Documentation / git.txton commit Merge branch 'sr/blame-incomplete' into maint (061c4d0)
   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]
  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:v1.6.5.2/git.html[documentation for release 1.6.5.2]
  47
  48* release notes for
  49  link:RelNotes-1.6.5.2.txt[1.6.5.2],
  50  link:RelNotes-1.6.5.1.txt[1.6.5.1],
  51  link:RelNotes-1.6.5.txt[1.6.5].
  52
  53* link:v1.6.4.4/git.html[documentation for release 1.6.4.4]
  54
  55* release notes for
  56  link:RelNotes-1.6.4.4.txt[1.6.4.4],
  57  link:RelNotes-1.6.4.3.txt[1.6.4.3],
  58  link:RelNotes-1.6.4.2.txt[1.6.4.2],
  59  link:RelNotes-1.6.4.1.txt[1.6.4.1],
  60  link:RelNotes-1.6.4.txt[1.6.4].
  61
  62* link:v1.6.3.4/git.html[documentation for release 1.6.3.4]
  63
  64* release notes for
  65  link:RelNotes-1.6.3.4.txt[1.6.3.4],
  66  link:RelNotes-1.6.3.3.txt[1.6.3.3],
  67  link:RelNotes-1.6.3.2.txt[1.6.3.2],
  68  link:RelNotes-1.6.3.1.txt[1.6.3.1],
  69  link:RelNotes-1.6.3.txt[1.6.3].
  70
  71* release notes for
  72  link:RelNotes-1.6.2.5.txt[1.6.2.5],
  73  link:RelNotes-1.6.2.4.txt[1.6.2.4],
  74  link:RelNotes-1.6.2.3.txt[1.6.2.3],
  75  link:RelNotes-1.6.2.2.txt[1.6.2.2],
  76  link:RelNotes-1.6.2.1.txt[1.6.2.1],
  77  link:RelNotes-1.6.2.txt[1.6.2].
  78
  79* link:v1.6.1.3/git.html[documentation for release 1.6.1.3]
  80
  81* release notes for
  82  link:RelNotes-1.6.1.3.txt[1.6.1.3],
  83  link:RelNotes-1.6.1.2.txt[1.6.1.2],
  84  link:RelNotes-1.6.1.1.txt[1.6.1.1],
  85  link:RelNotes-1.6.1.txt[1.6.1].
  86
  87* link:v1.6.0.6/git.html[documentation for release 1.6.0.6]
  88
  89* release notes for
  90  link:RelNotes-1.6.0.6.txt[1.6.0.6],
  91  link:RelNotes-1.6.0.5.txt[1.6.0.5],
  92  link:RelNotes-1.6.0.4.txt[1.6.0.4],
  93  link:RelNotes-1.6.0.3.txt[1.6.0.3],
  94  link:RelNotes-1.6.0.2.txt[1.6.0.2],
  95  link:RelNotes-1.6.0.1.txt[1.6.0.1],
  96  link:RelNotes-1.6.0.txt[1.6.0].
  97
  98* link:v1.5.6.6/git.html[documentation for release 1.5.6.6]
  99
 100* release notes for
 101  link:RelNotes-1.5.6.6.txt[1.5.6.6],
 102  link:RelNotes-1.5.6.5.txt[1.5.6.5],
 103  link:RelNotes-1.5.6.4.txt[1.5.6.4],
 104  link:RelNotes-1.5.6.3.txt[1.5.6.3],
 105  link:RelNotes-1.5.6.2.txt[1.5.6.2],
 106  link:RelNotes-1.5.6.1.txt[1.5.6.1],
 107  link:RelNotes-1.5.6.txt[1.5.6].
 108
 109* link:v1.5.5.6/git.html[documentation for release 1.5.5.6]
 110
 111* release notes for
 112  link:RelNotes-1.5.5.6.txt[1.5.5.6],
 113  link:RelNotes-1.5.5.5.txt[1.5.5.5],
 114  link:RelNotes-1.5.5.4.txt[1.5.5.4],
 115  link:RelNotes-1.5.5.3.txt[1.5.5.3],
 116  link:RelNotes-1.5.5.2.txt[1.5.5.2],
 117  link:RelNotes-1.5.5.1.txt[1.5.5.1],
 118  link:RelNotes-1.5.5.txt[1.5.5].
 119
 120* link:v1.5.4.7/git.html[documentation for release 1.5.4.7]
 121
 122* release notes for
 123  link:RelNotes-1.5.4.7.txt[1.5.4.7],
 124  link:RelNotes-1.5.4.6.txt[1.5.4.6],
 125  link:RelNotes-1.5.4.5.txt[1.5.4.5],
 126  link:RelNotes-1.5.4.4.txt[1.5.4.4],
 127  link:RelNotes-1.5.4.3.txt[1.5.4.3],
 128  link:RelNotes-1.5.4.2.txt[1.5.4.2],
 129  link:RelNotes-1.5.4.1.txt[1.5.4.1],
 130  link:RelNotes-1.5.4.txt[1.5.4].
 131
 132* link:v1.5.3.8/git.html[documentation for release 1.5.3.8]
 133
 134* release notes for
 135  link:RelNotes-1.5.3.8.txt[1.5.3.8],
 136  link:RelNotes-1.5.3.7.txt[1.5.3.7],
 137  link:RelNotes-1.5.3.6.txt[1.5.3.6],
 138  link:RelNotes-1.5.3.5.txt[1.5.3.5],
 139  link:RelNotes-1.5.3.4.txt[1.5.3.4],
 140  link:RelNotes-1.5.3.3.txt[1.5.3.3],
 141  link:RelNotes-1.5.3.2.txt[1.5.3.2],
 142  link:RelNotes-1.5.3.1.txt[1.5.3.1],
 143  link:RelNotes-1.5.3.txt[1.5.3].
 144
 145* link:v1.5.2.5/git.html[documentation for release 1.5.2.5]
 146
 147* release notes for
 148  link:RelNotes-1.5.2.5.txt[1.5.2.5],
 149  link:RelNotes-1.5.2.4.txt[1.5.2.4],
 150  link:RelNotes-1.5.2.3.txt[1.5.2.3],
 151  link:RelNotes-1.5.2.2.txt[1.5.2.2],
 152  link:RelNotes-1.5.2.1.txt[1.5.2.1],
 153  link:RelNotes-1.5.2.txt[1.5.2].
 154
 155* link:v1.5.1.6/git.html[documentation for release 1.5.1.6]
 156
 157* release notes for
 158  link:RelNotes-1.5.1.6.txt[1.5.1.6],
 159  link:RelNotes-1.5.1.5.txt[1.5.1.5],
 160  link:RelNotes-1.5.1.4.txt[1.5.1.4],
 161  link:RelNotes-1.5.1.3.txt[1.5.1.3],
 162  link:RelNotes-1.5.1.2.txt[1.5.1.2],
 163  link:RelNotes-1.5.1.1.txt[1.5.1.1],
 164  link:RelNotes-1.5.1.txt[1.5.1].
 165
 166* link:v1.5.0.7/git.html[documentation for release 1.5.0.7]
 167
 168* release notes for
 169  link:RelNotes-1.5.0.7.txt[1.5.0.7],
 170  link:RelNotes-1.5.0.6.txt[1.5.0.6],
 171  link:RelNotes-1.5.0.5.txt[1.5.0.5],
 172  link:RelNotes-1.5.0.3.txt[1.5.0.3],
 173  link:RelNotes-1.5.0.2.txt[1.5.0.2],
 174  link:RelNotes-1.5.0.1.txt[1.5.0.1],
 175  link:RelNotes-1.5.0.txt[1.5.0].
 176
 177* documentation for release link:v1.4.4.4/git.html[1.4.4.4],
 178  link:v1.3.3/git.html[1.3.3],
 179  link:v1.2.6/git.html[1.2.6],
 180  link:v1.0.13/git.html[1.0.13].
 181
 182============
 183
 184endif::stalenotes[]
 185
 186OPTIONS
 187-------
 188--version::
 189        Prints the git suite version that the 'git' program came from.
 190
 191--help::
 192        Prints the synopsis and a list of the most commonly used
 193        commands. If the option '--all' or '-a' is given then all
 194        available commands are printed. If a git command is named this
 195        option will bring up the manual page for that command.
 196+
 197Other options are available to control how the manual page is
 198displayed. See linkgit:git-help[1] for more information,
 199because `git --help ...` is converted internally into `git
 200help ...`.
 201
 202--exec-path::
 203        Path to wherever your core git programs are installed.
 204        This can also be controlled by setting the GIT_EXEC_PATH
 205        environment variable. If no path is given, 'git' will print
 206        the current setting and then exit.
 207
 208--html-path::
 209        Print the path to wherever your git HTML documentation is installed
 210        and exit.
 211
 212-p::
 213--paginate::
 214        Pipe all output into 'less' (or if set, $PAGER).
 215
 216--no-pager::
 217        Do not pipe git output into a pager.
 218
 219--git-dir=<path>::
 220        Set the path to the repository. This can also be controlled by
 221        setting the GIT_DIR environment variable. It can be an absolute
 222        path or relative path to current working directory.
 223
 224--work-tree=<path>::
 225        Set the path to the working tree.  The value will not be
 226        used in combination with repositories found automatically in
 227        a .git directory (i.e. $GIT_DIR is not set).
 228        This can also be controlled by setting the GIT_WORK_TREE
 229        environment variable and the core.worktree configuration
 230        variable. It can be an absolute path or relative path to
 231        the directory specified by --git-dir or GIT_DIR.
 232        Note: If --git-dir or GIT_DIR are specified but none of
 233        --work-tree, GIT_WORK_TREE and core.worktree is specified,
 234        the current working directory is regarded as the top directory
 235        of your working tree.
 236
 237--bare::
 238        Treat the repository as a bare repository.  If GIT_DIR
 239        environment is not set, it is set to the current working
 240        directory.
 241
 242
 243FURTHER DOCUMENTATION
 244---------------------
 245
 246See the references above to get started using git.  The following is
 247probably more detail than necessary for a first-time user.
 248
 249The link:user-manual.html#git-concepts[git concepts chapter of the
 250user-manual] and linkgit:gitcore-tutorial[7] both provide
 251introductions to the underlying git architecture.
 252
 253See linkgit:gitworkflows[7] for an overview of recommended workflows.
 254
 255See also the link:howto-index.html[howto] documents for some useful
 256examples.
 257
 258The internals are documented in the
 259link:technical/api-index.html[GIT API documentation].
 260
 261GIT COMMANDS
 262------------
 263
 264We divide git into high level ("porcelain") commands and low level
 265("plumbing") commands.
 266
 267High-level commands (porcelain)
 268-------------------------------
 269
 270We separate the porcelain commands into the main commands and some
 271ancillary user utilities.
 272
 273Main porcelain commands
 274~~~~~~~~~~~~~~~~~~~~~~~
 275
 276include::cmds-mainporcelain.txt[]
 277
 278Ancillary Commands
 279~~~~~~~~~~~~~~~~~~
 280Manipulators:
 281
 282include::cmds-ancillarymanipulators.txt[]
 283
 284Interrogators:
 285
 286include::cmds-ancillaryinterrogators.txt[]
 287
 288
 289Interacting with Others
 290~~~~~~~~~~~~~~~~~~~~~~~
 291
 292These commands are to interact with foreign SCM and with other
 293people via patch over e-mail.
 294
 295include::cmds-foreignscminterface.txt[]
 296
 297
 298Low-level commands (plumbing)
 299-----------------------------
 300
 301Although git includes its
 302own porcelain layer, its low-level commands are sufficient to support
 303development of alternative porcelains.  Developers of such porcelains
 304might start by reading about linkgit:git-update-index[1] and
 305linkgit:git-read-tree[1].
 306
 307The interface (input, output, set of options and the semantics)
 308to these low-level commands are meant to be a lot more stable
 309than Porcelain level commands, because these commands are
 310primarily for scripted use.  The interface to Porcelain commands
 311on the other hand are subject to change in order to improve the
 312end user experience.
 313
 314The following description divides
 315the low-level commands into commands that manipulate objects (in
 316the repository, index, and working tree), commands that interrogate and
 317compare objects, and commands that move objects and references between
 318repositories.
 319
 320
 321Manipulation commands
 322~~~~~~~~~~~~~~~~~~~~~
 323
 324include::cmds-plumbingmanipulators.txt[]
 325
 326
 327Interrogation commands
 328~~~~~~~~~~~~~~~~~~~~~~
 329
 330include::cmds-plumbinginterrogators.txt[]
 331
 332In general, the interrogate commands do not touch the files in
 333the working tree.
 334
 335
 336Synching repositories
 337~~~~~~~~~~~~~~~~~~~~~
 338
 339include::cmds-synchingrepositories.txt[]
 340
 341The following are helper commands used by the above; end users
 342typically do not use them directly.
 343
 344include::cmds-synchelpers.txt[]
 345
 346
 347Internal helper commands
 348~~~~~~~~~~~~~~~~~~~~~~~~
 349
 350These are internal helper commands used by other commands; end
 351users typically do not use them directly.
 352
 353include::cmds-purehelpers.txt[]
 354
 355
 356Configuration Mechanism
 357-----------------------
 358
 359Starting from 0.99.9 (actually mid 0.99.8.GIT), `.git/config` file
 360is used to hold per-repository configuration options.  It is a
 361simple text file modeled after `.ini` format familiar to some
 362people.  Here is an example:
 363
 364------------
 365#
 366# A '#' or ';' character indicates a comment.
 367#
 368
 369; core variables
 370[core]
 371        ; Don't trust file modes
 372        filemode = false
 373
 374; user identity
 375[user]
 376        name = "Junio C Hamano"
 377        email = "junkio@twinsun.com"
 378
 379------------
 380
 381Various commands read from the configuration file and adjust
 382their operation accordingly.
 383
 384
 385Identifier Terminology
 386----------------------
 387<object>::
 388        Indicates the object name for any type of object.
 389
 390<blob>::
 391        Indicates a blob object name.
 392
 393<tree>::
 394        Indicates a tree object name.
 395
 396<commit>::
 397        Indicates a commit object name.
 398
 399<tree-ish>::
 400        Indicates a tree, commit or tag object name.  A
 401        command that takes a <tree-ish> argument ultimately wants to
 402        operate on a <tree> object but automatically dereferences
 403        <commit> and <tag> objects that point at a <tree>.
 404
 405<commit-ish>::
 406        Indicates a commit or tag object name.  A
 407        command that takes a <commit-ish> argument ultimately wants to
 408        operate on a <commit> object but automatically dereferences
 409        <tag> objects that point at a <commit>.
 410
 411<type>::
 412        Indicates that an object type is required.
 413        Currently one of: `blob`, `tree`, `commit`, or `tag`.
 414
 415<file>::
 416        Indicates a filename - almost always relative to the
 417        root of the tree structure `GIT_INDEX_FILE` describes.
 418
 419Symbolic Identifiers
 420--------------------
 421Any git command accepting any <object> can also use the following
 422symbolic notation:
 423
 424HEAD::
 425        indicates the head of the current branch (i.e. the
 426        contents of `$GIT_DIR/HEAD`).
 427
 428<tag>::
 429        a valid tag 'name'
 430        (i.e. the contents of `$GIT_DIR/refs/tags/<tag>`).
 431
 432<head>::
 433        a valid head 'name'
 434        (i.e. the contents of `$GIT_DIR/refs/heads/<head>`).
 435
 436For a more complete list of ways to spell object names, see
 437"SPECIFYING REVISIONS" section in linkgit:git-rev-parse[1].
 438
 439
 440File/Directory Structure
 441------------------------
 442
 443Please see the linkgit:gitrepository-layout[5] document.
 444
 445Read linkgit:githooks[5] for more details about each hook.
 446
 447Higher level SCMs may provide and manage additional information in the
 448`$GIT_DIR`.
 449
 450
 451Terminology
 452-----------
 453Please see linkgit:gitglossary[7].
 454
 455
 456Environment Variables
 457---------------------
 458Various git commands use the following environment variables:
 459
 460The git Repository
 461~~~~~~~~~~~~~~~~~~
 462These environment variables apply to 'all' core git commands. Nb: it
 463is worth noting that they may be used/overridden by SCMS sitting above
 464git so take care if using Cogito etc.
 465
 466'GIT_INDEX_FILE'::
 467        This environment allows the specification of an alternate
 468        index file. If not specified, the default of `$GIT_DIR/index`
 469        is used.
 470
 471'GIT_OBJECT_DIRECTORY'::
 472        If the object storage directory is specified via this
 473        environment variable then the sha1 directories are created
 474        underneath - otherwise the default `$GIT_DIR/objects`
 475        directory is used.
 476
 477'GIT_ALTERNATE_OBJECT_DIRECTORIES'::
 478        Due to the immutable nature of git objects, old objects can be
 479        archived into shared, read-only directories. This variable
 480        specifies a ":" separated (on Windows ";" separated) list
 481        of git object directories which can be used to search for git
 482        objects. New objects will not be written to these directories.
 483
 484'GIT_DIR'::
 485        If the 'GIT_DIR' environment variable is set then it
 486        specifies a path to use instead of the default `.git`
 487        for the base of the repository.
 488
 489'GIT_WORK_TREE'::
 490        Set the path to the working tree.  The value will not be
 491        used in combination with repositories found automatically in
 492        a .git directory (i.e. $GIT_DIR is not set).
 493        This can also be controlled by the '--work-tree' command line
 494        option and the core.worktree configuration variable.
 495
 496'GIT_CEILING_DIRECTORIES'::
 497        This should be a colon-separated list of absolute paths.
 498        If set, it is a list of directories that git should not chdir
 499        up into while looking for a repository directory.
 500        It will not exclude the current working directory or
 501        a GIT_DIR set on the command line or in the environment.
 502        (Useful for excluding slow-loading network directories.)
 503
 504git Commits
 505~~~~~~~~~~~
 506'GIT_AUTHOR_NAME'::
 507'GIT_AUTHOR_EMAIL'::
 508'GIT_AUTHOR_DATE'::
 509'GIT_COMMITTER_NAME'::
 510'GIT_COMMITTER_EMAIL'::
 511'GIT_COMMITTER_DATE'::
 512'EMAIL'::
 513        see linkgit:git-commit-tree[1]
 514
 515git Diffs
 516~~~~~~~~~
 517'GIT_DIFF_OPTS'::
 518        Only valid setting is "--unified=??" or "-u??" to set the
 519        number of context lines shown when a unified diff is created.
 520        This takes precedence over any "-U" or "--unified" option
 521        value passed on the git diff command line.
 522
 523'GIT_EXTERNAL_DIFF'::
 524        When the environment variable 'GIT_EXTERNAL_DIFF' is set, the
 525        program named by it is called, instead of the diff invocation
 526        described above.  For a path that is added, removed, or modified,
 527        'GIT_EXTERNAL_DIFF' is called with 7 parameters:
 528
 529        path old-file old-hex old-mode new-file new-hex new-mode
 530+
 531where:
 532
 533        <old|new>-file:: are files GIT_EXTERNAL_DIFF can use to read the
 534                         contents of <old|new>,
 535        <old|new>-hex:: are the 40-hexdigit SHA1 hashes,
 536        <old|new>-mode:: are the octal representation of the file modes.
 537
 538+
 539The file parameters can point at the user's working file
 540(e.g. `new-file` in "git-diff-files"), `/dev/null` (e.g. `old-file`
 541when a new file is added), or a temporary file (e.g. `old-file` in the
 542index).  'GIT_EXTERNAL_DIFF' should not worry about unlinking the
 543temporary file --- it is removed when 'GIT_EXTERNAL_DIFF' exits.
 544+
 545For a path that is unmerged, 'GIT_EXTERNAL_DIFF' is called with 1
 546parameter, <path>.
 547
 548other
 549~~~~~
 550'GIT_MERGE_VERBOSITY'::
 551        A number controlling the amount of output shown by
 552        the recursive merge strategy.  Overrides merge.verbosity.
 553        See linkgit:git-merge[1]
 554
 555'GIT_PAGER'::
 556        This environment variable overrides `$PAGER`. If it is set
 557        to an empty string or to the value "cat", git will not launch
 558        a pager.  See also the `core.pager` option in
 559        linkgit:git-config[1].
 560
 561'GIT_SSH'::
 562        If this environment variable is set then 'git-fetch'
 563        and 'git-push' will use this command instead
 564        of 'ssh' when they need to connect to a remote system.
 565        The '$GIT_SSH' command will be given exactly two arguments:
 566        the 'username@host' (or just 'host') from the URL and the
 567        shell command to execute on that remote system.
 568+
 569To pass options to the program that you want to list in GIT_SSH
 570you will need to wrap the program and options into a shell script,
 571then set GIT_SSH to refer to the shell script.
 572+
 573Usually it is easier to configure any desired options through your
 574personal `.ssh/config` file.  Please consult your ssh documentation
 575for further details.
 576
 577'GIT_FLUSH'::
 578        If this environment variable is set to "1", then commands such
 579        as 'git-blame' (in incremental mode), 'git-rev-list', 'git-log',
 580        and 'git-whatchanged' will force a flush of the output stream
 581        after each commit-oriented record have been flushed.   If this
 582        variable is set to "0", the output of these commands will be done
 583        using completely buffered I/O.   If this environment variable is
 584        not set, git will choose buffered or record-oriented flushing
 585        based on whether stdout appears to be redirected to a file or not.
 586
 587'GIT_TRACE'::
 588        If this variable is set to "1", "2" or "true" (comparison
 589        is case insensitive), git will print `trace:` messages on
 590        stderr telling about alias expansion, built-in command
 591        execution and external command execution.
 592        If this variable is set to an integer value greater than 1
 593        and lower than 10 (strictly) then git will interpret this
 594        value as an open file descriptor and will try to write the
 595        trace messages into this file descriptor.
 596        Alternatively, if this variable is set to an absolute path
 597        (starting with a '/' character), git will interpret this
 598        as a file path and will try to write the trace messages
 599        into it.
 600
 601Discussion[[Discussion]]
 602------------------------
 603
 604More detail on the following is available from the
 605link:user-manual.html#git-concepts[git concepts chapter of the
 606user-manual] and linkgit:gitcore-tutorial[7].
 607
 608A git project normally consists of a working directory with a ".git"
 609subdirectory at the top level.  The .git directory contains, among other
 610things, a compressed object database representing the complete history
 611of the project, an "index" file which links that history to the current
 612contents of the working tree, and named pointers into that history such
 613as tags and branch heads.
 614
 615The object database contains objects of three main types: blobs, which
 616hold file data; trees, which point to blobs and other trees to build up
 617directory hierarchies; and commits, which each reference a single tree
 618and some number of parent commits.
 619
 620The commit, equivalent to what other systems call a "changeset" or
 621"version", represents a step in the project's history, and each parent
 622represents an immediately preceding step.  Commits with more than one
 623parent represent merges of independent lines of development.
 624
 625All objects are named by the SHA1 hash of their contents, normally
 626written as a string of 40 hex digits.  Such names are globally unique.
 627The entire history leading up to a commit can be vouched for by signing
 628just that commit.  A fourth object type, the tag, is provided for this
 629purpose.
 630
 631When first created, objects are stored in individual files, but for
 632efficiency may later be compressed together into "pack files".
 633
 634Named pointers called refs mark interesting points in history.  A ref
 635may contain the SHA1 name of an object or the name of another ref.  Refs
 636with names beginning `ref/head/` contain the SHA1 name of the most
 637recent commit (or "head") of a branch under development.  SHA1 names of
 638tags of interest are stored under `ref/tags/`.  A special ref named
 639`HEAD` contains the name of the currently checked-out branch.
 640
 641The index file is initialized with a list of all paths and, for each
 642path, a blob object and a set of attributes.  The blob object represents
 643the contents of the file as of the head of the current branch.  The
 644attributes (last modified time, size, etc.) are taken from the
 645corresponding file in the working tree.  Subsequent changes to the
 646working tree can be found by comparing these attributes.  The index may
 647be updated with new content, and new commits may be created from the
 648content stored in the index.
 649
 650The index is also capable of storing multiple entries (called "stages")
 651for a given pathname.  These stages are used to hold the various
 652unmerged version of a file when a merge is in progress.
 653
 654Authors
 655-------
 656* git's founding father is Linus Torvalds <torvalds@osdl.org>.
 657* The current git nurse is Junio C Hamano <gitster@pobox.com>.
 658* The git potty was written by Andreas Ericsson <ae@op5.se>.
 659* General upbringing is handled by the git-list <git@vger.kernel.org>.
 660
 661Documentation
 662--------------
 663The documentation for git suite was started by David Greaves
 664<david@dgreaves.com>, and later enhanced greatly by the
 665contributors on the git-list <git@vger.kernel.org>.
 666
 667SEE ALSO
 668--------
 669linkgit:gittutorial[7], linkgit:gittutorial-2[7],
 670link:everyday.html[Everyday Git], linkgit:gitcvs-migration[7],
 671linkgit:gitglossary[7], linkgit:gitcore-tutorial[7],
 672linkgit:gitcli[7], link:user-manual.html[The Git User's Manual],
 673linkgit:gitworkflows[7]
 674
 675GIT
 676---
 677Part of the linkgit:git[1] suite