Documentation/git.txt

   1 git(1)
   2 ======
   3
   4 NAME
   5 ----
   6 git - the stupid content tracker
   7
   8
   9 SYNOPSIS
  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
  17 DESCRIPTION
  18 -----------
  19 Git is a fast, scalable, distributed revision control system with an
  20 unusually rich command set that provides both high-level operations
  21 and full access to internals.
  22
  23 See linkgit:gittutorial[7] to get started, then see
  24 link:everyday.html[Everyday Git] for a useful minimum set of commands, and
  25 "man git-commandname" for documentation of each command.  CVS users may
  26 also want to read linkgit:gitcvs-migration[7].  See
  27 the link:user-manual.html[Git User's Manual] for a more in-depth
  28 introduction.
  29
  30 The COMMAND is either a name of a Git command (see below) or an alias
  31 as defined in the configuration file (see linkgit:git-config[1]).
  32
  33 Formatted and hyperlinked version of the latest git
  34 documentation can be viewed at
  35 `http://www.kernel.org/pub/software/scm/git/docs/`.
  36
  37 ifdef::stalenotes[]
  38 [NOTE]
  39 ============
  40
  41 You are reading the documentation for the latest (possibly
  42 unreleased) version of git, that is available from 'master'
  43 branch of the `git.git` repository.
  44 Documentation for older releases are available here:
  45
  46 * link:v1.6.4.3/git.html[documentation for release 1.6.4.3]
  47
  48 * release notes for
  49   link:RelNotes-1.6.4.3.txt[1.6.4.3],
  50   link:RelNotes-1.6.4.2.txt[1.6.4.2],
  51   link:RelNotes-1.6.4.1.txt[1.6.4.1],
  52   link:RelNotes-1.6.4.txt[1.6.4].
  53
  54 * link:v1.6.3.4/git.html[documentation for release 1.6.3.4]
  55
  56 * release notes for
  57   link:RelNotes-1.6.3.4.txt[1.6.3.4],
  58   link:RelNotes-1.6.3.3.txt[1.6.3.3],
  59   link:RelNotes-1.6.3.2.txt[1.6.3.2],
  60   link:RelNotes-1.6.3.1.txt[1.6.3.1],
  61   link:RelNotes-1.6.3.txt[1.6.3].
  62
  63 * release notes for
  64   link:RelNotes-1.6.2.5.txt[1.6.2.5],
  65   link:RelNotes-1.6.2.4.txt[1.6.2.4],
  66   link:RelNotes-1.6.2.3.txt[1.6.2.3],
  67   link:RelNotes-1.6.2.2.txt[1.6.2.2],
  68   link:RelNotes-1.6.2.1.txt[1.6.2.1],
  69   link:RelNotes-1.6.2.txt[1.6.2].
  70
  71 * link:v1.6.1.3/git.html[documentation for release 1.6.1.3]
  72
  73 * release notes for
  74   link:RelNotes-1.6.1.3.txt[1.6.1.3],
  75   link:RelNotes-1.6.1.2.txt[1.6.1.2],
  76   link:RelNotes-1.6.1.1.txt[1.6.1.1],
  77   link:RelNotes-1.6.1.txt[1.6.1].
  78
  79 * link:v1.6.0.6/git.html[documentation for release 1.6.0.6]
  80
  81 * release notes for
  82   link:RelNotes-1.6.0.6.txt[1.6.0.6],
  83   link:RelNotes-1.6.0.5.txt[1.6.0.5],
  84   link:RelNotes-1.6.0.4.txt[1.6.0.4],
  85   link:RelNotes-1.6.0.3.txt[1.6.0.3],
  86   link:RelNotes-1.6.0.2.txt[1.6.0.2],
  87   link:RelNotes-1.6.0.1.txt[1.6.0.1],
  88   link:RelNotes-1.6.0.txt[1.6.0].
  89
  90 * link:v1.5.6.6/git.html[documentation for release 1.5.6.6]
  91
  92 * release notes for
  93   link:RelNotes-1.5.6.6.txt[1.5.6.6],
  94   link:RelNotes-1.5.6.5.txt[1.5.6.5],
  95   link:RelNotes-1.5.6.4.txt[1.5.6.4],
  96   link:RelNotes-1.5.6.3.txt[1.5.6.3],
  97   link:RelNotes-1.5.6.2.txt[1.5.6.2],
  98   link:RelNotes-1.5.6.1.txt[1.5.6.1],
  99   link:RelNotes-1.5.6.txt[1.5.6].
 100
 101 * link:v1.5.5.6/git.html[documentation for release 1.5.5.6]
 102
 103 * release notes for
 104   link:RelNotes-1.5.5.6.txt[1.5.5.6],
 105   link:RelNotes-1.5.5.5.txt[1.5.5.5],
 106   link:RelNotes-1.5.5.4.txt[1.5.5.4],
 107   link:RelNotes-1.5.5.3.txt[1.5.5.3],
 108   link:RelNotes-1.5.5.2.txt[1.5.5.2],
 109   link:RelNotes-1.5.5.1.txt[1.5.5.1],
 110   link:RelNotes-1.5.5.txt[1.5.5].
 111
 112 * link:v1.5.4.7/git.html[documentation for release 1.5.4.7]
 113
 114 * release notes for
 115   link:RelNotes-1.5.4.7.txt[1.5.4.7],
 116   link:RelNotes-1.5.4.6.txt[1.5.4.6],
 117   link:RelNotes-1.5.4.5.txt[1.5.4.5],
 118   link:RelNotes-1.5.4.4.txt[1.5.4.4],
 119   link:RelNotes-1.5.4.3.txt[1.5.4.3],
 120   link:RelNotes-1.5.4.2.txt[1.5.4.2],
 121   link:RelNotes-1.5.4.1.txt[1.5.4.1],
 122   link:RelNotes-1.5.4.txt[1.5.4].
 123
 124 * link:v1.5.3.8/git.html[documentation for release 1.5.3.8]
 125
 126 * release notes for
 127   link:RelNotes-1.5.3.8.txt[1.5.3.8],
 128   link:RelNotes-1.5.3.7.txt[1.5.3.7],
 129   link:RelNotes-1.5.3.6.txt[1.5.3.6],
 130   link:RelNotes-1.5.3.5.txt[1.5.3.5],
 131   link:RelNotes-1.5.3.4.txt[1.5.3.4],
 132   link:RelNotes-1.5.3.3.txt[1.5.3.3],
 133   link:RelNotes-1.5.3.2.txt[1.5.3.2],
 134   link:RelNotes-1.5.3.1.txt[1.5.3.1],
 135   link:RelNotes-1.5.3.txt[1.5.3].
 136
 137 * link:v1.5.2.5/git.html[documentation for release 1.5.2.5]
 138
 139 * release notes for
 140   link:RelNotes-1.5.2.5.txt[1.5.2.5],
 141   link:RelNotes-1.5.2.4.txt[1.5.2.4],
 142   link:RelNotes-1.5.2.3.txt[1.5.2.3],
 143   link:RelNotes-1.5.2.2.txt[1.5.2.2],
 144   link:RelNotes-1.5.2.1.txt[1.5.2.1],
 145   link:RelNotes-1.5.2.txt[1.5.2].
 146
 147 * link:v1.5.1.6/git.html[documentation for release 1.5.1.6]
 148
 149 * release notes for
 150   link:RelNotes-1.5.1.6.txt[1.5.1.6],
 151   link:RelNotes-1.5.1.5.txt[1.5.1.5],
 152   link:RelNotes-1.5.1.4.txt[1.5.1.4],
 153   link:RelNotes-1.5.1.3.txt[1.5.1.3],
 154   link:RelNotes-1.5.1.2.txt[1.5.1.2],
 155   link:RelNotes-1.5.1.1.txt[1.5.1.1],
 156   link:RelNotes-1.5.1.txt[1.5.1].
 157
 158 * link:v1.5.0.7/git.html[documentation for release 1.5.0.7]
 159
 160 * release notes for
 161   link:RelNotes-1.5.0.7.txt[1.5.0.7],
 162   link:RelNotes-1.5.0.6.txt[1.5.0.6],
 163   link:RelNotes-1.5.0.5.txt[1.5.0.5],
 164   link:RelNotes-1.5.0.3.txt[1.5.0.3],
 165   link:RelNotes-1.5.0.2.txt[1.5.0.2],
 166   link:RelNotes-1.5.0.1.txt[1.5.0.1],
 167   link:RelNotes-1.5.0.txt[1.5.0].
 168
 169 * documentation for release link:v1.4.4.4/git.html[1.4.4.4],
 170   link:v1.3.3/git.html[1.3.3],
 171   link:v1.2.6/git.html[1.2.6],
 172   link:v1.0.13/git.html[1.0.13].
 173
 174 ============
 175
 176 endif::stalenotes[]
 177
 178 OPTIONS
 179 -------
 180 --version::
 181         Prints the git suite version that the 'git' program came from.
 182
 183 --help::
 184         Prints the synopsis and a list of the most commonly used
 185         commands. If the option '--all' or '-a' is given then all
 186         available commands are printed. If a git command is named this
 187         option will bring up the manual page for that command.
 188 +
 189 Other options are available to control how the manual page is
 190 displayed. See linkgit:git-help[1] for more information,
 191 because `git --help ...` is converted internally into `git
 192 help ...`.
 193
 194 --exec-path::
 195         Path to wherever your core git programs are installed.
 196         This can also be controlled by setting the GIT_EXEC_PATH
 197         environment variable. If no path is given, 'git' will print
 198         the current setting and then exit.
 199
 200 --html-path::
 201         Print the path to wherever your git HTML documentation is installed
 202         and exit.
 203
 204 -p::
 205 --paginate::
 206         Pipe all output into 'less' (or if set, $PAGER).
 207
 208 --no-pager::
 209         Do not pipe git output into a pager.
 210
 211 --git-dir=<path>::
 212         Set the path to the repository. This can also be controlled by
 213         setting the GIT_DIR environment variable. It can be an absolute
 214         path or relative path to current working directory.
 215
 216 --work-tree=<path>::
 217         Set the path to the working tree.  The value will not be
 218         used in combination with repositories found automatically in
 219         a .git directory (i.e. $GIT_DIR is not set).
 220         This can also be controlled by setting the GIT_WORK_TREE
 221         environment variable and the core.worktree configuration
 222         variable. It can be an absolute path or relative path to
 223         the directory specified by --git-dir or GIT_DIR.
 224         Note: If --git-dir or GIT_DIR are specified but none of
 225         --work-tree, GIT_WORK_TREE and core.worktree is specified,
 226         the current working directory is regarded as the top directory
 227         of your working tree.
 228
 229 --bare::
 230         Treat the repository as a bare repository.  If GIT_DIR
 231         environment is not set, it is set to the current working
 232         directory.
 233
 234
 235 FURTHER DOCUMENTATION
 236 ---------------------
 237
 238 See the references above to get started using git.  The following is
 239 probably more detail than necessary for a first-time user.
 240
 241 The link:user-manual.html#git-concepts[git concepts chapter of the
 242 user-manual] and linkgit:gitcore-tutorial[7] both provide
 243 introductions to the underlying git architecture.
 244
 245 See linkgit:gitworkflows[7] for an overview of recommended workflows.
 246
 247 See also the link:howto-index.html[howto] documents for some useful
 248 examples.
 249
 250 The internals are documented in the
 251 link:technical/api-index.html[GIT API documentation].
 252
 253 GIT COMMANDS
 254 ------------
 255
 256 We divide git into high level ("porcelain") commands and low level
 257 ("plumbing") commands.
 258
 259 High-level commands (porcelain)
 260 -------------------------------
 261
 262 We separate the porcelain commands into the main commands and some
 263 ancillary user utilities.
 264
 265 Main porcelain commands
 266 ~~~~~~~~~~~~~~~~~~~~~~~
 267
 268 include::cmds-mainporcelain.txt[]
 269
 270 Ancillary Commands
 271 ~~~~~~~~~~~~~~~~~~
 272 Manipulators:
 273
 274 include::cmds-ancillarymanipulators.txt[]
 275
 276 Interrogators:
 277
 278 include::cmds-ancillaryinterrogators.txt[]
 279
 280
 281 Interacting with Others
 282 ~~~~~~~~~~~~~~~~~~~~~~~
 283
 284 These commands are to interact with foreign SCM and with other
 285 people via patch over e-mail.
 286
 287 include::cmds-foreignscminterface.txt[]
 288
 289
 290 Low-level commands (plumbing)
 291 -----------------------------
 292
 293 Although git includes its
 294 own porcelain layer, its low-level commands are sufficient to support
 295 development of alternative porcelains.  Developers of such porcelains
 296 might start by reading about linkgit:git-update-index[1] and
 297 linkgit:git-read-tree[1].
 298
 299 The interface (input, output, set of options and the semantics)
 300 to these low-level commands are meant to be a lot more stable
 301 than Porcelain level commands, because these commands are
 302 primarily for scripted use.  The interface to Porcelain commands
 303 on the other hand are subject to change in order to improve the
 304 end user experience.
 305
 306 The following description divides
 307 the low-level commands into commands that manipulate objects (in
 308 the repository, index, and working tree), commands that interrogate and
 309 compare objects, and commands that move objects and references between
 310 repositories.
 311
 312
 313 Manipulation commands
 314 ~~~~~~~~~~~~~~~~~~~~~
 315
 316 include::cmds-plumbingmanipulators.txt[]
 317
 318
 319 Interrogation commands
 320 ~~~~~~~~~~~~~~~~~~~~~~
 321
 322 include::cmds-plumbinginterrogators.txt[]
 323
 324 In general, the interrogate commands do not touch the files in
 325 the working tree.
 326
 327
 328 Synching repositories
 329 ~~~~~~~~~~~~~~~~~~~~~
 330
 331 include::cmds-synchingrepositories.txt[]
 332
 333 The following are helper commands used by the above; end users
 334 typically do not use them directly.
 335
 336 include::cmds-synchelpers.txt[]
 337
 338
 339 Internal helper commands
 340 ~~~~~~~~~~~~~~~~~~~~~~~~
 341
 342 These are internal helper commands used by other commands; end
 343 users typically do not use them directly.
 344
 345 include::cmds-purehelpers.txt[]
 346
 347
 348 Configuration Mechanism
 349 -----------------------
 350
 351 Starting from 0.99.9 (actually mid 0.99.8.GIT), `.git/config` file
 352 is used to hold per-repository configuration options.  It is a
 353 simple text file modeled after `.ini` format familiar to some
 354 people.  Here is an example:
 355
 356 ------------
 357 #
 358 # A '#' or ';' character indicates a comment.
 359 #
 360
 361 ; core variables
 362 [core]
 363         ; Don't trust file modes
 364         filemode = false
 365
 366 ; user identity
 367 [user]
 368         name = "Junio C Hamano"
 369         email = "junkio@twinsun.com"
 370
 371 ------------
 372
 373 Various commands read from the configuration file and adjust
 374 their operation accordingly.
 375
 376
 377 Identifier Terminology
 378 ----------------------
 379 <object>::
 380         Indicates the object name for any type of object.
 381
 382 <blob>::
 383         Indicates a blob object name.
 384
 385 <tree>::
 386         Indicates a tree object name.
 387
 388 <commit>::
 389         Indicates a commit object name.
 390
 391 <tree-ish>::
 392         Indicates a tree, commit or tag object name.  A
 393         command that takes a <tree-ish> argument ultimately wants to
 394         operate on a <tree> object but automatically dereferences
 395         <commit> and <tag> objects that point at a <tree>.
 396
 397 <commit-ish>::
 398         Indicates a commit or tag object name.  A
 399         command that takes a <commit-ish> argument ultimately wants to
 400         operate on a <commit> object but automatically dereferences
 401         <tag> objects that point at a <commit>.
 402
 403 <type>::
 404         Indicates that an object type is required.
 405         Currently one of: `blob`, `tree`, `commit`, or `tag`.
 406
 407 <file>::
 408         Indicates a filename - almost always relative to the
 409         root of the tree structure `GIT_INDEX_FILE` describes.
 410
 411 Symbolic Identifiers
 412 --------------------
 413 Any git command accepting any <object> can also use the following
 414 symbolic notation:
 415
 416 HEAD::
 417         indicates the head of the current branch (i.e. the
 418         contents of `$GIT_DIR/HEAD`).
 419
 420 <tag>::
 421         a valid tag 'name'
 422         (i.e. the contents of `$GIT_DIR/refs/tags/<tag>`).
 423
 424 <head>::
 425         a valid head 'name'
 426         (i.e. the contents of `$GIT_DIR/refs/heads/<head>`).
 427
 428 For a more complete list of ways to spell object names, see
 429 "SPECIFYING REVISIONS" section in linkgit:git-rev-parse[1].
 430
 431
 432 File/Directory Structure
 433 ------------------------
 434
 435 Please see the linkgit:gitrepository-layout[5] document.
 436
 437 Read linkgit:githooks[5] for more details about each hook.
 438
 439 Higher level SCMs may provide and manage additional information in the
 440 `$GIT_DIR`.
 441
 442
 443 Terminology
 444 -----------
 445 Please see linkgit:gitglossary[7].
 446
 447
 448 Environment Variables
 449 ---------------------
 450 Various git commands use the following environment variables:
 451
 452 The git Repository
 453 ~~~~~~~~~~~~~~~~~~
 454 These environment variables apply to 'all' core git commands. Nb: it
 455 is worth noting that they may be used/overridden by SCMS sitting above
 456 git so take care if using Cogito etc.
 457
 458 'GIT_INDEX_FILE'::
 459         This environment allows the specification of an alternate
 460         index file. If not specified, the default of `$GIT_DIR/index`
 461         is used.
 462
 463 'GIT_OBJECT_DIRECTORY'::
 464         If the object storage directory is specified via this
 465         environment variable then the sha1 directories are created
 466         underneath - otherwise the default `$GIT_DIR/objects`
 467         directory is used.
 468
 469 'GIT_ALTERNATE_OBJECT_DIRECTORIES'::
 470         Due to the immutable nature of git objects, old objects can be
 471         archived into shared, read-only directories. This variable
 472         specifies a ":" separated (on Windows ";" separated) list
 473         of git object directories which can be used to search for git
 474         objects. New objects will not be written to these directories.
 475
 476 'GIT_DIR'::
 477         If the 'GIT_DIR' environment variable is set then it
 478         specifies a path to use instead of the default `.git`
 479         for the base of the repository.
 480
 481 'GIT_WORK_TREE'::
 482         Set the path to the working tree.  The value will not be
 483         used in combination with repositories found automatically in
 484         a .git directory (i.e. $GIT_DIR is not set).
 485         This can also be controlled by the '--work-tree' command line
 486         option and the core.worktree configuration variable.
 487
 488 'GIT_CEILING_DIRECTORIES'::
 489         This should be a colon-separated list of absolute paths.
 490         If set, it is a list of directories that git should not chdir
 491         up into while looking for a repository directory.
 492         It will not exclude the current working directory or
 493         a GIT_DIR set on the command line or in the environment.
 494         (Useful for excluding slow-loading network directories.)
 495
 496 git Commits
 497 ~~~~~~~~~~~
 498 'GIT_AUTHOR_NAME'::
 499 'GIT_AUTHOR_EMAIL'::
 500 'GIT_AUTHOR_DATE'::
 501 'GIT_COMMITTER_NAME'::
 502 'GIT_COMMITTER_EMAIL'::
 503 'GIT_COMMITTER_DATE'::
 504 'EMAIL'::
 505         see linkgit:git-commit-tree[1]
 506
 507 git Diffs
 508 ~~~~~~~~~
 509 'GIT_DIFF_OPTS'::
 510         Only valid setting is "--unified=??" or "-u??" to set the
 511         number of context lines shown when a unified diff is created.
 512         This takes precedence over any "-U" or "--unified" option
 513         value passed on the git diff command line.
 514
 515 'GIT_EXTERNAL_DIFF'::
 516         When the environment variable 'GIT_EXTERNAL_DIFF' is set, the
 517         program named by it is called, instead of the diff invocation
 518         described above.  For a path that is added, removed, or modified,
 519         'GIT_EXTERNAL_DIFF' is called with 7 parameters:
 520
 521         path old-file old-hex old-mode new-file new-hex new-mode
 522 +
 523 where:
 524
 525         <old|new>-file:: are files GIT_EXTERNAL_DIFF can use to read the
 526                          contents of <old|new>,
 527         <old|new>-hex:: are the 40-hexdigit SHA1 hashes,
 528         <old|new>-mode:: are the octal representation of the file modes.
 529
 530 +
 531 The file parameters can point at the user's working file
 532 (e.g. `new-file` in "git-diff-files"), `/dev/null` (e.g. `old-file`
 533 when a new file is added), or a temporary file (e.g. `old-file` in the
 534 index).  'GIT_EXTERNAL_DIFF' should not worry about unlinking the
 535 temporary file --- it is removed when 'GIT_EXTERNAL_DIFF' exits.
 536 +
 537 For a path that is unmerged, 'GIT_EXTERNAL_DIFF' is called with 1
 538 parameter, <path>.
 539
 540 other
 541 ~~~~~
 542 'GIT_MERGE_VERBOSITY'::
 543         A number controlling the amount of output shown by
 544         the recursive merge strategy.  Overrides merge.verbosity.
 545         See linkgit:git-merge[1]
 546
 547 'GIT_PAGER'::
 548         This environment variable overrides `$PAGER`. If it is set
 549         to an empty string or to the value "cat", git will not launch
 550         a pager.  See also the `core.pager` option in
 551         linkgit:git-config[1].
 552
 553 'GIT_SSH'::
 554         If this environment variable is set then 'git-fetch'
 555         and 'git-push' will use this command instead
 556         of 'ssh' when they need to connect to a remote system.
 557         The '$GIT_SSH' command will be given exactly two arguments:
 558         the 'username@host' (or just 'host') from the URL and the
 559         shell command to execute on that remote system.
 560 +
 561 To pass options to the program that you want to list in GIT_SSH
 562 you will need to wrap the program and options into a shell script,
 563 then set GIT_SSH to refer to the shell script.
 564 +
 565 Usually it is easier to configure any desired options through your
 566 personal `.ssh/config` file.  Please consult your ssh documentation
 567 for further details.
 568
 569 'GIT_FLUSH'::
 570         If this environment variable is set to "1", then commands such
 571         as 'git-blame' (in incremental mode), 'git-rev-list', 'git-log',
 572         and 'git-whatchanged' will force a flush of the output stream
 573         after each commit-oriented record have been flushed.   If this
 574         variable is set to "0", the output of these commands will be done
 575         using completely buffered I/O.   If this environment variable is
 576         not set, git will choose buffered or record-oriented flushing
 577         based on whether stdout appears to be redirected to a file or not.
 578
 579 'GIT_TRACE'::
 580         If this variable is set to "1", "2" or "true" (comparison
 581         is case insensitive), git will print `trace:` messages on
 582         stderr telling about alias expansion, built-in command
 583         execution and external command execution.
 584         If this variable is set to an integer value greater than 1
 585         and lower than 10 (strictly) then git will interpret this
 586         value as an open file descriptor and will try to write the
 587         trace messages into this file descriptor.
 588         Alternatively, if this variable is set to an absolute path
 589         (starting with a '/' character), git will interpret this
 590         as a file path and will try to write the trace messages
 591         into it.
 592
 593 Discussion[[Discussion]]
 594 ------------------------
 595
 596 More detail on the following is available from the
 597 link:user-manual.html#git-concepts[git concepts chapter of the
 598 user-manual] and linkgit:gitcore-tutorial[7].
 599
 600 A git project normally consists of a working directory with a ".git"
 601 subdirectory at the top level.  The .git directory contains, among other
 602 things, a compressed object database representing the complete history
 603 of the project, an "index" file which links that history to the current
 604 contents of the working tree, and named pointers into that history such
 605 as tags and branch heads.
 606
 607 The object database contains objects of three main types: blobs, which
 608 hold file data; trees, which point to blobs and other trees to build up
 609 directory hierarchies; and commits, which each reference a single tree
 610 and some number of parent commits.
 611
 612 The commit, equivalent to what other systems call a "changeset" or
 613 "version", represents a step in the project's history, and each parent
 614 represents an immediately preceding step.  Commits with more than one
 615 parent represent merges of independent lines of development.
 616
 617 All objects are named by the SHA1 hash of their contents, normally
 618 written as a string of 40 hex digits.  Such names are globally unique.
 619 The entire history leading up to a commit can be vouched for by signing
 620 just that commit.  A fourth object type, the tag, is provided for this
 621 purpose.
 622
 623 When first created, objects are stored in individual files, but for
 624 efficiency may later be compressed together into "pack files".
 625
 626 Named pointers called refs mark interesting points in history.  A ref
 627 may contain the SHA1 name of an object or the name of another ref.  Refs
 628 with names beginning `ref/head/` contain the SHA1 name of the most
 629 recent commit (or "head") of a branch under development.  SHA1 names of
 630 tags of interest are stored under `ref/tags/`.  A special ref named
 631 `HEAD` contains the name of the currently checked-out branch.
 632
 633 The index file is initialized with a list of all paths and, for each
 634 path, a blob object and a set of attributes.  The blob object represents
 635 the contents of the file as of the head of the current branch.  The
 636 attributes (last modified time, size, etc.) are taken from the
 637 corresponding file in the working tree.  Subsequent changes to the
 638 working tree can be found by comparing these attributes.  The index may
 639 be updated with new content, and new commits may be created from the
 640 content stored in the index.
 641
 642 The index is also capable of storing multiple entries (called "stages")
 643 for a given pathname.  These stages are used to hold the various
 644 unmerged version of a file when a merge is in progress.
 645
 646 Authors
 647 -------
 648 * git's founding father is Linus Torvalds <torvalds@osdl.org>.
 649 * The current git nurse is Junio C Hamano <gitster@pobox.com>.
 650 * The git potty was written by Andreas Ericsson <ae@op5.se>.
 651 * General upbringing is handled by the git-list <git@vger.kernel.org>.
 652
 653 Documentation
 654 --------------
 655 The documentation for git suite was started by David Greaves
 656 <david@dgreaves.com>, and later enhanced greatly by the
 657 contributors on the git-list <git@vger.kernel.org>.
 658
 659 SEE ALSO
 660 --------
 661 linkgit:gittutorial[7], linkgit:gittutorial-2[7],
 662 link:everyday.html[Everyday Git], linkgit:gitcvs-migration[7],
 663 linkgit:gitglossary[7], linkgit:gitcore-tutorial[7],
 664 linkgit:gitcli[7], link:user-manual.html[The Git User's Manual],
 665 linkgit:gitworkflows[7]
 666
 667 GIT
 668 ---
 669 Part of the linkgit:git[1] suite