Documentation / git.txton commit Sync with 1.6.5.5 (3880c18)
   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:v1.6.5.5/git.html[documentation for release 1.6.5.5]
  47
  48* release notes for
  49  link:RelNotes-1.6.5.5.txt[1.6.5.5],
  50  link:RelNotes-1.6.5.4.txt[1.6.5.4],
  51  link:RelNotes-1.6.5.3.txt[1.6.5.3],
  52  link:RelNotes-1.6.5.2.txt[1.6.5.2],
  53  link:RelNotes-1.6.5.1.txt[1.6.5.1],
  54  link:RelNotes-1.6.5.txt[1.6.5].
  55
  56* link:v1.6.4.4/git.html[documentation for release 1.6.4.4]
  57
  58* release notes for
  59  link:RelNotes-1.6.4.4.txt[1.6.4.4],
  60  link:RelNotes-1.6.4.3.txt[1.6.4.3],
  61  link:RelNotes-1.6.4.2.txt[1.6.4.2],
  62  link:RelNotes-1.6.4.1.txt[1.6.4.1],
  63  link:RelNotes-1.6.4.txt[1.6.4].
  64
  65* link:v1.6.3.4/git.html[documentation for release 1.6.3.4]
  66
  67* release notes for
  68  link:RelNotes-1.6.3.4.txt[1.6.3.4],
  69  link:RelNotes-1.6.3.3.txt[1.6.3.3],
  70  link:RelNotes-1.6.3.2.txt[1.6.3.2],
  71  link:RelNotes-1.6.3.1.txt[1.6.3.1],
  72  link:RelNotes-1.6.3.txt[1.6.3].
  73
  74* release notes for
  75  link:RelNotes-1.6.2.5.txt[1.6.2.5],
  76  link:RelNotes-1.6.2.4.txt[1.6.2.4],
  77  link:RelNotes-1.6.2.3.txt[1.6.2.3],
  78  link:RelNotes-1.6.2.2.txt[1.6.2.2],
  79  link:RelNotes-1.6.2.1.txt[1.6.2.1],
  80  link:RelNotes-1.6.2.txt[1.6.2].
  81
  82* link:v1.6.1.3/git.html[documentation for release 1.6.1.3]
  83
  84* release notes for
  85  link:RelNotes-1.6.1.3.txt[1.6.1.3],
  86  link:RelNotes-1.6.1.2.txt[1.6.1.2],
  87  link:RelNotes-1.6.1.1.txt[1.6.1.1],
  88  link:RelNotes-1.6.1.txt[1.6.1].
  89
  90* link:v1.6.0.6/git.html[documentation for release 1.6.0.6]
  91
  92* release notes for
  93  link:RelNotes-1.6.0.6.txt[1.6.0.6],
  94  link:RelNotes-1.6.0.5.txt[1.6.0.5],
  95  link:RelNotes-1.6.0.4.txt[1.6.0.4],
  96  link:RelNotes-1.6.0.3.txt[1.6.0.3],
  97  link:RelNotes-1.6.0.2.txt[1.6.0.2],
  98  link:RelNotes-1.6.0.1.txt[1.6.0.1],
  99  link:RelNotes-1.6.0.txt[1.6.0].
 100
 101* link:v1.5.6.6/git.html[documentation for release 1.5.6.6]
 102
 103* release notes for
 104  link:RelNotes-1.5.6.6.txt[1.5.6.6],
 105  link:RelNotes-1.5.6.5.txt[1.5.6.5],
 106  link:RelNotes-1.5.6.4.txt[1.5.6.4],
 107  link:RelNotes-1.5.6.3.txt[1.5.6.3],
 108  link:RelNotes-1.5.6.2.txt[1.5.6.2],
 109  link:RelNotes-1.5.6.1.txt[1.5.6.1],
 110  link:RelNotes-1.5.6.txt[1.5.6].
 111
 112* link:v1.5.5.6/git.html[documentation for release 1.5.5.6]
 113
 114* release notes for
 115  link:RelNotes-1.5.5.6.txt[1.5.5.6],
 116  link:RelNotes-1.5.5.5.txt[1.5.5.5],
 117  link:RelNotes-1.5.5.4.txt[1.5.5.4],
 118  link:RelNotes-1.5.5.3.txt[1.5.5.3],
 119  link:RelNotes-1.5.5.2.txt[1.5.5.2],
 120  link:RelNotes-1.5.5.1.txt[1.5.5.1],
 121  link:RelNotes-1.5.5.txt[1.5.5].
 122
 123* link:v1.5.4.7/git.html[documentation for release 1.5.4.7]
 124
 125* release notes for
 126  link:RelNotes-1.5.4.7.txt[1.5.4.7],
 127  link:RelNotes-1.5.4.6.txt[1.5.4.6],
 128  link:RelNotes-1.5.4.5.txt[1.5.4.5],
 129  link:RelNotes-1.5.4.4.txt[1.5.4.4],
 130  link:RelNotes-1.5.4.3.txt[1.5.4.3],
 131  link:RelNotes-1.5.4.2.txt[1.5.4.2],
 132  link:RelNotes-1.5.4.1.txt[1.5.4.1],
 133  link:RelNotes-1.5.4.txt[1.5.4].
 134
 135* link:v1.5.3.8/git.html[documentation for release 1.5.3.8]
 136
 137* release notes for
 138  link:RelNotes-1.5.3.8.txt[1.5.3.8],
 139  link:RelNotes-1.5.3.7.txt[1.5.3.7],
 140  link:RelNotes-1.5.3.6.txt[1.5.3.6],
 141  link:RelNotes-1.5.3.5.txt[1.5.3.5],
 142  link:RelNotes-1.5.3.4.txt[1.5.3.4],
 143  link:RelNotes-1.5.3.3.txt[1.5.3.3],
 144  link:RelNotes-1.5.3.2.txt[1.5.3.2],
 145  link:RelNotes-1.5.3.1.txt[1.5.3.1],
 146  link:RelNotes-1.5.3.txt[1.5.3].
 147
 148* link:v1.5.2.5/git.html[documentation for release 1.5.2.5]
 149
 150* release notes for
 151  link:RelNotes-1.5.2.5.txt[1.5.2.5],
 152  link:RelNotes-1.5.2.4.txt[1.5.2.4],
 153  link:RelNotes-1.5.2.3.txt[1.5.2.3],
 154  link:RelNotes-1.5.2.2.txt[1.5.2.2],
 155  link:RelNotes-1.5.2.1.txt[1.5.2.1],
 156  link:RelNotes-1.5.2.txt[1.5.2].
 157
 158* link:v1.5.1.6/git.html[documentation for release 1.5.1.6]
 159
 160* release notes for
 161  link:RelNotes-1.5.1.6.txt[1.5.1.6],
 162  link:RelNotes-1.5.1.5.txt[1.5.1.5],
 163  link:RelNotes-1.5.1.4.txt[1.5.1.4],
 164  link:RelNotes-1.5.1.3.txt[1.5.1.3],
 165  link:RelNotes-1.5.1.2.txt[1.5.1.2],
 166  link:RelNotes-1.5.1.1.txt[1.5.1.1],
 167  link:RelNotes-1.5.1.txt[1.5.1].
 168
 169* link:v1.5.0.7/git.html[documentation for release 1.5.0.7]
 170
 171* release notes for
 172  link:RelNotes-1.5.0.7.txt[1.5.0.7],
 173  link:RelNotes-1.5.0.6.txt[1.5.0.6],
 174  link:RelNotes-1.5.0.5.txt[1.5.0.5],
 175  link:RelNotes-1.5.0.3.txt[1.5.0.3],
 176  link:RelNotes-1.5.0.2.txt[1.5.0.2],
 177  link:RelNotes-1.5.0.1.txt[1.5.0.1],
 178  link:RelNotes-1.5.0.txt[1.5.0].
 179
 180* documentation for release link:v1.4.4.4/git.html[1.4.4.4],
 181  link:v1.3.3/git.html[1.3.3],
 182  link:v1.2.6/git.html[1.2.6],
 183  link:v1.0.13/git.html[1.0.13].
 184
 185============
 186
 187endif::stalenotes[]
 188
 189OPTIONS
 190-------
 191--version::
 192        Prints the git suite version that the 'git' program came from.
 193
 194--help::
 195        Prints the synopsis and a list of the most commonly used
 196        commands. If the option '--all' or '-a' is given then all
 197        available commands are printed. If a git command is named this
 198        option will bring up the manual page for that command.
 199+
 200Other options are available to control how the manual page is
 201displayed. See linkgit:git-help[1] for more information,
 202because `git --help ...` is converted internally into `git
 203help ...`.
 204
 205--exec-path::
 206        Path to wherever your core git programs are installed.
 207        This can also be controlled by setting the GIT_EXEC_PATH
 208        environment variable. If no path is given, 'git' will print
 209        the current setting and then exit.
 210
 211--html-path::
 212        Print the path to wherever your git HTML documentation is installed
 213        and exit.
 214
 215-p::
 216--paginate::
 217        Pipe all output into 'less' (or if set, $PAGER).
 218
 219--no-pager::
 220        Do not pipe git output into a pager.
 221
 222--git-dir=<path>::
 223        Set the path to the repository. This can also be controlled by
 224        setting the GIT_DIR environment variable. It can be an absolute
 225        path or relative path to current working directory.
 226
 227--work-tree=<path>::
 228        Set the path to the working tree.  The value will not be
 229        used in combination with repositories found automatically in
 230        a .git directory (i.e. $GIT_DIR is not set).
 231        This can also be controlled by setting the GIT_WORK_TREE
 232        environment variable and the core.worktree configuration
 233        variable. It can be an absolute path or relative path to
 234        the directory specified by --git-dir or GIT_DIR.
 235        Note: If --git-dir or GIT_DIR are specified but none of
 236        --work-tree, GIT_WORK_TREE and core.worktree is specified,
 237        the current working directory is regarded as the top directory
 238        of your working tree.
 239
 240--bare::
 241        Treat the repository as a bare repository.  If GIT_DIR
 242        environment is not set, it is set to the current working
 243        directory.
 244
 245--no-replace-objects::
 246        Do not use replacement refs to replace git objects. See
 247        linkgit:git-replace[1] for more information.
 248
 249
 250FURTHER DOCUMENTATION
 251---------------------
 252
 253See the references above to get started using git.  The following is
 254probably more detail than necessary for a first-time user.
 255
 256The link:user-manual.html#git-concepts[git concepts chapter of the
 257user-manual] and linkgit:gitcore-tutorial[7] both provide
 258introductions to the underlying git architecture.
 259
 260See linkgit:gitworkflows[7] for an overview of recommended workflows.
 261
 262See also the link:howto-index.html[howto] documents for some useful
 263examples.
 264
 265The internals are documented in the
 266link:technical/api-index.html[GIT API documentation].
 267
 268GIT COMMANDS
 269------------
 270
 271We divide git into high level ("porcelain") commands and low level
 272("plumbing") commands.
 273
 274High-level commands (porcelain)
 275-------------------------------
 276
 277We separate the porcelain commands into the main commands and some
 278ancillary user utilities.
 279
 280Main porcelain commands
 281~~~~~~~~~~~~~~~~~~~~~~~
 282
 283include::cmds-mainporcelain.txt[]
 284
 285Ancillary Commands
 286~~~~~~~~~~~~~~~~~~
 287Manipulators:
 288
 289include::cmds-ancillarymanipulators.txt[]
 290
 291Interrogators:
 292
 293include::cmds-ancillaryinterrogators.txt[]
 294
 295
 296Interacting with Others
 297~~~~~~~~~~~~~~~~~~~~~~~
 298
 299These commands are to interact with foreign SCM and with other
 300people via patch over e-mail.
 301
 302include::cmds-foreignscminterface.txt[]
 303
 304
 305Low-level commands (plumbing)
 306-----------------------------
 307
 308Although git includes its
 309own porcelain layer, its low-level commands are sufficient to support
 310development of alternative porcelains.  Developers of such porcelains
 311might start by reading about linkgit:git-update-index[1] and
 312linkgit:git-read-tree[1].
 313
 314The interface (input, output, set of options and the semantics)
 315to these low-level commands are meant to be a lot more stable
 316than Porcelain level commands, because these commands are
 317primarily for scripted use.  The interface to Porcelain commands
 318on the other hand are subject to change in order to improve the
 319end user experience.
 320
 321The following description divides
 322the low-level commands into commands that manipulate objects (in
 323the repository, index, and working tree), commands that interrogate and
 324compare objects, and commands that move objects and references between
 325repositories.
 326
 327
 328Manipulation commands
 329~~~~~~~~~~~~~~~~~~~~~
 330
 331include::cmds-plumbingmanipulators.txt[]
 332
 333
 334Interrogation commands
 335~~~~~~~~~~~~~~~~~~~~~~
 336
 337include::cmds-plumbinginterrogators.txt[]
 338
 339In general, the interrogate commands do not touch the files in
 340the working tree.
 341
 342
 343Synching repositories
 344~~~~~~~~~~~~~~~~~~~~~
 345
 346include::cmds-synchingrepositories.txt[]
 347
 348The following are helper commands used by the above; end users
 349typically do not use them directly.
 350
 351include::cmds-synchelpers.txt[]
 352
 353
 354Internal helper commands
 355~~~~~~~~~~~~~~~~~~~~~~~~
 356
 357These are internal helper commands used by other commands; end
 358users typically do not use them directly.
 359
 360include::cmds-purehelpers.txt[]
 361
 362
 363Configuration Mechanism
 364-----------------------
 365
 366Starting from 0.99.9 (actually mid 0.99.8.GIT), `.git/config` file
 367is used to hold per-repository configuration options.  It is a
 368simple text file modeled after `.ini` format familiar to some
 369people.  Here is an example:
 370
 371------------
 372#
 373# A '#' or ';' character indicates a comment.
 374#
 375
 376; core variables
 377[core]
 378        ; Don't trust file modes
 379        filemode = false
 380
 381; user identity
 382[user]
 383        name = "Junio C Hamano"
 384        email = "junkio@twinsun.com"
 385
 386------------
 387
 388Various commands read from the configuration file and adjust
 389their operation accordingly.
 390
 391
 392Identifier Terminology
 393----------------------
 394<object>::
 395        Indicates the object name for any type of object.
 396
 397<blob>::
 398        Indicates a blob object name.
 399
 400<tree>::
 401        Indicates a tree object name.
 402
 403<commit>::
 404        Indicates a commit object name.
 405
 406<tree-ish>::
 407        Indicates a tree, commit or tag object name.  A
 408        command that takes a <tree-ish> argument ultimately wants to
 409        operate on a <tree> object but automatically dereferences
 410        <commit> and <tag> objects that point at a <tree>.
 411
 412<commit-ish>::
 413        Indicates a commit or tag object name.  A
 414        command that takes a <commit-ish> argument ultimately wants to
 415        operate on a <commit> object but automatically dereferences
 416        <tag> objects that point at a <commit>.
 417
 418<type>::
 419        Indicates that an object type is required.
 420        Currently one of: `blob`, `tree`, `commit`, or `tag`.
 421
 422<file>::
 423        Indicates a filename - almost always relative to the
 424        root of the tree structure `GIT_INDEX_FILE` describes.
 425
 426Symbolic Identifiers
 427--------------------
 428Any git command accepting any <object> can also use the following
 429symbolic notation:
 430
 431HEAD::
 432        indicates the head of the current branch (i.e. the
 433        contents of `$GIT_DIR/HEAD`).
 434
 435<tag>::
 436        a valid tag 'name'
 437        (i.e. the contents of `$GIT_DIR/refs/tags/<tag>`).
 438
 439<head>::
 440        a valid head 'name'
 441        (i.e. the contents of `$GIT_DIR/refs/heads/<head>`).
 442
 443For a more complete list of ways to spell object names, see
 444"SPECIFYING REVISIONS" section in linkgit:git-rev-parse[1].
 445
 446
 447File/Directory Structure
 448------------------------
 449
 450Please see the linkgit:gitrepository-layout[5] document.
 451
 452Read linkgit:githooks[5] for more details about each hook.
 453
 454Higher level SCMs may provide and manage additional information in the
 455`$GIT_DIR`.
 456
 457
 458Terminology
 459-----------
 460Please see linkgit:gitglossary[7].
 461
 462
 463Environment Variables
 464---------------------
 465Various git commands use the following environment variables:
 466
 467The git Repository
 468~~~~~~~~~~~~~~~~~~
 469These environment variables apply to 'all' core git commands. Nb: it
 470is worth noting that they may be used/overridden by SCMS sitting above
 471git so take care if using Cogito etc.
 472
 473'GIT_INDEX_FILE'::
 474        This environment allows the specification of an alternate
 475        index file. If not specified, the default of `$GIT_DIR/index`
 476        is used.
 477
 478'GIT_OBJECT_DIRECTORY'::
 479        If the object storage directory is specified via this
 480        environment variable then the sha1 directories are created
 481        underneath - otherwise the default `$GIT_DIR/objects`
 482        directory is used.
 483
 484'GIT_ALTERNATE_OBJECT_DIRECTORIES'::
 485        Due to the immutable nature of git objects, old objects can be
 486        archived into shared, read-only directories. This variable
 487        specifies a ":" separated (on Windows ";" separated) list
 488        of git object directories which can be used to search for git
 489        objects. New objects will not be written to these directories.
 490
 491'GIT_DIR'::
 492        If the 'GIT_DIR' environment variable is set then it
 493        specifies a path to use instead of the default `.git`
 494        for the base of the repository.
 495
 496'GIT_WORK_TREE'::
 497        Set the path to the working tree.  The value will not be
 498        used in combination with repositories found automatically in
 499        a .git directory (i.e. $GIT_DIR is not set).
 500        This can also be controlled by the '--work-tree' command line
 501        option and the core.worktree configuration variable.
 502
 503'GIT_CEILING_DIRECTORIES'::
 504        This should be a colon-separated list of absolute paths.
 505        If set, it is a list of directories that git should not chdir
 506        up into while looking for a repository directory.
 507        It will not exclude the current working directory or
 508        a GIT_DIR set on the command line or in the environment.
 509        (Useful for excluding slow-loading network directories.)
 510
 511git Commits
 512~~~~~~~~~~~
 513'GIT_AUTHOR_NAME'::
 514'GIT_AUTHOR_EMAIL'::
 515'GIT_AUTHOR_DATE'::
 516'GIT_COMMITTER_NAME'::
 517'GIT_COMMITTER_EMAIL'::
 518'GIT_COMMITTER_DATE'::
 519'EMAIL'::
 520        see linkgit:git-commit-tree[1]
 521
 522git Diffs
 523~~~~~~~~~
 524'GIT_DIFF_OPTS'::
 525        Only valid setting is "--unified=??" or "-u??" to set the
 526        number of context lines shown when a unified diff is created.
 527        This takes precedence over any "-U" or "--unified" option
 528        value passed on the git diff command line.
 529
 530'GIT_EXTERNAL_DIFF'::
 531        When the environment variable 'GIT_EXTERNAL_DIFF' is set, the
 532        program named by it is called, instead of the diff invocation
 533        described above.  For a path that is added, removed, or modified,
 534        'GIT_EXTERNAL_DIFF' is called with 7 parameters:
 535
 536        path old-file old-hex old-mode new-file new-hex new-mode
 537+
 538where:
 539
 540        <old|new>-file:: are files GIT_EXTERNAL_DIFF can use to read the
 541                         contents of <old|new>,
 542        <old|new>-hex:: are the 40-hexdigit SHA1 hashes,
 543        <old|new>-mode:: are the octal representation of the file modes.
 544
 545+
 546The file parameters can point at the user's working file
 547(e.g. `new-file` in "git-diff-files"), `/dev/null` (e.g. `old-file`
 548when a new file is added), or a temporary file (e.g. `old-file` in the
 549index).  'GIT_EXTERNAL_DIFF' should not worry about unlinking the
 550temporary file --- it is removed when 'GIT_EXTERNAL_DIFF' exits.
 551+
 552For a path that is unmerged, 'GIT_EXTERNAL_DIFF' is called with 1
 553parameter, <path>.
 554
 555other
 556~~~~~
 557'GIT_MERGE_VERBOSITY'::
 558        A number controlling the amount of output shown by
 559        the recursive merge strategy.  Overrides merge.verbosity.
 560        See linkgit:git-merge[1]
 561
 562'GIT_PAGER'::
 563        This environment variable overrides `$PAGER`. If it is set
 564        to an empty string or to the value "cat", git will not launch
 565        a pager.  See also the `core.pager` option in
 566        linkgit:git-config[1].
 567
 568'GIT_SSH'::
 569        If this environment variable is set then 'git-fetch'
 570        and 'git-push' will use this command instead
 571        of 'ssh' when they need to connect to a remote system.
 572        The '$GIT_SSH' command will be given exactly two arguments:
 573        the 'username@host' (or just 'host') from the URL and the
 574        shell command to execute on that remote system.
 575+
 576To pass options to the program that you want to list in GIT_SSH
 577you will need to wrap the program and options into a shell script,
 578then set GIT_SSH to refer to the shell script.
 579+
 580Usually it is easier to configure any desired options through your
 581personal `.ssh/config` file.  Please consult your ssh documentation
 582for further details.
 583
 584'GIT_FLUSH'::
 585        If this environment variable is set to "1", then commands such
 586        as 'git-blame' (in incremental mode), 'git-rev-list', 'git-log',
 587        and 'git-whatchanged' will force a flush of the output stream
 588        after each commit-oriented record have been flushed.   If this
 589        variable is set to "0", the output of these commands will be done
 590        using completely buffered I/O.   If this environment variable is
 591        not set, git will choose buffered or record-oriented flushing
 592        based on whether stdout appears to be redirected to a file or not.
 593
 594'GIT_TRACE'::
 595        If this variable is set to "1", "2" or "true" (comparison
 596        is case insensitive), git will print `trace:` messages on
 597        stderr telling about alias expansion, built-in command
 598        execution and external command execution.
 599        If this variable is set to an integer value greater than 1
 600        and lower than 10 (strictly) then git will interpret this
 601        value as an open file descriptor and will try to write the
 602        trace messages into this file descriptor.
 603        Alternatively, if this variable is set to an absolute path
 604        (starting with a '/' character), git will interpret this
 605        as a file path and will try to write the trace messages
 606        into it.
 607
 608Discussion[[Discussion]]
 609------------------------
 610
 611More detail on the following is available from the
 612link:user-manual.html#git-concepts[git concepts chapter of the
 613user-manual] and linkgit:gitcore-tutorial[7].
 614
 615A git project normally consists of a working directory with a ".git"
 616subdirectory at the top level.  The .git directory contains, among other
 617things, a compressed object database representing the complete history
 618of the project, an "index" file which links that history to the current
 619contents of the working tree, and named pointers into that history such
 620as tags and branch heads.
 621
 622The object database contains objects of three main types: blobs, which
 623hold file data; trees, which point to blobs and other trees to build up
 624directory hierarchies; and commits, which each reference a single tree
 625and some number of parent commits.
 626
 627The commit, equivalent to what other systems call a "changeset" or
 628"version", represents a step in the project's history, and each parent
 629represents an immediately preceding step.  Commits with more than one
 630parent represent merges of independent lines of development.
 631
 632All objects are named by the SHA1 hash of their contents, normally
 633written as a string of 40 hex digits.  Such names are globally unique.
 634The entire history leading up to a commit can be vouched for by signing
 635just that commit.  A fourth object type, the tag, is provided for this
 636purpose.
 637
 638When first created, objects are stored in individual files, but for
 639efficiency may later be compressed together into "pack files".
 640
 641Named pointers called refs mark interesting points in history.  A ref
 642may contain the SHA1 name of an object or the name of another ref.  Refs
 643with names beginning `ref/head/` contain the SHA1 name of the most
 644recent commit (or "head") of a branch under development.  SHA1 names of
 645tags of interest are stored under `ref/tags/`.  A special ref named
 646`HEAD` contains the name of the currently checked-out branch.
 647
 648The index file is initialized with a list of all paths and, for each
 649path, a blob object and a set of attributes.  The blob object represents
 650the contents of the file as of the head of the current branch.  The
 651attributes (last modified time, size, etc.) are taken from the
 652corresponding file in the working tree.  Subsequent changes to the
 653working tree can be found by comparing these attributes.  The index may
 654be updated with new content, and new commits may be created from the
 655content stored in the index.
 656
 657The index is also capable of storing multiple entries (called "stages")
 658for a given pathname.  These stages are used to hold the various
 659unmerged version of a file when a merge is in progress.
 660
 661Authors
 662-------
 663* git's founding father is Linus Torvalds <torvalds@osdl.org>.
 664* The current git nurse is Junio C Hamano <gitster@pobox.com>.
 665* The git potty was written by Andreas Ericsson <ae@op5.se>.
 666* General upbringing is handled by the git-list <git@vger.kernel.org>.
 667
 668Documentation
 669--------------
 670The documentation for git suite was started by David Greaves
 671<david@dgreaves.com>, and later enhanced greatly by the
 672contributors on the git-list <git@vger.kernel.org>.
 673
 674SEE ALSO
 675--------
 676linkgit:gittutorial[7], linkgit:gittutorial-2[7],
 677link:everyday.html[Everyday Git], linkgit:gitcvs-migration[7],
 678linkgit:gitglossary[7], linkgit:gitcore-tutorial[7],
 679linkgit:gitcli[7], link:user-manual.html[The Git User's Manual],
 680linkgit:gitworkflows[7]
 681
 682GIT
 683---
 684Part of the linkgit:git[1] suite