Documentation / git.txton commit merge-recursive: Avoid doubly merging rename/add conflict contents (2a669c3)
   1git(1)
   2======
   3
   4NAME
   5----
   6git - the stupid content tracker
   7
   8
   9SYNOPSIS
  10--------
  11[verse]
  12'git' [--version] [--exec-path[=GIT_EXEC_PATH]] [--html-path]
  13    [-p|--paginate|--no-pager] [--no-replace-objects]
  14    [--bare] [--git-dir=GIT_DIR] [--work-tree=GIT_WORK_TREE]
  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/git.html[documentation for release 1.7.3]
  48
  49* release notes for
  50  link:RelNotes/1.7.3.txt[1.7.3].
  51
  52* link:v1.7.2.3/git.html[documentation for release 1.7.2.3]
  53
  54* release notes for
  55  link:RelNotes/1.7.2.3.txt[1.7.2.3],
  56  link:RelNotes/1.7.2.2.txt[1.7.2.2],
  57  link:RelNotes/1.7.2.1.txt[1.7.2.1],
  58  link:RelNotes/1.7.2.txt[1.7.2].
  59
  60* link:v1.7.1.2/git.html[documentation for release 1.7.1.2]
  61
  62* release notes for
  63  link:RelNotes/1.7.1.2.txt[1.7.1.2],
  64  link:RelNotes/1.7.1.1.txt[1.7.1.1],
  65  link:RelNotes/1.7.1.txt[1.7.1].
  66
  67* link:v1.7.0.7/git.html[documentation for release 1.7.0.7]
  68
  69* release notes for
  70  link:RelNotes/1.7.0.7.txt[1.7.0.7],
  71  link:RelNotes/1.7.0.6.txt[1.7.0.6],
  72  link:RelNotes/1.7.0.5.txt[1.7.0.5],
  73  link:RelNotes/1.7.0.4.txt[1.7.0.4],
  74  link:RelNotes/1.7.0.3.txt[1.7.0.3],
  75  link:RelNotes/1.7.0.2.txt[1.7.0.2],
  76  link:RelNotes/1.7.0.1.txt[1.7.0.1],
  77  link:RelNotes/1.7.0.txt[1.7.0].
  78
  79* link:v1.6.6.2/git.html[documentation for release 1.6.6.2]
  80
  81* release notes for
  82  link:RelNotes/1.6.6.2.txt[1.6.6.2],
  83  link:RelNotes/1.6.6.1.txt[1.6.6.1],
  84  link:RelNotes/1.6.6.txt[1.6.6].
  85
  86* link:v1.6.5.8/git.html[documentation for release 1.6.5.8]
  87
  88* release notes for
  89  link:RelNotes/1.6.5.8.txt[1.6.5.8],
  90  link:RelNotes/1.6.5.7.txt[1.6.5.7],
  91  link:RelNotes/1.6.5.6.txt[1.6.5.6],
  92  link:RelNotes/1.6.5.5.txt[1.6.5.5],
  93  link:RelNotes/1.6.5.4.txt[1.6.5.4],
  94  link:RelNotes/1.6.5.3.txt[1.6.5.3],
  95  link:RelNotes/1.6.5.2.txt[1.6.5.2],
  96  link:RelNotes/1.6.5.1.txt[1.6.5.1],
  97  link:RelNotes/1.6.5.txt[1.6.5].
  98
  99* link:v1.6.4.4/git.html[documentation for release 1.6.4.4]
 100
 101* release notes for
 102  link:RelNotes/1.6.4.4.txt[1.6.4.4],
 103  link:RelNotes/1.6.4.3.txt[1.6.4.3],
 104  link:RelNotes/1.6.4.2.txt[1.6.4.2],
 105  link:RelNotes/1.6.4.1.txt[1.6.4.1],
 106  link:RelNotes/1.6.4.txt[1.6.4].
 107
 108* link:v1.6.3.4/git.html[documentation for release 1.6.3.4]
 109
 110* release notes for
 111  link:RelNotes/1.6.3.4.txt[1.6.3.4],
 112  link:RelNotes/1.6.3.3.txt[1.6.3.3],
 113  link:RelNotes/1.6.3.2.txt[1.6.3.2],
 114  link:RelNotes/1.6.3.1.txt[1.6.3.1],
 115  link:RelNotes/1.6.3.txt[1.6.3].
 116
 117* release notes for
 118  link:RelNotes/1.6.2.5.txt[1.6.2.5],
 119  link:RelNotes/1.6.2.4.txt[1.6.2.4],
 120  link:RelNotes/1.6.2.3.txt[1.6.2.3],
 121  link:RelNotes/1.6.2.2.txt[1.6.2.2],
 122  link:RelNotes/1.6.2.1.txt[1.6.2.1],
 123  link:RelNotes/1.6.2.txt[1.6.2].
 124
 125* link:v1.6.1.3/git.html[documentation for release 1.6.1.3]
 126
 127* release notes for
 128  link:RelNotes/1.6.1.3.txt[1.6.1.3],
 129  link:RelNotes/1.6.1.2.txt[1.6.1.2],
 130  link:RelNotes/1.6.1.1.txt[1.6.1.1],
 131  link:RelNotes/1.6.1.txt[1.6.1].
 132
 133* link:v1.6.0.6/git.html[documentation for release 1.6.0.6]
 134
 135* release notes for
 136  link:RelNotes/1.6.0.6.txt[1.6.0.6],
 137  link:RelNotes/1.6.0.5.txt[1.6.0.5],
 138  link:RelNotes/1.6.0.4.txt[1.6.0.4],
 139  link:RelNotes/1.6.0.3.txt[1.6.0.3],
 140  link:RelNotes/1.6.0.2.txt[1.6.0.2],
 141  link:RelNotes/1.6.0.1.txt[1.6.0.1],
 142  link:RelNotes/1.6.0.txt[1.6.0].
 143
 144* link:v1.5.6.6/git.html[documentation for release 1.5.6.6]
 145
 146* release notes for
 147  link:RelNotes/1.5.6.6.txt[1.5.6.6],
 148  link:RelNotes/1.5.6.5.txt[1.5.6.5],
 149  link:RelNotes/1.5.6.4.txt[1.5.6.4],
 150  link:RelNotes/1.5.6.3.txt[1.5.6.3],
 151  link:RelNotes/1.5.6.2.txt[1.5.6.2],
 152  link:RelNotes/1.5.6.1.txt[1.5.6.1],
 153  link:RelNotes/1.5.6.txt[1.5.6].
 154
 155* link:v1.5.5.6/git.html[documentation for release 1.5.5.6]
 156
 157* release notes for
 158  link:RelNotes/1.5.5.6.txt[1.5.5.6],
 159  link:RelNotes/1.5.5.5.txt[1.5.5.5],
 160  link:RelNotes/1.5.5.4.txt[1.5.5.4],
 161  link:RelNotes/1.5.5.3.txt[1.5.5.3],
 162  link:RelNotes/1.5.5.2.txt[1.5.5.2],
 163  link:RelNotes/1.5.5.1.txt[1.5.5.1],
 164  link:RelNotes/1.5.5.txt[1.5.5].
 165
 166* link:v1.5.4.7/git.html[documentation for release 1.5.4.7]
 167
 168* release notes for
 169  link:RelNotes/1.5.4.7.txt[1.5.4.7],
 170  link:RelNotes/1.5.4.6.txt[1.5.4.6],
 171  link:RelNotes/1.5.4.5.txt[1.5.4.5],
 172  link:RelNotes/1.5.4.4.txt[1.5.4.4],
 173  link:RelNotes/1.5.4.3.txt[1.5.4.3],
 174  link:RelNotes/1.5.4.2.txt[1.5.4.2],
 175  link:RelNotes/1.5.4.1.txt[1.5.4.1],
 176  link:RelNotes/1.5.4.txt[1.5.4].
 177
 178* link:v1.5.3.8/git.html[documentation for release 1.5.3.8]
 179
 180* release notes for
 181  link:RelNotes/1.5.3.8.txt[1.5.3.8],
 182  link:RelNotes/1.5.3.7.txt[1.5.3.7],
 183  link:RelNotes/1.5.3.6.txt[1.5.3.6],
 184  link:RelNotes/1.5.3.5.txt[1.5.3.5],
 185  link:RelNotes/1.5.3.4.txt[1.5.3.4],
 186  link:RelNotes/1.5.3.3.txt[1.5.3.3],
 187  link:RelNotes/1.5.3.2.txt[1.5.3.2],
 188  link:RelNotes/1.5.3.1.txt[1.5.3.1],
 189  link:RelNotes/1.5.3.txt[1.5.3].
 190
 191* link:v1.5.2.5/git.html[documentation for release 1.5.2.5]
 192
 193* release notes for
 194  link:RelNotes/1.5.2.5.txt[1.5.2.5],
 195  link:RelNotes/1.5.2.4.txt[1.5.2.4],
 196  link:RelNotes/1.5.2.3.txt[1.5.2.3],
 197  link:RelNotes/1.5.2.2.txt[1.5.2.2],
 198  link:RelNotes/1.5.2.1.txt[1.5.2.1],
 199  link:RelNotes/1.5.2.txt[1.5.2].
 200
 201* link:v1.5.1.6/git.html[documentation for release 1.5.1.6]
 202
 203* release notes for
 204  link:RelNotes/1.5.1.6.txt[1.5.1.6],
 205  link:RelNotes/1.5.1.5.txt[1.5.1.5],
 206  link:RelNotes/1.5.1.4.txt[1.5.1.4],
 207  link:RelNotes/1.5.1.3.txt[1.5.1.3],
 208  link:RelNotes/1.5.1.2.txt[1.5.1.2],
 209  link:RelNotes/1.5.1.1.txt[1.5.1.1],
 210  link:RelNotes/1.5.1.txt[1.5.1].
 211
 212* link:v1.5.0.7/git.html[documentation for release 1.5.0.7]
 213
 214* release notes for
 215  link:RelNotes/1.5.0.7.txt[1.5.0.7],
 216  link:RelNotes/1.5.0.6.txt[1.5.0.6],
 217  link:RelNotes/1.5.0.5.txt[1.5.0.5],
 218  link:RelNotes/1.5.0.3.txt[1.5.0.3],
 219  link:RelNotes/1.5.0.2.txt[1.5.0.2],
 220  link:RelNotes/1.5.0.1.txt[1.5.0.1],
 221  link:RelNotes/1.5.0.txt[1.5.0].
 222
 223* documentation for release link:v1.4.4.4/git.html[1.4.4.4],
 224  link:v1.3.3/git.html[1.3.3],
 225  link:v1.2.6/git.html[1.2.6],
 226  link:v1.0.13/git.html[1.0.13].
 227
 228============
 229
 230endif::stalenotes[]
 231
 232OPTIONS
 233-------
 234--version::
 235        Prints the git suite version that the 'git' program came from.
 236
 237--help::
 238        Prints the synopsis and a list of the most commonly used
 239        commands. If the option '--all' or '-a' is given then all
 240        available commands are printed. If a git command is named this
 241        option will bring up the manual page for that command.
 242+
 243Other options are available to control how the manual page is
 244displayed. See linkgit:git-help[1] for more information,
 245because `git --help ...` is converted internally into `git
 246help ...`.
 247
 248-c <name>=<value>::
 249        Pass a configuration parameter to the command. The value
 250        given will override values from configuration files.
 251        The <name> is expected in the same format as listed by
 252        'git config' (subkeys separated by dots).
 253
 254--exec-path::
 255        Path to wherever your core git programs are installed.
 256        This can also be controlled by setting the GIT_EXEC_PATH
 257        environment variable. If no path is given, 'git' will print
 258        the current setting and then exit.
 259
 260--html-path::
 261        Print the path to wherever your git HTML documentation is installed
 262        and exit.
 263
 264-p::
 265--paginate::
 266        Pipe all output into 'less' (or if set, $PAGER) if standard
 267        output is a terminal.  This overrides the `pager.<cmd>`
 268        configuration options (see the "Configuration Mechanism" section
 269        below).
 270
 271--no-pager::
 272        Do not pipe git output into a pager.
 273
 274--git-dir=<path>::
 275        Set the path to the repository. This can also be controlled by
 276        setting the GIT_DIR environment variable. It can be an absolute
 277        path or relative path to current working directory.
 278
 279--work-tree=<path>::
 280        Set the path to the working tree.  The value will not be
 281        used in combination with repositories found automatically in
 282        a .git directory (i.e. $GIT_DIR is not set).
 283        This can also be controlled by setting the GIT_WORK_TREE
 284        environment variable and the core.worktree configuration
 285        variable. It can be an absolute path or relative path to
 286        the directory specified by --git-dir or GIT_DIR.
 287        Note: If --git-dir or GIT_DIR are specified but none of
 288        --work-tree, GIT_WORK_TREE and core.worktree is specified,
 289        the current working directory is regarded as the top directory
 290        of your working tree.
 291
 292--bare::
 293        Treat the repository as a bare repository.  If GIT_DIR
 294        environment is not set, it is set to the current working
 295        directory.
 296
 297--no-replace-objects::
 298        Do not use replacement refs to replace git objects. See
 299        linkgit:git-replace[1] for more information.
 300
 301
 302FURTHER DOCUMENTATION
 303---------------------
 304
 305See the references above to get started using git.  The following is
 306probably more detail than necessary for a first-time user.
 307
 308The link:user-manual.html#git-concepts[git concepts chapter of the
 309user-manual] and linkgit:gitcore-tutorial[7] both provide
 310introductions to the underlying git architecture.
 311
 312See linkgit:gitworkflows[7] for an overview of recommended workflows.
 313
 314See also the link:howto-index.html[howto] documents for some useful
 315examples.
 316
 317The internals are documented in the
 318link:technical/api-index.html[GIT API documentation].
 319
 320GIT COMMANDS
 321------------
 322
 323We divide git into high level ("porcelain") commands and low level
 324("plumbing") commands.
 325
 326High-level commands (porcelain)
 327-------------------------------
 328
 329We separate the porcelain commands into the main commands and some
 330ancillary user utilities.
 331
 332Main porcelain commands
 333~~~~~~~~~~~~~~~~~~~~~~~
 334
 335include::cmds-mainporcelain.txt[]
 336
 337Ancillary Commands
 338~~~~~~~~~~~~~~~~~~
 339Manipulators:
 340
 341include::cmds-ancillarymanipulators.txt[]
 342
 343Interrogators:
 344
 345include::cmds-ancillaryinterrogators.txt[]
 346
 347
 348Interacting with Others
 349~~~~~~~~~~~~~~~~~~~~~~~
 350
 351These commands are to interact with foreign SCM and with other
 352people via patch over e-mail.
 353
 354include::cmds-foreignscminterface.txt[]
 355
 356
 357Low-level commands (plumbing)
 358-----------------------------
 359
 360Although git includes its
 361own porcelain layer, its low-level commands are sufficient to support
 362development of alternative porcelains.  Developers of such porcelains
 363might start by reading about linkgit:git-update-index[1] and
 364linkgit:git-read-tree[1].
 365
 366The interface (input, output, set of options and the semantics)
 367to these low-level commands are meant to be a lot more stable
 368than Porcelain level commands, because these commands are
 369primarily for scripted use.  The interface to Porcelain commands
 370on the other hand are subject to change in order to improve the
 371end user experience.
 372
 373The following description divides
 374the low-level commands into commands that manipulate objects (in
 375the repository, index, and working tree), commands that interrogate and
 376compare objects, and commands that move objects and references between
 377repositories.
 378
 379
 380Manipulation commands
 381~~~~~~~~~~~~~~~~~~~~~
 382
 383include::cmds-plumbingmanipulators.txt[]
 384
 385
 386Interrogation commands
 387~~~~~~~~~~~~~~~~~~~~~~
 388
 389include::cmds-plumbinginterrogators.txt[]
 390
 391In general, the interrogate commands do not touch the files in
 392the working tree.
 393
 394
 395Synching repositories
 396~~~~~~~~~~~~~~~~~~~~~
 397
 398include::cmds-synchingrepositories.txt[]
 399
 400The following are helper commands used by the above; end users
 401typically do not use them directly.
 402
 403include::cmds-synchelpers.txt[]
 404
 405
 406Internal helper commands
 407~~~~~~~~~~~~~~~~~~~~~~~~
 408
 409These are internal helper commands used by other commands; end
 410users typically do not use them directly.
 411
 412include::cmds-purehelpers.txt[]
 413
 414
 415Configuration Mechanism
 416-----------------------
 417
 418Starting from 0.99.9 (actually mid 0.99.8.GIT), `.git/config` file
 419is used to hold per-repository configuration options.  It is a
 420simple text file modeled after `.ini` format familiar to some
 421people.  Here is an example:
 422
 423------------
 424#
 425# A '#' or ';' character indicates a comment.
 426#
 427
 428; core variables
 429[core]
 430        ; Don't trust file modes
 431        filemode = false
 432
 433; user identity
 434[user]
 435        name = "Junio C Hamano"
 436        email = "junkio@twinsun.com"
 437
 438------------
 439
 440Various commands read from the configuration file and adjust
 441their operation accordingly.  See linkgit:git-config[1] for a
 442list.
 443
 444
 445Identifier Terminology
 446----------------------
 447<object>::
 448        Indicates the object name for any type of object.
 449
 450<blob>::
 451        Indicates a blob object name.
 452
 453<tree>::
 454        Indicates a tree object name.
 455
 456<commit>::
 457        Indicates a commit object name.
 458
 459<tree-ish>::
 460        Indicates a tree, commit or tag object name.  A
 461        command that takes a <tree-ish> argument ultimately wants to
 462        operate on a <tree> object but automatically dereferences
 463        <commit> and <tag> objects that point at a <tree>.
 464
 465<commit-ish>::
 466        Indicates a commit or tag object name.  A
 467        command that takes a <commit-ish> argument ultimately wants to
 468        operate on a <commit> object but automatically dereferences
 469        <tag> objects that point at a <commit>.
 470
 471<type>::
 472        Indicates that an object type is required.
 473        Currently one of: `blob`, `tree`, `commit`, or `tag`.
 474
 475<file>::
 476        Indicates a filename - almost always relative to the
 477        root of the tree structure `GIT_INDEX_FILE` describes.
 478
 479Symbolic Identifiers
 480--------------------
 481Any git command accepting any <object> can also use the following
 482symbolic notation:
 483
 484HEAD::
 485        indicates the head of the current branch (i.e. the
 486        contents of `$GIT_DIR/HEAD`).
 487
 488<tag>::
 489        a valid tag 'name'
 490        (i.e. the contents of `$GIT_DIR/refs/tags/<tag>`).
 491
 492<head>::
 493        a valid head 'name'
 494        (i.e. the contents of `$GIT_DIR/refs/heads/<head>`).
 495
 496For a more complete list of ways to spell object names, see
 497"SPECIFYING REVISIONS" section in linkgit:gitrevisions[1].
 498
 499
 500File/Directory Structure
 501------------------------
 502
 503Please see the linkgit:gitrepository-layout[5] document.
 504
 505Read linkgit:githooks[5] for more details about each hook.
 506
 507Higher level SCMs may provide and manage additional information in the
 508`$GIT_DIR`.
 509
 510
 511Terminology
 512-----------
 513Please see linkgit:gitglossary[7].
 514
 515
 516Environment Variables
 517---------------------
 518Various git commands use the following environment variables:
 519
 520The git Repository
 521~~~~~~~~~~~~~~~~~~
 522These environment variables apply to 'all' core git commands. Nb: it
 523is worth noting that they may be used/overridden by SCMS sitting above
 524git so take care if using Cogito etc.
 525
 526'GIT_INDEX_FILE'::
 527        This environment allows the specification of an alternate
 528        index file. If not specified, the default of `$GIT_DIR/index`
 529        is used.
 530
 531'GIT_OBJECT_DIRECTORY'::
 532        If the object storage directory is specified via this
 533        environment variable then the sha1 directories are created
 534        underneath - otherwise the default `$GIT_DIR/objects`
 535        directory is used.
 536
 537'GIT_ALTERNATE_OBJECT_DIRECTORIES'::
 538        Due to the immutable nature of git objects, old objects can be
 539        archived into shared, read-only directories. This variable
 540        specifies a ":" separated (on Windows ";" separated) list
 541        of git object directories which can be used to search for git
 542        objects. New objects will not be written to these directories.
 543
 544'GIT_DIR'::
 545        If the 'GIT_DIR' environment variable is set then it
 546        specifies a path to use instead of the default `.git`
 547        for the base of the repository.
 548
 549'GIT_WORK_TREE'::
 550        Set the path to the working tree.  The value will not be
 551        used in combination with repositories found automatically in
 552        a .git directory (i.e. $GIT_DIR is not set).
 553        This can also be controlled by the '--work-tree' command line
 554        option and the core.worktree configuration variable.
 555
 556'GIT_CEILING_DIRECTORIES'::
 557        This should be a colon-separated list of absolute paths.
 558        If set, it is a list of directories that git should not chdir
 559        up into while looking for a repository directory.
 560        It will not exclude the current working directory or
 561        a GIT_DIR set on the command line or in the environment.
 562        (Useful for excluding slow-loading network directories.)
 563
 564'GIT_DISCOVERY_ACROSS_FILESYSTEM'::
 565        When run in a directory that does not have ".git" repository
 566        directory, git tries to find such a directory in the parent
 567        directories to find the top of the working tree, but by default it
 568        does not cross filesystem boundaries.  This environment variable
 569        can be set to true to tell git not to stop at filesystem
 570        boundaries.  Like 'GIT_CEILING_DIRECTORIES', this will not affect
 571        an explicit repository directory set via 'GIT_DIR' or on the
 572        command line.
 573
 574git Commits
 575~~~~~~~~~~~
 576'GIT_AUTHOR_NAME'::
 577'GIT_AUTHOR_EMAIL'::
 578'GIT_AUTHOR_DATE'::
 579'GIT_COMMITTER_NAME'::
 580'GIT_COMMITTER_EMAIL'::
 581'GIT_COMMITTER_DATE'::
 582'EMAIL'::
 583        see linkgit:git-commit-tree[1]
 584
 585git Diffs
 586~~~~~~~~~
 587'GIT_DIFF_OPTS'::
 588        Only valid setting is "--unified=??" or "-u??" to set the
 589        number of context lines shown when a unified diff is created.
 590        This takes precedence over any "-U" or "--unified" option
 591        value passed on the git diff command line.
 592
 593'GIT_EXTERNAL_DIFF'::
 594        When the environment variable 'GIT_EXTERNAL_DIFF' is set, the
 595        program named by it is called, instead of the diff invocation
 596        described above.  For a path that is added, removed, or modified,
 597        'GIT_EXTERNAL_DIFF' is called with 7 parameters:
 598
 599        path old-file old-hex old-mode new-file new-hex new-mode
 600+
 601where:
 602
 603        <old|new>-file:: are files GIT_EXTERNAL_DIFF can use to read the
 604                         contents of <old|new>,
 605        <old|new>-hex:: are the 40-hexdigit SHA1 hashes,
 606        <old|new>-mode:: are the octal representation of the file modes.
 607
 608+
 609The file parameters can point at the user's working file
 610(e.g. `new-file` in "git-diff-files"), `/dev/null` (e.g. `old-file`
 611when a new file is added), or a temporary file (e.g. `old-file` in the
 612index).  'GIT_EXTERNAL_DIFF' should not worry about unlinking the
 613temporary file --- it is removed when 'GIT_EXTERNAL_DIFF' exits.
 614+
 615For a path that is unmerged, 'GIT_EXTERNAL_DIFF' is called with 1
 616parameter, <path>.
 617
 618other
 619~~~~~
 620'GIT_MERGE_VERBOSITY'::
 621        A number controlling the amount of output shown by
 622        the recursive merge strategy.  Overrides merge.verbosity.
 623        See linkgit:git-merge[1]
 624
 625'GIT_PAGER'::
 626        This environment variable overrides `$PAGER`. If it is set
 627        to an empty string or to the value "cat", git will not launch
 628        a pager.  See also the `core.pager` option in
 629        linkgit:git-config[1].
 630
 631'GIT_SSH'::
 632        If this environment variable is set then 'git fetch'
 633        and 'git push' will use this command instead
 634        of 'ssh' when they need to connect to a remote system.
 635        The '$GIT_SSH' command will be given exactly two arguments:
 636        the 'username@host' (or just 'host') from the URL and the
 637        shell command to execute on that remote system.
 638+
 639To pass options to the program that you want to list in GIT_SSH
 640you will need to wrap the program and options into a shell script,
 641then set GIT_SSH to refer to the shell script.
 642+
 643Usually it is easier to configure any desired options through your
 644personal `.ssh/config` file.  Please consult your ssh documentation
 645for further details.
 646
 647'GIT_ASKPASS'::
 648        If this environment variable is set, then git commands which need to
 649        acquire passwords or passphrases (e.g. for HTTP or IMAP authentication)
 650        will call this program with a suitable prompt as command line argument
 651        and read the password from its STDOUT. See also the 'core.askpass'
 652        option in linkgit:git-config[1].
 653
 654'GIT_FLUSH'::
 655        If this environment variable is set to "1", then commands such
 656        as 'git blame' (in incremental mode), 'git rev-list', 'git log',
 657        and 'git whatchanged' will force a flush of the output stream
 658        after each commit-oriented record have been flushed.   If this
 659        variable is set to "0", the output of these commands will be done
 660        using completely buffered I/O.   If this environment variable is
 661        not set, git will choose buffered or record-oriented flushing
 662        based on whether stdout appears to be redirected to a file or not.
 663
 664'GIT_TRACE'::
 665        If this variable is set to "1", "2" or "true" (comparison
 666        is case insensitive), git will print `trace:` messages on
 667        stderr telling about alias expansion, built-in command
 668        execution and external command execution.
 669        If this variable is set to an integer value greater than 1
 670        and lower than 10 (strictly) then git will interpret this
 671        value as an open file descriptor and will try to write the
 672        trace messages into this file descriptor.
 673        Alternatively, if this variable is set to an absolute path
 674        (starting with a '/' character), git will interpret this
 675        as a file path and will try to write the trace messages
 676        into it.
 677
 678Discussion[[Discussion]]
 679------------------------
 680
 681More detail on the following is available from the
 682link:user-manual.html#git-concepts[git concepts chapter of the
 683user-manual] and linkgit:gitcore-tutorial[7].
 684
 685A git project normally consists of a working directory with a ".git"
 686subdirectory at the top level.  The .git directory contains, among other
 687things, a compressed object database representing the complete history
 688of the project, an "index" file which links that history to the current
 689contents of the working tree, and named pointers into that history such
 690as tags and branch heads.
 691
 692The object database contains objects of three main types: blobs, which
 693hold file data; trees, which point to blobs and other trees to build up
 694directory hierarchies; and commits, which each reference a single tree
 695and some number of parent commits.
 696
 697The commit, equivalent to what other systems call a "changeset" or
 698"version", represents a step in the project's history, and each parent
 699represents an immediately preceding step.  Commits with more than one
 700parent represent merges of independent lines of development.
 701
 702All objects are named by the SHA1 hash of their contents, normally
 703written as a string of 40 hex digits.  Such names are globally unique.
 704The entire history leading up to a commit can be vouched for by signing
 705just that commit.  A fourth object type, the tag, is provided for this
 706purpose.
 707
 708When first created, objects are stored in individual files, but for
 709efficiency may later be compressed together into "pack files".
 710
 711Named pointers called refs mark interesting points in history.  A ref
 712may contain the SHA1 name of an object or the name of another ref.  Refs
 713with names beginning `ref/head/` contain the SHA1 name of the most
 714recent commit (or "head") of a branch under development.  SHA1 names of
 715tags of interest are stored under `ref/tags/`.  A special ref named
 716`HEAD` contains the name of the currently checked-out branch.
 717
 718The index file is initialized with a list of all paths and, for each
 719path, a blob object and a set of attributes.  The blob object represents
 720the contents of the file as of the head of the current branch.  The
 721attributes (last modified time, size, etc.) are taken from the
 722corresponding file in the working tree.  Subsequent changes to the
 723working tree can be found by comparing these attributes.  The index may
 724be updated with new content, and new commits may be created from the
 725content stored in the index.
 726
 727The index is also capable of storing multiple entries (called "stages")
 728for a given pathname.  These stages are used to hold the various
 729unmerged version of a file when a merge is in progress.
 730
 731Authors
 732-------
 733* git's founding father is Linus Torvalds <torvalds@osdl.org>.
 734* The current git nurse is Junio C Hamano <gitster@pobox.com>.
 735* The git potty was written by Andreas Ericsson <ae@op5.se>.
 736* General upbringing is handled by the git-list <git@vger.kernel.org>.
 737
 738Documentation
 739--------------
 740The documentation for git suite was started by David Greaves
 741<david@dgreaves.com>, and later enhanced greatly by the
 742contributors on the git-list <git@vger.kernel.org>.
 743
 744Reporting Bugs
 745--------------
 746
 747Report bugs to the Git mailing list <git@vger.kernel.org> where the
 748development and maintenance is primarily done.  You do not have to be
 749subscribed to the list to send a message there.
 750
 751SEE ALSO
 752--------
 753linkgit:gittutorial[7], linkgit:gittutorial-2[7],
 754link:everyday.html[Everyday Git], linkgit:gitcvs-migration[7],
 755linkgit:gitglossary[7], linkgit:gitcore-tutorial[7],
 756linkgit:gitcli[7], link:user-manual.html[The Git User's Manual],
 757linkgit:gitworkflows[7]
 758
 759GIT
 760---
 761Part of the linkgit:git[1] suite