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 [-c name=value] 16 [--help] COMMAND [ARGS] 17 18DESCRIPTION 19----------- 20Git is a fast, scalable, distributed revision control system with an 21unusually rich command set that provides both high-level operations 22and full access to internals. 23 24See linkgit:gittutorial[7] to get started, then see 25link:everyday.html[Everyday Git] for a useful minimum set of commands, and 26"man git-commandname" for documentation of each command. CVS users may 27also want to read linkgit:gitcvs-migration[7]. See 28the link:user-manual.html[Git User's Manual] for a more in-depth 29introduction. 30 31The COMMAND is either a name of a Git command (see below) or an alias 32as defined in the configuration file (see linkgit:git-config[1]). 33 34Formatted and hyperlinked version of the latest git 35documentation can be viewed at 36`http://www.kernel.org/pub/software/scm/git/docs/`. 37 38ifdef::stalenotes[] 39[NOTE] 40============ 41 42You are reading the documentation for the latest (possibly 43unreleased) version of git, that is available from 'master' 44branch of the `git.git` repository. 45Documentation for older releases are available here: 46 47* link:v1.7.2/git.html[documentation for release 1.7.2] 48 49* release notes for 50 link:RelNotes-1.7.2.txt[1.7.2]. 51 52* link:v1.7.1.1/git.html[documentation for release 1.7.1.1] 53 54* release notes for 55 link:RelNotes-1.7.1.1.txt[1.7.1.1], 56 link:RelNotes-1.7.1.txt[1.7.1]. 57 58* link:v1.7.0.6/git.html[documentation for release 1.7.0.6] 59 60* release notes for 61 link:RelNotes-1.7.0.6.txt[1.7.0.6], 62 link:RelNotes-1.7.0.5.txt[1.7.0.5], 63 link:RelNotes-1.7.0.4.txt[1.7.0.4], 64 link:RelNotes-1.7.0.3.txt[1.7.0.3], 65 link:RelNotes-1.7.0.2.txt[1.7.0.2], 66 link:RelNotes-1.7.0.1.txt[1.7.0.1], 67 link:RelNotes-1.7.0.txt[1.7.0]. 68 69* link:v1.6.6.2/git.html[documentation for release 1.6.6.2] 70 71* release notes for 72 link:RelNotes-1.6.6.2.txt[1.6.6.2], 73 link:RelNotes-1.6.6.1.txt[1.6.6.1], 74 link:RelNotes-1.6.6.txt[1.6.6]. 75 76* link:v1.6.5.8/git.html[documentation for release 1.6.5.8] 77 78* release notes for 79 link:RelNotes-1.6.5.8.txt[1.6.5.8], 80 link:RelNotes-1.6.5.7.txt[1.6.5.7], 81 link:RelNotes-1.6.5.6.txt[1.6.5.6], 82 link:RelNotes-1.6.5.5.txt[1.6.5.5], 83 link:RelNotes-1.6.5.4.txt[1.6.5.4], 84 link:RelNotes-1.6.5.3.txt[1.6.5.3], 85 link:RelNotes-1.6.5.2.txt[1.6.5.2], 86 link:RelNotes-1.6.5.1.txt[1.6.5.1], 87 link:RelNotes-1.6.5.txt[1.6.5]. 88 89* link:v1.6.4.4/git.html[documentation for release 1.6.4.4] 90 91* release notes for 92 link:RelNotes-1.6.4.4.txt[1.6.4.4], 93 link:RelNotes-1.6.4.3.txt[1.6.4.3], 94 link:RelNotes-1.6.4.2.txt[1.6.4.2], 95 link:RelNotes-1.6.4.1.txt[1.6.4.1], 96 link:RelNotes-1.6.4.txt[1.6.4]. 97 98* link:v1.6.3.4/git.html[documentation for release 1.6.3.4] 99 100* release notes for 101 link:RelNotes-1.6.3.4.txt[1.6.3.4], 102 link:RelNotes-1.6.3.3.txt[1.6.3.3], 103 link:RelNotes-1.6.3.2.txt[1.6.3.2], 104 link:RelNotes-1.6.3.1.txt[1.6.3.1], 105 link:RelNotes-1.6.3.txt[1.6.3]. 106 107* release notes for 108 link:RelNotes-1.6.2.5.txt[1.6.2.5], 109 link:RelNotes-1.6.2.4.txt[1.6.2.4], 110 link:RelNotes-1.6.2.3.txt[1.6.2.3], 111 link:RelNotes-1.6.2.2.txt[1.6.2.2], 112 link:RelNotes-1.6.2.1.txt[1.6.2.1], 113 link:RelNotes-1.6.2.txt[1.6.2]. 114 115* link:v1.6.1.3/git.html[documentation for release 1.6.1.3] 116 117* release notes for 118 link:RelNotes-1.6.1.3.txt[1.6.1.3], 119 link:RelNotes-1.6.1.2.txt[1.6.1.2], 120 link:RelNotes-1.6.1.1.txt[1.6.1.1], 121 link:RelNotes-1.6.1.txt[1.6.1]. 122 123* link:v1.6.0.6/git.html[documentation for release 1.6.0.6] 124 125* release notes for 126 link:RelNotes-1.6.0.6.txt[1.6.0.6], 127 link:RelNotes-1.6.0.5.txt[1.6.0.5], 128 link:RelNotes-1.6.0.4.txt[1.6.0.4], 129 link:RelNotes-1.6.0.3.txt[1.6.0.3], 130 link:RelNotes-1.6.0.2.txt[1.6.0.2], 131 link:RelNotes-1.6.0.1.txt[1.6.0.1], 132 link:RelNotes-1.6.0.txt[1.6.0]. 133 134* link:v1.5.6.6/git.html[documentation for release 1.5.6.6] 135 136* release notes for 137 link:RelNotes-1.5.6.6.txt[1.5.6.6], 138 link:RelNotes-1.5.6.5.txt[1.5.6.5], 139 link:RelNotes-1.5.6.4.txt[1.5.6.4], 140 link:RelNotes-1.5.6.3.txt[1.5.6.3], 141 link:RelNotes-1.5.6.2.txt[1.5.6.2], 142 link:RelNotes-1.5.6.1.txt[1.5.6.1], 143 link:RelNotes-1.5.6.txt[1.5.6]. 144 145* link:v1.5.5.6/git.html[documentation for release 1.5.5.6] 146 147* release notes for 148 link:RelNotes-1.5.5.6.txt[1.5.5.6], 149 link:RelNotes-1.5.5.5.txt[1.5.5.5], 150 link:RelNotes-1.5.5.4.txt[1.5.5.4], 151 link:RelNotes-1.5.5.3.txt[1.5.5.3], 152 link:RelNotes-1.5.5.2.txt[1.5.5.2], 153 link:RelNotes-1.5.5.1.txt[1.5.5.1], 154 link:RelNotes-1.5.5.txt[1.5.5]. 155 156* link:v1.5.4.7/git.html[documentation for release 1.5.4.7] 157 158* release notes for 159 link:RelNotes-1.5.4.7.txt[1.5.4.7], 160 link:RelNotes-1.5.4.6.txt[1.5.4.6], 161 link:RelNotes-1.5.4.5.txt[1.5.4.5], 162 link:RelNotes-1.5.4.4.txt[1.5.4.4], 163 link:RelNotes-1.5.4.3.txt[1.5.4.3], 164 link:RelNotes-1.5.4.2.txt[1.5.4.2], 165 link:RelNotes-1.5.4.1.txt[1.5.4.1], 166 link:RelNotes-1.5.4.txt[1.5.4]. 167 168* link:v1.5.3.8/git.html[documentation for release 1.5.3.8] 169 170* release notes for 171 link:RelNotes-1.5.3.8.txt[1.5.3.8], 172 link:RelNotes-1.5.3.7.txt[1.5.3.7], 173 link:RelNotes-1.5.3.6.txt[1.5.3.6], 174 link:RelNotes-1.5.3.5.txt[1.5.3.5], 175 link:RelNotes-1.5.3.4.txt[1.5.3.4], 176 link:RelNotes-1.5.3.3.txt[1.5.3.3], 177 link:RelNotes-1.5.3.2.txt[1.5.3.2], 178 link:RelNotes-1.5.3.1.txt[1.5.3.1], 179 link:RelNotes-1.5.3.txt[1.5.3]. 180 181* link:v1.5.2.5/git.html[documentation for release 1.5.2.5] 182 183* release notes for 184 link:RelNotes-1.5.2.5.txt[1.5.2.5], 185 link:RelNotes-1.5.2.4.txt[1.5.2.4], 186 link:RelNotes-1.5.2.3.txt[1.5.2.3], 187 link:RelNotes-1.5.2.2.txt[1.5.2.2], 188 link:RelNotes-1.5.2.1.txt[1.5.2.1], 189 link:RelNotes-1.5.2.txt[1.5.2]. 190 191* link:v1.5.1.6/git.html[documentation for release 1.5.1.6] 192 193* release notes for 194 link:RelNotes-1.5.1.6.txt[1.5.1.6], 195 link:RelNotes-1.5.1.5.txt[1.5.1.5], 196 link:RelNotes-1.5.1.4.txt[1.5.1.4], 197 link:RelNotes-1.5.1.3.txt[1.5.1.3], 198 link:RelNotes-1.5.1.2.txt[1.5.1.2], 199 link:RelNotes-1.5.1.1.txt[1.5.1.1], 200 link:RelNotes-1.5.1.txt[1.5.1]. 201 202* link:v1.5.0.7/git.html[documentation for release 1.5.0.7] 203 204* release notes for 205 link:RelNotes-1.5.0.7.txt[1.5.0.7], 206 link:RelNotes-1.5.0.6.txt[1.5.0.6], 207 link:RelNotes-1.5.0.5.txt[1.5.0.5], 208 link:RelNotes-1.5.0.3.txt[1.5.0.3], 209 link:RelNotes-1.5.0.2.txt[1.5.0.2], 210 link:RelNotes-1.5.0.1.txt[1.5.0.1], 211 link:RelNotes-1.5.0.txt[1.5.0]. 212 213* documentation for release link:v1.4.4.4/git.html[1.4.4.4], 214 link:v1.3.3/git.html[1.3.3], 215 link:v1.2.6/git.html[1.2.6], 216 link:v1.0.13/git.html[1.0.13]. 217 218============ 219 220endif::stalenotes[] 221 222OPTIONS 223------- 224--version:: 225 Prints the git suite version that the 'git' program came from. 226 227--help:: 228 Prints the synopsis and a list of the most commonly used 229 commands. If the option '--all' or '-a' is given then all 230 available commands are printed. If a git command is named this 231 option will bring up the manual page for that command. 232+ 233Other options are available to control how the manual page is 234displayed. See linkgit:git-help[1] for more information, 235because `git --help ...` is converted internally into `git 236help ...`. 237 238-c <name>=<value>:: 239 Pass a configuration parameter to the command. The value 240 given will override values from configuration files. 241 The <name> is expected in the same format as listed by 242 'git config' (subkeys separated by dots). 243 244--exec-path:: 245 Path to wherever your core git programs are installed. 246 This can also be controlled by setting the GIT_EXEC_PATH 247 environment variable. If no path is given, 'git' will print 248 the current setting and then exit. 249 250--html-path:: 251 Print the path to wherever your git HTML documentation is installed 252 and exit. 253 254-p:: 255--paginate:: 256 Pipe all output into 'less' (or if set, $PAGER) if standard 257 output is a terminal. This overrides the `pager.<cmd>` 258 configuration options (see the "Configuration Mechanism" section 259 below). 260 261--no-pager:: 262 Do not pipe git output into a pager. 263 264--git-dir=<path>:: 265 Set the path to the repository. This can also be controlled by 266 setting the GIT_DIR environment variable. It can be an absolute 267 path or relative path to current working directory. 268 269--work-tree=<path>:: 270 Set the path to the working tree. The value will not be 271 used in combination with repositories found automatically in 272 a .git directory (i.e. $GIT_DIR is not set). 273 This can also be controlled by setting the GIT_WORK_TREE 274 environment variable and the core.worktree configuration 275 variable. It can be an absolute path or relative path to 276 the directory specified by --git-dir or GIT_DIR. 277 Note: If --git-dir or GIT_DIR are specified but none of 278 --work-tree, GIT_WORK_TREE and core.worktree is specified, 279 the current working directory is regarded as the top directory 280 of your working tree. 281 282--bare:: 283 Treat the repository as a bare repository. If GIT_DIR 284 environment is not set, it is set to the current working 285 directory. 286 287--no-replace-objects:: 288 Do not use replacement refs to replace git objects. See 289 linkgit:git-replace[1] for more information. 290 291 292FURTHER DOCUMENTATION 293--------------------- 294 295See the references above to get started using git. The following is 296probably more detail than necessary for a first-time user. 297 298The link:user-manual.html#git-concepts[git concepts chapter of the 299user-manual] and linkgit:gitcore-tutorial[7] both provide 300introductions to the underlying git architecture. 301 302See linkgit:gitworkflows[7] for an overview of recommended workflows. 303 304See also the link:howto-index.html[howto] documents for some useful 305examples. 306 307The internals are documented in the 308link:technical/api-index.html[GIT API documentation]. 309 310GIT COMMANDS 311------------ 312 313We divide git into high level ("porcelain") commands and low level 314("plumbing") commands. 315 316High-level commands (porcelain) 317------------------------------- 318 319We separate the porcelain commands into the main commands and some 320ancillary user utilities. 321 322Main porcelain commands 323~~~~~~~~~~~~~~~~~~~~~~~ 324 325include::cmds-mainporcelain.txt[] 326 327Ancillary Commands 328~~~~~~~~~~~~~~~~~~ 329Manipulators: 330 331include::cmds-ancillarymanipulators.txt[] 332 333Interrogators: 334 335include::cmds-ancillaryinterrogators.txt[] 336 337 338Interacting with Others 339~~~~~~~~~~~~~~~~~~~~~~~ 340 341These commands are to interact with foreign SCM and with other 342people via patch over e-mail. 343 344include::cmds-foreignscminterface.txt[] 345 346 347Low-level commands (plumbing) 348----------------------------- 349 350Although git includes its 351own porcelain layer, its low-level commands are sufficient to support 352development of alternative porcelains. Developers of such porcelains 353might start by reading about linkgit:git-update-index[1] and 354linkgit:git-read-tree[1]. 355 356The interface (input, output, set of options and the semantics) 357to these low-level commands are meant to be a lot more stable 358than Porcelain level commands, because these commands are 359primarily for scripted use. The interface to Porcelain commands 360on the other hand are subject to change in order to improve the 361end user experience. 362 363The following description divides 364the low-level commands into commands that manipulate objects (in 365the repository, index, and working tree), commands that interrogate and 366compare objects, and commands that move objects and references between 367repositories. 368 369 370Manipulation commands 371~~~~~~~~~~~~~~~~~~~~~ 372 373include::cmds-plumbingmanipulators.txt[] 374 375 376Interrogation commands 377~~~~~~~~~~~~~~~~~~~~~~ 378 379include::cmds-plumbinginterrogators.txt[] 380 381In general, the interrogate commands do not touch the files in 382the working tree. 383 384 385Synching repositories 386~~~~~~~~~~~~~~~~~~~~~ 387 388include::cmds-synchingrepositories.txt[] 389 390The following are helper commands used by the above; end users 391typically do not use them directly. 392 393include::cmds-synchelpers.txt[] 394 395 396Internal helper commands 397~~~~~~~~~~~~~~~~~~~~~~~~ 398 399These are internal helper commands used by other commands; end 400users typically do not use them directly. 401 402include::cmds-purehelpers.txt[] 403 404 405Configuration Mechanism 406----------------------- 407 408Starting from 0.99.9 (actually mid 0.99.8.GIT), `.git/config` file 409is used to hold per-repository configuration options. It is a 410simple text file modeled after `.ini` format familiar to some 411people. Here is an example: 412 413------------ 414# 415# A '#' or ';' character indicates a comment. 416# 417 418; core variables 419[core] 420 ; Don't trust file modes 421 filemode = false 422 423; user identity 424[user] 425 name = "Junio C Hamano" 426 email = "junkio@twinsun.com" 427 428------------ 429 430Various commands read from the configuration file and adjust 431their operation accordingly. See linkgit:git-config[1] for a 432list. 433 434 435Identifier Terminology 436---------------------- 437<object>:: 438 Indicates the object name for any type of object. 439 440<blob>:: 441 Indicates a blob object name. 442 443<tree>:: 444 Indicates a tree object name. 445 446<commit>:: 447 Indicates a commit object name. 448 449<tree-ish>:: 450 Indicates a tree, commit or tag object name. A 451 command that takes a <tree-ish> argument ultimately wants to 452 operate on a <tree> object but automatically dereferences 453 <commit> and <tag> objects that point at a <tree>. 454 455<commit-ish>:: 456 Indicates a commit or tag object name. A 457 command that takes a <commit-ish> argument ultimately wants to 458 operate on a <commit> object but automatically dereferences 459 <tag> objects that point at a <commit>. 460 461<type>:: 462 Indicates that an object type is required. 463 Currently one of: `blob`, `tree`, `commit`, or `tag`. 464 465<file>:: 466 Indicates a filename - almost always relative to the 467 root of the tree structure `GIT_INDEX_FILE` describes. 468 469Symbolic Identifiers 470-------------------- 471Any git command accepting any <object> can also use the following 472symbolic notation: 473 474HEAD:: 475 indicates the head of the current branch (i.e. the 476 contents of `$GIT_DIR/HEAD`). 477 478<tag>:: 479 a valid tag 'name' 480 (i.e. the contents of `$GIT_DIR/refs/tags/<tag>`). 481 482<head>:: 483 a valid head 'name' 484 (i.e. the contents of `$GIT_DIR/refs/heads/<head>`). 485 486For a more complete list of ways to spell object names, see 487"SPECIFYING REVISIONS" section in linkgit:gitrevisions[1]. 488 489 490File/Directory Structure 491------------------------ 492 493Please see the linkgit:gitrepository-layout[5] document. 494 495Read linkgit:githooks[5] for more details about each hook. 496 497Higher level SCMs may provide and manage additional information in the 498`$GIT_DIR`. 499 500 501Terminology 502----------- 503Please see linkgit:gitglossary[7]. 504 505 506Environment Variables 507--------------------- 508Various git commands use the following environment variables: 509 510The git Repository 511~~~~~~~~~~~~~~~~~~ 512These environment variables apply to 'all' core git commands. Nb: it 513is worth noting that they may be used/overridden by SCMS sitting above 514git so take care if using Cogito etc. 515 516'GIT_INDEX_FILE':: 517 This environment allows the specification of an alternate 518 index file. If not specified, the default of `$GIT_DIR/index` 519 is used. 520 521'GIT_OBJECT_DIRECTORY':: 522 If the object storage directory is specified via this 523 environment variable then the sha1 directories are created 524 underneath - otherwise the default `$GIT_DIR/objects` 525 directory is used. 526 527'GIT_ALTERNATE_OBJECT_DIRECTORIES':: 528 Due to the immutable nature of git objects, old objects can be 529 archived into shared, read-only directories. This variable 530 specifies a ":" separated (on Windows ";" separated) list 531 of git object directories which can be used to search for git 532 objects. New objects will not be written to these directories. 533 534'GIT_DIR':: 535 If the 'GIT_DIR' environment variable is set then it 536 specifies a path to use instead of the default `.git` 537 for the base of the repository. 538 539'GIT_WORK_TREE':: 540 Set the path to the working tree. The value will not be 541 used in combination with repositories found automatically in 542 a .git directory (i.e. $GIT_DIR is not set). 543 This can also be controlled by the '--work-tree' command line 544 option and the core.worktree configuration variable. 545 546'GIT_CEILING_DIRECTORIES':: 547 This should be a colon-separated list of absolute paths. 548 If set, it is a list of directories that git should not chdir 549 up into while looking for a repository directory. 550 It will not exclude the current working directory or 551 a GIT_DIR set on the command line or in the environment. 552 (Useful for excluding slow-loading network directories.) 553 554'GIT_DISCOVERY_ACROSS_FILESYSTEM':: 555 When run in a directory that does not have ".git" repository 556 directory, git tries to find such a directory in the parent 557 directories to find the top of the working tree, but by default it 558 does not cross filesystem boundaries. This environment variable 559 can be set to true to tell git not to stop at filesystem 560 boundaries. Like 'GIT_CEILING_DIRECTORIES', this will not affect 561 an explicit repository directory set via 'GIT_DIR' or on the 562 command line. 563 564git Commits 565~~~~~~~~~~~ 566'GIT_AUTHOR_NAME':: 567'GIT_AUTHOR_EMAIL':: 568'GIT_AUTHOR_DATE':: 569'GIT_COMMITTER_NAME':: 570'GIT_COMMITTER_EMAIL':: 571'GIT_COMMITTER_DATE':: 572'EMAIL':: 573 see linkgit:git-commit-tree[1] 574 575git Diffs 576~~~~~~~~~ 577'GIT_DIFF_OPTS':: 578 Only valid setting is "--unified=??" or "-u??" to set the 579 number of context lines shown when a unified diff is created. 580 This takes precedence over any "-U" or "--unified" option 581 value passed on the git diff command line. 582 583'GIT_EXTERNAL_DIFF':: 584 When the environment variable 'GIT_EXTERNAL_DIFF' is set, the 585 program named by it is called, instead of the diff invocation 586 described above. For a path that is added, removed, or modified, 587 'GIT_EXTERNAL_DIFF' is called with 7 parameters: 588 589 path old-file old-hex old-mode new-file new-hex new-mode 590+ 591where: 592 593 <old|new>-file:: are files GIT_EXTERNAL_DIFF can use to read the 594 contents of <old|new>, 595 <old|new>-hex:: are the 40-hexdigit SHA1 hashes, 596 <old|new>-mode:: are the octal representation of the file modes. 597 598+ 599The file parameters can point at the user's working file 600(e.g. `new-file` in "git-diff-files"), `/dev/null` (e.g. `old-file` 601when a new file is added), or a temporary file (e.g. `old-file` in the 602index). 'GIT_EXTERNAL_DIFF' should not worry about unlinking the 603temporary file --- it is removed when 'GIT_EXTERNAL_DIFF' exits. 604+ 605For a path that is unmerged, 'GIT_EXTERNAL_DIFF' is called with 1 606parameter, <path>. 607 608other 609~~~~~ 610'GIT_MERGE_VERBOSITY':: 611 A number controlling the amount of output shown by 612 the recursive merge strategy. Overrides merge.verbosity. 613 See linkgit:git-merge[1] 614 615'GIT_PAGER':: 616 This environment variable overrides `$PAGER`. If it is set 617 to an empty string or to the value "cat", git will not launch 618 a pager. See also the `core.pager` option in 619 linkgit:git-config[1]. 620 621'GIT_SSH':: 622 If this environment variable is set then 'git fetch' 623 and 'git push' will use this command instead 624 of 'ssh' when they need to connect to a remote system. 625 The '$GIT_SSH' command will be given exactly two arguments: 626 the 'username@host' (or just 'host') from the URL and the 627 shell command to execute on that remote system. 628+ 629To pass options to the program that you want to list in GIT_SSH 630you will need to wrap the program and options into a shell script, 631then set GIT_SSH to refer to the shell script. 632+ 633Usually it is easier to configure any desired options through your 634personal `.ssh/config` file. Please consult your ssh documentation 635for further details. 636 637'GIT_FLUSH':: 638 If this environment variable is set to "1", then commands such 639 as 'git blame' (in incremental mode), 'git rev-list', 'git log', 640 and 'git whatchanged' will force a flush of the output stream 641 after each commit-oriented record have been flushed. If this 642 variable is set to "0", the output of these commands will be done 643 using completely buffered I/O. If this environment variable is 644 not set, git will choose buffered or record-oriented flushing 645 based on whether stdout appears to be redirected to a file or not. 646 647'GIT_TRACE':: 648 If this variable is set to "1", "2" or "true" (comparison 649 is case insensitive), git will print `trace:` messages on 650 stderr telling about alias expansion, built-in command 651 execution and external command execution. 652 If this variable is set to an integer value greater than 1 653 and lower than 10 (strictly) then git will interpret this 654 value as an open file descriptor and will try to write the 655 trace messages into this file descriptor. 656 Alternatively, if this variable is set to an absolute path 657 (starting with a '/' character), git will interpret this 658 as a file path and will try to write the trace messages 659 into it. 660 661Discussion[[Discussion]] 662------------------------ 663 664More detail on the following is available from the 665link:user-manual.html#git-concepts[git concepts chapter of the 666user-manual] and linkgit:gitcore-tutorial[7]. 667 668A git project normally consists of a working directory with a ".git" 669subdirectory at the top level. The .git directory contains, among other 670things, a compressed object database representing the complete history 671of the project, an "index" file which links that history to the current 672contents of the working tree, and named pointers into that history such 673as tags and branch heads. 674 675The object database contains objects of three main types: blobs, which 676hold file data; trees, which point to blobs and other trees to build up 677directory hierarchies; and commits, which each reference a single tree 678and some number of parent commits. 679 680The commit, equivalent to what other systems call a "changeset" or 681"version", represents a step in the project's history, and each parent 682represents an immediately preceding step. Commits with more than one 683parent represent merges of independent lines of development. 684 685All objects are named by the SHA1 hash of their contents, normally 686written as a string of 40 hex digits. Such names are globally unique. 687The entire history leading up to a commit can be vouched for by signing 688just that commit. A fourth object type, the tag, is provided for this 689purpose. 690 691When first created, objects are stored in individual files, but for 692efficiency may later be compressed together into "pack files". 693 694Named pointers called refs mark interesting points in history. A ref 695may contain the SHA1 name of an object or the name of another ref. Refs 696with names beginning `ref/head/` contain the SHA1 name of the most 697recent commit (or "head") of a branch under development. SHA1 names of 698tags of interest are stored under `ref/tags/`. A special ref named 699`HEAD` contains the name of the currently checked-out branch. 700 701The index file is initialized with a list of all paths and, for each 702path, a blob object and a set of attributes. The blob object represents 703the contents of the file as of the head of the current branch. The 704attributes (last modified time, size, etc.) are taken from the 705corresponding file in the working tree. Subsequent changes to the 706working tree can be found by comparing these attributes. The index may 707be updated with new content, and new commits may be created from the 708content stored in the index. 709 710The index is also capable of storing multiple entries (called "stages") 711for a given pathname. These stages are used to hold the various 712unmerged version of a file when a merge is in progress. 713 714Authors 715------- 716* git's founding father is Linus Torvalds <torvalds@osdl.org>. 717* The current git nurse is Junio C Hamano <gitster@pobox.com>. 718* The git potty was written by Andreas Ericsson <ae@op5.se>. 719* General upbringing is handled by the git-list <git@vger.kernel.org>. 720 721Documentation 722-------------- 723The documentation for git suite was started by David Greaves 724<david@dgreaves.com>, and later enhanced greatly by the 725contributors on the git-list <git@vger.kernel.org>. 726 727SEE ALSO 728-------- 729linkgit:gittutorial[7], linkgit:gittutorial-2[7], 730link:everyday.html[Everyday Git], linkgit:gitcvs-migration[7], 731linkgit:gitglossary[7], linkgit:gitcore-tutorial[7], 732linkgit:gitcli[7], link:user-manual.html[The Git User's Manual], 733linkgit:gitworkflows[7] 734 735GIT 736--- 737Part of the linkgit:git[1] suite