `$EDITOR` and `$VISUAL`.
 739        It is used by several git commands when, on interactive mode,
 740        an editor is to be launched. See also linkgit:git-var[1]
 741        and the `core.editor` option in linkgit:git-config[1].
 742
 743'GIT_SSH'::
 744        If this environment variable is set then 'git fetch'
 745        and 'git push' will use this command instead
 746        of 'ssh' when they need to connect to a remote system.
 747        The '$GIT_SSH' command will be given exactly two arguments:
 748        the 'username@host' (or just 'host') from the URL and the
 749        shell command to execute on that remote system.
 750+
 751To pass options to the program that you want to list in GIT_SSH
 752you will need to wrap the program and options into a shell script,
 753then set GIT_SSH to refer to the shell script.
 754+
 755Usually it is easier to configure any desired options through your
 756personal `.ssh/config` file.  Please consult your ssh documentation
 757for further details.
 758
 759'GIT_ASKPASS'::
 760        If this environment variable is set, then git commands which need to
 761        acquire passwords or passphrases (e.g. for HTTP or IMAP authentication)
 762        will call this program with a suitable prompt as command line argument
 763        and read the password from its STDOUT. See also the 'core.askpass'
 764        option in linkgit:git-config[1].
 765
 766'GIT_FLUSH'::
 767        If this environment variable is set to "1", then commands such
 768        as 'git blame' (in incremental mode), 'git rev-list', 'git log',
 769        and 'git whatchanged' will force a flush of the output stream
 770        after each commit-oriented record have been flushed.   If this
 771        variable is set to "0", the output of these commands will be done
 772        using completely buffered I/O.   If this environment variable is
 773        not set, git will choose buffered or record-oriented flushing
 774        based on whether stdout appears to be redirected to a file or not.
 775
 776'GIT_TRACE'::
 777        If this variable is set to "1", "2" or "true" (comparison
 778        is case insensitive), git will print `trace:` messages on
 779        stderr telling about alias expansion, built-in command
 780        execution and external command execution.
 781        If this variable is set to an integer value greater than 1
 782        and lower than 10 (strictly) then git will interpret this
 783        value as an open file descriptor and will try to write the
 784        trace messages into this file descriptor.
 785        Alternatively, if this variable is set to an absolute path
 786        (starting with a '/' character), git will interpret this
 787        as a file path and will try to write the trace messages
 788        into it.
 789
 790Discussion[[Discussion]]
 791------------------------
 792
 793More detail on the following is available from the
 794link:user-manual.html#git-concepts[git concepts chapter of the
 795user-manual] and linkgit:gitcore-tutorial[7].
 796
 797A git project normally consists of a working directory with a ".git"
 798subdirectory at the top level.  The .git directory contains, among other
 799things, a compressed object database representing the complete history
 800of the project, an "index" file which links that history to the current
 801contents of the working tree, and named pointers into that history such
 802as tags and branch heads.
 803
 804The object database contains objects of three main types: blobs, which
 805hold file data; trees, which point to blobs and other trees to build up
 806directory hierarchies; and commits, which each reference a single tree
 807and some number of parent commits.
 808
 809The commit, equivalent to what other systems call a "changeset" or
 810"version", represents a step in the project's history, and each parent
 811represents an immediately preceding step.  Commits with more than one
 812parent represent merges of independent lines of development.
 813
 814All objects are named by the SHA1 hash of their contents, normally
 815written as a string of 40 hex digits.  Such names are globally unique.
 816The entire history leading up to a commit can be vouched for by signing
 817just that commit.  A fourth object type, the tag, is provided for this
 818purpose.
 819
 820When first created, objects are stored in individual files, but for
 821efficiency may later be compressed together into "pack files".
 822
 823Named pointers called refs mark interesting points in history.  A ref
 824may contain the SHA1 name of an object or the name of another ref.  Refs
 825with names beginning `ref/head/` contain the SHA1 name of the most
 826recent commit (or "head") of a branch under development.  SHA1 names of
 827tags of interest are stored under `ref/tags/`.  A special ref named
 828`HEAD` contains the name of the currently checked-out branch.
 829
 830The index file is initialized with a list of all paths and, for each
 831path, a blob object and a set of attributes.  The blob object represents
 832the contents of the file as of the head of the current branch.  The
 833attributes (last modified time, size, etc.) are taken from the
 834corresponding file in the working tree.  Subsequent changes to the
 835working tree can be found by comparing these attributes.  The index may
 836be updated with new content, and new commits may be created from the
 837content stored in the index.
 838
 839The index is also capable of storing multiple entries (called "stages")
 840for a given pathname.  These stages are used to hold the various
 841unmerged version of a file when a merge is in progress.
 842
 843FURTHER DOCUMENTATION
 844---------------------
 845
 846See the references in the "description" section to get started
 847using git.  The following is probably more detail than necessary
 848for a first-time user.
 849
 850The link:user-manual.html#git-concepts[git concepts chapter of the
 851user-manual] and linkgit:gitcore-tutorial[7] both provide
 852introductions to the underlying git architecture.
 853
 854See linkgit:gitworkflows[7] for an overview of recommended workflows.
 855
 856See also the link:howto-index.html[howto] documents for some useful
 857examples.
 858
 859The internals are documented in the
 860link:technical/api-index.html[GIT API documentation].
 861
 862Users migrating from CVS may also want to
 863read linkgit:gitcvs-migration[7].
 864
 865
 866Authors
 867-------
 868Git was started by Linus Torvalds, and is currently maintained by Junio
 869C Hamano. Numerous contributions have come from the git mailing list
 870<git@vger.kernel.org>. For a more complete list of contributors, see
 871http://git-scm.com/about. If you have a clone of git.git itself, the
 872output of linkgit:git-shortlog[1] and linkgit:git-blame[1] can show you
 873the authors for specific parts of the project.
 874
 875Reporting Bugs
 876--------------
 877
 878Report bugs to the Git mailing list <git@vger.kernel.org> where the
 879development and maintenance is primarily done.  You do not have to be
 880subscribed to the list to send a message there.
 881
 882SEE ALSO
 883--------
 884linkgit:gittutorial[7], linkgit:gittutorial-2[7],
 885link:everyday.html[Everyday Git], linkgit:gitcvs-migration[7],
 886linkgit:gitglossary[7], linkgit:gitcore-tutorial[7],
 887linkgit:gitcli[7], link:user-manual.html[The Git User's Manual],
 888linkgit:gitworkflows[7]
 889
 890GIT
 891---
 892Part of the linkgit:git[1] suite