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:v1.7.2.2/git.html[documentation for release 1.7.2.2] 48 49* release notes for 50 link:RelNotes-1.7.2.2.txt[1.7.2.2], 51 link:RelNotes-1.7.2.1.txt[1.7.2.1], 52 link:RelNotes-1.7.2.txt[1.7.2]. 53 54* link:v1.7.1.2/git.html[documentation for release 1.7.1.2] 55 56* release notes for 57 link:RelNotes-1.7.1.2.txt[1.7.1.2], 58 link:RelNotes-1.7.1.1.txt[1.7.1.1], 59 link:RelNotes-1.7.1.txt[1.7.1]. 60 61* link:v1.7.0.7/git.html[documentation for release 1.7.0.7] 62 63* release notes for 64 link:RelNotes-1.7.0.7.txt[1.7.0.7], 65 link:RelNotes-1.7.0.6.txt[1.7.0.6], 66 link:RelNotes-1.7.0.5.txt[1.7.0.5], 67 link:RelNotes-1.7.0.4.txt[1.7.0.4], 68 link:RelNotes-1.7.0.3.txt[1.7.0.3], 69 link:RelNotes-1.7.0.2.txt[1.7.0.2], 70 link:RelNotes-1.7.0.1.txt[1.7.0.1], 71 link:RelNotes-1.7.0.txt[1.7.0]. 72 73* link:v1.6.6.2/git.html[documentation for release 1.6.6.2] 74 75* release notes for 76 link:RelNotes-1.6.6.2.txt[1.6.6.2], 77 link:RelNotes-1.6.6.1.txt[1.6.6.1], 78 link:RelNotes-1.6.6.txt[1.6.6]. 79 80* link:v1.6.5.8/git.html[documentation for release 1.6.5.8] 81 82* release notes for 83 link:RelNotes-1.6.5.8.txt[1.6.5.8], 84 link:RelNotes-1.6.5.7.txt[1.6.5.7], 85 link:RelNotes-1.6.5.6.txt[1.6.5.6], 86 link:RelNotes-1.6.5.5.txt[1.6.5.5], 87 link:RelNotes-1.6.5.4.txt[1.6.5.4], 88 link:RelNotes-1.6.5.3.txt[1.6.5.3], 89 link:RelNotes-1.6.5.2.txt[1.6.5.2], 90 link:RelNotes-1.6.5.1.txt[1.6.5.1], 91 link:RelNotes-1.6.5.txt[1.6.5]. 92 93* link:v1.6.4.4/git.html[documentation for release 1.6.4.4] 94 95* release notes for 96 link:RelNotes-1.6.4.4.txt[1.6.4.4], 97 link:RelNotes-1.6.4.3.txt[1.6.4.3], 98 link:RelNotes-1.6.4.2.txt[1.6.4.2], 99 link:RelNotes-1.6.4.1.txt[1.6.4.1], 100 link:RelNotes-1.6.4.txt[1.6.4]. 101 102* link:v1.6.3.4/git.html[documentation for release 1.6.3.4] 103 104* release notes for 105 link:RelNotes-1.6.3.4.txt[1.6.3.4], 106 link:RelNotes-1.6.3.3.txt[1.6.3.3], 107 link:RelNotes-1.6.3.2.txt[1.6.3.2], 108 link:RelNotes-1.6.3.1.txt[1.6.3.1], 109 link:RelNotes-1.6.3.txt[1.6.3]. 110 111* release notes for 112 link:RelNotes-1.6.2.5.txt[1.6.2.5], 113 link:RelNotes-1.6.2.4.txt[1.6.2.4], 114 link:RelNotes-1.6.2.3.txt[1.6.2.3], 115 link:RelNotes-1.6.2.2.txt[1.6.2.2], 116 link:RelNotes-1.6.2.1.txt[1.6.2.1], 117 link:RelNotes-1.6.2.txt[1.6.2]. 118 119* link:v1.6.1.3/git.html[documentation for release 1.6.1.3] 120 121* release notes for 122 link:RelNotes-1.6.1.3.txt[1.6.1.3], 123 link:RelNotes-1.6.1.2.txt[1.6.1.2], 124 link:RelNotes-1.6.1.1.txt[1.6.1.1], 125 link:RelNotes-1.6.1.txt[1.6.1]. 126 127* link:v1.6.0.6/git.html[documentation for release 1.6.0.6] 128 129* release notes for 130 link:RelNotes-1.6.0.6.txt[1.6.0.6], 131 link:RelNotes-1.6.0.5.txt[1.6.0.5], 132 link:RelNotes-1.6.0.4.txt[1.6.0.4], 133 link:RelNotes-1.6.0.3.txt[1.6.0.3], 134 link:RelNotes-1.6.0.2.txt[1.6.0.2], 135 link:RelNotes-1.6.0.1.txt[1.6.0.1], 136 link:RelNotes-1.6.0.txt[1.6.0]. 137 138* link:v1.5.6.6/git.html[documentation for release 1.5.6.6] 139 140* release notes for 141 link:RelNotes-1.5.6.6.txt[1.5.6.6], 142 link:RelNotes-1.5.6.5.txt[1.5.6.5], 143 link:RelNotes-1.5.6.4.txt[1.5.6.4], 144 link:RelNotes-1.5.6.3.txt[1.5.6.3], 145 link:RelNotes-1.5.6.2.txt[1.5.6.2], 146 link:RelNotes-1.5.6.1.txt[1.5.6.1], 147 link:RelNotes-1.5.6.txt[1.5.6]. 148 149* link:v1.5.5.6/git.html[documentation for release 1.5.5.6] 150 151* release notes for 152 link:RelNotes-1.5.5.6.txt[1.5.5.6], 153 link:RelNotes-1.5.5.5.txt[1.5.5.5], 154 link:RelNotes-1.5.5.4.txt[1.5.5.4], 155 link:RelNotes-1.5.5.3.txt[1.5.5.3], 156 link:RelNotes-1.5.5.2.txt[1.5.5.2], 157 link:RelNotes-1.5.5.1.txt[1.5.5.1], 158 link:RelNotes-1.5.5.txt[1.5.5]. 159 160* link:v1.5.4.7/git.html[documentation for release 1.5.4.7] 161 162* release notes for 163 link:RelNotes-1.5.4.7.txt[1.5.4.7], 164 link:RelNotes-1.5.4.6.txt[1.5.4.6], 165 link:RelNotes-1.5.4.5.txt[1.5.4.5], 166 link:RelNotes-1.5.4.4.txt[1.5.4.4], 167 link:RelNotes-1.5.4.3.txt[1.5.4.3], 168 link:RelNotes-1.5.4.2.txt[1.5.4.2], 169 link:RelNotes-1.5.4.1.txt[1.5.4.1], 170 link:RelNotes-1.5.4.txt[1.5.4]. 171 172* link:v1.5.3.8/git.html[documentation for release 1.5.3.8] 173 174* release notes for 175 link:RelNotes-1.5.3.8.txt[1.5.3.8], 176 link:RelNotes-1.5.3.7.txt[1.5.3.7], 177 link:RelNotes-1.5.3.6.txt[1.5.3.6], 178 link:RelNotes-1.5.3.5.txt[1.5.3.5], 179 link:RelNotes-1.5.3.4.txt[1.5.3.4], 180 link:RelNotes-1.5.3.3.txt[1.5.3.3], 181 link:RelNotes-1.5.3.2.txt[1.5.3.2], 182 link:RelNotes-1.5.3.1.txt[1.5.3.1], 183 link:RelNotes-1.5.3.txt[1.5.3]. 184 185* link:v1.5.2.5/git.html[documentation for release 1.5.2.5] 186 187* release notes for 188 link:RelNotes-1.5.2.5.txt[1.5.2.5], 189 link:RelNotes-1.5.2.4.txt[1.5.2.4], 190 link:RelNotes-1.5.2.3.txt[1.5.2.3], 191 link:RelNotes-1.5.2.2.txt[1.5.2.2], 192 link:RelNotes-1.5.2.1.txt[1.5.2.1], 193 link:RelNotes-1.5.2.txt[1.5.2]. 194 195* link:v1.5.1.6/git.html[documentation for release 1.5.1.6] 196 197* release notes for 198 link:RelNotes-1.5.1.6.txt[1.5.1.6], 199 link:RelNotes-1.5.1.5.txt[1.5.1.5], 200 link:RelNotes-1.5.1.4.txt[1.5.1.4], 201 link:RelNotes-1.5.1.3.txt[1.5.1.3], 202 link:RelNotes-1.5.1.2.txt[1.5.1.2], 203 link:RelNotes-1.5.1.1.txt[1.5.1.1], 204 link:RelNotes-1.5.1.txt[1.5.1]. 205 206* link:v1.5.0.7/git.html[documentation for release 1.5.0.7] 207 208* release notes for 209 link:RelNotes-1.5.0.7.txt[1.5.0.7], 210 link:RelNotes-1.5.0.6.txt[1.5.0.6], 211 link:RelNotes-1.5.0.5.txt[1.5.0.5], 212 link:RelNotes-1.5.0.3.txt[1.5.0.3], 213 link:RelNotes-1.5.0.2.txt[1.5.0.2], 214 link:RelNotes-1.5.0.1.txt[1.5.0.1], 215 link:RelNotes-1.5.0.txt[1.5.0]. 216 217* documentation for release link:v1.4.4.4/git.html[1.4.4.4], 218 link:v1.3.3/git.html[1.3.3], 219 link:v1.2.6/git.html[1.2.6], 220 link:v1.0.13/git.html[1.0.13]. 221 222============ 223 224endif::stalenotes[] 225 226OPTIONS 227------- 228--version:: 229 Prints the git suite version that the 'git' program came from. 230 231--help:: 232 Prints the synopsis and a list of the most commonly used 233 commands. If the option '--all' or '-a' is given then all 234 available commands are printed. If a git command is named this 235 option will bring up the manual page for that command. 236+ 237Other options are available to control how the manual page is 238displayed. See linkgit:git-help[1] for more information, 239because `git --help ...` is converted internally into `git 240help ...`. 241 242-c <name>=<value>:: 243 Pass a configuration parameter to the command. The value 244 given will override values from configuration files. 245 The <name> is expected in the same format as listed by 246 'git config' (subkeys separated by dots). 247 248--exec-path:: 249 Path to wherever your core git programs are installed. 250 This can also be controlled by setting the GIT_EXEC_PATH 251 environment variable. If no path is given, 'git' will print 252 the current setting and then exit. 253 254--html-path:: 255 Print the path to wherever your git HTML documentation is installed 256 and exit. 257 258-p:: 259--paginate:: 260 Pipe all output into 'less' (or if set, $PAGER) if standard 261 output is a terminal. This overrides the `pager.<cmd>` 262 configuration options (see the "Configuration Mechanism" section 263 below). 264 265--no-pager:: 266 Do not pipe git output into a pager. 267 268--git-dir=<path>:: 269 Set the path to the repository. This can also be controlled by 270 setting the GIT_DIR environment variable. It can be an absolute 271 path or relative path to current working directory. 272 273--work-tree=<path>:: 274 Set the path to the working tree. The value will not be 275 used in combination with repositories found automatically in 276 a .git directory (i.e. $GIT_DIR is not set). 277 This can also be controlled by setting the GIT_WORK_TREE 278 environment variable and the core.worktree configuration 279 variable. It can be an absolute path or relative path to 280 the directory specified by --git-dir or GIT_DIR. 281 Note: If --git-dir or GIT_DIR are specified but none of 282 --work-tree, GIT_WORK_TREE and core.worktree is specified, 283 the current working directory is regarded as the top directory 284 of your working tree. 285 286--bare:: 287 Treat the repository as a bare repository. If GIT_DIR 288 environment is not set, it is set to the current working 289 directory. 290 291--no-replace-objects:: 292 Do not use replacement refs to replace git objects. See 293 linkgit:git-replace[1] for more information. 294 295 296FURTHER DOCUMENTATION 297--------------------- 298 299See the references above to get started using git. The following is 300probably more detail than necessary for a first-time user. 301 302The link:user-manual.html#git-concepts[git concepts chapter of the 303user-manual] and linkgit:gitcore-tutorial[7] both provide 304introductions to the underlying git architecture. 305 306See linkgit:gitworkflows[7] for an overview of recommended workflows. 307 308See also the link:howto-index.html[howto] documents for some useful 309examples. 310 311The internals are documented in the 312link:technical/api-index.html[GIT API documentation]. 313 314GIT COMMANDS 315------------ 316 317We divide git into high level ("porcelain") commands and low level 318("plumbing") commands. 319 320High-level commands (porcelain) 321------------------------------- 322 323We separate the porcelain commands into the main commands and some 324ancillary user utilities. 325 326Main porcelain commands 327~~~~~~~~~~~~~~~~~~~~~~~ 328 329include::cmds-mainporcelain.txt[] 330 331Ancillary Commands 332~~~~~~~~~~~~~~~~~~ 333Manipulators: 334 335include::cmds-ancillarymanipulators.txt[] 336 337Interrogators: 338 339include::cmds-ancillaryinterrogators.txt[] 340 341 342Interacting with Others 343~~~~~~~~~~~~~~~~~~~~~~~ 344 345These commands are to interact with foreign SCM and with other 346people via patch over e-mail. 347 348include::cmds-foreignscminterface.txt[] 349 350 351Low-level commands (plumbing) 352----------------------------- 353 354Although git includes its 355own porcelain layer, its low-level commands are sufficient to support 356development of alternative porcelains. Developers of such porcelains 357might start by reading about linkgit:git-update-index[1] and 358linkgit:git-read-tree[1]. 359 360The interface (input, output, set of options and the semantics) 361to these low-level commands are meant to be a lot more stable 362than Porcelain level commands, because these commands are 363primarily for scripted use. The interface to Porcelain commands 364on the other hand are subject to change in order to improve the 365end user experience. 366 367The following description divides 368the low-level commands into commands that manipulate objects (in 369the repository, index, and working tree), commands that interrogate and 370compare objects, and commands that move objects and references between 371repositories. 372 373 374Manipulation commands 375~~~~~~~~~~~~~~~~~~~~~ 376 377include::cmds-plumbingmanipulators.txt[] 378 379 380Interrogation commands 381~~~~~~~~~~~~~~~~~~~~~~ 382 383include::cmds-plumbinginterrogators.txt[] 384 385In general, the interrogate commands do not touch the files in 386the working tree. 387 388 389Synching repositories 390~~~~~~~~~~~~~~~~~~~~~ 391 392include::cmds-synchingrepositories.txt[] 393 394The following are helper commands used by the above; end users 395typically do not use them directly. 396 397include::cmds-synchelpers.txt[] 398 399 400Internal helper commands 401~~~~~~~~~~~~~~~~~~~~~~~~ 402 403These are internal helper commands used by other commands; end 404users typically do not use them directly. 405 406include::cmds-purehelpers.txt[] 407 408 409Configuration Mechanism 410----------------------- 411 412Starting from 0.99.9 (actually mid 0.99.8.GIT), `.git/config` file 413is used to hold per-repository configuration options. It is a 414simple text file modeled after `.ini` format familiar to some 415people. Here is an example: 416 417------------ 418# 419# A '#' or ';' character indicates a comment. 420# 421 422; core variables 423[core] 424 ; Don't trust file modes 425 filemode = false 426 427; user identity 428[user] 429 name = "Junio C Hamano" 430 email = "junkio@twinsun.com" 431 432------------ 433 434Various commands read from the configuration file and adjust 435their operation accordingly. See linkgit:git-config[1] for a 436list. 437 438 439Identifier Terminology 440---------------------- 441<object>:: 442 Indicates the object name for any type of object. 443 444<blob>:: 445 Indicates a blob object name. 446 447<tree>:: 448 Indicates a tree object name. 449 450<commit>:: 451 Indicates a commit object name. 452 453<tree-ish>:: 454 Indicates a tree, commit or tag object name. A 455 command that takes a <tree-ish> argument ultimately wants to 456 operate on a <tree> object but automatically dereferences 457 <commit> and <tag> objects that point at a <tree>. 458 459<commit-ish>:: 460 Indicates a commit or tag object name. A 461 command that takes a <commit-ish> argument ultimately wants to 462 operate on a <commit> object but automatically dereferences 463 <tag> objects that point at a <commit>. 464 465<type>:: 466 Indicates that an object type is required. 467 Currently one of: `blob`, `tree`, `commit`, or `tag`. 468 469<file>:: 470 Indicates a filename - almost always relative to the 471 root of the tree structure `GIT_INDEX_FILE` describes. 472 473Symbolic Identifiers 474-------------------- 475Any git command accepting any <object> can also use the following 476symbolic notation: 477 478HEAD:: 479 indicates the head of the current branch (i.e. the 480 contents of `$GIT_DIR/HEAD`). 481 482<tag>:: 483 a valid tag 'name' 484 (i.e. the contents of `$GIT_DIR/refs/tags/<tag>`). 485 486<head>:: 487 a valid head 'name' 488 (i.e. the contents of `$GIT_DIR/refs/heads/<head>`). 489 490For a more complete list of ways to spell object names, see 491"SPECIFYING REVISIONS" section in linkgit:gitrevisions[1]. 492 493 494File/Directory Structure 495------------------------ 496 497Please see the linkgit:gitrepository-layout[5] document. 498 499Read linkgit:githooks[5] for more details about each hook. 500 501Higher level SCMs may provide and manage additional information in the 502`$GIT_DIR`. 503 504 505Terminology 506----------- 507Please see linkgit:gitglossary[7]. 508 509 510Environment Variables 511--------------------- 512Various git commands use the following environment variables: 513 514The git Repository 515~~~~~~~~~~~~~~~~~~ 516These environment variables apply to 'all' core git commands. Nb: it 517is worth noting that they may be used/overridden by SCMS sitting above 518git so take care if using Cogito etc. 519 520'GIT_INDEX_FILE':: 521 This environment allows the specification of an alternate 522 index file. If not specified, the default of `$GIT_DIR/index` 523 is used. 524 525'GIT_OBJECT_DIRECTORY':: 526 If the object storage directory is specified via this 527 environment variable then the sha1 directories are created 528 underneath - otherwise the default `$GIT_DIR/objects` 529 directory is used. 530 531'GIT_ALTERNATE_OBJECT_DIRECTORIES':: 532 Due to the immutable nature of git objects, old objects can be 533 archived into shared, read-only directories. This variable 534 specifies a ":" separated (on Windows ";" separated) list 535 of git object directories which can be used to search for git 536 objects. New objects will not be written to these directories. 537 538'GIT_DIR':: 539 If the 'GIT_DIR' environment variable is set then it 540 specifies a path to use instead of the default `.git` 541 for the base of the repository. 542 543'GIT_WORK_TREE':: 544 Set the path to the working tree. The value will not be 545 used in combination with repositories found automatically in 546 a .git directory (i.e. $GIT_DIR is not set). 547 This can also be controlled by the '--work-tree' command line 548 option and the core.worktree configuration variable. 549 550'GIT_CEILING_DIRECTORIES':: 551 This should be a colon-separated list of absolute paths. 552 If set, it is a list of directories that git should not chdir 553 up into while looking for a repository directory. 554 It will not exclude the current working directory or 555 a GIT_DIR set on the command line or in the environment. 556 (Useful for excluding slow-loading network directories.) 557 558'GIT_DISCOVERY_ACROSS_FILESYSTEM':: 559 When run in a directory that does not have ".git" repository 560 directory, git tries to find such a directory in the parent 561 directories to find the top of the working tree, but by default it 562 does not cross filesystem boundaries. This environment variable 563 can be set to true to tell git not to stop at filesystem 564 boundaries. Like 'GIT_CEILING_DIRECTORIES', this will not affect 565 an explicit repository directory set via 'GIT_DIR' or on the 566 command line. 567 568git Commits 569~~~~~~~~~~~ 570'GIT_AUTHOR_NAME':: 571'GIT_AUTHOR_EMAIL':: 572'GIT_AUTHOR_DATE':: 573'GIT_COMMITTER_NAME':: 574'GIT_COMMITTER_EMAIL':: 575'GIT_COMMITTER_DATE':: 576'EMAIL':: 577 see linkgit:git-commit-tree[1] 578 579git Diffs 580~~~~~~~~~ 581'GIT_DIFF_OPTS':: 582 Only valid setting is "--unified=??" or "-u??" to set the 583 number of context lines shown when a unified diff is created. 584 This takes precedence over any "-U" or "--unified" option 585 value passed on the git diff command line. 586 587'GIT_EXTERNAL_DIFF':: 588 When the environment variable 'GIT_EXTERNAL_DIFF' is set, the 589 program named by it is called, instead of the diff invocation 590 described above. For a path that is added, removed, or modified, 591 'GIT_EXTERNAL_DIFF' is called with 7 parameters: 592 593 path old-file old-hex old-mode new-file new-hex new-mode 594+ 595where: 596 597 <old|new>-file:: are files GIT_EXTERNAL_DIFF can use to read the 598 contents of <old|new>, 599 <old|new>-hex:: are the 40-hexdigit SHA1 hashes, 600 <old|new>-mode:: are the octal representation of the file modes. 601 602+ 603The file parameters can point at the user's working file 604(e.g. `new-file` in "git-diff-files"), `/dev/null` (e.g. `old-file` 605when a new file is added), or a temporary file (e.g. `old-file` in the 606index). 'GIT_EXTERNAL_DIFF' should not worry about unlinking the 607temporary file --- it is removed when 'GIT_EXTERNAL_DIFF' exits. 608+ 609For a path that is unmerged, 'GIT_EXTERNAL_DIFF' is called with 1 610parameter, <path>. 611 612other 613~~~~~ 614'GIT_MERGE_VERBOSITY':: 615 A number controlling the amount of output shown by 616 the recursive merge strategy. Overrides merge.verbosity. 617 See linkgit:git-merge[1] 618 619'GIT_PAGER':: 620 This environment variable overrides `$PAGER`. If it is set 621 to an empty string or to the value "cat", git will not launch 622 a pager. See also the `core.pager` option in 623 linkgit:git-config[1]. 624 625'GIT_SSH':: 626 If this environment variable is set then 'git fetch' 627 and 'git push' will use this command instead 628 of 'ssh' when they need to connect to a remote system. 629 The '$GIT_SSH' command will be given exactly two arguments: 630 the 'username@host' (or just 'host') from the URL and the 631 shell command to execute on that remote system. 632+ 633To pass options to the program that you want to list in GIT_SSH 634you will need to wrap the program and options into a shell script, 635then set GIT_SSH to refer to the shell script. 636+ 637Usually it is easier to configure any desired options through your 638personal `.ssh/config` file. Please consult your ssh documentation 639for further details. 640 641'GIT_FLUSH':: 642 If this environment variable is set to "1", then commands such 643 as 'git blame' (in incremental mode), 'git rev-list', 'git log', 644 and 'git whatchanged' will force a flush of the output stream 645 after each commit-oriented record have been flushed. If this 646 variable is set to "0", the output of these commands will be done 647 using completely buffered I/O. If this environment variable is 648 not set, git will choose buffered or record-oriented flushing 649 based on whether stdout appears to be redirected to a file or not. 650 651'GIT_TRACE':: 652 If this variable is set to "1", "2" or "true" (comparison 653 is case insensitive), git will print `trace:` messages on 654 stderr telling about alias expansion, built-in command 655 execution and external command execution. 656 If this variable is set to an integer value greater than 1 657 and lower than 10 (strictly) then git will interpret this 658 value as an open file descriptor and will try to write the 659 trace messages into this file descriptor. 660 Alternatively, if this variable is set to an absolute path 661 (starting with a '/' character), git will interpret this 662 as a file path and will try to write the trace messages 663 into it. 664 665Discussion[[Discussion]] 666------------------------ 667 668More detail on the following is available from the 669link:user-manual.html#git-concepts[git concepts chapter of the 670user-manual] and linkgit:gitcore-tutorial[7]. 671 672A git project normally consists of a working directory with a ".git" 673subdirectory at the top level. The .git directory contains, among other 674things, a compressed object database representing the complete history 675of the project, an "index" file which links that history to the current 676contents of the working tree, and named pointers into that history such 677as tags and branch heads. 678 679The object database contains objects of three main types: blobs, which 680hold file data; trees, which point to blobs and other trees to build up 681directory hierarchies; and commits, which each reference a single tree 682and some number of parent commits. 683 684The commit, equivalent to what other systems call a "changeset" or 685"version", represents a step in the project's history, and each parent 686represents an immediately preceding step. Commits with more than one 687parent represent merges of independent lines of development. 688 689All objects are named by the SHA1 hash of their contents, normally 690written as a string of 40 hex digits. Such names are globally unique. 691The entire history leading up to a commit can be vouched for by signing 692just that commit. A fourth object type, the tag, is provided for this 693purpose. 694 695When first created, objects are stored in individual files, but for 696efficiency may later be compressed together into "pack files". 697 698Named pointers called refs mark interesting points in history. A ref 699may contain the SHA1 name of an object or the name of another ref. Refs 700with names beginning `ref/head/` contain the SHA1 name of the most 701recent commit (or "head") of a branch under development. SHA1 names of 702tags of interest are stored under `ref/tags/`. A special ref named 703`HEAD` contains the name of the currently checked-out branch. 704 705The index file is initialized with a list of all paths and, for each 706path, a blob object and a set of attributes. The blob object represents 707the contents of the file as of the head of the current branch. The 708attributes (last modified time, size, etc.) are taken from the 709corresponding file in the working tree. Subsequent changes to the 710working tree can be found by comparing these attributes. The index may 711be updated with new content, and new commits may be created from the 712content stored in the index. 713 714The index is also capable of storing multiple entries (called "stages") 715for a given pathname. These stages are used to hold the various 716unmerged version of a file when a merge is in progress. 717 718Authors 719------- 720* git's founding father is Linus Torvalds <torvalds@osdl.org>. 721* The current git nurse is Junio C Hamano <gitster@pobox.com>. 722* The git potty was written by Andreas Ericsson <ae@op5.se>. 723* General upbringing is handled by the git-list <git@vger.kernel.org>. 724 725Documentation 726-------------- 727The documentation for git suite was started by David Greaves 728<david@dgreaves.com>, and later enhanced greatly by the 729contributors on the git-list <git@vger.kernel.org>. 730 731Reporting Bugs 732-------------- 733 734Report bugs to the Git mailing list <git@vger.kernel.org> where the 735development and maintenance is primarily done. You do not have to be 736subscribed to the list to send a message there. 737 738SEE ALSO 739-------- 740linkgit:gittutorial[7], linkgit:gittutorial-2[7], 741link:everyday.html[Everyday Git], linkgit:gitcvs-migration[7], 742linkgit:gitglossary[7], linkgit:gitcore-tutorial[7], 743linkgit:gitcli[7], link:user-manual.html[The Git User's Manual], 744linkgit:gitworkflows[7] 745 746GIT 747--- 748Part of the linkgit:git[1] suite