80d795dc567553fe3a89b34e200d881026de1aba
   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]
  13    [-p|--paginate|--no-pager] [--no-replace-objects]
  14    [--bare] [--git-dir=<path>] [--work-tree=<path>]
  15    [-c <name>=<value>]
  16    [--help] <command> [<args>]
  17
  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:v1.7.3.4/git.html[documentation for release 1.7.3.4]
  48
  49* release notes for
  50  link:RelNotes/1.7.3.4.txt[1.7.3.4],
  51  link:RelNotes/1.7.3.3.txt[1.7.3.3],
  52  link:RelNotes/1.7.3.2.txt[1.7.3.2],
  53  link:RelNotes/1.7.3.1.txt[1.7.3.1],
  54  link:RelNotes/1.7.3.txt[1.7.3].
  55
  56* link:v1.7.2.4/git.html[documentation for release 1.7.2.4]
  57
  58* release notes for
  59  link:RelNotes/1.7.2.4.txt[1.7.2.4],
  60  link:RelNotes/1.7.2.3.txt[1.7.2.3],
  61  link:RelNotes/1.7.2.2.txt[1.7.2.2],
  62  link:RelNotes/1.7.2.1.txt[1.7.2.1],
  63  link:RelNotes/1.7.2.txt[1.7.2].
  64
  65* link:v1.7.1.3/git.html[documentation for release 1.7.1.3]
  66
  67* release notes for
  68  link:RelNotes/1.7.1.3.txt[1.7.1.3],
  69  link:RelNotes/1.7.1.2.txt[1.7.1.2],
  70  link:RelNotes/1.7.1.1.txt[1.7.1.1],
  71  link:RelNotes/1.7.1.txt[1.7.1].
  72
  73* link:v1.7.0.8/git.html[documentation for release 1.7.0.8]
  74
  75* release notes for
  76  link:RelNotes/1.7.0.8.txt[1.7.0.8],
  77  link:RelNotes/1.7.0.7.txt[1.7.0.7],
  78  link:RelNotes/1.7.0.6.txt[1.7.0.6],
  79  link:RelNotes/1.7.0.5.txt[1.7.0.5],
  80  link:RelNotes/1.7.0.4.txt[1.7.0.4],
  81  link:RelNotes/1.7.0.3.txt[1.7.0.3],
  82  link:RelNotes/1.7.0.2.txt[1.7.0.2],
  83  link:RelNotes/1.7.0.1.txt[1.7.0.1],
  84  link:RelNotes/1.7.0.txt[1.7.0].
  85
  86* link:v1.6.6.2/git.html[documentation for release 1.6.6.2]
  87
  88* release notes for
  89  link:RelNotes/1.6.6.2.txt[1.6.6.2],
  90  link:RelNotes/1.6.6.1.txt[1.6.6.1],
  91  link:RelNotes/1.6.6.txt[1.6.6].
  92
  93* link:v1.6.5.8/git.html[documentation for release 1.6.5.8]
  94
  95* release notes for
  96  link:RelNotes/1.6.5.8.txt[1.6.5.8],
  97  link:RelNotes/1.6.5.7.txt[1.6.5.7],
  98  link:RelNotes/1.6.5.6.txt[1.6.5.6],
  99  link:RelNotes/1.6.5.5.txt[1.6.5.5],
 100  link:RelNotes/1.6.5.4.txt[1.6.5.4],
 101  link:RelNotes/1.6.5.3.txt[1.6.5.3],
 102  link:RelNotes/1.6.5.2.txt[1.6.5.2],
 103  link:RelNotes/1.6.5.1.txt[1.6.5.1],
 104  link:RelNotes/1.6.5.txt[1.6.5].
 105
 106* link:v1.6.4.4/git.html[documentation for release 1.6.4.4]
 107
 108* release notes for
 109  link:RelNotes/1.6.4.4.txt[1.6.4.4],
 110  link:RelNotes/1.6.4.3.txt[1.6.4.3],
 111  link:RelNotes/1.6.4.2.txt[1.6.4.2],
 112  link:RelNotes/1.6.4.1.txt[1.6.4.1],
 113  link:RelNotes/1.6.4.txt[1.6.4].
 114
 115* link:v1.6.3.4/git.html[documentation for release 1.6.3.4]
 116
 117* release notes for
 118  link:RelNotes/1.6.3.4.txt[1.6.3.4],
 119  link:RelNotes/1.6.3.3.txt[1.6.3.3],
 120  link:RelNotes/1.6.3.2.txt[1.6.3.2],
 121  link:RelNotes/1.6.3.1.txt[1.6.3.1],
 122  link:RelNotes/1.6.3.txt[1.6.3].
 123
 124* release notes for
 125  link:RelNotes/1.6.2.5.txt[1.6.2.5],
 126  link:RelNotes/1.6.2.4.txt[1.6.2.4],
 127  link:RelNotes/1.6.2.3.txt[1.6.2.3],
 128  link:RelNotes/1.6.2.2.txt[1.6.2.2],
 129  link:RelNotes/1.6.2.1.txt[1.6.2.1],
 130  link:RelNotes/1.6.2.txt[1.6.2].
 131
 132* link:v1.6.1.3/git.html[documentation for release 1.6.1.3]
 133
 134* release notes for
 135  link:RelNotes/1.6.1.3.txt[1.6.1.3],
 136  link:RelNotes/1.6.1.2.txt[1.6.1.2],
 137  link:RelNotes/1.6.1.1.txt[1.6.1.1],
 138  link:RelNotes/1.6.1.txt[1.6.1].
 139
 140* link:v1.6.0.6/git.html[documentation for release 1.6.0.6]
 141
 142* release notes for
 143  link:RelNotes/1.6.0.6.txt[1.6.0.6],
 144  link:RelNotes/1.6.0.5.txt[1.6.0.5],
 145  link:RelNotes/1.6.0.4.txt[1.6.0.4],
 146  link:RelNotes/1.6.0.3.txt[1.6.0.3],
 147  link:RelNotes/1.6.0.2.txt[1.6.0.2],
 148  link:RelNotes/1.6.0.1.txt[1.6.0.1],
 149  link:RelNotes/1.6.0.txt[1.6.0].
 150
 151* link:v1.5.6.6/git.html[documentation for release 1.5.6.6]
 152
 153* release notes for
 154  link:RelNotes/1.5.6.6.txt[1.5.6.6],
 155  link:RelNotes/1.5.6.5.txt[1.5.6.5],
 156  link:RelNotes/1.5.6.4.txt[1.5.6.4],
 157  link:RelNotes/1.5.6.3.txt[1.5.6.3],
 158  link:RelNotes/1.5.6.2.txt[1.5.6.2],
 159  link:RelNotes/1.5.6.1.txt[1.5.6.1],
 160  link:RelNotes/1.5.6.txt[1.5.6].
 161
 162* link:v1.5.5.6/git.html[documentation for release 1.5.5.6]
 163
 164* release notes for
 165  link:RelNotes/1.5.5.6.txt[1.5.5.6],
 166  link:RelNotes/1.5.5.5.txt[1.5.5.5],
 167  link:RelNotes/1.5.5.4.txt[1.5.5.4],
 168  link:RelNotes/1.5.5.3.txt[1.5.5.3],
 169  link:RelNotes/1.5.5.2.txt[1.5.5.2],
 170  link:RelNotes/1.5.5.1.txt[1.5.5.1],
 171  link:RelNotes/1.5.5.txt[1.5.5].
 172
 173* link:v1.5.4.7/git.html[documentation for release 1.5.4.7]
 174
 175* release notes for
 176  link:RelNotes/1.5.4.7.txt[1.5.4.7],
 177  link:RelNotes/1.5.4.6.txt[1.5.4.6],
 178  link:RelNotes/1.5.4.5.txt[1.5.4.5],
 179  link:RelNotes/1.5.4.4.txt[1.5.4.4],
 180  link:RelNotes/1.5.4.3.txt[1.5.4.3],
 181  link:RelNotes/1.5.4.2.txt[1.5.4.2],
 182  link:RelNotes/1.5.4.1.txt[1.5.4.1],
 183  link:RelNotes/1.5.4.txt[1.5.4].
 184
 185* link:v1.5.3.8/git.html[documentation for release 1.5.3.8]
 186
 187* release notes for
 188  link:RelNotes/1.5.3.8.txt[1.5.3.8],
 189  link:RelNotes/1.5.3.7.txt[1.5.3.7],
 190  link:RelNotes/1.5.3.6.txt[1.5.3.6],
 191  link:RelNotes/1.5.3.5.txt[1.5.3.5],
 192  link:RelNotes/1.5.3.4.txt[1.5.3.4],
 193  link:RelNotes/1.5.3.3.txt[1.5.3.3],
 194  link:RelNotes/1.5.3.2.txt[1.5.3.2],
 195  link:RelNotes/1.5.3.1.txt[1.5.3.1],
 196  link:RelNotes/1.5.3.txt[1.5.3].
 197
 198* link:v1.5.2.5/git.html[documentation for release 1.5.2.5]
 199
 200* release notes for
 201  link:RelNotes/1.5.2.5.txt[1.5.2.5],
 202  link:RelNotes/1.5.2.4.txt[1.5.2.4],
 203  link:RelNotes/1.5.2.3.txt[1.5.2.3],
 204  link:RelNotes/1.5.2.2.txt[1.5.2.2],
 205  link:RelNotes/1.5.2.1.txt[1.5.2.1],
 206  link:RelNotes/1.5.2.txt[1.5.2].
 207
 208* link:v1.5.1.6/git.html[documentation for release 1.5.1.6]
 209
 210* release notes for
 211  link:RelNotes/1.5.1.6.txt[1.5.1.6],
 212  link:RelNotes/1.5.1.5.txt[1.5.1.5],
 213  link:RelNotes/1.5.1.4.txt[1.5.1.4],
 214  link:RelNotes/1.5.1.3.txt[1.5.1.3],
 215  link:RelNotes/1.5.1.2.txt[1.5.1.2],
 216  link:RelNotes/1.5.1.1.txt[1.5.1.1],
 217  link:RelNotes/1.5.1.txt[1.5.1].
 218
 219* link:v1.5.0.7/git.html[documentation for release 1.5.0.7]
 220
 221* release notes for
 222  link:RelNotes/1.5.0.7.txt[1.5.0.7],
 223  link:RelNotes/1.5.0.6.txt[1.5.0.6],
 224  link:RelNotes/1.5.0.5.txt[1.5.0.5],
 225  link:RelNotes/1.5.0.3.txt[1.5.0.3],
 226  link:RelNotes/1.5.0.2.txt[1.5.0.2],
 227  link:RelNotes/1.5.0.1.txt[1.5.0.1],
 228  link:RelNotes/1.5.0.txt[1.5.0].
 229
 230* documentation for release link:v1.4.4.4/git.html[1.4.4.4],
 231  link:v1.3.3/git.html[1.3.3],
 232  link:v1.2.6/git.html[1.2.6],
 233  link:v1.0.13/git.html[1.0.13].
 234
 235============
 236
 237endif::stalenotes[]
 238
 239OPTIONS
 240-------
 241--version::
 242        Prints the git suite version that the 'git' program came from.
 243
 244--help::
 245        Prints the synopsis and a list of the most commonly used
 246        commands. If the option '--all' or '-a' is given then all
 247        available commands are printed. If a git command is named this
 248        option will bring up the manual page for that command.
 249+
 250Other options are available to control how the manual page is
 251displayed. See linkgit:git-help[1] for more information,
 252because `git --help ...` is converted internally into `git
 253help ...`.
 254
 255-c <name>=<value>::
 256        Pass a configuration parameter to the command. The value
 257        given will override values from configuration files.
 258        The <name> is expected in the same format as listed by
 259        'git config' (subkeys separated by dots).
 260
 261--exec-path[=<path>]::
 262        Path to wherever your core git programs are installed.
 263        This can also be controlled by setting the GIT_EXEC_PATH
 264        environment variable. If no path is given, 'git' will print
 265        the current setting and then exit.
 266
 267--html-path::
 268        Print the path to wherever your git HTML documentation is installed
 269        and exit.
 270
 271-p::
 272--paginate::
 273        Pipe all output into 'less' (or if set, $PAGER) if standard
 274        output is a terminal.  This overrides the `pager.<cmd>`
 275        configuration options (see the "Configuration Mechanism" section
 276        below).
 277
 278--no-pager::
 279        Do not pipe git output into a pager.
 280
 281--git-dir=<path>::
 282        Set the path to the repository. This can also be controlled by
 283        setting the GIT_DIR environment variable. It can be an absolute
 284        path or relative path to current working directory.
 285
 286--work-tree=<path>::
 287        Set the path to the working tree.  The value will not be
 288        used in combination with repositories found automatically in
 289        a .git directory (i.e. $GIT_DIR is not set).
 290        This can also be controlled by setting the GIT_WORK_TREE
 291        environment variable and the core.worktree configuration
 292        variable. It can be an absolute path or relative path to
 293        the directory specified by --git-dir or GIT_DIR.
 294        Note: If --git-dir or GIT_DIR are specified but none of
 295        --work-tree, GIT_WORK_TREE and core.worktree is specified,
 296        the current working directory is regarded as the top directory
 297        of your working tree.
 298
 299--bare::
 300        Treat the repository as a bare repository.  If GIT_DIR
 301        environment is not set, it is set to the current working
 302        directory.
 303
 304--no-replace-objects::
 305        Do not use replacement refs to replace git objects. See
 306        linkgit:git-replace[1] for more information.
 307
 308
 309FURTHER DOCUMENTATION
 310---------------------
 311
 312See the references above to get started using git.  The following is
 313probably more detail than necessary for a first-time user.
 314
 315The link:user-manual.html#git-concepts[git concepts chapter of the
 316user-manual] and linkgit:gitcore-tutorial[7] both provide
 317introductions to the underlying git architecture.
 318
 319See linkgit:gitworkflows[7] for an overview of recommended workflows.
 320
 321See also the link:howto-index.html[howto] documents for some useful
 322examples.
 323
 324The internals are documented in the
 325link:technical/api-index.html[GIT API documentation].
 326
 327GIT COMMANDS
 328------------
 329
 330We divide git into high level ("porcelain") commands and low level
 331("plumbing") commands.
 332
 333High-level commands (porcelain)
 334-------------------------------
 335
 336We separate the porcelain commands into the main commands and some
 337ancillary user utilities.
 338
 339Main porcelain commands
 340~~~~~~~~~~~~~~~~~~~~~~~
 341
 342include::cmds-mainporcelain.txt[]
 343
 344Ancillary Commands
 345~~~~~~~~~~~~~~~~~~
 346Manipulators:
 347
 348include::cmds-ancillarymanipulators.txt[]
 349
 350Interrogators:
 351
 352include::cmds-ancillaryinterrogators.txt[]
 353
 354
 355Interacting with Others
 356~~~~~~~~~~~~~~~~~~~~~~~
 357
 358These commands are to interact with foreign SCM and with other
 359people via patch over e-mail.
 360
 361include::cmds-foreignscminterface.txt[]
 362
 363
 364Low-level commands (plumbing)
 365-----------------------------
 366
 367Although git includes its
 368own porcelain layer, its low-level commands are sufficient to support
 369development of alternative porcelains.  Developers of such porcelains
 370might start by reading about linkgit:git-update-index[1] and
 371linkgit:git-read-tree[1].
 372
 373The interface (input, output, set of options and the semantics)
 374to these low-level commands are meant to be a lot more stable
 375than Porcelain level commands, because these commands are
 376primarily for scripted use.  The interface to Porcelain commands
 377on the other hand are subject to change in order to improve the
 378end user experience.
 379
 380The following description divides
 381the low-level commands into commands that manipulate objects (in
 382the repository, index, and working tree), commands that interrogate and
 383compare objects, and commands that move objects and references between
 384repositories.
 385
 386
 387Manipulation commands
 388~~~~~~~~~~~~~~~~~~~~~
 389
 390include::cmds-plumbingmanipulators.txt[]
 391
 392
 393Interrogation commands
 394~~~~~~~~~~~~~~~~~~~~~~
 395
 396include::cmds-plumbinginterrogators.txt[]
 397
 398In general, the interrogate commands do not touch the files in
 399the working tree.
 400
 401
 402Synching repositories
 403~~~~~~~~~~~~~~~~~~~~~
 404
 405include::cmds-synchingrepositories.txt[]
 406
 407The following are helper commands used by the above; end users
 408typically do not use them directly.
 409
 410include::cmds-synchelpers.txt[]
 411
 412
 413Internal helper commands
 414~~~~~~~~~~~~~~~~~~~~~~~~
 415
 416These are internal helper commands used by other commands; end
 417users typically do not use them directly.
 418
 419include::cmds-purehelpers.txt[]
 420
 421
 422Configuration Mechanism
 423-----------------------
 424
 425Starting from 0.99.9 (actually mid 0.99.8.GIT), `.git/config` file
 426is used to hold per-repository configuration options.  It is a
 427simple text file modeled after `.ini` format familiar to some
 428people.  Here is an example:
 429
 430------------
 431#
 432# A '#' or ';' character indicates a comment.
 433#
 434
 435; core variables
 436[core]
 437        ; Don't trust file modes
 438        filemode = false
 439
 440; user identity
 441[user]
 442        name = "Junio C Hamano"
 443        email = "junkio@twinsun.com"
 444
 445------------
 446
 447Various commands read from the configuration file and adjust
 448their operation accordingly.  See linkgit:git-config[1] for a
 449list.
 450
 451
 452Identifier Terminology
 453----------------------
 454<object>::
 455        Indicates the object name for any type of object.
 456
 457<blob>::
 458        Indicates a blob object name.
 459
 460<tree>::
 461        Indicates a tree object name.
 462
 463<commit>::
 464        Indicates a commit object name.
 465
 466<tree-ish>::
 467        Indicates a tree, commit or tag object name.  A
 468        command that takes a <tree-ish> argument ultimately wants to
 469        operate on a <tree> object but automatically dereferences
 470        <commit> and <tag> objects that point at a <tree>.
 471
 472<commit-ish>::
 473        Indicates a commit or tag object name.  A
 474        command that takes a <commit-ish> argument ultimately wants to
 475        operate on a <commit> object but automatically dereferences
 476        <tag> objects that point at a <commit>.
 477
 478<type>::
 479        Indicates that an object type is required.
 480        Currently one of: `blob`, `tree`, `commit`, or `tag`.
 481
 482<file>::
 483        Indicates a filename - almost always relative to the
 484        root of the tree structure `GIT_INDEX_FILE` describes.
 485
 486Symbolic Identifiers
 487--------------------
 488Any git command accepting any <object> can also use the following
 489symbolic notation:
 490
 491HEAD::
 492        indicates the head of the current branch (i.e. the
 493        contents of `$GIT_DIR/HEAD`).
 494
 495<tag>::
 496        a valid tag 'name'
 497        (i.e. the contents of `$GIT_DIR/refs/tags/<tag>`).
 498
 499<head>::
 500        a valid head 'name'
 501        (i.e. the contents of `$GIT_DIR/refs/heads/<head>`).
 502
 503For a more complete list of ways to spell object names, see
 504"SPECIFYING REVISIONS" section in linkgit:gitrevisions[7].
 505
 506
 507File/Directory Structure
 508------------------------
 509
 510Please see the linkgit:gitrepository-layout[5] document.
 511
 512Read linkgit:githooks[5] for more details about each hook.
 513
 514Higher level SCMs may provide and manage additional information in the
 515`$GIT_DIR`.
 516
 517
 518Terminology
 519-----------
 520Please see linkgit:gitglossary[7].
 521
 522
 523Environment Variables
 524---------------------
 525Various git commands use the following environment variables:
 526
 527The git Repository
 528~~~~~~~~~~~~~~~~~~
 529These environment variables apply to 'all' core git commands. Nb: it
 530is worth noting that they may be used/overridden by SCMS sitting above
 531git so take care if using Cogito etc.
 532
 533'GIT_INDEX_FILE'::
 534        This environment allows the specification of an alternate
 535        index file. If not specified, the default of `$GIT_DIR/index`
 536        is used.
 537
 538'GIT_OBJECT_DIRECTORY'::
 539        If the object storage directory is specified via this
 540        environment variable then the sha1 directories are created
 541        underneath - otherwise the default `$GIT_DIR/objects`
 542        directory is used.
 543
 544'GIT_ALTERNATE_OBJECT_DIRECTORIES'::
 545        Due to the immutable nature of git objects, old objects can be
 546        archived into shared, read-only directories. This variable
 547        specifies a ":" separated (on Windows ";" separated) list
 548        of git object directories which can be used to search for git
 549        objects. New objects will not be written to these directories.
 550
 551'GIT_DIR'::
 552        If the 'GIT_DIR' environment variable is set then it
 553        specifies a path to use instead of the default `.git`
 554        for the base of the repository.
 555
 556'GIT_WORK_TREE'::
 557        Set the path to the working tree.  The value will not be
 558        used in combination with repositories found automatically in
 559        a .git directory (i.e. $GIT_DIR is not set).
 560        This can also be controlled by the '--work-tree' command line
 561        option and the core.worktree configuration variable.
 562
 563'GIT_CEILING_DIRECTORIES'::
 564        This should be a colon-separated list of absolute paths.
 565        If set, it is a list of directories that git should not chdir
 566        up into while looking for a repository directory.
 567        It will not exclude the current working directory or
 568        a GIT_DIR set on the command line or in the environment.
 569        (Useful for excluding slow-loading network directories.)
 570
 571'GIT_DISCOVERY_ACROSS_FILESYSTEM'::
 572        When run in a directory that does not have ".git" repository
 573        directory, git tries to find such a directory in the parent
 574        directories to find the top of the working tree, but by default it
 575        does not cross filesystem boundaries.  This environment variable
 576        can be set to true to tell git not to stop at filesystem
 577        boundaries.  Like 'GIT_CEILING_DIRECTORIES', this will not affect
 578        an explicit repository directory set via 'GIT_DIR' or on the
 579        command line.
 580
 581git Commits
 582~~~~~~~~~~~
 583'GIT_AUTHOR_NAME'::
 584'GIT_AUTHOR_EMAIL'::
 585'GIT_AUTHOR_DATE'::
 586'GIT_COMMITTER_NAME'::
 587'GIT_COMMITTER_EMAIL'::
 588'GIT_COMMITTER_DATE'::
 589'EMAIL'::
 590        see linkgit:git-commit-tree[1]
 591
 592git Diffs
 593~~~~~~~~~
 594'GIT_DIFF_OPTS'::
 595        Only valid setting is "--unified=??" or "-u??" to set the
 596        number of context lines shown when a unified diff is created.
 597        This takes precedence over any "-U" or "--unified" option
 598        value passed on the git diff command line.
 599
 600'GIT_EXTERNAL_DIFF'::
 601        When the environment variable 'GIT_EXTERNAL_DIFF' is set, the
 602        program named by it is called, instead of the diff invocation
 603        described above.  For a path that is added, removed, or modified,
 604        'GIT_EXTERNAL_DIFF' is called with 7 parameters:
 605
 606        path old-file old-hex old-mode new-file new-hex new-mode
 607+
 608where:
 609
 610        <old|new>-file:: are files GIT_EXTERNAL_DIFF can use to read the
 611                         contents of <old|new>,
 612        <old|new>-hex:: are the 40-hexdigit SHA1 hashes,
 613        <old|new>-mode:: are the octal representation of the file modes.
 614
 615+
 616The file parameters can point at the user's working file
 617(e.g. `new-file` in "git-diff-files"), `/dev/null` (e.g. `old-file`
 618when a new file is added), or a temporary file (e.g. `old-file` in the
 619index).  'GIT_EXTERNAL_DIFF' should not worry about unlinking the
 620temporary file --- it is removed when 'GIT_EXTERNAL_DIFF' exits.
 621+
 622For a path that is unmerged, 'GIT_EXTERNAL_DIFF' is called with 1
 623parameter, <path>.
 624
 625other
 626~~~~~
 627'GIT_MERGE_VERBOSITY'::
 628        A number controlling the amount of output shown by
 629        the recursive merge strategy.  Overrides merge.verbosity.
 630        See linkgit:git-merge[1]
 631
 632'GIT_PAGER'::
 633        This environment variable overrides `$PAGER`. If it is set
 634        to an empty string or to the value "cat", git will not launch
 635        a pager.  See also the `core.pager` option in
 636        linkgit:git-config[1].
 637
 638'GIT_SSH'::
 639        If this environment variable is set then 'git fetch'
 640        and 'git push' will use this command instead
 641        of 'ssh' when they need to connect to a remote system.
 642        The '$GIT_SSH' command will be given exactly two arguments:
 643        the 'username@host' (or just 'host') from the URL and the
 644        shell command to execute on that remote system.
 645+
 646To pass options to the program that you want to list in GIT_SSH
 647you will need to wrap the program and options into a shell script,
 648then set GIT_SSH to refer to the shell script.
 649+
 650Usually it is easier to configure any desired options through your
 651personal `.ssh/config` file.  Please consult your ssh documentation
 652for further details.
 653
 654'GIT_ASKPASS'::
 655        If this environment variable is set, then git commands which need to
 656        acquire passwords or passphrases (e.g. for HTTP or IMAP authentication)
 657        will call this program with a suitable prompt as command line argument
 658        and read the password from its STDOUT. See also the 'core.askpass'
 659        option in linkgit:git-config[1].
 660
 661'GIT_FLUSH'::
 662        If this environment variable is set to "1", then commands such
 663        as 'git blame' (in incremental mode), 'git rev-list', 'git log',
 664        and 'git whatchanged' will force a flush of the output stream
 665        after each commit-oriented record have been flushed.   If this
 666        variable is set to "0", the output of these commands will be done
 667        using completely buffered I/O.   If this environment variable is
 668        not set, git will choose buffered or record-oriented flushing
 669        based on whether stdout appears to be redirected to a file or not.
 670
 671'GIT_TRACE'::
 672        If this variable is set to "1", "2" or "true" (comparison
 673        is case insensitive), git will print `trace:` messages on
 674        stderr telling about alias expansion, built-in command
 675        execution and external command execution.
 676        If this variable is set to an integer value greater than 1
 677        and lower than 10 (strictly) then git will interpret this
 678        value as an open file descriptor and will try to write the
 679        trace messages into this file descriptor.
 680        Alternatively, if this variable is set to an absolute path
 681        (starting with a '/' character), git will interpret this
 682        as a file path and will try to write the trace messages
 683        into it.
 684
 685Discussion[[Discussion]]
 686------------------------
 687
 688More detail on the following is available from the
 689link:user-manual.html#git-concepts[git concepts chapter of the
 690user-manual] and linkgit:gitcore-tutorial[7].
 691
 692A git project normally consists of a working directory with a ".git"
 693subdirectory at the top level.  The .git directory contains, among other
 694things, a compressed object database representing the complete history
 695of the project, an "index" file which links that history to the current
 696contents of the working tree, and named pointers into that history such
 697as tags and branch heads.
 698
 699The object database contains objects of three main types: blobs, which
 700hold file data; trees, which point to blobs and other trees to build up
 701directory hierarchies; and commits, which each reference a single tree
 702and some number of parent commits.
 703
 704The commit, equivalent to what other systems call a "changeset" or
 705"version", represents a step in the project's history, and each parent
 706represents an immediately preceding step.  Commits with more than one
 707parent represent merges of independent lines of development.
 708
 709All objects are named by the SHA1 hash of their contents, normally
 710written as a string of 40 hex digits.  Such names are globally unique.
 711The entire history leading up to a commit can be vouched for by signing
 712just that commit.  A fourth object type, the tag, is provided for this
 713purpose.
 714
 715When first created, objects are stored in individual files, but for
 716efficiency may later be compressed together into "pack files".
 717
 718Named pointers called refs mark interesting points in history.  A ref
 719may contain the SHA1 name of an object or the name of another ref.  Refs
 720with names beginning `ref/head/` contain the SHA1 name of the most
 721recent commit (or "head") of a branch under development.  SHA1 names of
 722tags of interest are stored under `ref/tags/`.  A special ref named
 723`HEAD` contains the name of the currently checked-out branch.
 724
 725The index file is initialized with a list of all paths and, for each
 726path, a blob object and a set of attributes.  The blob object represents
 727the contents of the file as of the head of the current branch.  The
 728attributes (last modified time, size, etc.) are taken from the
 729corresponding file in the working tree.  Subsequent changes to the
 730working tree can be found by comparing these attributes.  The index may
 731be updated with new content, and new commits may be created from the
 732content stored in the index.
 733
 734The index is also capable of storing multiple entries (called "stages")
 735for a given pathname.  These stages are used to hold the various
 736unmerged version of a file when a merge is in progress.
 737
 738Authors
 739-------
 740* git's founding father is Linus Torvalds <torvalds@osdl.org>.
 741* The current git nurse is Junio C Hamano <gitster@pobox.com>.
 742* The git potty was written by Andreas Ericsson <ae@op5.se>.
 743* General upbringing is handled by the git-list <git@vger.kernel.org>.
 744
 745Documentation
 746--------------
 747The documentation for git suite was started by David Greaves
 748<david@dgreaves.com>, and later enhanced greatly by the
 749contributors on the git-list <git@vger.kernel.org>.
 750
 751Reporting Bugs
 752--------------
 753
 754Report bugs to the Git mailing list <git@vger.kernel.org> where the
 755development and maintenance is primarily done.  You do not have to be
 756subscribed to the list to send a message there.
 757
 758SEE ALSO
 759--------
 760linkgit:gittutorial[7], linkgit:gittutorial-2[7],
 761link:everyday.html[Everyday Git], linkgit:gitcvs-migration[7],
 762linkgit:gitglossary[7], linkgit:gitcore-tutorial[7],
 763linkgit:gitcli[7], link:user-manual.html[The Git User's Manual],
 764linkgit:gitworkflows[7]
 765
 766GIT
 767---
 768Part of the linkgit:git[1] suite