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 47* link:v1.7.1/git.html[documentation for release 1.7.1] 48 49* release notes for 50 link:RelNotes-1.7.1.txt[1.7.1]. 51 52* link:v1.7.0.7/git.html[documentation for release 1.7.0.7] 53 54* release notes for 55 link:RelNotes-1.7.0.7.txt[1.7.0.7], 56 link:RelNotes-1.7.0.6.txt[1.7.0.6], 57 link:RelNotes-1.7.0.5.txt[1.7.0.5], 58 link:RelNotes-1.7.0.4.txt[1.7.0.4], 59 link:RelNotes-1.7.0.3.txt[1.7.0.3], 60 link:RelNotes-1.7.0.2.txt[1.7.0.2], 61 link:RelNotes-1.7.0.1.txt[1.7.0.1], 62 link:RelNotes-1.7.0.txt[1.7.0]. 63 64* link:v1.6.6.2/git.html[documentation for release 1.6.6.2] 65 66* release notes for 67 link:RelNotes-1.6.6.2.txt[1.6.6.2], 68 link:RelNotes-1.6.6.1.txt[1.6.6.1], 69 link:RelNotes-1.6.6.txt[1.6.6]. 70 71* link:v1.6.5.8/git.html[documentation for release 1.6.5.8] 72 73* release notes for 74 link:RelNotes-1.6.5.8.txt[1.6.5.8], 75 link:RelNotes-1.6.5.7.txt[1.6.5.7], 76 link:RelNotes-1.6.5.6.txt[1.6.5.6], 77 link:RelNotes-1.6.5.5.txt[1.6.5.5], 78 link:RelNotes-1.6.5.4.txt[1.6.5.4], 79 link:RelNotes-1.6.5.3.txt[1.6.5.3], 80 link:RelNotes-1.6.5.2.txt[1.6.5.2], 81 link:RelNotes-1.6.5.1.txt[1.6.5.1], 82 link:RelNotes-1.6.5.txt[1.6.5]. 83 84* link:v1.6.4.4/git.html[documentation for release 1.6.4.4] 85 86* release notes for 87 link:RelNotes-1.6.4.4.txt[1.6.4.4], 88 link:RelNotes-1.6.4.3.txt[1.6.4.3], 89 link:RelNotes-1.6.4.2.txt[1.6.4.2], 90 link:RelNotes-1.6.4.1.txt[1.6.4.1], 91 link:RelNotes-1.6.4.txt[1.6.4]. 92 93* link:v1.6.3.4/git.html[documentation for release 1.6.3.4] 94 95* release notes for 96 link:RelNotes-1.6.3.4.txt[1.6.3.4], 97 link:RelNotes-1.6.3.3.txt[1.6.3.3], 98 link:RelNotes-1.6.3.2.txt[1.6.3.2], 99 link:RelNotes-1.6.3.1.txt[1.6.3.1], 100 link:RelNotes-1.6.3.txt[1.6.3]. 101 102* release notes for 103 link:RelNotes-1.6.2.5.txt[1.6.2.5], 104 link:RelNotes-1.6.2.4.txt[1.6.2.4], 105 link:RelNotes-1.6.2.3.txt[1.6.2.3], 106 link:RelNotes-1.6.2.2.txt[1.6.2.2], 107 link:RelNotes-1.6.2.1.txt[1.6.2.1], 108 link:RelNotes-1.6.2.txt[1.6.2]. 109 110* link:v1.6.1.3/git.html[documentation for release 1.6.1.3] 111 112* release notes for 113 link:RelNotes-1.6.1.3.txt[1.6.1.3], 114 link:RelNotes-1.6.1.2.txt[1.6.1.2], 115 link:RelNotes-1.6.1.1.txt[1.6.1.1], 116 link:RelNotes-1.6.1.txt[1.6.1]. 117 118* link:v1.6.0.6/git.html[documentation for release 1.6.0.6] 119 120* release notes for 121 link:RelNotes-1.6.0.6.txt[1.6.0.6], 122 link:RelNotes-1.6.0.5.txt[1.6.0.5], 123 link:RelNotes-1.6.0.4.txt[1.6.0.4], 124 link:RelNotes-1.6.0.3.txt[1.6.0.3], 125 link:RelNotes-1.6.0.2.txt[1.6.0.2], 126 link:RelNotes-1.6.0.1.txt[1.6.0.1], 127 link:RelNotes-1.6.0.txt[1.6.0]. 128 129* link:v1.5.6.6/git.html[documentation for release 1.5.6.6] 130 131* release notes for 132 link:RelNotes-1.5.6.6.txt[1.5.6.6], 133 link:RelNotes-1.5.6.5.txt[1.5.6.5], 134 link:RelNotes-1.5.6.4.txt[1.5.6.4], 135 link:RelNotes-1.5.6.3.txt[1.5.6.3], 136 link:RelNotes-1.5.6.2.txt[1.5.6.2], 137 link:RelNotes-1.5.6.1.txt[1.5.6.1], 138 link:RelNotes-1.5.6.txt[1.5.6]. 139 140* link:v1.5.5.6/git.html[documentation for release 1.5.5.6] 141 142* release notes for 143 link:RelNotes-1.5.5.6.txt[1.5.5.6], 144 link:RelNotes-1.5.5.5.txt[1.5.5.5], 145 link:RelNotes-1.5.5.4.txt[1.5.5.4], 146 link:RelNotes-1.5.5.3.txt[1.5.5.3], 147 link:RelNotes-1.5.5.2.txt[1.5.5.2], 148 link:RelNotes-1.5.5.1.txt[1.5.5.1], 149 link:RelNotes-1.5.5.txt[1.5.5]. 150 151* link:v1.5.4.7/git.html[documentation for release 1.5.4.7] 152 153* release notes for 154 link:RelNotes-1.5.4.7.txt[1.5.4.7], 155 link:RelNotes-1.5.4.6.txt[1.5.4.6], 156 link:RelNotes-1.5.4.5.txt[1.5.4.5], 157 link:RelNotes-1.5.4.4.txt[1.5.4.4], 158 link:RelNotes-1.5.4.3.txt[1.5.4.3], 159 link:RelNotes-1.5.4.2.txt[1.5.4.2], 160 link:RelNotes-1.5.4.1.txt[1.5.4.1], 161 link:RelNotes-1.5.4.txt[1.5.4]. 162 163* link:v1.5.3.8/git.html[documentation for release 1.5.3.8] 164 165* release notes for 166 link:RelNotes-1.5.3.8.txt[1.5.3.8], 167 link:RelNotes-1.5.3.7.txt[1.5.3.7], 168 link:RelNotes-1.5.3.6.txt[1.5.3.6], 169 link:RelNotes-1.5.3.5.txt[1.5.3.5], 170 link:RelNotes-1.5.3.4.txt[1.5.3.4], 171 link:RelNotes-1.5.3.3.txt[1.5.3.3], 172 link:RelNotes-1.5.3.2.txt[1.5.3.2], 173 link:RelNotes-1.5.3.1.txt[1.5.3.1], 174 link:RelNotes-1.5.3.txt[1.5.3]. 175 176* link:v1.5.2.5/git.html[documentation for release 1.5.2.5] 177 178* release notes for 179 link:RelNotes-1.5.2.5.txt[1.5.2.5], 180 link:RelNotes-1.5.2.4.txt[1.5.2.4], 181 link:RelNotes-1.5.2.3.txt[1.5.2.3], 182 link:RelNotes-1.5.2.2.txt[1.5.2.2], 183 link:RelNotes-1.5.2.1.txt[1.5.2.1], 184 link:RelNotes-1.5.2.txt[1.5.2]. 185 186* link:v1.5.1.6/git.html[documentation for release 1.5.1.6] 187 188* release notes for 189 link:RelNotes-1.5.1.6.txt[1.5.1.6], 190 link:RelNotes-1.5.1.5.txt[1.5.1.5], 191 link:RelNotes-1.5.1.4.txt[1.5.1.4], 192 link:RelNotes-1.5.1.3.txt[1.5.1.3], 193 link:RelNotes-1.5.1.2.txt[1.5.1.2], 194 link:RelNotes-1.5.1.1.txt[1.5.1.1], 195 link:RelNotes-1.5.1.txt[1.5.1]. 196 197* link:v1.5.0.7/git.html[documentation for release 1.5.0.7] 198 199* release notes for 200 link:RelNotes-1.5.0.7.txt[1.5.0.7], 201 link:RelNotes-1.5.0.6.txt[1.5.0.6], 202 link:RelNotes-1.5.0.5.txt[1.5.0.5], 203 link:RelNotes-1.5.0.3.txt[1.5.0.3], 204 link:RelNotes-1.5.0.2.txt[1.5.0.2], 205 link:RelNotes-1.5.0.1.txt[1.5.0.1], 206 link:RelNotes-1.5.0.txt[1.5.0]. 207 208* documentation for release link:v1.4.4.4/git.html[1.4.4.4], 209 link:v1.3.3/git.html[1.3.3], 210 link:v1.2.6/git.html[1.2.6], 211 link:v1.0.13/git.html[1.0.13]. 212 213============ 214 215endif::stalenotes[] 216 217OPTIONS 218------- 219--version:: 220 Prints the git suite version that the 'git' program came from. 221 222--help:: 223 Prints the synopsis and a list of the most commonly used 224 commands. If the option '--all' or '-a' is given then all 225 available commands are printed. If a git command is named this 226 option will bring up the manual page for that command. 227+ 228Other options are available to control how the manual page is 229displayed. See linkgit:git-help[1] for more information, 230because `git --help ...` is converted internally into `git 231help ...`. 232 233--exec-path:: 234 Path to wherever your core git programs are installed. 235 This can also be controlled by setting the GIT_EXEC_PATH 236 environment variable. If no path is given, 'git' will print 237 the current setting and then exit. 238 239--html-path:: 240 Print the path to wherever your git HTML documentation is installed 241 and exit. 242 243-p:: 244--paginate:: 245 Pipe all output into 'less' (or if set, $PAGER) if standard 246 output is a terminal. This overrides the `pager.<cmd>` 247 configuration options (see the "Configuration Mechanism" section 248 below). 249 250--no-pager:: 251 Do not pipe git output into a pager. 252 253--git-dir=<path>:: 254 Set the path to the repository. This can also be controlled by 255 setting the GIT_DIR environment variable. It can be an absolute 256 path or relative path to current working directory. 257 258--work-tree=<path>:: 259 Set the path to the working tree. The value will not be 260 used in combination with repositories found automatically in 261 a .git directory (i.e. $GIT_DIR is not set). 262 This can also be controlled by setting the GIT_WORK_TREE 263 environment variable and the core.worktree configuration 264 variable. It can be an absolute path or relative path to 265 the directory specified by --git-dir or GIT_DIR. 266 Note: If --git-dir or GIT_DIR are specified but none of 267 --work-tree, GIT_WORK_TREE and core.worktree is specified, 268 the current working directory is regarded as the top directory 269 of your working tree. 270 271--bare:: 272 Treat the repository as a bare repository. If GIT_DIR 273 environment is not set, it is set to the current working 274 directory. 275 276--no-replace-objects:: 277 Do not use replacement refs to replace git objects. See 278 linkgit:git-replace[1] for more information. 279 280 281FURTHER DOCUMENTATION 282--------------------- 283 284See the references above to get started using git. The following is 285probably more detail than necessary for a first-time user. 286 287The link:user-manual.html#git-concepts[git concepts chapter of the 288user-manual] and linkgit:gitcore-tutorial[7] both provide 289introductions to the underlying git architecture. 290 291See linkgit:gitworkflows[7] for an overview of recommended workflows. 292 293See also the link:howto-index.html[howto] documents for some useful 294examples. 295 296The internals are documented in the 297link:technical/api-index.html[GIT API documentation]. 298 299GIT COMMANDS 300------------ 301 302We divide git into high level ("porcelain") commands and low level 303("plumbing") commands. 304 305High-level commands (porcelain) 306------------------------------- 307 308We separate the porcelain commands into the main commands and some 309ancillary user utilities. 310 311Main porcelain commands 312~~~~~~~~~~~~~~~~~~~~~~~ 313 314include::cmds-mainporcelain.txt[] 315 316Ancillary Commands 317~~~~~~~~~~~~~~~~~~ 318Manipulators: 319 320include::cmds-ancillarymanipulators.txt[] 321 322Interrogators: 323 324include::cmds-ancillaryinterrogators.txt[] 325 326 327Interacting with Others 328~~~~~~~~~~~~~~~~~~~~~~~ 329 330These commands are to interact with foreign SCM and with other 331people via patch over e-mail. 332 333include::cmds-foreignscminterface.txt[] 334 335 336Low-level commands (plumbing) 337----------------------------- 338 339Although git includes its 340own porcelain layer, its low-level commands are sufficient to support 341development of alternative porcelains. Developers of such porcelains 342might start by reading about linkgit:git-update-index[1] and 343linkgit:git-read-tree[1]. 344 345The interface (input, output, set of options and the semantics) 346to these low-level commands are meant to be a lot more stable 347than Porcelain level commands, because these commands are 348primarily for scripted use. The interface to Porcelain commands 349on the other hand are subject to change in order to improve the 350end user experience. 351 352The following description divides 353the low-level commands into commands that manipulate objects (in 354the repository, index, and working tree), commands that interrogate and 355compare objects, and commands that move objects and references between 356repositories. 357 358 359Manipulation commands 360~~~~~~~~~~~~~~~~~~~~~ 361 362include::cmds-plumbingmanipulators.txt[] 363 364 365Interrogation commands 366~~~~~~~~~~~~~~~~~~~~~~ 367 368include::cmds-plumbinginterrogators.txt[] 369 370In general, the interrogate commands do not touch the files in 371the working tree. 372 373 374Synching repositories 375~~~~~~~~~~~~~~~~~~~~~ 376 377include::cmds-synchingrepositories.txt[] 378 379The following are helper commands used by the above; end users 380typically do not use them directly. 381 382include::cmds-synchelpers.txt[] 383 384 385Internal helper commands 386~~~~~~~~~~~~~~~~~~~~~~~~ 387 388These are internal helper commands used by other commands; end 389users typically do not use them directly. 390 391include::cmds-purehelpers.txt[] 392 393 394Configuration Mechanism 395----------------------- 396 397Starting from 0.99.9 (actually mid 0.99.8.GIT), `.git/config` file 398is used to hold per-repository configuration options. It is a 399simple text file modeled after `.ini` format familiar to some 400people. Here is an example: 401 402------------ 403# 404# A '#' or ';' character indicates a comment. 405# 406 407; core variables 408[core] 409 ; Don't trust file modes 410 filemode = false 411 412; user identity 413[user] 414 name = "Junio C Hamano" 415 email = "junkio@twinsun.com" 416 417------------ 418 419Various commands read from the configuration file and adjust 420their operation accordingly. See linkgit:git-config[1] for a 421list. 422 423 424Identifier Terminology 425---------------------- 426<object>:: 427 Indicates the object name for any type of object. 428 429<blob>:: 430 Indicates a blob object name. 431 432<tree>:: 433 Indicates a tree object name. 434 435<commit>:: 436 Indicates a commit object name. 437 438<tree-ish>:: 439 Indicates a tree, commit or tag object name. A 440 command that takes a <tree-ish> argument ultimately wants to 441 operate on a <tree> object but automatically dereferences 442 <commit> and <tag> objects that point at a <tree>. 443 444<commit-ish>:: 445 Indicates a commit or tag object name. A 446 command that takes a <commit-ish> argument ultimately wants to 447 operate on a <commit> object but automatically dereferences 448 <tag> objects that point at a <commit>. 449 450<type>:: 451 Indicates that an object type is required. 452 Currently one of: `blob`, `tree`, `commit`, or `tag`. 453 454<file>:: 455 Indicates a filename - almost always relative to the 456 root of the tree structure `GIT_INDEX_FILE` describes. 457 458Symbolic Identifiers 459-------------------- 460Any git command accepting any <object> can also use the following 461symbolic notation: 462 463HEAD:: 464 indicates the head of the current branch (i.e. the 465 contents of `$GIT_DIR/HEAD`). 466 467<tag>:: 468 a valid tag 'name' 469 (i.e. the contents of `$GIT_DIR/refs/tags/<tag>`). 470 471<head>:: 472 a valid head 'name' 473 (i.e. the contents of `$GIT_DIR/refs/heads/<head>`). 474 475For a more complete list of ways to spell object names, see 476"SPECIFYING REVISIONS" section in linkgit:git-rev-parse[1]. 477 478 479File/Directory Structure 480------------------------ 481 482Please see the linkgit:gitrepository-layout[5] document. 483 484Read linkgit:githooks[5] for more details about each hook. 485 486Higher level SCMs may provide and manage additional information in the 487`$GIT_DIR`. 488 489 490Terminology 491----------- 492Please see linkgit:gitglossary[7]. 493 494 495Environment Variables 496--------------------- 497Various git commands use the following environment variables: 498 499The git Repository 500~~~~~~~~~~~~~~~~~~ 501These environment variables apply to 'all' core git commands. Nb: it 502is worth noting that they may be used/overridden by SCMS sitting above 503git so take care if using Cogito etc. 504 505'GIT_INDEX_FILE':: 506 This environment allows the specification of an alternate 507 index file. If not specified, the default of `$GIT_DIR/index` 508 is used. 509 510'GIT_OBJECT_DIRECTORY':: 511 If the object storage directory is specified via this 512 environment variable then the sha1 directories are created 513 underneath - otherwise the default `$GIT_DIR/objects` 514 directory is used. 515 516'GIT_ALTERNATE_OBJECT_DIRECTORIES':: 517 Due to the immutable nature of git objects, old objects can be 518 archived into shared, read-only directories. This variable 519 specifies a ":" separated (on Windows ";" separated) list 520 of git object directories which can be used to search for git 521 objects. New objects will not be written to these directories. 522 523'GIT_DIR':: 524 If the 'GIT_DIR' environment variable is set then it 525 specifies a path to use instead of the default `.git` 526 for the base of the repository. 527 528'GIT_WORK_TREE':: 529 Set the path to the working tree. The value will not be 530 used in combination with repositories found automatically in 531 a .git directory (i.e. $GIT_DIR is not set). 532 This can also be controlled by the '--work-tree' command line 533 option and the core.worktree configuration variable. 534 535'GIT_CEILING_DIRECTORIES':: 536 This should be a colon-separated list of absolute paths. 537 If set, it is a list of directories that git should not chdir 538 up into while looking for a repository directory. 539 It will not exclude the current working directory or 540 a GIT_DIR set on the command line or in the environment. 541 (Useful for excluding slow-loading network directories.) 542 543git Commits 544~~~~~~~~~~~ 545'GIT_AUTHOR_NAME':: 546'GIT_AUTHOR_EMAIL':: 547'GIT_AUTHOR_DATE':: 548'GIT_COMMITTER_NAME':: 549'GIT_COMMITTER_EMAIL':: 550'GIT_COMMITTER_DATE':: 551'EMAIL':: 552 see linkgit:git-commit-tree[1] 553 554git Diffs 555~~~~~~~~~ 556'GIT_DIFF_OPTS':: 557 Only valid setting is "--unified=??" or "-u??" to set the 558 number of context lines shown when a unified diff is created. 559 This takes precedence over any "-U" or "--unified" option 560 value passed on the git diff command line. 561 562'GIT_EXTERNAL_DIFF':: 563 When the environment variable 'GIT_EXTERNAL_DIFF' is set, the 564 program named by it is called, instead of the diff invocation 565 described above. For a path that is added, removed, or modified, 566 'GIT_EXTERNAL_DIFF' is called with 7 parameters: 567 568 path old-file old-hex old-mode new-file new-hex new-mode 569+ 570where: 571 572 <old|new>-file:: are files GIT_EXTERNAL_DIFF can use to read the 573 contents of <old|new>, 574 <old|new>-hex:: are the 40-hexdigit SHA1 hashes, 575 <old|new>-mode:: are the octal representation of the file modes. 576 577+ 578The file parameters can point at the user's working file 579(e.g. `new-file` in "git-diff-files"), `/dev/null` (e.g. `old-file` 580when a new file is added), or a temporary file (e.g. `old-file` in the 581index). 'GIT_EXTERNAL_DIFF' should not worry about unlinking the 582temporary file --- it is removed when 'GIT_EXTERNAL_DIFF' exits. 583+ 584For a path that is unmerged, 'GIT_EXTERNAL_DIFF' is called with 1 585parameter, <path>. 586 587other 588~~~~~ 589'GIT_MERGE_VERBOSITY':: 590 A number controlling the amount of output shown by 591 the recursive merge strategy. Overrides merge.verbosity. 592 See linkgit:git-merge[1] 593 594'GIT_PAGER':: 595 This environment variable overrides `$PAGER`. If it is set 596 to an empty string or to the value "cat", git will not launch 597 a pager. See also the `core.pager` option in 598 linkgit:git-config[1]. 599 600'GIT_SSH':: 601 If this environment variable is set then 'git fetch' 602 and 'git push' will use this command instead 603 of 'ssh' when they need to connect to a remote system. 604 The '$GIT_SSH' command will be given exactly two arguments: 605 the 'username@host' (or just 'host') from the URL and the 606 shell command to execute on that remote system. 607+ 608To pass options to the program that you want to list in GIT_SSH 609you will need to wrap the program and options into a shell script, 610then set GIT_SSH to refer to the shell script. 611+ 612Usually it is easier to configure any desired options through your 613personal `.ssh/config` file. Please consult your ssh documentation 614for further details. 615 616'GIT_FLUSH':: 617 If this environment variable is set to "1", then commands such 618 as 'git blame' (in incremental mode), 'git rev-list', 'git log', 619 and 'git whatchanged' will force a flush of the output stream 620 after each commit-oriented record have been flushed. If this 621 variable is set to "0", the output of these commands will be done 622 using completely buffered I/O. If this environment variable is 623 not set, git will choose buffered or record-oriented flushing 624 based on whether stdout appears to be redirected to a file or not. 625 626'GIT_TRACE':: 627 If this variable is set to "1", "2" or "true" (comparison 628 is case insensitive), git will print `trace:` messages on 629 stderr telling about alias expansion, built-in command 630 execution and external command execution. 631 If this variable is set to an integer value greater than 1 632 and lower than 10 (strictly) then git will interpret this 633 value as an open file descriptor and will try to write the 634 trace messages into this file descriptor. 635 Alternatively, if this variable is set to an absolute path 636 (starting with a '/' character), git will interpret this 637 as a file path and will try to write the trace messages 638 into it. 639 640Discussion[[Discussion]] 641------------------------ 642 643More detail on the following is available from the 644link:user-manual.html#git-concepts[git concepts chapter of the 645user-manual] and linkgit:gitcore-tutorial[7]. 646 647A git project normally consists of a working directory with a ".git" 648subdirectory at the top level. The .git directory contains, among other 649things, a compressed object database representing the complete history 650of the project, an "index" file which links that history to the current 651contents of the working tree, and named pointers into that history such 652as tags and branch heads. 653 654The object database contains objects of three main types: blobs, which 655hold file data; trees, which point to blobs and other trees to build up 656directory hierarchies; and commits, which each reference a single tree 657and some number of parent commits. 658 659The commit, equivalent to what other systems call a "changeset" or 660"version", represents a step in the project's history, and each parent 661represents an immediately preceding step. Commits with more than one 662parent represent merges of independent lines of development. 663 664All objects are named by the SHA1 hash of their contents, normally 665written as a string of 40 hex digits. Such names are globally unique. 666The entire history leading up to a commit can be vouched for by signing 667just that commit. A fourth object type, the tag, is provided for this 668purpose. 669 670When first created, objects are stored in individual files, but for 671efficiency may later be compressed together into "pack files". 672 673Named pointers called refs mark interesting points in history. A ref 674may contain the SHA1 name of an object or the name of another ref. Refs 675with names beginning `ref/head/` contain the SHA1 name of the most 676recent commit (or "head") of a branch under development. SHA1 names of 677tags of interest are stored under `ref/tags/`. A special ref named 678`HEAD` contains the name of the currently checked-out branch. 679 680The index file is initialized with a list of all paths and, for each 681path, a blob object and a set of attributes. The blob object represents 682the contents of the file as of the head of the current branch. The 683attributes (last modified time, size, etc.) are taken from the 684corresponding file in the working tree. Subsequent changes to the 685working tree can be found by comparing these attributes. The index may 686be updated with new content, and new commits may be created from the 687content stored in the index. 688 689The index is also capable of storing multiple entries (called "stages") 690for a given pathname. These stages are used to hold the various 691unmerged version of a file when a merge is in progress. 692 693Authors 694------- 695* git's founding father is Linus Torvalds <torvalds@osdl.org>. 696* The current git nurse is Junio C Hamano <gitster@pobox.com>. 697* The git potty was written by Andreas Ericsson <ae@op5.se>. 698* General upbringing is handled by the git-list <git@vger.kernel.org>. 699 700Documentation 701-------------- 702The documentation for git suite was started by David Greaves 703<david@dgreaves.com>, and later enhanced greatly by the 704contributors on the git-list <git@vger.kernel.org>. 705 706SEE ALSO 707-------- 708linkgit:gittutorial[7], linkgit:gittutorial-2[7], 709link:everyday.html[Everyday Git], linkgit:gitcvs-migration[7], 710linkgit:gitglossary[7], linkgit:gitcore-tutorial[7], 711linkgit:gitcli[7], link:user-manual.html[The Git User's Manual], 712linkgit:gitworkflows[7] 713 714GIT 715--- 716Part of the linkgit:git[1] suite