1git(1) 2====== 3 4NAME 5---- 6git - the stupid content tracker 7 8 9SYNOPSIS 10-------- 11[verse] 12'git' [--version] [--exec-path[=<path>]] [--html-path] 13 [-p|--paginate|--no-pager] [--no-replace-objects] 14 [--bare] [--git-dir=<path>] [--work-tree=<path>] 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:v1.7.3.3/git.html[documentation for release 1.7.3.3] 48 49* release notes for 50 link:RelNotes/1.7.3.3.txt[1.7.3.3], 51 link:RelNotes/1.7.3.2.txt[1.7.3.2], 52 link:RelNotes/1.7.3.1.txt[1.7.3.1], 53 link:RelNotes/1.7.3.txt[1.7.3]. 54 55* link:v1.7.2.4/git.html[documentation for release 1.7.2.4] 56 57* release notes for 58 link:RelNotes/1.7.2.4.txt[1.7.2.4], 59 link:RelNotes/1.7.2.3.txt[1.7.2.3], 60 link:RelNotes/1.7.2.2.txt[1.7.2.2], 61 link:RelNotes/1.7.2.1.txt[1.7.2.1], 62 link:RelNotes/1.7.2.txt[1.7.2]. 63 64* link:v1.7.1.3/git.html[documentation for release 1.7.1.3] 65 66* release notes for 67 link:RelNotes/1.7.1.3.txt[1.7.1.3], 68 link:RelNotes/1.7.1.2.txt[1.7.1.2], 69 link:RelNotes/1.7.1.1.txt[1.7.1.1], 70 link:RelNotes/1.7.1.txt[1.7.1]. 71 72* link:v1.7.0.8/git.html[documentation for release 1.7.0.8] 73 74* release notes for 75 link:RelNotes/1.7.0.8.txt[1.7.0.8], 76 link:RelNotes/1.7.0.7.txt[1.7.0.7], 77 link:RelNotes/1.7.0.6.txt[1.7.0.6], 78 link:RelNotes/1.7.0.5.txt[1.7.0.5], 79 link:RelNotes/1.7.0.4.txt[1.7.0.4], 80 link:RelNotes/1.7.0.3.txt[1.7.0.3], 81 link:RelNotes/1.7.0.2.txt[1.7.0.2], 82 link:RelNotes/1.7.0.1.txt[1.7.0.1], 83 link:RelNotes/1.7.0.txt[1.7.0]. 84 85* link:v1.6.6.2/git.html[documentation for release 1.6.6.2] 86 87* release notes for 88 link:RelNotes/1.6.6.2.txt[1.6.6.2], 89 link:RelNotes/1.6.6.1.txt[1.6.6.1], 90 link:RelNotes/1.6.6.txt[1.6.6]. 91 92* link:v1.6.5.8/git.html[documentation for release 1.6.5.8] 93 94* release notes for 95 link:RelNotes/1.6.5.8.txt[1.6.5.8], 96 link:RelNotes/1.6.5.7.txt[1.6.5.7], 97 link:RelNotes/1.6.5.6.txt[1.6.5.6], 98 link:RelNotes/1.6.5.5.txt[1.6.5.5], 99 link:RelNotes/1.6.5.4.txt[1.6.5.4], 100 link:RelNotes/1.6.5.3.txt[1.6.5.3], 101 link:RelNotes/1.6.5.2.txt[1.6.5.2], 102 link:RelNotes/1.6.5.1.txt[1.6.5.1], 103 link:RelNotes/1.6.5.txt[1.6.5]. 104 105* link:v1.6.4.4/git.html[documentation for release 1.6.4.4] 106 107* release notes for 108 link:RelNotes/1.6.4.4.txt[1.6.4.4], 109 link:RelNotes/1.6.4.3.txt[1.6.4.3], 110 link:RelNotes/1.6.4.2.txt[1.6.4.2], 111 link:RelNotes/1.6.4.1.txt[1.6.4.1], 112 link:RelNotes/1.6.4.txt[1.6.4]. 113 114* link:v1.6.3.4/git.html[documentation for release 1.6.3.4] 115 116* release notes for 117 link:RelNotes/1.6.3.4.txt[1.6.3.4], 118 link:RelNotes/1.6.3.3.txt[1.6.3.3], 119 link:RelNotes/1.6.3.2.txt[1.6.3.2], 120 link:RelNotes/1.6.3.1.txt[1.6.3.1], 121 link:RelNotes/1.6.3.txt[1.6.3]. 122 123* release notes for 124 link:RelNotes/1.6.2.5.txt[1.6.2.5], 125 link:RelNotes/1.6.2.4.txt[1.6.2.4], 126 link:RelNotes/1.6.2.3.txt[1.6.2.3], 127 link:RelNotes/1.6.2.2.txt[1.6.2.2], 128 link:RelNotes/1.6.2.1.txt[1.6.2.1], 129 link:RelNotes/1.6.2.txt[1.6.2]. 130 131* link:v1.6.1.3/git.html[documentation for release 1.6.1.3] 132 133* release notes for 134 link:RelNotes/1.6.1.3.txt[1.6.1.3], 135 link:RelNotes/1.6.1.2.txt[1.6.1.2], 136 link:RelNotes/1.6.1.1.txt[1.6.1.1], 137 link:RelNotes/1.6.1.txt[1.6.1]. 138 139* link:v1.6.0.6/git.html[documentation for release 1.6.0.6] 140 141* release notes for 142 link:RelNotes/1.6.0.6.txt[1.6.0.6], 143 link:RelNotes/1.6.0.5.txt[1.6.0.5], 144 link:RelNotes/1.6.0.4.txt[1.6.0.4], 145 link:RelNotes/1.6.0.3.txt[1.6.0.3], 146 link:RelNotes/1.6.0.2.txt[1.6.0.2], 147 link:RelNotes/1.6.0.1.txt[1.6.0.1], 148 link:RelNotes/1.6.0.txt[1.6.0]. 149 150* link:v1.5.6.6/git.html[documentation for release 1.5.6.6] 151 152* release notes for 153 link:RelNotes/1.5.6.6.txt[1.5.6.6], 154 link:RelNotes/1.5.6.5.txt[1.5.6.5], 155 link:RelNotes/1.5.6.4.txt[1.5.6.4], 156 link:RelNotes/1.5.6.3.txt[1.5.6.3], 157 link:RelNotes/1.5.6.2.txt[1.5.6.2], 158 link:RelNotes/1.5.6.1.txt[1.5.6.1], 159 link:RelNotes/1.5.6.txt[1.5.6]. 160 161* link:v1.5.5.6/git.html[documentation for release 1.5.5.6] 162 163* release notes for 164 link:RelNotes/1.5.5.6.txt[1.5.5.6], 165 link:RelNotes/1.5.5.5.txt[1.5.5.5], 166 link:RelNotes/1.5.5.4.txt[1.5.5.4], 167 link:RelNotes/1.5.5.3.txt[1.5.5.3], 168 link:RelNotes/1.5.5.2.txt[1.5.5.2], 169 link:RelNotes/1.5.5.1.txt[1.5.5.1], 170 link:RelNotes/1.5.5.txt[1.5.5]. 171 172* link:v1.5.4.7/git.html[documentation for release 1.5.4.7] 173 174* release notes for 175 link:RelNotes/1.5.4.7.txt[1.5.4.7], 176 link:RelNotes/1.5.4.6.txt[1.5.4.6], 177 link:RelNotes/1.5.4.5.txt[1.5.4.5], 178 link:RelNotes/1.5.4.4.txt[1.5.4.4], 179 link:RelNotes/1.5.4.3.txt[1.5.4.3], 180 link:RelNotes/1.5.4.2.txt[1.5.4.2], 181 link:RelNotes/1.5.4.1.txt[1.5.4.1], 182 link:RelNotes/1.5.4.txt[1.5.4]. 183 184* link:v1.5.3.8/git.html[documentation for release 1.5.3.8] 185 186* release notes for 187 link:RelNotes/1.5.3.8.txt[1.5.3.8], 188 link:RelNotes/1.5.3.7.txt[1.5.3.7], 189 link:RelNotes/1.5.3.6.txt[1.5.3.6], 190 link:RelNotes/1.5.3.5.txt[1.5.3.5], 191 link:RelNotes/1.5.3.4.txt[1.5.3.4], 192 link:RelNotes/1.5.3.3.txt[1.5.3.3], 193 link:RelNotes/1.5.3.2.txt[1.5.3.2], 194 link:RelNotes/1.5.3.1.txt[1.5.3.1], 195 link:RelNotes/1.5.3.txt[1.5.3]. 196 197* link:v1.5.2.5/git.html[documentation for release 1.5.2.5] 198 199* release notes for 200 link:RelNotes/1.5.2.5.txt[1.5.2.5], 201 link:RelNotes/1.5.2.4.txt[1.5.2.4], 202 link:RelNotes/1.5.2.3.txt[1.5.2.3], 203 link:RelNotes/1.5.2.2.txt[1.5.2.2], 204 link:RelNotes/1.5.2.1.txt[1.5.2.1], 205 link:RelNotes/1.5.2.txt[1.5.2]. 206 207* link:v1.5.1.6/git.html[documentation for release 1.5.1.6] 208 209* release notes for 210 link:RelNotes/1.5.1.6.txt[1.5.1.6], 211 link:RelNotes/1.5.1.5.txt[1.5.1.5], 212 link:RelNotes/1.5.1.4.txt[1.5.1.4], 213 link:RelNotes/1.5.1.3.txt[1.5.1.3], 214 link:RelNotes/1.5.1.2.txt[1.5.1.2], 215 link:RelNotes/1.5.1.1.txt[1.5.1.1], 216 link:RelNotes/1.5.1.txt[1.5.1]. 217 218* link:v1.5.0.7/git.html[documentation for release 1.5.0.7] 219 220* release notes for 221 link:RelNotes/1.5.0.7.txt[1.5.0.7], 222 link:RelNotes/1.5.0.6.txt[1.5.0.6], 223 link:RelNotes/1.5.0.5.txt[1.5.0.5], 224 link:RelNotes/1.5.0.3.txt[1.5.0.3], 225 link:RelNotes/1.5.0.2.txt[1.5.0.2], 226 link:RelNotes/1.5.0.1.txt[1.5.0.1], 227 link:RelNotes/1.5.0.txt[1.5.0]. 228 229* documentation for release link:v1.4.4.4/git.html[1.4.4.4], 230 link:v1.3.3/git.html[1.3.3], 231 link:v1.2.6/git.html[1.2.6], 232 link:v1.0.13/git.html[1.0.13]. 233 234============ 235 236endif::stalenotes[] 237 238OPTIONS 239------- 240--version:: 241 Prints the git suite version that the 'git' program came from. 242 243--help:: 244 Prints the synopsis and a list of the most commonly used 245 commands. If the option '--all' or '-a' is given then all 246 available commands are printed. If a git command is named this 247 option will bring up the manual page for that command. 248+ 249Other options are available to control how the manual page is 250displayed. See linkgit:git-help[1] for more information, 251because `git --help ...` is converted internally into `git 252help ...`. 253 254-c <name>=<value>:: 255 Pass a configuration parameter to the command. The value 256 given will override values from configuration files. 257 The <name> is expected in the same format as listed by 258 'git config' (subkeys separated by dots). 259 260--exec-path[=<path>]:: 261 Path to wherever your core git programs are installed. 262 This can also be controlled by setting the GIT_EXEC_PATH 263 environment variable. If no path is given, 'git' will print 264 the current setting and then exit. 265 266--html-path:: 267 Print the path to wherever your git HTML documentation is installed 268 and exit. 269 270-p:: 271--paginate:: 272 Pipe all output into 'less' (or if set, $PAGER) if standard 273 output is a terminal. This overrides the `pager.<cmd>` 274 configuration options (see the "Configuration Mechanism" section 275 below). 276 277--no-pager:: 278 Do not pipe git output into a pager. 279 280--git-dir=<path>:: 281 Set the path to the repository. This can also be controlled by 282 setting the GIT_DIR environment variable. It can be an absolute 283 path or relative path to current working directory. 284 285--work-tree=<path>:: 286 Set the path to the working tree. The value will not be 287 used in combination with repositories found automatically in 288 a .git directory (i.e. $GIT_DIR is not set). 289 This can also be controlled by setting the GIT_WORK_TREE 290 environment variable and the core.worktree configuration 291 variable. It can be an absolute path or relative path to 292 the directory specified by --git-dir or GIT_DIR. 293 Note: If --git-dir or GIT_DIR are specified but none of 294 --work-tree, GIT_WORK_TREE and core.worktree is specified, 295 the current working directory is regarded as the top directory 296 of your working tree. 297 298--bare:: 299 Treat the repository as a bare repository. If GIT_DIR 300 environment is not set, it is set to the current working 301 directory. 302 303--no-replace-objects:: 304 Do not use replacement refs to replace git objects. See 305 linkgit:git-replace[1] for more information. 306 307 308FURTHER DOCUMENTATION 309--------------------- 310 311See the references above to get started using git. The following is 312probably more detail than necessary for a first-time user. 313 314The link:user-manual.html#git-concepts[git concepts chapter of the 315user-manual] and linkgit:gitcore-tutorial[7] both provide 316introductions to the underlying git architecture. 317 318See linkgit:gitworkflows[7] for an overview of recommended workflows. 319 320See also the link:howto-index.html[howto] documents for some useful 321examples. 322 323The internals are documented in the 324link:technical/api-index.html[GIT API documentation]. 325 326GIT COMMANDS 327------------ 328 329We divide git into high level ("porcelain") commands and low level 330("plumbing") commands. 331 332High-level commands (porcelain) 333------------------------------- 334 335We separate the porcelain commands into the main commands and some 336ancillary user utilities. 337 338Main porcelain commands 339~~~~~~~~~~~~~~~~~~~~~~~ 340 341include::cmds-mainporcelain.txt[] 342 343Ancillary Commands 344~~~~~~~~~~~~~~~~~~ 345Manipulators: 346 347include::cmds-ancillarymanipulators.txt[] 348 349Interrogators: 350 351include::cmds-ancillaryinterrogators.txt[] 352 353 354Interacting with Others 355~~~~~~~~~~~~~~~~~~~~~~~ 356 357These commands are to interact with foreign SCM and with other 358people via patch over e-mail. 359 360include::cmds-foreignscminterface.txt[] 361 362 363Low-level commands (plumbing) 364----------------------------- 365 366Although git includes its 367own porcelain layer, its low-level commands are sufficient to support 368development of alternative porcelains. Developers of such porcelains 369might start by reading about linkgit:git-update-index[1] and 370linkgit:git-read-tree[1]. 371 372The interface (input, output, set of options and the semantics) 373to these low-level commands are meant to be a lot more stable 374than Porcelain level commands, because these commands are 375primarily for scripted use. The interface to Porcelain commands 376on the other hand are subject to change in order to improve the 377end user experience. 378 379The following description divides 380the low-level commands into commands that manipulate objects (in 381the repository, index, and working tree), commands that interrogate and 382compare objects, and commands that move objects and references between 383repositories. 384 385 386Manipulation commands 387~~~~~~~~~~~~~~~~~~~~~ 388 389include::cmds-plumbingmanipulators.txt[] 390 391 392Interrogation commands 393~~~~~~~~~~~~~~~~~~~~~~ 394 395include::cmds-plumbinginterrogators.txt[] 396 397In general, the interrogate commands do not touch the files in 398the working tree. 399 400 401Synching repositories 402~~~~~~~~~~~~~~~~~~~~~ 403 404include::cmds-synchingrepositories.txt[] 405 406The following are helper commands used by the above; end users 407typically do not use them directly. 408 409include::cmds-synchelpers.txt[] 410 411 412Internal helper commands 413~~~~~~~~~~~~~~~~~~~~~~~~ 414 415These are internal helper commands used by other commands; end 416users typically do not use them directly. 417 418include::cmds-purehelpers.txt[] 419 420 421Configuration Mechanism 422----------------------- 423 424Starting from 0.99.9 (actually mid 0.99.8.GIT), `.git/config` file 425is used to hold per-repository configuration options. It is a 426simple text file modeled after `.ini` format familiar to some 427people. Here is an example: 428 429------------ 430# 431# A '#' or ';' character indicates a comment. 432# 433 434; core variables 435[core] 436 ; Don't trust file modes 437 filemode = false 438 439; user identity 440[user] 441 name = "Junio C Hamano" 442 email = "junkio@twinsun.com" 443 444------------ 445 446Various commands read from the configuration file and adjust 447their operation accordingly. See linkgit:git-config[1] for a 448list. 449 450 451Identifier Terminology 452---------------------- 453<object>:: 454 Indicates the object name for any type of object. 455 456<blob>:: 457 Indicates a blob object name. 458 459<tree>:: 460 Indicates a tree object name. 461 462<commit>:: 463 Indicates a commit object name. 464 465<tree-ish>:: 466 Indicates a tree, commit or tag object name. A 467 command that takes a <tree-ish> argument ultimately wants to 468 operate on a <tree> object but automatically dereferences 469 <commit> and <tag> objects that point at a <tree>. 470 471<commit-ish>:: 472 Indicates a commit or tag object name. A 473 command that takes a <commit-ish> argument ultimately wants to 474 operate on a <commit> object but automatically dereferences 475 <tag> objects that point at a <commit>. 476 477<type>:: 478 Indicates that an object type is required. 479 Currently one of: `blob`, `tree`, `commit`, or `tag`. 480 481<file>:: 482 Indicates a filename - almost always relative to the 483 root of the tree structure `GIT_INDEX_FILE` describes. 484 485Symbolic Identifiers 486-------------------- 487Any git command accepting any <object> can also use the following 488symbolic notation: 489 490HEAD:: 491 indicates the head of the current branch (i.e. the 492 contents of `$GIT_DIR/HEAD`). 493 494<tag>:: 495 a valid tag 'name' 496 (i.e. the contents of `$GIT_DIR/refs/tags/<tag>`). 497 498<head>:: 499 a valid head 'name' 500 (i.e. the contents of `$GIT_DIR/refs/heads/<head>`). 501 502For a more complete list of ways to spell object names, see 503"SPECIFYING REVISIONS" section in linkgit:gitrevisions[7]. 504 505 506File/Directory Structure 507------------------------ 508 509Please see the linkgit:gitrepository-layout[5] document. 510 511Read linkgit:githooks[5] for more details about each hook. 512 513Higher level SCMs may provide and manage additional information in the 514`$GIT_DIR`. 515 516 517Terminology 518----------- 519Please see linkgit:gitglossary[7]. 520 521 522Environment Variables 523--------------------- 524Various git commands use the following environment variables: 525 526The git Repository 527~~~~~~~~~~~~~~~~~~ 528These environment variables apply to 'all' core git commands. Nb: it 529is worth noting that they may be used/overridden by SCMS sitting above 530git so take care if using Cogito etc. 531 532'GIT_INDEX_FILE':: 533 This environment allows the specification of an alternate 534 index file. If not specified, the default of `$GIT_DIR/index` 535 is used. 536 537'GIT_OBJECT_DIRECTORY':: 538 If the object storage directory is specified via this 539 environment variable then the sha1 directories are created 540 underneath - otherwise the default `$GIT_DIR/objects` 541 directory is used. 542 543'GIT_ALTERNATE_OBJECT_DIRECTORIES':: 544 Due to the immutable nature of git objects, old objects can be 545 archived into shared, read-only directories. This variable 546 specifies a ":" separated (on Windows ";" separated) list 547 of git object directories which can be used to search for git 548 objects. New objects will not be written to these directories. 549 550'GIT_DIR':: 551 If the 'GIT_DIR' environment variable is set then it 552 specifies a path to use instead of the default `.git` 553 for the base of the repository. 554 555'GIT_WORK_TREE':: 556 Set the path to the working tree. The value will not be 557 used in combination with repositories found automatically in 558 a .git directory (i.e. $GIT_DIR is not set). 559 This can also be controlled by the '--work-tree' command line 560 option and the core.worktree configuration variable. 561 562'GIT_CEILING_DIRECTORIES':: 563 This should be a colon-separated list of absolute paths. 564 If set, it is a list of directories that git should not chdir 565 up into while looking for a repository directory. 566 It will not exclude the current working directory or 567 a GIT_DIR set on the command line or in the environment. 568 (Useful for excluding slow-loading network directories.) 569 570'GIT_DISCOVERY_ACROSS_FILESYSTEM':: 571 When run in a directory that does not have ".git" repository 572 directory, git tries to find such a directory in the parent 573 directories to find the top of the working tree, but by default it 574 does not cross filesystem boundaries. This environment variable 575 can be set to true to tell git not to stop at filesystem 576 boundaries. Like 'GIT_CEILING_DIRECTORIES', this will not affect 577 an explicit repository directory set via 'GIT_DIR' or on the 578 command line. 579 580git Commits 581~~~~~~~~~~~ 582'GIT_AUTHOR_NAME':: 583'GIT_AUTHOR_EMAIL':: 584'GIT_AUTHOR_DATE':: 585'GIT_COMMITTER_NAME':: 586'GIT_COMMITTER_EMAIL':: 587'GIT_COMMITTER_DATE':: 588'EMAIL':: 589 see linkgit:git-commit-tree[1] 590 591git Diffs 592~~~~~~~~~ 593'GIT_DIFF_OPTS':: 594 Only valid setting is "--unified=??" or "-u??" to set the 595 number of context lines shown when a unified diff is created. 596 This takes precedence over any "-U" or "--unified" option 597 value passed on the git diff command line. 598 599'GIT_EXTERNAL_DIFF':: 600 When the environment variable 'GIT_EXTERNAL_DIFF' is set, the 601 program named by it is called, instead of the diff invocation 602 described above. For a path that is added, removed, or modified, 603 'GIT_EXTERNAL_DIFF' is called with 7 parameters: 604 605 path old-file old-hex old-mode new-file new-hex new-mode 606+ 607where: 608 609 <old|new>-file:: are files GIT_EXTERNAL_DIFF can use to read the 610 contents of <old|new>, 611 <old|new>-hex:: are the 40-hexdigit SHA1 hashes, 612 <old|new>-mode:: are the octal representation of the file modes. 613 614+ 615The file parameters can point at the user's working file 616(e.g. `new-file` in "git-diff-files"), `/dev/null` (e.g. `old-file` 617when a new file is added), or a temporary file (e.g. `old-file` in the 618index). 'GIT_EXTERNAL_DIFF' should not worry about unlinking the 619temporary file --- it is removed when 'GIT_EXTERNAL_DIFF' exits. 620+ 621For a path that is unmerged, 'GIT_EXTERNAL_DIFF' is called with 1 622parameter, <path>. 623 624other 625~~~~~ 626'GIT_MERGE_VERBOSITY':: 627 A number controlling the amount of output shown by 628 the recursive merge strategy. Overrides merge.verbosity. 629 See linkgit:git-merge[1] 630 631'GIT_PAGER':: 632 This environment variable overrides `$PAGER`. If it is set 633 to an empty string or to the value "cat", git will not launch 634 a pager. See also the `core.pager` option in 635 linkgit:git-config[1]. 636 637'GIT_SSH':: 638 If this environment variable is set then 'git fetch' 639 and 'git push' will use this command instead 640 of 'ssh' when they need to connect to a remote system. 641 The '$GIT_SSH' command will be given exactly two arguments: 642 the 'username@host' (or just 'host') from the URL and the 643 shell command to execute on that remote system. 644+ 645To pass options to the program that you want to list in GIT_SSH 646you will need to wrap the program and options into a shell script, 647then set GIT_SSH to refer to the shell script. 648+ 649Usually it is easier to configure any desired options through your 650personal `.ssh/config` file. Please consult your ssh documentation 651for further details. 652 653'GIT_ASKPASS':: 654 If this environment variable is set, then git commands which need to 655 acquire passwords or passphrases (e.g. for HTTP or IMAP authentication) 656 will call this program with a suitable prompt as command line argument 657 and read the password from its STDOUT. See also the 'core.askpass' 658 option in linkgit:git-config[1]. 659 660'GIT_FLUSH':: 661 If this environment variable is set to "1", then commands such 662 as 'git blame' (in incremental mode), 'git rev-list', 'git log', 663 and 'git whatchanged' will force a flush of the output stream 664 after each commit-oriented record have been flushed. If this 665 variable is set to "0", the output of these commands will be done 666 using completely buffered I/O. If this environment variable is 667 not set, git will choose buffered or record-oriented flushing 668 based on whether stdout appears to be redirected to a file or not. 669 670'GIT_TRACE':: 671 If this variable is set to "1", "2" or "true" (comparison 672 is case insensitive), git will print `trace:` messages on 673 stderr telling about alias expansion, built-in command 674 execution and external command execution. 675 If this variable is set to an integer value greater than 1 676 and lower than 10 (strictly) then git will interpret this 677 value as an open file descriptor and will try to write the 678 trace messages into this file descriptor. 679 Alternatively, if this variable is set to an absolute path 680 (starting with a '/' character), git will interpret this 681 as a file path and will try to write the trace messages 682 into it. 683 684Discussion[[Discussion]] 685------------------------ 686 687More detail on the following is available from the 688link:user-manual.html#git-concepts[git concepts chapter of the 689user-manual] and linkgit:gitcore-tutorial[7]. 690 691A git project normally consists of a working directory with a ".git" 692subdirectory at the top level. The .git directory contains, among other 693things, a compressed object database representing the complete history 694of the project, an "index" file which links that history to the current 695contents of the working tree, and named pointers into that history such 696as tags and branch heads. 697 698The object database contains objects of three main types: blobs, which 699hold file data; trees, which point to blobs and other trees to build up 700directory hierarchies; and commits, which each reference a single tree 701and some number of parent commits. 702 703The commit, equivalent to what other systems call a "changeset" or 704"version", represents a step in the project's history, and each parent 705represents an immediately preceding step. Commits with more than one 706parent represent merges of independent lines of development. 707 708All objects are named by the SHA1 hash of their contents, normally 709written as a string of 40 hex digits. Such names are globally unique. 710The entire history leading up to a commit can be vouched for by signing 711just that commit. A fourth object type, the tag, is provided for this 712purpose. 713 714When first created, objects are stored in individual files, but for 715efficiency may later be compressed together into "pack files". 716 717Named pointers called refs mark interesting points in history. A ref 718may contain the SHA1 name of an object or the name of another ref. Refs 719with names beginning `ref/head/` contain the SHA1 name of the most 720recent commit (or "head") of a branch under development. SHA1 names of 721tags of interest are stored under `ref/tags/`. A special ref named 722`HEAD` contains the name of the currently checked-out branch. 723 724The index file is initialized with a list of all paths and, for each 725path, a blob object and a set of attributes. The blob object represents 726the contents of the file as of the head of the current branch. The 727attributes (last modified time, size, etc.) are taken from the 728corresponding file in the working tree. Subsequent changes to the 729working tree can be found by comparing these attributes. The index may 730be updated with new content, and new commits may be created from the 731content stored in the index. 732 733The index is also capable of storing multiple entries (called "stages") 734for a given pathname. These stages are used to hold the various 735unmerged version of a file when a merge is in progress. 736 737Authors 738------- 739* git's founding father is Linus Torvalds <torvalds@osdl.org>. 740* The current git nurse is Junio C Hamano <gitster@pobox.com>. 741* The git potty was written by Andreas Ericsson <ae@op5.se>. 742* General upbringing is handled by the git-list <git@vger.kernel.org>. 743 744Documentation 745-------------- 746The documentation for git suite was started by David Greaves 747<david@dgreaves.com>, and later enhanced greatly by the 748contributors on the git-list <git@vger.kernel.org>. 749 750Reporting Bugs 751-------------- 752 753Report bugs to the Git mailing list <git@vger.kernel.org> where the 754development and maintenance is primarily done. You do not have to be 755subscribed to the list to send a message there. 756 757SEE ALSO 758-------- 759linkgit:gittutorial[7], linkgit:gittutorial-2[7], 760link:everyday.html[Everyday Git], linkgit:gitcvs-migration[7], 761linkgit:gitglossary[7], linkgit:gitcore-tutorial[7], 762linkgit:gitcli[7], link:user-manual.html[The Git User's Manual], 763linkgit:gitworkflows[7] 764 765GIT 766--- 767Part of the linkgit:git[1] suite