c05efdaa647816c7e1e306fa62aed90c80202b58
   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    [--help] COMMAND [ARGS]
  16
  17DESCRIPTION
  18-----------
  19Git is a fast, scalable, distributed revision control system with an
  20unusually rich command set that provides both high-level operations
  21and full access to internals.
  22
  23See linkgit:gittutorial[7] to get started, then see
  24link:everyday.html[Everyday Git] for a useful minimum set of commands, and
  25"man git-commandname" for documentation of each command.  CVS users may
  26also want to read linkgit:gitcvs-migration[7].  See
  27the link:user-manual.html[Git User's Manual] for a more in-depth
  28introduction.
  29
  30The COMMAND is either a name of a Git command (see below) or an alias
  31as defined in the configuration file (see linkgit:git-config[1]).
  32
  33Formatted and hyperlinked version of the latest git
  34documentation can be viewed at
  35`http://www.kernel.org/pub/software/scm/git/docs/`.
  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:v1.6.6/git.html[documentation for release 1.6.6]
  47
  48* release notes for
  49  link:RelNotes-1.6.6.txt[1.6.6].
  50
  51* link:v1.6.5.8/git.html[documentation for release 1.6.5.8]
  52
  53* release notes for
  54  link:RelNotes-1.6.5.8.txt[1.6.5.8],
  55  link:RelNotes-1.6.5.7.txt[1.6.5.7],
  56  link:RelNotes-1.6.5.6.txt[1.6.5.6],
  57  link:RelNotes-1.6.5.5.txt[1.6.5.5],
  58  link:RelNotes-1.6.5.4.txt[1.6.5.4],
  59  link:RelNotes-1.6.5.3.txt[1.6.5.3],
  60  link:RelNotes-1.6.5.2.txt[1.6.5.2],
  61  link:RelNotes-1.6.5.1.txt[1.6.5.1],
  62  link:RelNotes-1.6.5.txt[1.6.5].
  63
  64* link:v1.6.4.4/git.html[documentation for release 1.6.4.4]
  65
  66* release notes for
  67  link:RelNotes-1.6.4.4.txt[1.6.4.4],
  68  link:RelNotes-1.6.4.3.txt[1.6.4.3],
  69  link:RelNotes-1.6.4.2.txt[1.6.4.2],
  70  link:RelNotes-1.6.4.1.txt[1.6.4.1],
  71  link:RelNotes-1.6.4.txt[1.6.4].
  72
  73* link:v1.6.3.4/git.html[documentation for release 1.6.3.4]
  74
  75* release notes for
  76  link:RelNotes-1.6.3.4.txt[1.6.3.4],
  77  link:RelNotes-1.6.3.3.txt[1.6.3.3],
  78  link:RelNotes-1.6.3.2.txt[1.6.3.2],
  79  link:RelNotes-1.6.3.1.txt[1.6.3.1],
  80  link:RelNotes-1.6.3.txt[1.6.3].
  81
  82* release notes for
  83  link:RelNotes-1.6.2.5.txt[1.6.2.5],
  84  link:RelNotes-1.6.2.4.txt[1.6.2.4],
  85  link:RelNotes-1.6.2.3.txt[1.6.2.3],
  86  link:RelNotes-1.6.2.2.txt[1.6.2.2],
  87  link:RelNotes-1.6.2.1.txt[1.6.2.1],
  88  link:RelNotes-1.6.2.txt[1.6.2].
  89
  90* link:v1.6.1.3/git.html[documentation for release 1.6.1.3]
  91
  92* release notes for
  93  link:RelNotes-1.6.1.3.txt[1.6.1.3],
  94  link:RelNotes-1.6.1.2.txt[1.6.1.2],
  95  link:RelNotes-1.6.1.1.txt[1.6.1.1],
  96  link:RelNotes-1.6.1.txt[1.6.1].
  97
  98* link:v1.6.0.6/git.html[documentation for release 1.6.0.6]
  99
 100* release notes for
 101  link:RelNotes-1.6.0.6.txt[1.6.0.6],
 102  link:RelNotes-1.6.0.5.txt[1.6.0.5],
 103  link:RelNotes-1.6.0.4.txt[1.6.0.4],
 104  link:RelNotes-1.6.0.3.txt[1.6.0.3],
 105  link:RelNotes-1.6.0.2.txt[1.6.0.2],
 106  link:RelNotes-1.6.0.1.txt[1.6.0.1],
 107  link:RelNotes-1.6.0.txt[1.6.0].
 108
 109* link:v1.5.6.6/git.html[documentation for release 1.5.6.6]
 110
 111* release notes for
 112  link:RelNotes-1.5.6.6.txt[1.5.6.6],
 113  link:RelNotes-1.5.6.5.txt[1.5.6.5],
 114  link:RelNotes-1.5.6.4.txt[1.5.6.4],
 115  link:RelNotes-1.5.6.3.txt[1.5.6.3],
 116  link:RelNotes-1.5.6.2.txt[1.5.6.2],
 117  link:RelNotes-1.5.6.1.txt[1.5.6.1],
 118  link:RelNotes-1.5.6.txt[1.5.6].
 119
 120* link:v1.5.5.6/git.html[documentation for release 1.5.5.6]
 121
 122* release notes for
 123  link:RelNotes-1.5.5.6.txt[1.5.5.6],
 124  link:RelNotes-1.5.5.5.txt[1.5.5.5],
 125  link:RelNotes-1.5.5.4.txt[1.5.5.4],
 126  link:RelNotes-1.5.5.3.txt[1.5.5.3],
 127  link:RelNotes-1.5.5.2.txt[1.5.5.2],
 128  link:RelNotes-1.5.5.1.txt[1.5.5.1],
 129  link:RelNotes-1.5.5.txt[1.5.5].
 130
 131* link:v1.5.4.7/git.html[documentation for release 1.5.4.7]
 132
 133* release notes for
 134  link:RelNotes-1.5.4.7.txt[1.5.4.7],
 135  link:RelNotes-1.5.4.6.txt[1.5.4.6],
 136  link:RelNotes-1.5.4.5.txt[1.5.4.5],
 137  link:RelNotes-1.5.4.4.txt[1.5.4.4],
 138  link:RelNotes-1.5.4.3.txt[1.5.4.3],
 139  link:RelNotes-1.5.4.2.txt[1.5.4.2],
 140  link:RelNotes-1.5.4.1.txt[1.5.4.1],
 141  link:RelNotes-1.5.4.txt[1.5.4].
 142
 143* link:v1.5.3.8/git.html[documentation for release 1.5.3.8]
 144
 145* release notes for
 146  link:RelNotes-1.5.3.8.txt[1.5.3.8],
 147  link:RelNotes-1.5.3.7.txt[1.5.3.7],
 148  link:RelNotes-1.5.3.6.txt[1.5.3.6],
 149  link:RelNotes-1.5.3.5.txt[1.5.3.5],
 150  link:RelNotes-1.5.3.4.txt[1.5.3.4],
 151  link:RelNotes-1.5.3.3.txt[1.5.3.3],
 152  link:RelNotes-1.5.3.2.txt[1.5.3.2],
 153  link:RelNotes-1.5.3.1.txt[1.5.3.1],
 154  link:RelNotes-1.5.3.txt[1.5.3].
 155
 156* link:v1.5.2.5/git.html[documentation for release 1.5.2.5]
 157
 158* release notes for
 159  link:RelNotes-1.5.2.5.txt[1.5.2.5],
 160  link:RelNotes-1.5.2.4.txt[1.5.2.4],
 161  link:RelNotes-1.5.2.3.txt[1.5.2.3],
 162  link:RelNotes-1.5.2.2.txt[1.5.2.2],
 163  link:RelNotes-1.5.2.1.txt[1.5.2.1],
 164  link:RelNotes-1.5.2.txt[1.5.2].
 165
 166* link:v1.5.1.6/git.html[documentation for release 1.5.1.6]
 167
 168* release notes for
 169  link:RelNotes-1.5.1.6.txt[1.5.1.6],
 170  link:RelNotes-1.5.1.5.txt[1.5.1.5],
 171  link:RelNotes-1.5.1.4.txt[1.5.1.4],
 172  link:RelNotes-1.5.1.3.txt[1.5.1.3],
 173  link:RelNotes-1.5.1.2.txt[1.5.1.2],
 174  link:RelNotes-1.5.1.1.txt[1.5.1.1],
 175  link:RelNotes-1.5.1.txt[1.5.1].
 176
 177* link:v1.5.0.7/git.html[documentation for release 1.5.0.7]
 178
 179* release notes for
 180  link:RelNotes-1.5.0.7.txt[1.5.0.7],
 181  link:RelNotes-1.5.0.6.txt[1.5.0.6],
 182  link:RelNotes-1.5.0.5.txt[1.5.0.5],
 183  link:RelNotes-1.5.0.3.txt[1.5.0.3],
 184  link:RelNotes-1.5.0.2.txt[1.5.0.2],
 185  link:RelNotes-1.5.0.1.txt[1.5.0.1],
 186  link:RelNotes-1.5.0.txt[1.5.0].
 187
 188* documentation for release link:v1.4.4.4/git.html[1.4.4.4],
 189  link:v1.3.3/git.html[1.3.3],
 190  link:v1.2.6/git.html[1.2.6],
 191  link:v1.0.13/git.html[1.0.13].
 192
 193============
 194
 195endif::stalenotes[]
 196
 197OPTIONS
 198-------
 199--version::
 200        Prints the git suite version that the 'git' program came from.
 201
 202--help::
 203        Prints the synopsis and a list of the most commonly used
 204        commands. If the option '--all' or '-a' is given then all
 205        available commands are printed. If a git command is named this
 206        option will bring up the manual page for that command.
 207+
 208Other options are available to control how the manual page is
 209displayed. See linkgit:git-help[1] for more information,
 210because `git --help ...` is converted internally into `git
 211help ...`.
 212
 213--exec-path::
 214        Path to wherever your core git programs are installed.
 215        This can also be controlled by setting the GIT_EXEC_PATH
 216        environment variable. If no path is given, 'git' will print
 217        the current setting and then exit.
 218
 219--html-path::
 220        Print the path to wherever your git HTML documentation is installed
 221        and exit.
 222
 223-p::
 224--paginate::
 225        Pipe all output into 'less' (or if set, $PAGER).
 226
 227--no-pager::
 228        Do not pipe git output into a pager.
 229
 230--git-dir=<path>::
 231        Set the path to the repository. This can also be controlled by
 232        setting the GIT_DIR environment variable. It can be an absolute
 233        path or relative path to current working directory.
 234
 235--work-tree=<path>::
 236        Set the path to the working tree.  The value will not be
 237        used in combination with repositories found automatically in
 238        a .git directory (i.e. $GIT_DIR is not set).
 239        This can also be controlled by setting the GIT_WORK_TREE
 240        environment variable and the core.worktree configuration
 241        variable. It can be an absolute path or relative path to
 242        the directory specified by --git-dir or GIT_DIR.
 243        Note: If --git-dir or GIT_DIR are specified but none of
 244        --work-tree, GIT_WORK_TREE and core.worktree is specified,
 245        the current working directory is regarded as the top directory
 246        of your working tree.
 247
 248--bare::
 249        Treat the repository as a bare repository.  If GIT_DIR
 250        environment is not set, it is set to the current working
 251        directory.
 252
 253--no-replace-objects::
 254        Do not use replacement refs to replace git objects. See
 255        linkgit:git-replace[1] for more information.
 256
 257
 258FURTHER DOCUMENTATION
 259---------------------
 260
 261See the references above to get started using git.  The following is
 262probably more detail than necessary for a first-time user.
 263
 264The link:user-manual.html#git-concepts[git concepts chapter of the
 265user-manual] and linkgit:gitcore-tutorial[7] both provide
 266introductions to the underlying git architecture.
 267
 268See linkgit:gitworkflows[7] for an overview of recommended workflows.
 269
 270See also the link:howto-index.html[howto] documents for some useful
 271examples.
 272
 273The internals are documented in the
 274link:technical/api-index.html[GIT API documentation].
 275
 276GIT COMMANDS
 277------------
 278
 279We divide git into high level ("porcelain") commands and low level
 280("plumbing") commands.
 281
 282High-level commands (porcelain)
 283-------------------------------
 284
 285We separate the porcelain commands into the main commands and some
 286ancillary user utilities.
 287
 288Main porcelain commands
 289~~~~~~~~~~~~~~~~~~~~~~~
 290
 291include::cmds-mainporcelain.txt[]
 292
 293Ancillary Commands
 294~~~~~~~~~~~~~~~~~~
 295Manipulators:
 296
 297include::cmds-ancillarymanipulators.txt[]
 298
 299Interrogators:
 300
 301include::cmds-ancillaryinterrogators.txt[]
 302
 303
 304Interacting with Others
 305~~~~~~~~~~~~~~~~~~~~~~~
 306
 307These commands are to interact with foreign SCM and with other
 308people via patch over e-mail.
 309
 310include::cmds-foreignscminterface.txt[]
 311
 312
 313Low-level commands (plumbing)
 314-----------------------------
 315
 316Although git includes its
 317own porcelain layer, its low-level commands are sufficient to support
 318development of alternative porcelains.  Developers of such porcelains
 319might start by reading about linkgit:git-update-index[1] and
 320linkgit:git-read-tree[1].
 321
 322The interface (input, output, set of options and the semantics)
 323to these low-level commands are meant to be a lot more stable
 324than Porcelain level commands, because these commands are
 325primarily for scripted use.  The interface to Porcelain commands
 326on the other hand are subject to change in order to improve the
 327end user experience.
 328
 329The following description divides
 330the low-level commands into commands that manipulate objects (in
 331the repository, index, and working tree), commands that interrogate and
 332compare objects, and commands that move objects and references between
 333repositories.
 334
 335
 336Manipulation commands
 337~~~~~~~~~~~~~~~~~~~~~
 338
 339include::cmds-plumbingmanipulators.txt[]
 340
 341
 342Interrogation commands
 343~~~~~~~~~~~~~~~~~~~~~~
 344
 345include::cmds-plumbinginterrogators.txt[]
 346
 347In general, the interrogate commands do not touch the files in
 348the working tree.
 349
 350
 351Synching repositories
 352~~~~~~~~~~~~~~~~~~~~~
 353
 354include::cmds-synchingrepositories.txt[]
 355
 356The following are helper commands used by the above; end users
 357typically do not use them directly.
 358
 359include::cmds-synchelpers.txt[]
 360
 361
 362Internal helper commands
 363~~~~~~~~~~~~~~~~~~~~~~~~
 364
 365These are internal helper commands used by other commands; end
 366users typically do not use them directly.
 367
 368include::cmds-purehelpers.txt[]
 369
 370
 371Configuration Mechanism
 372-----------------------
 373
 374Starting from 0.99.9 (actually mid 0.99.8.GIT), `.git/config` file
 375is used to hold per-repository configuration options.  It is a
 376simple text file modeled after `.ini` format familiar to some
 377people.  Here is an example:
 378
 379------------
 380#
 381# A '#' or ';' character indicates a comment.
 382#
 383
 384; core variables
 385[core]
 386        ; Don't trust file modes
 387        filemode = false
 388
 389; user identity
 390[user]
 391        name = "Junio C Hamano"
 392        email = "junkio@twinsun.com"
 393
 394------------
 395
 396Various commands read from the configuration file and adjust
 397their operation accordingly.
 398
 399
 400Identifier Terminology
 401----------------------
 402<object>::
 403        Indicates the object name for any type of object.
 404
 405<blob>::
 406        Indicates a blob object name.
 407
 408<tree>::
 409        Indicates a tree object name.
 410
 411<commit>::
 412        Indicates a commit object name.
 413
 414<tree-ish>::
 415        Indicates a tree, commit or tag object name.  A
 416        command that takes a <tree-ish> argument ultimately wants to
 417        operate on a <tree> object but automatically dereferences
 418        <commit> and <tag> objects that point at a <tree>.
 419
 420<commit-ish>::
 421        Indicates a commit or tag object name.  A
 422        command that takes a <commit-ish> argument ultimately wants to
 423        operate on a <commit> object but automatically dereferences
 424        <tag> objects that point at a <commit>.
 425
 426<type>::
 427        Indicates that an object type is required.
 428        Currently one of: `blob`, `tree`, `commit`, or `tag`.
 429
 430<file>::
 431        Indicates a filename - almost always relative to the
 432        root of the tree structure `GIT_INDEX_FILE` describes.
 433
 434Symbolic Identifiers
 435--------------------
 436Any git command accepting any <object> can also use the following
 437symbolic notation:
 438
 439HEAD::
 440        indicates the head of the current branch (i.e. the
 441        contents of `$GIT_DIR/HEAD`).
 442
 443<tag>::
 444        a valid tag 'name'
 445        (i.e. the contents of `$GIT_DIR/refs/tags/<tag>`).
 446
 447<head>::
 448        a valid head 'name'
 449        (i.e. the contents of `$GIT_DIR/refs/heads/<head>`).
 450
 451For a more complete list of ways to spell object names, see
 452"SPECIFYING REVISIONS" section in linkgit:git-rev-parse[1].
 453
 454
 455File/Directory Structure
 456------------------------
 457
 458Please see the linkgit:gitrepository-layout[5] document.
 459
 460Read linkgit:githooks[5] for more details about each hook.
 461
 462Higher level SCMs may provide and manage additional information in the
 463`$GIT_DIR`.
 464
 465
 466Terminology
 467-----------
 468Please see linkgit:gitglossary[7].
 469
 470
 471Environment Variables
 472---------------------
 473Various git commands use the following environment variables:
 474
 475The git Repository
 476~~~~~~~~~~~~~~~~~~
 477These environment variables apply to 'all' core git commands. Nb: it
 478is worth noting that they may be used/overridden by SCMS sitting above
 479git so take care if using Cogito etc.
 480
 481'GIT_INDEX_FILE'::
 482        This environment allows the specification of an alternate
 483        index file. If not specified, the default of `$GIT_DIR/index`
 484        is used.
 485
 486'GIT_OBJECT_DIRECTORY'::
 487        If the object storage directory is specified via this
 488        environment variable then the sha1 directories are created
 489        underneath - otherwise the default `$GIT_DIR/objects`
 490        directory is used.
 491
 492'GIT_ALTERNATE_OBJECT_DIRECTORIES'::
 493        Due to the immutable nature of git objects, old objects can be
 494        archived into shared, read-only directories. This variable
 495        specifies a ":" separated (on Windows ";" separated) list
 496        of git object directories which can be used to search for git
 497        objects. New objects will not be written to these directories.
 498
 499'GIT_DIR'::
 500        If the 'GIT_DIR' environment variable is set then it
 501        specifies a path to use instead of the default `.git`
 502        for the base of the repository.
 503
 504'GIT_WORK_TREE'::
 505        Set the path to the working tree.  The value will not be
 506        used in combination with repositories found automatically in
 507        a .git directory (i.e. $GIT_DIR is not set).
 508        This can also be controlled by the '--work-tree' command line
 509        option and the core.worktree configuration variable.
 510
 511'GIT_CEILING_DIRECTORIES'::
 512        This should be a colon-separated list of absolute paths.
 513        If set, it is a list of directories that git should not chdir
 514        up into while looking for a repository directory.
 515        It will not exclude the current working directory or
 516        a GIT_DIR set on the command line or in the environment.
 517        (Useful for excluding slow-loading network directories.)
 518
 519git Commits
 520~~~~~~~~~~~
 521'GIT_AUTHOR_NAME'::
 522'GIT_AUTHOR_EMAIL'::
 523'GIT_AUTHOR_DATE'::
 524'GIT_COMMITTER_NAME'::
 525'GIT_COMMITTER_EMAIL'::
 526'GIT_COMMITTER_DATE'::
 527'EMAIL'::
 528        see linkgit:git-commit-tree[1]
 529
 530git Diffs
 531~~~~~~~~~
 532'GIT_DIFF_OPTS'::
 533        Only valid setting is "--unified=??" or "-u??" to set the
 534        number of context lines shown when a unified diff is created.
 535        This takes precedence over any "-U" or "--unified" option
 536        value passed on the git diff command line.
 537
 538'GIT_EXTERNAL_DIFF'::
 539        When the environment variable 'GIT_EXTERNAL_DIFF' is set, the
 540        program named by it is called, instead of the diff invocation
 541        described above.  For a path that is added, removed, or modified,
 542        'GIT_EXTERNAL_DIFF' is called with 7 parameters:
 543
 544        path old-file old-hex old-mode new-file new-hex new-mode
 545+
 546where:
 547
 548        <old|new>-file:: are files GIT_EXTERNAL_DIFF can use to read the
 549                         contents of <old|new>,
 550        <old|new>-hex:: are the 40-hexdigit SHA1 hashes,
 551        <old|new>-mode:: are the octal representation of the file modes.
 552
 553+
 554The file parameters can point at the user's working file
 555(e.g. `new-file` in "git-diff-files"), `/dev/null` (e.g. `old-file`
 556when a new file is added), or a temporary file (e.g. `old-file` in the
 557index).  'GIT_EXTERNAL_DIFF' should not worry about unlinking the
 558temporary file --- it is removed when 'GIT_EXTERNAL_DIFF' exits.
 559+
 560For a path that is unmerged, 'GIT_EXTERNAL_DIFF' is called with 1
 561parameter, <path>.
 562
 563other
 564~~~~~
 565'GIT_MERGE_VERBOSITY'::
 566        A number controlling the amount of output shown by
 567        the recursive merge strategy.  Overrides merge.verbosity.
 568        See linkgit:git-merge[1]
 569
 570'GIT_PAGER'::
 571        This environment variable overrides `$PAGER`. If it is set
 572        to an empty string or to the value "cat", git will not launch
 573        a pager.  See also the `core.pager` option in
 574        linkgit:git-config[1].
 575
 576'GIT_SSH'::
 577        If this environment variable is set then 'git-fetch'
 578        and 'git-push' will use this command instead
 579        of 'ssh' when they need to connect to a remote system.
 580        The '$GIT_SSH' command will be given exactly two arguments:
 581        the 'username@host' (or just 'host') from the URL and the
 582        shell command to execute on that remote system.
 583+
 584To pass options to the program that you want to list in GIT_SSH
 585you will need to wrap the program and options into a shell script,
 586then set GIT_SSH to refer to the shell script.
 587+
 588Usually it is easier to configure any desired options through your
 589personal `.ssh/config` file.  Please consult your ssh documentation
 590for further details.
 591
 592'GIT_FLUSH'::
 593        If this environment variable is set to "1", then commands such
 594        as 'git-blame' (in incremental mode), 'git-rev-list', 'git-log',
 595        and 'git-whatchanged' will force a flush of the output stream
 596        after each commit-oriented record have been flushed.   If this
 597        variable is set to "0", the output of these commands will be done
 598        using completely buffered I/O.   If this environment variable is
 599        not set, git will choose buffered or record-oriented flushing
 600        based on whether stdout appears to be redirected to a file or not.
 601
 602'GIT_TRACE'::
 603        If this variable is set to "1", "2" or "true" (comparison
 604        is case insensitive), git will print `trace:` messages on
 605        stderr telling about alias expansion, built-in command
 606        execution and external command execution.
 607        If this variable is set to an integer value greater than 1
 608        and lower than 10 (strictly) then git will interpret this
 609        value as an open file descriptor and will try to write the
 610        trace messages into this file descriptor.
 611        Alternatively, if this variable is set to an absolute path
 612        (starting with a '/' character), git will interpret this
 613        as a file path and will try to write the trace messages
 614        into it.
 615
 616Discussion[[Discussion]]
 617------------------------
 618
 619More detail on the following is available from the
 620link:user-manual.html#git-concepts[git concepts chapter of the
 621user-manual] and linkgit:gitcore-tutorial[7].
 622
 623A git project normally consists of a working directory with a ".git"
 624subdirectory at the top level.  The .git directory contains, among other
 625things, a compressed object database representing the complete history
 626of the project, an "index" file which links that history to the current
 627contents of the working tree, and named pointers into that history such
 628as tags and branch heads.
 629
 630The object database contains objects of three main types: blobs, which
 631hold file data; trees, which point to blobs and other trees to build up
 632directory hierarchies; and commits, which each reference a single tree
 633and some number of parent commits.
 634
 635The commit, equivalent to what other systems call a "changeset" or
 636"version", represents a step in the project's history, and each parent
 637represents an immediately preceding step.  Commits with more than one
 638parent represent merges of independent lines of development.
 639
 640All objects are named by the SHA1 hash of their contents, normally
 641written as a string of 40 hex digits.  Such names are globally unique.
 642The entire history leading up to a commit can be vouched for by signing
 643just that commit.  A fourth object type, the tag, is provided for this
 644purpose.
 645
 646When first created, objects are stored in individual files, but for
 647efficiency may later be compressed together into "pack files".
 648
 649Named pointers called refs mark interesting points in history.  A ref
 650may contain the SHA1 name of an object or the name of another ref.  Refs
 651with names beginning `ref/head/` contain the SHA1 name of the most
 652recent commit (or "head") of a branch under development.  SHA1 names of
 653tags of interest are stored under `ref/tags/`.  A special ref named
 654`HEAD` contains the name of the currently checked-out branch.
 655
 656The index file is initialized with a list of all paths and, for each
 657path, a blob object and a set of attributes.  The blob object represents
 658the contents of the file as of the head of the current branch.  The
 659attributes (last modified time, size, etc.) are taken from the
 660corresponding file in the working tree.  Subsequent changes to the
 661working tree can be found by comparing these attributes.  The index may
 662be updated with new content, and new commits may be created from the
 663content stored in the index.
 664
 665The index is also capable of storing multiple entries (called "stages")
 666for a given pathname.  These stages are used to hold the various
 667unmerged version of a file when a merge is in progress.
 668
 669Authors
 670-------
 671* git's founding father is Linus Torvalds <torvalds@osdl.org>.
 672* The current git nurse is Junio C Hamano <gitster@pobox.com>.
 673* The git potty was written by Andreas Ericsson <ae@op5.se>.
 674* General upbringing is handled by the git-list <git@vger.kernel.org>.
 675
 676Documentation
 677--------------
 678The documentation for git suite was started by David Greaves
 679<david@dgreaves.com>, and later enhanced greatly by the
 680contributors on the git-list <git@vger.kernel.org>.
 681
 682SEE ALSO
 683--------
 684linkgit:gittutorial[7], linkgit:gittutorial-2[7],
 685link:everyday.html[Everyday Git], linkgit:gitcvs-migration[7],
 686linkgit:gitglossary[7], linkgit:gitcore-tutorial[7],
 687linkgit:gitcli[7], link:user-manual.html[The Git User's Manual],
 688linkgit:gitworkflows[7]
 689
 690GIT
 691---
 692Part of the linkgit:git[1] suite