Documentation / git.txton commit Merge branch 'fc/send-email-envelope' (0c7cc13)
   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:v1.6.5.3/git.html[documentation for release 1.6.5.3]
  47
  48* release notes for
  49  link:RelNotes-1.6.5.3.txt[1.6.5.3],
  50  link:RelNotes-1.6.5.2.txt[1.6.5.2],
  51  link:RelNotes-1.6.5.1.txt[1.6.5.1],
  52  link:RelNotes-1.6.5.txt[1.6.5].
  53
  54* link:v1.6.4.4/git.html[documentation for release 1.6.4.4]
  55
  56* release notes for
  57  link:RelNotes-1.6.4.4.txt[1.6.4.4],
  58  link:RelNotes-1.6.4.3.txt[1.6.4.3],
  59  link:RelNotes-1.6.4.2.txt[1.6.4.2],
  60  link:RelNotes-1.6.4.1.txt[1.6.4.1],
  61  link:RelNotes-1.6.4.txt[1.6.4].
  62
  63* link:v1.6.3.4/git.html[documentation for release 1.6.3.4]
  64
  65* release notes for
  66  link:RelNotes-1.6.3.4.txt[1.6.3.4],
  67  link:RelNotes-1.6.3.3.txt[1.6.3.3],
  68  link:RelNotes-1.6.3.2.txt[1.6.3.2],
  69  link:RelNotes-1.6.3.1.txt[1.6.3.1],
  70  link:RelNotes-1.6.3.txt[1.6.3].
  71
  72* release notes for
  73  link:RelNotes-1.6.2.5.txt[1.6.2.5],
  74  link:RelNotes-1.6.2.4.txt[1.6.2.4],
  75  link:RelNotes-1.6.2.3.txt[1.6.2.3],
  76  link:RelNotes-1.6.2.2.txt[1.6.2.2],
  77  link:RelNotes-1.6.2.1.txt[1.6.2.1],
  78  link:RelNotes-1.6.2.txt[1.6.2].
  79
  80* link:v1.6.1.3/git.html[documentation for release 1.6.1.3]
  81
  82* release notes for
  83  link:RelNotes-1.6.1.3.txt[1.6.1.3],
  84  link:RelNotes-1.6.1.2.txt[1.6.1.2],
  85  link:RelNotes-1.6.1.1.txt[1.6.1.1],
  86  link:RelNotes-1.6.1.txt[1.6.1].
  87
  88* link:v1.6.0.6/git.html[documentation for release 1.6.0.6]
  89
  90* release notes for
  91  link:RelNotes-1.6.0.6.txt[1.6.0.6],
  92  link:RelNotes-1.6.0.5.txt[1.6.0.5],
  93  link:RelNotes-1.6.0.4.txt[1.6.0.4],
  94  link:RelNotes-1.6.0.3.txt[1.6.0.3],
  95  link:RelNotes-1.6.0.2.txt[1.6.0.2],
  96  link:RelNotes-1.6.0.1.txt[1.6.0.1],
  97  link:RelNotes-1.6.0.txt[1.6.0].
  98
  99* link:v1.5.6.6/git.html[documentation for release 1.5.6.6]
 100
 101* release notes for
 102  link:RelNotes-1.5.6.6.txt[1.5.6.6],
 103  link:RelNotes-1.5.6.5.txt[1.5.6.5],
 104  link:RelNotes-1.5.6.4.txt[1.5.6.4],
 105  link:RelNotes-1.5.6.3.txt[1.5.6.3],
 106  link:RelNotes-1.5.6.2.txt[1.5.6.2],
 107  link:RelNotes-1.5.6.1.txt[1.5.6.1],
 108  link:RelNotes-1.5.6.txt[1.5.6].
 109
 110* link:v1.5.5.6/git.html[documentation for release 1.5.5.6]
 111
 112* release notes for
 113  link:RelNotes-1.5.5.6.txt[1.5.5.6],
 114  link:RelNotes-1.5.5.5.txt[1.5.5.5],
 115  link:RelNotes-1.5.5.4.txt[1.5.5.4],
 116  link:RelNotes-1.5.5.3.txt[1.5.5.3],
 117  link:RelNotes-1.5.5.2.txt[1.5.5.2],
 118  link:RelNotes-1.5.5.1.txt[1.5.5.1],
 119  link:RelNotes-1.5.5.txt[1.5.5].
 120
 121* link:v1.5.4.7/git.html[documentation for release 1.5.4.7]
 122
 123* release notes for
 124  link:RelNotes-1.5.4.7.txt[1.5.4.7],
 125  link:RelNotes-1.5.4.6.txt[1.5.4.6],
 126  link:RelNotes-1.5.4.5.txt[1.5.4.5],
 127  link:RelNotes-1.5.4.4.txt[1.5.4.4],
 128  link:RelNotes-1.5.4.3.txt[1.5.4.3],
 129  link:RelNotes-1.5.4.2.txt[1.5.4.2],
 130  link:RelNotes-1.5.4.1.txt[1.5.4.1],
 131  link:RelNotes-1.5.4.txt[1.5.4].
 132
 133* link:v1.5.3.8/git.html[documentation for release 1.5.3.8]
 134
 135* release notes for
 136  link:RelNotes-1.5.3.8.txt[1.5.3.8],
 137  link:RelNotes-1.5.3.7.txt[1.5.3.7],
 138  link:RelNotes-1.5.3.6.txt[1.5.3.6],
 139  link:RelNotes-1.5.3.5.txt[1.5.3.5],
 140  link:RelNotes-1.5.3.4.txt[1.5.3.4],
 141  link:RelNotes-1.5.3.3.txt[1.5.3.3],
 142  link:RelNotes-1.5.3.2.txt[1.5.3.2],
 143  link:RelNotes-1.5.3.1.txt[1.5.3.1],
 144  link:RelNotes-1.5.3.txt[1.5.3].
 145
 146* link:v1.5.2.5/git.html[documentation for release 1.5.2.5]
 147
 148* release notes for
 149  link:RelNotes-1.5.2.5.txt[1.5.2.5],
 150  link:RelNotes-1.5.2.4.txt[1.5.2.4],
 151  link:RelNotes-1.5.2.3.txt[1.5.2.3],
 152  link:RelNotes-1.5.2.2.txt[1.5.2.2],
 153  link:RelNotes-1.5.2.1.txt[1.5.2.1],
 154  link:RelNotes-1.5.2.txt[1.5.2].
 155
 156* link:v1.5.1.6/git.html[documentation for release 1.5.1.6]
 157
 158* release notes for
 159  link:RelNotes-1.5.1.6.txt[1.5.1.6],
 160  link:RelNotes-1.5.1.5.txt[1.5.1.5],
 161  link:RelNotes-1.5.1.4.txt[1.5.1.4],
 162  link:RelNotes-1.5.1.3.txt[1.5.1.3],
 163  link:RelNotes-1.5.1.2.txt[1.5.1.2],
 164  link:RelNotes-1.5.1.1.txt[1.5.1.1],
 165  link:RelNotes-1.5.1.txt[1.5.1].
 166
 167* link:v1.5.0.7/git.html[documentation for release 1.5.0.7]
 168
 169* release notes for
 170  link:RelNotes-1.5.0.7.txt[1.5.0.7],
 171  link:RelNotes-1.5.0.6.txt[1.5.0.6],
 172  link:RelNotes-1.5.0.5.txt[1.5.0.5],
 173  link:RelNotes-1.5.0.3.txt[1.5.0.3],
 174  link:RelNotes-1.5.0.2.txt[1.5.0.2],
 175  link:RelNotes-1.5.0.1.txt[1.5.0.1],
 176  link:RelNotes-1.5.0.txt[1.5.0].
 177
 178* documentation for release link:v1.4.4.4/git.html[1.4.4.4],
 179  link:v1.3.3/git.html[1.3.3],
 180  link:v1.2.6/git.html[1.2.6],
 181  link:v1.0.13/git.html[1.0.13].
 182
 183============
 184
 185endif::stalenotes[]
 186
 187OPTIONS
 188-------
 189--version::
 190        Prints the git suite version that the 'git' program came from.
 191
 192--help::
 193        Prints the synopsis and a list of the most commonly used
 194        commands. If the option '--all' or '-a' is given then all
 195        available commands are printed. If a git command is named this
 196        option will bring up the manual page for that command.
 197+
 198Other options are available to control how the manual page is
 199displayed. See linkgit:git-help[1] for more information,
 200because `git --help ...` is converted internally into `git
 201help ...`.
 202
 203--exec-path::
 204        Path to wherever your core git programs are installed.
 205        This can also be controlled by setting the GIT_EXEC_PATH
 206        environment variable. If no path is given, 'git' will print
 207        the current setting and then exit.
 208
 209--html-path::
 210        Print the path to wherever your git HTML documentation is installed
 211        and exit.
 212
 213-p::
 214--paginate::
 215        Pipe all output into 'less' (or if set, $PAGER).
 216
 217--no-pager::
 218        Do not pipe git output into a pager.
 219
 220--git-dir=<path>::
 221        Set the path to the repository. This can also be controlled by
 222        setting the GIT_DIR environment variable. It can be an absolute
 223        path or relative path to current working directory.
 224
 225--work-tree=<path>::
 226        Set the path to the working tree.  The value will not be
 227        used in combination with repositories found automatically in
 228        a .git directory (i.e. $GIT_DIR is not set).
 229        This can also be controlled by setting the GIT_WORK_TREE
 230        environment variable and the core.worktree configuration
 231        variable. It can be an absolute path or relative path to
 232        the directory specified by --git-dir or GIT_DIR.
 233        Note: If --git-dir or GIT_DIR are specified but none of
 234        --work-tree, GIT_WORK_TREE and core.worktree is specified,
 235        the current working directory is regarded as the top directory
 236        of your working tree.
 237
 238--bare::
 239        Treat the repository as a bare repository.  If GIT_DIR
 240        environment is not set, it is set to the current working
 241        directory.
 242
 243--no-replace-objects::
 244        Do not use replacement refs to replace git objects. See
 245        linkgit:git-replace[1] for more information.
 246
 247
 248FURTHER DOCUMENTATION
 249---------------------
 250
 251See the references above to get started using git.  The following is
 252probably more detail than necessary for a first-time user.
 253
 254The link:user-manual.html#git-concepts[git concepts chapter of the
 255user-manual] and linkgit:gitcore-tutorial[7] both provide
 256introductions to the underlying git architecture.
 257
 258See linkgit:gitworkflows[7] for an overview of recommended workflows.
 259
 260See also the link:howto-index.html[howto] documents for some useful
 261examples.
 262
 263The internals are documented in the
 264link:technical/api-index.html[GIT API documentation].
 265
 266GIT COMMANDS
 267------------
 268
 269We divide git into high level ("porcelain") commands and low level
 270("plumbing") commands.
 271
 272High-level commands (porcelain)
 273-------------------------------
 274
 275We separate the porcelain commands into the main commands and some
 276ancillary user utilities.
 277
 278Main porcelain commands
 279~~~~~~~~~~~~~~~~~~~~~~~
 280
 281include::cmds-mainporcelain.txt[]
 282
 283Ancillary Commands
 284~~~~~~~~~~~~~~~~~~
 285Manipulators:
 286
 287include::cmds-ancillarymanipulators.txt[]
 288
 289Interrogators:
 290
 291include::cmds-ancillaryinterrogators.txt[]
 292
 293
 294Interacting with Others
 295~~~~~~~~~~~~~~~~~~~~~~~
 296
 297These commands are to interact with foreign SCM and with other
 298people via patch over e-mail.
 299
 300include::cmds-foreignscminterface.txt[]
 301
 302
 303Low-level commands (plumbing)
 304-----------------------------
 305
 306Although git includes its
 307own porcelain layer, its low-level commands are sufficient to support
 308development of alternative porcelains.  Developers of such porcelains
 309might start by reading about linkgit:git-update-index[1] and
 310linkgit:git-read-tree[1].
 311
 312The interface (input, output, set of options and the semantics)
 313to these low-level commands are meant to be a lot more stable
 314than Porcelain level commands, because these commands are
 315primarily for scripted use.  The interface to Porcelain commands
 316on the other hand are subject to change in order to improve the
 317end user experience.
 318
 319The following description divides
 320the low-level commands into commands that manipulate objects (in
 321the repository, index, and working tree), commands that interrogate and
 322compare objects, and commands that move objects and references between
 323repositories.
 324
 325
 326Manipulation commands
 327~~~~~~~~~~~~~~~~~~~~~
 328
 329include::cmds-plumbingmanipulators.txt[]
 330
 331
 332Interrogation commands
 333~~~~~~~~~~~~~~~~~~~~~~
 334
 335include::cmds-plumbinginterrogators.txt[]
 336
 337In general, the interrogate commands do not touch the files in
 338the working tree.
 339
 340
 341Synching repositories
 342~~~~~~~~~~~~~~~~~~~~~
 343
 344include::cmds-synchingrepositories.txt[]
 345
 346The following are helper commands used by the above; end users
 347typically do not use them directly.
 348
 349include::cmds-synchelpers.txt[]
 350
 351
 352Internal helper commands
 353~~~~~~~~~~~~~~~~~~~~~~~~
 354
 355These are internal helper commands used by other commands; end
 356users typically do not use them directly.
 357
 358include::cmds-purehelpers.txt[]
 359
 360
 361Configuration Mechanism
 362-----------------------
 363
 364Starting from 0.99.9 (actually mid 0.99.8.GIT), `.git/config` file
 365is used to hold per-repository configuration options.  It is a
 366simple text file modeled after `.ini` format familiar to some
 367people.  Here is an example:
 368
 369------------
 370#
 371# A '#' or ';' character indicates a comment.
 372#
 373
 374; core variables
 375[core]
 376        ; Don't trust file modes
 377        filemode = false
 378
 379; user identity
 380[user]
 381        name = "Junio C Hamano"
 382        email = "junkio@twinsun.com"
 383
 384------------
 385
 386Various commands read from the configuration file and adjust
 387their operation accordingly.
 388
 389
 390Identifier Terminology
 391----------------------
 392<object>::
 393        Indicates the object name for any type of object.
 394
 395<blob>::
 396        Indicates a blob object name.
 397
 398<tree>::
 399        Indicates a tree object name.
 400
 401<commit>::
 402        Indicates a commit object name.
 403
 404<tree-ish>::
 405        Indicates a tree, commit or tag object name.  A
 406        command that takes a <tree-ish> argument ultimately wants to
 407        operate on a <tree> object but automatically dereferences
 408        <commit> and <tag> objects that point at a <tree>.
 409
 410<commit-ish>::
 411        Indicates a commit or tag object name.  A
 412        command that takes a <commit-ish> argument ultimately wants to
 413        operate on a <commit> object but automatically dereferences
 414        <tag> objects that point at a <commit>.
 415
 416<type>::
 417        Indicates that an object type is required.
 418        Currently one of: `blob`, `tree`, `commit`, or `tag`.
 419
 420<file>::
 421        Indicates a filename - almost always relative to the
 422        root of the tree structure `GIT_INDEX_FILE` describes.
 423
 424Symbolic Identifiers
 425--------------------
 426Any git command accepting any <object> can also use the following
 427symbolic notation:
 428
 429HEAD::
 430        indicates the head of the current branch (i.e. the
 431        contents of `$GIT_DIR/HEAD`).
 432
 433<tag>::
 434        a valid tag 'name'
 435        (i.e. the contents of `$GIT_DIR/refs/tags/<tag>`).
 436
 437<head>::
 438        a valid head 'name'
 439        (i.e. the contents of `$GIT_DIR/refs/heads/<head>`).
 440
 441For a more complete list of ways to spell object names, see
 442"SPECIFYING REVISIONS" section in linkgit:git-rev-parse[1].
 443
 444
 445File/Directory Structure
 446------------------------
 447
 448Please see the linkgit:gitrepository-layout[5] document.
 449
 450Read linkgit:githooks[5] for more details about each hook.
 451
 452Higher level SCMs may provide and manage additional information in the
 453`$GIT_DIR`.
 454
 455
 456Terminology
 457-----------
 458Please see linkgit:gitglossary[7].
 459
 460
 461Environment Variables
 462---------------------
 463Various git commands use the following environment variables:
 464
 465The git Repository
 466~~~~~~~~~~~~~~~~~~
 467These environment variables apply to 'all' core git commands. Nb: it
 468is worth noting that they may be used/overridden by SCMS sitting above
 469git so take care if using Cogito etc.
 470
 471'GIT_INDEX_FILE'::
 472        This environment allows the specification of an alternate
 473        index file. If not specified, the default of `$GIT_DIR/index`
 474        is used.
 475
 476'GIT_OBJECT_DIRECTORY'::
 477        If the object storage directory is specified via this
 478        environment variable then the sha1 directories are created
 479        underneath - otherwise the default `$GIT_DIR/objects`
 480        directory is used.
 481
 482'GIT_ALTERNATE_OBJECT_DIRECTORIES'::
 483        Due to the immutable nature of git objects, old objects can be
 484        archived into shared, read-only directories. This variable
 485        specifies a ":" separated (on Windows ";" separated) list
 486        of git object directories which can be used to search for git
 487        objects. New objects will not be written to these directories.
 488
 489'GIT_DIR'::
 490        If the 'GIT_DIR' environment variable is set then it
 491        specifies a path to use instead of the default `.git`
 492        for the base of the repository.
 493
 494'GIT_WORK_TREE'::
 495        Set the path to the working tree.  The value will not be
 496        used in combination with repositories found automatically in
 497        a .git directory (i.e. $GIT_DIR is not set).
 498        This can also be controlled by the '--work-tree' command line
 499        option and the core.worktree configuration variable.
 500
 501'GIT_CEILING_DIRECTORIES'::
 502        This should be a colon-separated list of absolute paths.
 503        If set, it is a list of directories that git should not chdir
 504        up into while looking for a repository directory.
 505        It will not exclude the current working directory or
 506        a GIT_DIR set on the command line or in the environment.
 507        (Useful for excluding slow-loading network directories.)
 508
 509git Commits
 510~~~~~~~~~~~
 511'GIT_AUTHOR_NAME'::
 512'GIT_AUTHOR_EMAIL'::
 513'GIT_AUTHOR_DATE'::
 514'GIT_COMMITTER_NAME'::
 515'GIT_COMMITTER_EMAIL'::
 516'GIT_COMMITTER_DATE'::
 517'EMAIL'::
 518        see linkgit:git-commit-tree[1]
 519
 520git Diffs
 521~~~~~~~~~
 522'GIT_DIFF_OPTS'::
 523        Only valid setting is "--unified=??" or "-u??" to set the
 524        number of context lines shown when a unified diff is created.
 525        This takes precedence over any "-U" or "--unified" option
 526        value passed on the git diff command line.
 527
 528'GIT_EXTERNAL_DIFF'::
 529        When the environment variable 'GIT_EXTERNAL_DIFF' is set, the
 530        program named by it is called, instead of the diff invocation
 531        described above.  For a path that is added, removed, or modified,
 532        'GIT_EXTERNAL_DIFF' is called with 7 parameters:
 533
 534        path old-file old-hex old-mode new-file new-hex new-mode
 535+
 536where:
 537
 538        <old|new>-file:: are files GIT_EXTERNAL_DIFF can use to read the
 539                         contents of <old|new>,
 540        <old|new>-hex:: are the 40-hexdigit SHA1 hashes,
 541        <old|new>-mode:: are the octal representation of the file modes.
 542
 543+
 544The file parameters can point at the user's working file
 545(e.g. `new-file` in "git-diff-files"), `/dev/null` (e.g. `old-file`
 546when a new file is added), or a temporary file (e.g. `old-file` in the
 547index).  'GIT_EXTERNAL_DIFF' should not worry about unlinking the
 548temporary file --- it is removed when 'GIT_EXTERNAL_DIFF' exits.
 549+
 550For a path that is unmerged, 'GIT_EXTERNAL_DIFF' is called with 1
 551parameter, <path>.
 552
 553other
 554~~~~~
 555'GIT_MERGE_VERBOSITY'::
 556        A number controlling the amount of output shown by
 557        the recursive merge strategy.  Overrides merge.verbosity.
 558        See linkgit:git-merge[1]
 559
 560'GIT_PAGER'::
 561        This environment variable overrides `$PAGER`. If it is set
 562        to an empty string or to the value "cat", git will not launch
 563        a pager.  See also the `core.pager` option in
 564        linkgit:git-config[1].
 565
 566'GIT_SSH'::
 567        If this environment variable is set then 'git-fetch'
 568        and 'git-push' will use this command instead
 569        of 'ssh' when they need to connect to a remote system.
 570        The '$GIT_SSH' command will be given exactly two arguments:
 571        the 'username@host' (or just 'host') from the URL and the
 572        shell command to execute on that remote system.
 573+
 574To pass options to the program that you want to list in GIT_SSH
 575you will need to wrap the program and options into a shell script,
 576then set GIT_SSH to refer to the shell script.
 577+
 578Usually it is easier to configure any desired options through your
 579personal `.ssh/config` file.  Please consult your ssh documentation
 580for further details.
 581
 582'GIT_FLUSH'::
 583        If this environment variable is set to "1", then commands such
 584        as 'git-blame' (in incremental mode), 'git-rev-list', 'git-log',
 585        and 'git-whatchanged' will force a flush of the output stream
 586        after each commit-oriented record have been flushed.   If this
 587        variable is set to "0", the output of these commands will be done
 588        using completely buffered I/O.   If this environment variable is
 589        not set, git will choose buffered or record-oriented flushing
 590        based on whether stdout appears to be redirected to a file or not.
 591
 592'GIT_TRACE'::
 593        If this variable is set to "1", "2" or "true" (comparison
 594        is case insensitive), git will print `trace:` messages on
 595        stderr telling about alias expansion, built-in command
 596        execution and external command execution.
 597        If this variable is set to an integer value greater than 1
 598        and lower than 10 (strictly) then git will interpret this
 599        value as an open file descriptor and will try to write the
 600        trace messages into this file descriptor.
 601        Alternatively, if this variable is set to an absolute path
 602        (starting with a '/' character), git will interpret this
 603        as a file path and will try to write the trace messages
 604        into it.
 605
 606Discussion[[Discussion]]
 607------------------------
 608
 609More detail on the following is available from the
 610link:user-manual.html#git-concepts[git concepts chapter of the
 611user-manual] and linkgit:gitcore-tutorial[7].
 612
 613A git project normally consists of a working directory with a ".git"
 614subdirectory at the top level.  The .git directory contains, among other
 615things, a compressed object database representing the complete history
 616of the project, an "index" file which links that history to the current
 617contents of the working tree, and named pointers into that history such
 618as tags and branch heads.
 619
 620The object database contains objects of three main types: blobs, which
 621hold file data; trees, which point to blobs and other trees to build up
 622directory hierarchies; and commits, which each reference a single tree
 623and some number of parent commits.
 624
 625The commit, equivalent to what other systems call a "changeset" or
 626"version", represents a step in the project's history, and each parent
 627represents an immediately preceding step.  Commits with more than one
 628parent represent merges of independent lines of development.
 629
 630All objects are named by the SHA1 hash of their contents, normally
 631written as a string of 40 hex digits.  Such names are globally unique.
 632The entire history leading up to a commit can be vouched for by signing
 633just that commit.  A fourth object type, the tag, is provided for this
 634purpose.
 635
 636When first created, objects are stored in individual files, but for
 637efficiency may later be compressed together into "pack files".
 638
 639Named pointers called refs mark interesting points in history.  A ref
 640may contain the SHA1 name of an object or the name of another ref.  Refs
 641with names beginning `ref/head/` contain the SHA1 name of the most
 642recent commit (or "head") of a branch under development.  SHA1 names of
 643tags of interest are stored under `ref/tags/`.  A special ref named
 644`HEAD` contains the name of the currently checked-out branch.
 645
 646The index file is initialized with a list of all paths and, for each
 647path, a blob object and a set of attributes.  The blob object represents
 648the contents of the file as of the head of the current branch.  The
 649attributes (last modified time, size, etc.) are taken from the
 650corresponding file in the working tree.  Subsequent changes to the
 651working tree can be found by comparing these attributes.  The index may
 652be updated with new content, and new commits may be created from the
 653content stored in the index.
 654
 655The index is also capable of storing multiple entries (called "stages")
 656for a given pathname.  These stages are used to hold the various
 657unmerged version of a file when a merge is in progress.
 658
 659Authors
 660-------
 661* git's founding father is Linus Torvalds <torvalds@osdl.org>.
 662* The current git nurse is Junio C Hamano <gitster@pobox.com>.
 663* The git potty was written by Andreas Ericsson <ae@op5.se>.
 664* General upbringing is handled by the git-list <git@vger.kernel.org>.
 665
 666Documentation
 667--------------
 668The documentation for git suite was started by David Greaves
 669<david@dgreaves.com>, and later enhanced greatly by the
 670contributors on the git-list <git@vger.kernel.org>.
 671
 672SEE ALSO
 673--------
 674linkgit:gittutorial[7], linkgit:gittutorial-2[7],
 675link:everyday.html[Everyday Git], linkgit:gitcvs-migration[7],
 676linkgit:gitglossary[7], linkgit:gitcore-tutorial[7],
 677linkgit:gitcli[7], link:user-manual.html[The Git User's Manual],
 678linkgit:gitworkflows[7]
 679
 680GIT
 681---
 682Part of the linkgit:git[1] suite