Documentation / git.txton commit Merge branch 'tr/merge-edit-guidance' (873ce7c)
   1git(1)
   2======
   3
   4NAME
   5----
   6git - the stupid content tracker
   7
   8
   9SYNOPSIS
  10--------
  11[verse]
  12'git' [--version] [--exec-path[=<path>]] [--html-path] [--man-path] [--info-path]
  13    [-p|--paginate|--no-pager] [--no-replace-objects] [--bare]
  14    [--git-dir=<path>] [--work-tree=<path>] [--namespace=<name>]
  15    [-c <name>=<value>]
  16    [--help] <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 commands, and
  26"man git-commandname" for documentation of each command.  CVS users may
  27also want to read linkgit:gitcvs-migration[7].  See
  28the link:user-manual.html[Git User's Manual] for a more in-depth
  29introduction.
  30
  31The '<command>' is either a name of a Git command (see below) or an alias
  32as defined in the configuration file (see linkgit:git-config[1]).
  33
  34Formatted and hyperlinked version of the latest git
  35documentation can be viewed at
  36`http://www.kernel.org/pub/software/scm/git/docs/`.
  37
  38ifdef::stalenotes[]
  39[NOTE]
  40============
  41
  42You are reading the documentation for the latest (possibly
  43unreleased) version of git, that is available from 'master'
  44branch of the `git.git` repository.
  45Documentation for older releases are available here:
  46
  47* link:v1.7.9/git.html[documentation for release 1.7.9]
  48
  49* release notes for
  50  link:RelNotes/1.7.9.txt[1.7.9].
  51
  52* link:v1.7.8.4/git.html[documentation for release 1.7.8.4]
  53
  54* release notes for
  55  link:RelNotes/1.7.8.4.txt[1.7.8.4],
  56  link:RelNotes/1.7.8.3.txt[1.7.8.3],
  57  link:RelNotes/1.7.8.2.txt[1.7.8.2],
  58  link:RelNotes/1.7.8.1.txt[1.7.8.1],
  59  link:RelNotes/1.7.8.txt[1.7.8].
  60
  61* link:v1.7.7.6/git.html[documentation for release 1.7.7.6]
  62
  63* release notes for
  64  link:RelNotes/1.7.7.6.txt[1.7.7.6],
  65  link:RelNotes/1.7.7.5.txt[1.7.7.5],
  66  link:RelNotes/1.7.7.4.txt[1.7.7.4],
  67  link:RelNotes/1.7.7.3.txt[1.7.7.3],
  68  link:RelNotes/1.7.7.2.txt[1.7.7.2],
  69  link:RelNotes/1.7.7.1.txt[1.7.7.1],
  70  link:RelNotes/1.7.7.txt[1.7.7].
  71
  72* link:v1.7.6.5/git.html[documentation for release 1.7.6.5]
  73
  74* release notes for
  75  link:RelNotes/1.7.6.5.txt[1.7.6.5],
  76  link:RelNotes/1.7.6.4.txt[1.7.6.4],
  77  link:RelNotes/1.7.6.3.txt[1.7.6.3],
  78  link:RelNotes/1.7.6.2.txt[1.7.6.2],
  79  link:RelNotes/1.7.6.1.txt[1.7.6.1],
  80  link:RelNotes/1.7.6.txt[1.7.6].
  81
  82* link:v1.7.5.4/git.html[documentation for release 1.7.5.4]
  83
  84* release notes for
  85  link:RelNotes/1.7.5.4.txt[1.7.5.4],
  86  link:RelNotes/1.7.5.3.txt[1.7.5.3],
  87  link:RelNotes/1.7.5.2.txt[1.7.5.2],
  88  link:RelNotes/1.7.5.1.txt[1.7.5.1],
  89  link:RelNotes/1.7.5.txt[1.7.5].
  90
  91* link:v1.7.4.5/git.html[documentation for release 1.7.4.5]
  92
  93* release notes for
  94  link:RelNotes/1.7.4.5.txt[1.7.4.5],
  95  link:RelNotes/1.7.4.4.txt[1.7.4.4],
  96  link:RelNotes/1.7.4.3.txt[1.7.4.3],
  97  link:RelNotes/1.7.4.2.txt[1.7.4.2],
  98  link:RelNotes/1.7.4.1.txt[1.7.4.1],
  99  link:RelNotes/1.7.4.txt[1.7.4].
 100
 101* link:v1.7.3.5/git.html[documentation for release 1.7.3.5]
 102
 103* release notes for
 104  link:RelNotes/1.7.3.5.txt[1.7.3.5],
 105  link:RelNotes/1.7.3.4.txt[1.7.3.4],
 106  link:RelNotes/1.7.3.3.txt[1.7.3.3],
 107  link:RelNotes/1.7.3.2.txt[1.7.3.2],
 108  link:RelNotes/1.7.3.1.txt[1.7.3.1],
 109  link:RelNotes/1.7.3.txt[1.7.3].
 110
 111* link:v1.7.2.5/git.html[documentation for release 1.7.2.5]
 112
 113* release notes for
 114  link:RelNotes/1.7.2.5.txt[1.7.2.5],
 115  link:RelNotes/1.7.2.4.txt[1.7.2.4],
 116  link:RelNotes/1.7.2.3.txt[1.7.2.3],
 117  link:RelNotes/1.7.2.2.txt[1.7.2.2],
 118  link:RelNotes/1.7.2.1.txt[1.7.2.1],
 119  link:RelNotes/1.7.2.txt[1.7.2].
 120
 121* link:v1.7.1.4/git.html[documentation for release 1.7.1.4]
 122
 123* release notes for
 124  link:RelNotes/1.7.1.4.txt[1.7.1.4],
 125  link:RelNotes/1.7.1.3.txt[1.7.1.3],
 126  link:RelNotes/1.7.1.2.txt[1.7.1.2],
 127  link:RelNotes/1.7.1.1.txt[1.7.1.1],
 128  link:RelNotes/1.7.1.txt[1.7.1].
 129
 130* link:v1.7.0.9/git.html[documentation for release 1.7.0.9]
 131
 132* release notes for
 133  link:RelNotes/1.7.0.9.txt[1.7.0.9],
 134  link:RelNotes/1.7.0.8.txt[1.7.0.8],
 135  link:RelNotes/1.7.0.7.txt[1.7.0.7],
 136  link:RelNotes/1.7.0.6.txt[1.7.0.6],
 137  link:RelNotes/1.7.0.5.txt[1.7.0.5],
 138  link:RelNotes/1.7.0.4.txt[1.7.0.4],
 139  link:RelNotes/1.7.0.3.txt[1.7.0.3],
 140  link:RelNotes/1.7.0.2.txt[1.7.0.2],
 141  link:RelNotes/1.7.0.1.txt[1.7.0.1],
 142  link:RelNotes/1.7.0.txt[1.7.0].
 143
 144* link:v1.6.6.3/git.html[documentation for release 1.6.6.3]
 145
 146* release notes for
 147  link:RelNotes/1.6.6.3.txt[1.6.6.3],
 148  link:RelNotes/1.6.6.2.txt[1.6.6.2],
 149  link:RelNotes/1.6.6.1.txt[1.6.6.1],
 150  link:RelNotes/1.6.6.txt[1.6.6].
 151
 152* link:v1.6.5.9/git.html[documentation for release 1.6.5.9]
 153
 154* release notes for
 155  link:RelNotes/1.6.5.9.txt[1.6.5.9],
 156  link:RelNotes/1.6.5.8.txt[1.6.5.8],
 157  link:RelNotes/1.6.5.7.txt[1.6.5.7],
 158  link:RelNotes/1.6.5.6.txt[1.6.5.6],
 159  link:RelNotes/1.6.5.5.txt[1.6.5.5],
 160  link:RelNotes/1.6.5.4.txt[1.6.5.4],
 161  link:RelNotes/1.6.5.3.txt[1.6.5.3],
 162  link:RelNotes/1.6.5.2.txt[1.6.5.2],
 163  link:RelNotes/1.6.5.1.txt[1.6.5.1],
 164  link:RelNotes/1.6.5.txt[1.6.5].
 165
 166* link:v1.6.4.5/git.html[documentation for release 1.6.4.5]
 167
 168* release notes for
 169  link:RelNotes/1.6.4.5.txt[1.6.4.5],
 170  link:RelNotes/1.6.4.4.txt[1.6.4.4],
 171  link:RelNotes/1.6.4.3.txt[1.6.4.3],
 172  link:RelNotes/1.6.4.2.txt[1.6.4.2],
 173  link:RelNotes/1.6.4.1.txt[1.6.4.1],
 174  link:RelNotes/1.6.4.txt[1.6.4].
 175
 176* link:v1.6.3.4/git.html[documentation for release 1.6.3.4]
 177
 178* release notes for
 179  link:RelNotes/1.6.3.4.txt[1.6.3.4],
 180  link:RelNotes/1.6.3.3.txt[1.6.3.3],
 181  link:RelNotes/1.6.3.2.txt[1.6.3.2],
 182  link:RelNotes/1.6.3.1.txt[1.6.3.1],
 183  link:RelNotes/1.6.3.txt[1.6.3].
 184
 185* release notes for
 186  link:RelNotes/1.6.2.5.txt[1.6.2.5],
 187  link:RelNotes/1.6.2.4.txt[1.6.2.4],
 188  link:RelNotes/1.6.2.3.txt[1.6.2.3],
 189  link:RelNotes/1.6.2.2.txt[1.6.2.2],
 190  link:RelNotes/1.6.2.1.txt[1.6.2.1],
 191  link:RelNotes/1.6.2.txt[1.6.2].
 192
 193* link:v1.6.1.3/git.html[documentation for release 1.6.1.3]
 194
 195* release notes for
 196  link:RelNotes/1.6.1.3.txt[1.6.1.3],
 197  link:RelNotes/1.6.1.2.txt[1.6.1.2],
 198  link:RelNotes/1.6.1.1.txt[1.6.1.1],
 199  link:RelNotes/1.6.1.txt[1.6.1].
 200
 201* link:v1.6.0.6/git.html[documentation for release 1.6.0.6]
 202
 203* release notes for
 204  link:RelNotes/1.6.0.6.txt[1.6.0.6],
 205  link:RelNotes/1.6.0.5.txt[1.6.0.5],
 206  link:RelNotes/1.6.0.4.txt[1.6.0.4],
 207  link:RelNotes/1.6.0.3.txt[1.6.0.3],
 208  link:RelNotes/1.6.0.2.txt[1.6.0.2],
 209  link:RelNotes/1.6.0.1.txt[1.6.0.1],
 210  link:RelNotes/1.6.0.txt[1.6.0].
 211
 212* link:v1.5.6.6/git.html[documentation for release 1.5.6.6]
 213
 214* release notes for
 215  link:RelNotes/1.5.6.6.txt[1.5.6.6],
 216  link:RelNotes/1.5.6.5.txt[1.5.6.5],
 217  link:RelNotes/1.5.6.4.txt[1.5.6.4],
 218  link:RelNotes/1.5.6.3.txt[1.5.6.3],
 219  link:RelNotes/1.5.6.2.txt[1.5.6.2],
 220  link:RelNotes/1.5.6.1.txt[1.5.6.1],
 221  link:RelNotes/1.5.6.txt[1.5.6].
 222
 223* link:v1.5.5.6/git.html[documentation for release 1.5.5.6]
 224
 225* release notes for
 226  link:RelNotes/1.5.5.6.txt[1.5.5.6],
 227  link:RelNotes/1.5.5.5.txt[1.5.5.5],
 228  link:RelNotes/1.5.5.4.txt[1.5.5.4],
 229  link:RelNotes/1.5.5.3.txt[1.5.5.3],
 230  link:RelNotes/1.5.5.2.txt[1.5.5.2],
 231  link:RelNotes/1.5.5.1.txt[1.5.5.1],
 232  link:RelNotes/1.5.5.txt[1.5.5].
 233
 234* link:v1.5.4.7/git.html[documentation for release 1.5.4.7]
 235
 236* release notes for
 237  link:RelNotes/1.5.4.7.txt[1.5.4.7],
 238  link:RelNotes/1.5.4.6.txt[1.5.4.6],
 239  link:RelNotes/1.5.4.5.txt[1.5.4.5],
 240  link:RelNotes/1.5.4.4.txt[1.5.4.4],
 241  link:RelNotes/1.5.4.3.txt[1.5.4.3],
 242  link:RelNotes/1.5.4.2.txt[1.5.4.2],
 243  link:RelNotes/1.5.4.1.txt[1.5.4.1],
 244  link:RelNotes/1.5.4.txt[1.5.4].
 245
 246* link:v1.5.3.8/git.html[documentation for release 1.5.3.8]
 247
 248* release notes for
 249  link:RelNotes/1.5.3.8.txt[1.5.3.8],
 250  link:RelNotes/1.5.3.7.txt[1.5.3.7],
 251  link:RelNotes/1.5.3.6.txt[1.5.3.6],
 252  link:RelNotes/1.5.3.5.txt[1.5.3.5],
 253  link:RelNotes/1.5.3.4.txt[1.5.3.4],
 254  link:RelNotes/1.5.3.3.txt[1.5.3.3],
 255  link:RelNotes/1.5.3.2.txt[1.5.3.2],
 256  link:RelNotes/1.5.3.1.txt[1.5.3.1],
 257  link:RelNotes/1.5.3.txt[1.5.3].
 258
 259* link:v1.5.2.5/git.html[documentation for release 1.5.2.5]
 260
 261* release notes for
 262  link:RelNotes/1.5.2.5.txt[1.5.2.5],
 263  link:RelNotes/1.5.2.4.txt[1.5.2.4],
 264  link:RelNotes/1.5.2.3.txt[1.5.2.3],
 265  link:RelNotes/1.5.2.2.txt[1.5.2.2],
 266  link:RelNotes/1.5.2.1.txt[1.5.2.1],
 267  link:RelNotes/1.5.2.txt[1.5.2].
 268
 269* link:v1.5.1.6/git.html[documentation for release 1.5.1.6]
 270
 271* release notes for
 272  link:RelNotes/1.5.1.6.txt[1.5.1.6],
 273  link:RelNotes/1.5.1.5.txt[1.5.1.5],
 274  link:RelNotes/1.5.1.4.txt[1.5.1.4],
 275  link:RelNotes/1.5.1.3.txt[1.5.1.3],
 276  link:RelNotes/1.5.1.2.txt[1.5.1.2],
 277  link:RelNotes/1.5.1.1.txt[1.5.1.1],
 278  link:RelNotes/1.5.1.txt[1.5.1].
 279
 280* link:v1.5.0.7/git.html[documentation for release 1.5.0.7]
 281
 282* release notes for
 283  link:RelNotes/1.5.0.7.txt[1.5.0.7],
 284  link:RelNotes/1.5.0.6.txt[1.5.0.6],
 285  link:RelNotes/1.5.0.5.txt[1.5.0.5],
 286  link:RelNotes/1.5.0.3.txt[1.5.0.3],
 287  link:RelNotes/1.5.0.2.txt[1.5.0.2],
 288  link:RelNotes/1.5.0.1.txt[1.5.0.1],
 289  link:RelNotes/1.5.0.txt[1.5.0].
 290
 291* documentation for release link:v1.4.4.4/git.html[1.4.4.4],
 292  link:v1.3.3/git.html[1.3.3],
 293  link:v1.2.6/git.html[1.2.6],
 294  link:v1.0.13/git.html[1.0.13].
 295
 296============
 297
 298endif::stalenotes[]
 299
 300OPTIONS
 301-------
 302--version::
 303        Prints the git suite version that the 'git' program came from.
 304
 305--help::
 306        Prints the synopsis and a list of the most commonly used
 307        commands. If the option '--all' or '-a' is given then all
 308        available commands are printed. If a git command is named this
 309        option will bring up the manual page for that command.
 310+
 311Other options are available to control how the manual page is
 312displayed. See linkgit:git-help[1] for more information,
 313because `git --help ...` is converted internally into `git
 314help ...`.
 315
 316-c <name>=<value>::
 317        Pass a configuration parameter to the command. The value
 318        given will override values from configuration files.
 319        The <name> is expected in the same format as listed by
 320        'git config' (subkeys separated by dots).
 321
 322--exec-path[=<path>]::
 323        Path to wherever your core git programs are installed.
 324        This can also be controlled by setting the GIT_EXEC_PATH
 325        environment variable. If no path is given, 'git' will print
 326        the current setting and then exit.
 327
 328--html-path::
 329        Print the path, without trailing slash, where git's HTML
 330        documentation is installed and exit.
 331
 332--man-path::
 333        Print the manpath (see `man(1)`) for the man pages for
 334        this version of git and exit.
 335
 336--info-path::
 337        Print the path where the Info files documenting this
 338        version of git are installed and exit.
 339
 340-p::
 341--paginate::
 342        Pipe all output into 'less' (or if set, $PAGER) if standard
 343        output is a terminal.  This overrides the `pager.<cmd>`
 344        configuration options (see the "Configuration Mechanism" section
 345        below).
 346
 347--no-pager::
 348        Do not pipe git output into a pager.
 349
 350--git-dir=<path>::
 351        Set the path to the repository. This can also be controlled by
 352        setting the GIT_DIR environment variable. It can be an absolute
 353        path or relative path to current working directory.
 354
 355--work-tree=<path>::
 356        Set the path to the working tree. It can be an absolute path
 357        or a path relative to the current working directory.
 358        This can also be controlled by setting the GIT_WORK_TREE
 359        environment variable and the core.worktree configuration
 360        variable (see core.worktree in linkgit:git-config[1] for a
 361        more detailed discussion).
 362
 363--namespace=<path>::
 364        Set the git namespace.  See linkgit:gitnamespaces[7] for more
 365        details.  Equivalent to setting the `GIT_NAMESPACE` environment
 366        variable.
 367
 368--bare::
 369        Treat the repository as a bare repository.  If GIT_DIR
 370        environment is not set, it is set to the current working
 371        directory.
 372
 373--no-replace-objects::
 374        Do not use replacement refs to replace git objects. See
 375        linkgit:git-replace[1] for more information.
 376
 377
 378FURTHER DOCUMENTATION
 379---------------------
 380
 381See the references above to get started using git.  The following is
 382probably more detail than necessary for a first-time user.
 383
 384The link:user-manual.html#git-concepts[git concepts chapter of the
 385user-manual] and linkgit:gitcore-tutorial[7] both provide
 386introductions to the underlying git architecture.
 387
 388See linkgit:gitworkflows[7] for an overview of recommended workflows.
 389
 390See also the link:howto-index.html[howto] documents for some useful
 391examples.
 392
 393The internals are documented in the
 394link:technical/api-index.html[GIT API documentation].
 395
 396GIT COMMANDS
 397------------
 398
 399We divide git into high level ("porcelain") commands and low level
 400("plumbing") commands.
 401
 402High-level commands (porcelain)
 403-------------------------------
 404
 405We separate the porcelain commands into the main commands and some
 406ancillary user utilities.
 407
 408Main porcelain commands
 409~~~~~~~~~~~~~~~~~~~~~~~
 410
 411include::cmds-mainporcelain.txt[]
 412
 413Ancillary Commands
 414~~~~~~~~~~~~~~~~~~
 415Manipulators:
 416
 417include::cmds-ancillarymanipulators.txt[]
 418
 419Interrogators:
 420
 421include::cmds-ancillaryinterrogators.txt[]
 422
 423
 424Interacting with Others
 425~~~~~~~~~~~~~~~~~~~~~~~
 426
 427These commands are to interact with foreign SCM and with other
 428people via patch over e-mail.
 429
 430include::cmds-foreignscminterface.txt[]
 431
 432
 433Low-level commands (plumbing)
 434-----------------------------
 435
 436Although git includes its
 437own porcelain layer, its low-level commands are sufficient to support
 438development of alternative porcelains.  Developers of such porcelains
 439might start by reading about linkgit:git-update-index[1] and
 440linkgit:git-read-tree[1].
 441
 442The interface (input, output, set of options and the semantics)
 443to these low-level commands are meant to be a lot more stable
 444than Porcelain level commands, because these commands are
 445primarily for scripted use.  The interface to Porcelain commands
 446on the other hand are subject to change in order to improve the
 447end user experience.
 448
 449The following description divides
 450the low-level commands into commands that manipulate objects (in
 451the repository, index, and working tree), commands that interrogate and
 452compare objects, and commands that move objects and references between
 453repositories.
 454
 455
 456Manipulation commands
 457~~~~~~~~~~~~~~~~~~~~~
 458
 459include::cmds-plumbingmanipulators.txt[]
 460
 461
 462Interrogation commands
 463~~~~~~~~~~~~~~~~~~~~~~
 464
 465include::cmds-plumbinginterrogators.txt[]
 466
 467In general, the interrogate commands do not touch the files in
 468the working tree.
 469
 470
 471Synching repositories
 472~~~~~~~~~~~~~~~~~~~~~
 473
 474include::cmds-synchingrepositories.txt[]
 475
 476The following are helper commands used by the above; end users
 477typically do not use them directly.
 478
 479include::cmds-synchelpers.txt[]
 480
 481
 482Internal helper commands
 483~~~~~~~~~~~~~~~~~~~~~~~~
 484
 485These are internal helper commands used by other commands; end
 486users typically do not use them directly.
 487
 488include::cmds-purehelpers.txt[]
 489
 490
 491Configuration Mechanism
 492-----------------------
 493
 494Starting from 0.99.9 (actually mid 0.99.8.GIT), `.git/config` file
 495is used to hold per-repository configuration options.  It is a
 496simple text file modeled after `.ini` format familiar to some
 497people.  Here is an example:
 498
 499------------
 500#
 501# A '#' or ';' character indicates a comment.
 502#
 503
 504; core variables
 505[core]
 506        ; Don't trust file modes
 507        filemode = false
 508
 509; user identity
 510[user]
 511        name = "Junio C Hamano"
 512        email = "junkio@twinsun.com"
 513
 514------------
 515
 516Various commands read from the configuration file and adjust
 517their operation accordingly.  See linkgit:git-config[1] for a
 518list.
 519
 520
 521Identifier Terminology
 522----------------------
 523<object>::
 524        Indicates the object name for any type of object.
 525
 526<blob>::
 527        Indicates a blob object name.
 528
 529<tree>::
 530        Indicates a tree object name.
 531
 532<commit>::
 533        Indicates a commit object name.
 534
 535<tree-ish>::
 536        Indicates a tree, commit or tag object name.  A
 537        command that takes a <tree-ish> argument ultimately wants to
 538        operate on a <tree> object but automatically dereferences
 539        <commit> and <tag> objects that point at a <tree>.
 540
 541<commit-ish>::
 542        Indicates a commit or tag object name.  A
 543        command that takes a <commit-ish> argument ultimately wants to
 544        operate on a <commit> object but automatically dereferences
 545        <tag> objects that point at a <commit>.
 546
 547<type>::
 548        Indicates that an object type is required.
 549        Currently one of: `blob`, `tree`, `commit`, or `tag`.
 550
 551<file>::
 552        Indicates a filename - almost always relative to the
 553        root of the tree structure `GIT_INDEX_FILE` describes.
 554
 555Symbolic Identifiers
 556--------------------
 557Any git command accepting any <object> can also use the following
 558symbolic notation:
 559
 560HEAD::
 561        indicates the head of the current branch.
 562
 563<tag>::
 564        a valid tag 'name'
 565        (i.e. a `refs/tags/<tag>` reference).
 566
 567<head>::
 568        a valid head 'name'
 569        (i.e. a `refs/heads/<head>` reference).
 570
 571For a more complete list of ways to spell object names, see
 572"SPECIFYING REVISIONS" section in linkgit:gitrevisions[7].
 573
 574
 575File/Directory Structure
 576------------------------
 577
 578Please see the linkgit:gitrepository-layout[5] document.
 579
 580Read linkgit:githooks[5] for more details about each hook.
 581
 582Higher level SCMs may provide and manage additional information in the
 583`$GIT_DIR`.
 584
 585
 586Terminology
 587-----------
 588Please see linkgit:gitglossary[7].
 589
 590
 591Environment Variables
 592---------------------
 593Various git commands use the following environment variables:
 594
 595The git Repository
 596~~~~~~~~~~~~~~~~~~
 597These environment variables apply to 'all' core git commands. Nb: it
 598is worth noting that they may be used/overridden by SCMS sitting above
 599git so take care if using Cogito etc.
 600
 601'GIT_INDEX_FILE'::
 602        This environment allows the specification of an alternate
 603        index file. If not specified, the default of `$GIT_DIR/index`
 604        is used.
 605
 606'GIT_OBJECT_DIRECTORY'::
 607        If the object storage directory is specified via this
 608        environment variable then the sha1 directories are created
 609        underneath - otherwise the default `$GIT_DIR/objects`
 610        directory is used.
 611
 612'GIT_ALTERNATE_OBJECT_DIRECTORIES'::
 613        Due to the immutable nature of git objects, old objects can be
 614        archived into shared, read-only directories. This variable
 615        specifies a ":" separated (on Windows ";" separated) list
 616        of git object directories which can be used to search for git
 617        objects. New objects will not be written to these directories.
 618
 619'GIT_DIR'::
 620        If the 'GIT_DIR' environment variable is set then it
 621        specifies a path to use instead of the default `.git`
 622        for the base of the repository.
 623
 624'GIT_WORK_TREE'::
 625        Set the path to the working tree.  The value will not be
 626        used in combination with repositories found automatically in
 627        a .git directory (i.e. $GIT_DIR is not set).
 628        This can also be controlled by the '--work-tree' command line
 629        option and the core.worktree configuration variable.
 630
 631'GIT_NAMESPACE'::
 632        Set the git namespace; see linkgit:gitnamespaces[7] for details.
 633        The '--namespace' command-line option also sets this value.
 634
 635'GIT_CEILING_DIRECTORIES'::
 636        This should be a colon-separated list of absolute paths.
 637        If set, it is a list of directories that git should not chdir
 638        up into while looking for a repository directory.
 639        It will not exclude the current working directory or
 640        a GIT_DIR set on the command line or in the environment.
 641        (Useful for excluding slow-loading network directories.)
 642
 643'GIT_DISCOVERY_ACROSS_FILESYSTEM'::
 644        When run in a directory that does not have ".git" repository
 645        directory, git tries to find such a directory in the parent
 646        directories to find the top of the working tree, but by default it
 647        does not cross filesystem boundaries.  This environment variable
 648        can be set to true to tell git not to stop at filesystem
 649        boundaries.  Like 'GIT_CEILING_DIRECTORIES', this will not affect
 650        an explicit repository directory set via 'GIT_DIR' or on the
 651        command line.
 652
 653git Commits
 654~~~~~~~~~~~
 655'GIT_AUTHOR_NAME'::
 656'GIT_AUTHOR_EMAIL'::
 657'GIT_AUTHOR_DATE'::
 658'GIT_COMMITTER_NAME'::
 659'GIT_COMMITTER_EMAIL'::
 660'GIT_COMMITTER_DATE'::
 661'EMAIL'::
 662        see linkgit:git-commit-tree[1]
 663
 664git Diffs
 665~~~~~~~~~
 666'GIT_DIFF_OPTS'::
 667        Only valid setting is "--unified=??" or "-u??" to set the
 668        number of context lines shown when a unified diff is created.
 669        This takes precedence over any "-U" or "--unified" option
 670        value passed on the git diff command line.
 671
 672'GIT_EXTERNAL_DIFF'::
 673        When the environment variable 'GIT_EXTERNAL_DIFF' is set, the
 674        program named by it is called, instead of the diff invocation
 675        described above.  For a path that is added, removed, or modified,
 676        'GIT_EXTERNAL_DIFF' is called with 7 parameters:
 677
 678        path old-file old-hex old-mode new-file new-hex new-mode
 679+
 680where:
 681
 682        <old|new>-file:: are files GIT_EXTERNAL_DIFF can use to read the
 683                         contents of <old|new>,
 684        <old|new>-hex:: are the 40-hexdigit SHA1 hashes,
 685        <old|new>-mode:: are the octal representation of the file modes.
 686+
 687The file parameters can point at the user's working file
 688(e.g. `new-file` in "git-diff-files"), `/dev/null` (e.g. `old-file`
 689when a new file is added), or a temporary file (e.g. `old-file` in the
 690index).  'GIT_EXTERNAL_DIFF' should not worry about unlinking the
 691temporary file --- it is removed when 'GIT_EXTERNAL_DIFF' exits.
 692+
 693For a path that is unmerged, 'GIT_EXTERNAL_DIFF' is called with 1
 694parameter, <path>.
 695
 696other
 697~~~~~
 698'GIT_MERGE_VERBOSITY'::
 699        A number controlling the amount of output shown by
 700        the recursive merge strategy.  Overrides merge.verbosity.
 701        See linkgit:git-merge[1]
 702
 703'GIT_PAGER'::
 704        This environment variable overrides `$PAGER`. If it is set
 705        to an empty string or to the value "cat", git will not launch
 706        a pager.  See also the `core.pager` option in
 707        linkgit:git-config[1].
 708
 709'GIT_SSH'::
 710        If this environment variable is set then 'git fetch'
 711        and 'git push' will use this command instead
 712        of 'ssh' when they need to connect to a remote system.
 713        The '$GIT_SSH' command will be given exactly two arguments:
 714        the 'username@host' (or just 'host') from the URL and the
 715        shell command to execute on that remote system.
 716+
 717To pass options to the program that you want to list in GIT_SSH
 718you will need to wrap the program and options into a shell script,
 719then set GIT_SSH to refer to the shell script.
 720+
 721Usually it is easier to configure any desired options through your
 722personal `.ssh/config` file.  Please consult your ssh documentation
 723for further details.
 724
 725'GIT_ASKPASS'::
 726        If this environment variable is set, then git commands which need to
 727        acquire passwords or passphrases (e.g. for HTTP or IMAP authentication)
 728        will call this program with a suitable prompt as command line argument
 729        and read the password from its STDOUT. See also the 'core.askpass'
 730        option in linkgit:git-config[1].
 731
 732'GIT_FLUSH'::
 733        If this environment variable is set to "1", then commands such
 734        as 'git blame' (in incremental mode), 'git rev-list', 'git log',
 735        and 'git whatchanged' will force a flush of the output stream
 736        after each commit-oriented record have been flushed.   If this
 737        variable is set to "0", the output of these commands will be done
 738        using completely buffered I/O.   If this environment variable is
 739        not set, git will choose buffered or record-oriented flushing
 740        based on whether stdout appears to be redirected to a file or not.
 741
 742'GIT_TRACE'::
 743        If this variable is set to "1", "2" or "true" (comparison
 744        is case insensitive), git will print `trace:` messages on
 745        stderr telling about alias expansion, built-in command
 746        execution and external command execution.
 747        If this variable is set to an integer value greater than 1
 748        and lower than 10 (strictly) then git will interpret this
 749        value as an open file descriptor and will try to write the
 750        trace messages into this file descriptor.
 751        Alternatively, if this variable is set to an absolute path
 752        (starting with a '/' character), git will interpret this
 753        as a file path and will try to write the trace messages
 754        into it.
 755
 756Discussion[[Discussion]]
 757------------------------
 758
 759More detail on the following is available from the
 760link:user-manual.html#git-concepts[git concepts chapter of the
 761user-manual] and linkgit:gitcore-tutorial[7].
 762
 763A git project normally consists of a working directory with a ".git"
 764subdirectory at the top level.  The .git directory contains, among other
 765things, a compressed object database representing the complete history
 766of the project, an "index" file which links that history to the current
 767contents of the working tree, and named pointers into that history such
 768as tags and branch heads.
 769
 770The object database contains objects of three main types: blobs, which
 771hold file data; trees, which point to blobs and other trees to build up
 772directory hierarchies; and commits, which each reference a single tree
 773and some number of parent commits.
 774
 775The commit, equivalent to what other systems call a "changeset" or
 776"version", represents a step in the project's history, and each parent
 777represents an immediately preceding step.  Commits with more than one
 778parent represent merges of independent lines of development.
 779
 780All objects are named by the SHA1 hash of their contents, normally
 781written as a string of 40 hex digits.  Such names are globally unique.
 782The entire history leading up to a commit can be vouched for by signing
 783just that commit.  A fourth object type, the tag, is provided for this
 784purpose.
 785
 786When first created, objects are stored in individual files, but for
 787efficiency may later be compressed together into "pack files".
 788
 789Named pointers called refs mark interesting points in history.  A ref
 790may contain the SHA1 name of an object or the name of another ref.  Refs
 791with names beginning `ref/head/` contain the SHA1 name of the most
 792recent commit (or "head") of a branch under development.  SHA1 names of
 793tags of interest are stored under `ref/tags/`.  A special ref named
 794`HEAD` contains the name of the currently checked-out branch.
 795
 796The index file is initialized with a list of all paths and, for each
 797path, a blob object and a set of attributes.  The blob object represents
 798the contents of the file as of the head of the current branch.  The
 799attributes (last modified time, size, etc.) are taken from the
 800corresponding file in the working tree.  Subsequent changes to the
 801working tree can be found by comparing these attributes.  The index may
 802be updated with new content, and new commits may be created from the
 803content stored in the index.
 804
 805The index is also capable of storing multiple entries (called "stages")
 806for a given pathname.  These stages are used to hold the various
 807unmerged version of a file when a merge is in progress.
 808
 809Authors
 810-------
 811Git was started by Linus Torvalds, and is currently maintained by Junio
 812C Hamano. Numerous contributions have come from the git mailing list
 813<git@vger.kernel.org>. For a more complete list of contributors, see
 814http://git-scm.com/about. If you have a clone of git.git itself, the
 815output of linkgit:git-shortlog[1] and linkgit:git-blame[1] can show you
 816the authors for specific parts of the project.
 817
 818Reporting Bugs
 819--------------
 820
 821Report bugs to the Git mailing list <git@vger.kernel.org> where the
 822development and maintenance is primarily done.  You do not have to be
 823subscribed to the list to send a message there.
 824
 825SEE ALSO
 826--------
 827linkgit:gittutorial[7], linkgit:gittutorial-2[7],
 828link:everyday.html[Everyday Git], linkgit:gitcvs-migration[7],
 829linkgit:gitglossary[7], linkgit:gitcore-tutorial[7],
 830linkgit:gitcli[7], link:user-manual.html[The Git User's Manual],
 831linkgit:gitworkflows[7]
 832
 833GIT
 834---
 835Part of the linkgit:git[1] suite