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] [--man-path] [--info-path] 13 [-p|--paginate|--no-pager] [--no-replace-objects] [--bare] 14 [--git-dir=<path>] [--work-tree=<path>] [--namespace=<name>] 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:v1.7.5.2/git.html[documentation for release 1.7.5.2] 48 49* release notes for 50 link:RelNotes/1.7.5.2.txt[1.7.5.2], 51 link:RelNotes/1.7.5.1.txt[1.7.5.1], 52 link:RelNotes/1.7.5.txt[1.7.5]. 53 54* link:v1.7.4.5/git.html[documentation for release 1.7.4.5] 55 56* release notes for 57 link:RelNotes/1.7.4.5.txt[1.7.4.5], 58 link:RelNotes/1.7.4.4.txt[1.7.4.4], 59 link:RelNotes/1.7.4.3.txt[1.7.4.3], 60 link:RelNotes/1.7.4.2.txt[1.7.4.2], 61 link:RelNotes/1.7.4.1.txt[1.7.4.1], 62 link:RelNotes/1.7.4.txt[1.7.4]. 63 64* link:v1.7.3.5/git.html[documentation for release 1.7.3.5] 65 66* release notes for 67 link:RelNotes/1.7.3.5.txt[1.7.3.5], 68 link:RelNotes/1.7.3.4.txt[1.7.3.4], 69 link:RelNotes/1.7.3.3.txt[1.7.3.3], 70 link:RelNotes/1.7.3.2.txt[1.7.3.2], 71 link:RelNotes/1.7.3.1.txt[1.7.3.1], 72 link:RelNotes/1.7.3.txt[1.7.3]. 73 74* link:v1.7.2.5/git.html[documentation for release 1.7.2.5] 75 76* release notes for 77 link:RelNotes/1.7.2.5.txt[1.7.2.5], 78 link:RelNotes/1.7.2.4.txt[1.7.2.4], 79 link:RelNotes/1.7.2.3.txt[1.7.2.3], 80 link:RelNotes/1.7.2.2.txt[1.7.2.2], 81 link:RelNotes/1.7.2.1.txt[1.7.2.1], 82 link:RelNotes/1.7.2.txt[1.7.2]. 83 84* link:v1.7.1.4/git.html[documentation for release 1.7.1.4] 85 86* release notes for 87 link:RelNotes/1.7.1.4.txt[1.7.1.4], 88 link:RelNotes/1.7.1.3.txt[1.7.1.3], 89 link:RelNotes/1.7.1.2.txt[1.7.1.2], 90 link:RelNotes/1.7.1.1.txt[1.7.1.1], 91 link:RelNotes/1.7.1.txt[1.7.1]. 92 93* link:v1.7.0.9/git.html[documentation for release 1.7.0.9] 94 95* release notes for 96 link:RelNotes/1.7.0.9.txt[1.7.0.9], 97 link:RelNotes/1.7.0.8.txt[1.7.0.8], 98 link:RelNotes/1.7.0.7.txt[1.7.0.7], 99 link:RelNotes/1.7.0.6.txt[1.7.0.6], 100 link:RelNotes/1.7.0.5.txt[1.7.0.5], 101 link:RelNotes/1.7.0.4.txt[1.7.0.4], 102 link:RelNotes/1.7.0.3.txt[1.7.0.3], 103 link:RelNotes/1.7.0.2.txt[1.7.0.2], 104 link:RelNotes/1.7.0.1.txt[1.7.0.1], 105 link:RelNotes/1.7.0.txt[1.7.0]. 106 107* link:v1.6.6.3/git.html[documentation for release 1.6.6.3] 108 109* release notes for 110 link:RelNotes/1.6.6.3.txt[1.6.6.3], 111 link:RelNotes/1.6.6.2.txt[1.6.6.2], 112 link:RelNotes/1.6.6.1.txt[1.6.6.1], 113 link:RelNotes/1.6.6.txt[1.6.6]. 114 115* link:v1.6.5.9/git.html[documentation for release 1.6.5.9] 116 117* release notes for 118 link:RelNotes/1.6.5.9.txt[1.6.5.9], 119 link:RelNotes/1.6.5.8.txt[1.6.5.8], 120 link:RelNotes/1.6.5.7.txt[1.6.5.7], 121 link:RelNotes/1.6.5.6.txt[1.6.5.6], 122 link:RelNotes/1.6.5.5.txt[1.6.5.5], 123 link:RelNotes/1.6.5.4.txt[1.6.5.4], 124 link:RelNotes/1.6.5.3.txt[1.6.5.3], 125 link:RelNotes/1.6.5.2.txt[1.6.5.2], 126 link:RelNotes/1.6.5.1.txt[1.6.5.1], 127 link:RelNotes/1.6.5.txt[1.6.5]. 128 129* link:v1.6.4.5/git.html[documentation for release 1.6.4.5] 130 131* release notes for 132 link:RelNotes/1.6.4.5.txt[1.6.4.5], 133 link:RelNotes/1.6.4.4.txt[1.6.4.4], 134 link:RelNotes/1.6.4.3.txt[1.6.4.3], 135 link:RelNotes/1.6.4.2.txt[1.6.4.2], 136 link:RelNotes/1.6.4.1.txt[1.6.4.1], 137 link:RelNotes/1.6.4.txt[1.6.4]. 138 139* link:v1.6.3.4/git.html[documentation for release 1.6.3.4] 140 141* release notes for 142 link:RelNotes/1.6.3.4.txt[1.6.3.4], 143 link:RelNotes/1.6.3.3.txt[1.6.3.3], 144 link:RelNotes/1.6.3.2.txt[1.6.3.2], 145 link:RelNotes/1.6.3.1.txt[1.6.3.1], 146 link:RelNotes/1.6.3.txt[1.6.3]. 147 148* release notes for 149 link:RelNotes/1.6.2.5.txt[1.6.2.5], 150 link:RelNotes/1.6.2.4.txt[1.6.2.4], 151 link:RelNotes/1.6.2.3.txt[1.6.2.3], 152 link:RelNotes/1.6.2.2.txt[1.6.2.2], 153 link:RelNotes/1.6.2.1.txt[1.6.2.1], 154 link:RelNotes/1.6.2.txt[1.6.2]. 155 156* link:v1.6.1.3/git.html[documentation for release 1.6.1.3] 157 158* release notes for 159 link:RelNotes/1.6.1.3.txt[1.6.1.3], 160 link:RelNotes/1.6.1.2.txt[1.6.1.2], 161 link:RelNotes/1.6.1.1.txt[1.6.1.1], 162 link:RelNotes/1.6.1.txt[1.6.1]. 163 164* link:v1.6.0.6/git.html[documentation for release 1.6.0.6] 165 166* release notes for 167 link:RelNotes/1.6.0.6.txt[1.6.0.6], 168 link:RelNotes/1.6.0.5.txt[1.6.0.5], 169 link:RelNotes/1.6.0.4.txt[1.6.0.4], 170 link:RelNotes/1.6.0.3.txt[1.6.0.3], 171 link:RelNotes/1.6.0.2.txt[1.6.0.2], 172 link:RelNotes/1.6.0.1.txt[1.6.0.1], 173 link:RelNotes/1.6.0.txt[1.6.0]. 174 175* link:v1.5.6.6/git.html[documentation for release 1.5.6.6] 176 177* release notes for 178 link:RelNotes/1.5.6.6.txt[1.5.6.6], 179 link:RelNotes/1.5.6.5.txt[1.5.6.5], 180 link:RelNotes/1.5.6.4.txt[1.5.6.4], 181 link:RelNotes/1.5.6.3.txt[1.5.6.3], 182 link:RelNotes/1.5.6.2.txt[1.5.6.2], 183 link:RelNotes/1.5.6.1.txt[1.5.6.1], 184 link:RelNotes/1.5.6.txt[1.5.6]. 185 186* link:v1.5.5.6/git.html[documentation for release 1.5.5.6] 187 188* release notes for 189 link:RelNotes/1.5.5.6.txt[1.5.5.6], 190 link:RelNotes/1.5.5.5.txt[1.5.5.5], 191 link:RelNotes/1.5.5.4.txt[1.5.5.4], 192 link:RelNotes/1.5.5.3.txt[1.5.5.3], 193 link:RelNotes/1.5.5.2.txt[1.5.5.2], 194 link:RelNotes/1.5.5.1.txt[1.5.5.1], 195 link:RelNotes/1.5.5.txt[1.5.5]. 196 197* link:v1.5.4.7/git.html[documentation for release 1.5.4.7] 198 199* release notes for 200 link:RelNotes/1.5.4.7.txt[1.5.4.7], 201 link:RelNotes/1.5.4.6.txt[1.5.4.6], 202 link:RelNotes/1.5.4.5.txt[1.5.4.5], 203 link:RelNotes/1.5.4.4.txt[1.5.4.4], 204 link:RelNotes/1.5.4.3.txt[1.5.4.3], 205 link:RelNotes/1.5.4.2.txt[1.5.4.2], 206 link:RelNotes/1.5.4.1.txt[1.5.4.1], 207 link:RelNotes/1.5.4.txt[1.5.4]. 208 209* link:v1.5.3.8/git.html[documentation for release 1.5.3.8] 210 211* release notes for 212 link:RelNotes/1.5.3.8.txt[1.5.3.8], 213 link:RelNotes/1.5.3.7.txt[1.5.3.7], 214 link:RelNotes/1.5.3.6.txt[1.5.3.6], 215 link:RelNotes/1.5.3.5.txt[1.5.3.5], 216 link:RelNotes/1.5.3.4.txt[1.5.3.4], 217 link:RelNotes/1.5.3.3.txt[1.5.3.3], 218 link:RelNotes/1.5.3.2.txt[1.5.3.2], 219 link:RelNotes/1.5.3.1.txt[1.5.3.1], 220 link:RelNotes/1.5.3.txt[1.5.3]. 221 222* link:v1.5.2.5/git.html[documentation for release 1.5.2.5] 223 224* release notes for 225 link:RelNotes/1.5.2.5.txt[1.5.2.5], 226 link:RelNotes/1.5.2.4.txt[1.5.2.4], 227 link:RelNotes/1.5.2.3.txt[1.5.2.3], 228 link:RelNotes/1.5.2.2.txt[1.5.2.2], 229 link:RelNotes/1.5.2.1.txt[1.5.2.1], 230 link:RelNotes/1.5.2.txt[1.5.2]. 231 232* link:v1.5.1.6/git.html[documentation for release 1.5.1.6] 233 234* release notes for 235 link:RelNotes/1.5.1.6.txt[1.5.1.6], 236 link:RelNotes/1.5.1.5.txt[1.5.1.5], 237 link:RelNotes/1.5.1.4.txt[1.5.1.4], 238 link:RelNotes/1.5.1.3.txt[1.5.1.3], 239 link:RelNotes/1.5.1.2.txt[1.5.1.2], 240 link:RelNotes/1.5.1.1.txt[1.5.1.1], 241 link:RelNotes/1.5.1.txt[1.5.1]. 242 243* link:v1.5.0.7/git.html[documentation for release 1.5.0.7] 244 245* release notes for 246 link:RelNotes/1.5.0.7.txt[1.5.0.7], 247 link:RelNotes/1.5.0.6.txt[1.5.0.6], 248 link:RelNotes/1.5.0.5.txt[1.5.0.5], 249 link:RelNotes/1.5.0.3.txt[1.5.0.3], 250 link:RelNotes/1.5.0.2.txt[1.5.0.2], 251 link:RelNotes/1.5.0.1.txt[1.5.0.1], 252 link:RelNotes/1.5.0.txt[1.5.0]. 253 254* documentation for release link:v1.4.4.4/git.html[1.4.4.4], 255 link:v1.3.3/git.html[1.3.3], 256 link:v1.2.6/git.html[1.2.6], 257 link:v1.0.13/git.html[1.0.13]. 258 259============ 260 261endif::stalenotes[] 262 263OPTIONS 264------- 265--version:: 266 Prints the git suite version that the 'git' program came from. 267 268--help:: 269 Prints the synopsis and a list of the most commonly used 270 commands. If the option '--all' or '-a' is given then all 271 available commands are printed. If a git command is named this 272 option will bring up the manual page for that command. 273+ 274Other options are available to control how the manual page is 275displayed. See linkgit:git-help[1] for more information, 276because `git --help ...` is converted internally into `git 277help ...`. 278 279-c <name>=<value>:: 280 Pass a configuration parameter to the command. The value 281 given will override values from configuration files. 282 The <name> is expected in the same format as listed by 283 'git config' (subkeys separated by dots). 284 285--exec-path[=<path>]:: 286 Path to wherever your core git programs are installed. 287 This can also be controlled by setting the GIT_EXEC_PATH 288 environment variable. If no path is given, 'git' will print 289 the current setting and then exit. 290 291--html-path:: 292 Print the path, without trailing slash, where git's HTML 293 documentation is installed and exit. 294 295--man-path:: 296 Print the manpath (see `man(1)`) for the man pages for 297 this version of git and exit. 298 299--info-path:: 300 Print the path where the Info files documenting this 301 version of git are installed and exit. 302 303-p:: 304--paginate:: 305 Pipe all output into 'less' (or if set, $PAGER) if standard 306 output is a terminal. This overrides the `pager.<cmd>` 307 configuration options (see the "Configuration Mechanism" section 308 below). 309 310--no-pager:: 311 Do not pipe git output into a pager. 312 313--git-dir=<path>:: 314 Set the path to the repository. This can also be controlled by 315 setting the GIT_DIR environment variable. It can be an absolute 316 path or relative path to current working directory. 317 318--work-tree=<path>:: 319 Set the path to the working tree. It can be an absolute path 320 or a path relative to the current working directory. 321 This can also be controlled by setting the GIT_WORK_TREE 322 environment variable and the core.worktree configuration 323 variable (see core.worktree in linkgit:git-config[1] for a 324 more detailed discussion). 325 326--namespace=<path>:: 327 Set the git namespace. See linkgit:gitnamespaces[7] for more 328 details. Equivalent to setting the `GIT_NAMESPACE` environment 329 variable. 330 331--bare:: 332 Treat the repository as a bare repository. If GIT_DIR 333 environment is not set, it is set to the current working 334 directory. 335 336--no-replace-objects:: 337 Do not use replacement refs to replace git objects. See 338 linkgit:git-replace[1] for more information. 339 340 341FURTHER DOCUMENTATION 342--------------------- 343 344See the references above to get started using git. The following is 345probably more detail than necessary for a first-time user. 346 347The link:user-manual.html#git-concepts[git concepts chapter of the 348user-manual] and linkgit:gitcore-tutorial[7] both provide 349introductions to the underlying git architecture. 350 351See linkgit:gitworkflows[7] for an overview of recommended workflows. 352 353See also the link:howto-index.html[howto] documents for some useful 354examples. 355 356The internals are documented in the 357link:technical/api-index.html[GIT API documentation]. 358 359GIT COMMANDS 360------------ 361 362We divide git into high level ("porcelain") commands and low level 363("plumbing") commands. 364 365High-level commands (porcelain) 366------------------------------- 367 368We separate the porcelain commands into the main commands and some 369ancillary user utilities. 370 371Main porcelain commands 372~~~~~~~~~~~~~~~~~~~~~~~ 373 374include::cmds-mainporcelain.txt[] 375 376Ancillary Commands 377~~~~~~~~~~~~~~~~~~ 378Manipulators: 379 380include::cmds-ancillarymanipulators.txt[] 381 382Interrogators: 383 384include::cmds-ancillaryinterrogators.txt[] 385 386 387Interacting with Others 388~~~~~~~~~~~~~~~~~~~~~~~ 389 390These commands are to interact with foreign SCM and with other 391people via patch over e-mail. 392 393include::cmds-foreignscminterface.txt[] 394 395 396Low-level commands (plumbing) 397----------------------------- 398 399Although git includes its 400own porcelain layer, its low-level commands are sufficient to support 401development of alternative porcelains. Developers of such porcelains 402might start by reading about linkgit:git-update-index[1] and 403linkgit:git-read-tree[1]. 404 405The interface (input, output, set of options and the semantics) 406to these low-level commands are meant to be a lot more stable 407than Porcelain level commands, because these commands are 408primarily for scripted use. The interface to Porcelain commands 409on the other hand are subject to change in order to improve the 410end user experience. 411 412The following description divides 413the low-level commands into commands that manipulate objects (in 414the repository, index, and working tree), commands that interrogate and 415compare objects, and commands that move objects and references between 416repositories. 417 418 419Manipulation commands 420~~~~~~~~~~~~~~~~~~~~~ 421 422include::cmds-plumbingmanipulators.txt[] 423 424 425Interrogation commands 426~~~~~~~~~~~~~~~~~~~~~~ 427 428include::cmds-plumbinginterrogators.txt[] 429 430In general, the interrogate commands do not touch the files in 431the working tree. 432 433 434Synching repositories 435~~~~~~~~~~~~~~~~~~~~~ 436 437include::cmds-synchingrepositories.txt[] 438 439The following are helper commands used by the above; end users 440typically do not use them directly. 441 442include::cmds-synchelpers.txt[] 443 444 445Internal helper commands 446~~~~~~~~~~~~~~~~~~~~~~~~ 447 448These are internal helper commands used by other commands; end 449users typically do not use them directly. 450 451include::cmds-purehelpers.txt[] 452 453 454Configuration Mechanism 455----------------------- 456 457Starting from 0.99.9 (actually mid 0.99.8.GIT), `.git/config` file 458is used to hold per-repository configuration options. It is a 459simple text file modeled after `.ini` format familiar to some 460people. Here is an example: 461 462------------ 463# 464# A '#' or ';' character indicates a comment. 465# 466 467; core variables 468[core] 469 ; Don't trust file modes 470 filemode = false 471 472; user identity 473[user] 474 name = "Junio C Hamano" 475 email = "junkio@twinsun.com" 476 477------------ 478 479Various commands read from the configuration file and adjust 480their operation accordingly. See linkgit:git-config[1] for a 481list. 482 483 484Identifier Terminology 485---------------------- 486<object>:: 487 Indicates the object name for any type of object. 488 489<blob>:: 490 Indicates a blob object name. 491 492<tree>:: 493 Indicates a tree object name. 494 495<commit>:: 496 Indicates a commit object name. 497 498<tree-ish>:: 499 Indicates a tree, commit or tag object name. A 500 command that takes a <tree-ish> argument ultimately wants to 501 operate on a <tree> object but automatically dereferences 502 <commit> and <tag> objects that point at a <tree>. 503 504<commit-ish>:: 505 Indicates a commit or tag object name. A 506 command that takes a <commit-ish> argument ultimately wants to 507 operate on a <commit> object but automatically dereferences 508 <tag> objects that point at a <commit>. 509 510<type>:: 511 Indicates that an object type is required. 512 Currently one of: `blob`, `tree`, `commit`, or `tag`. 513 514<file>:: 515 Indicates a filename - almost always relative to the 516 root of the tree structure `GIT_INDEX_FILE` describes. 517 518Symbolic Identifiers 519-------------------- 520Any git command accepting any <object> can also use the following 521symbolic notation: 522 523HEAD:: 524 indicates the head of the current branch (i.e. the 525 contents of `$GIT_DIR/HEAD`). 526 527<tag>:: 528 a valid tag 'name' 529 (i.e. the contents of `$GIT_DIR/refs/tags/<tag>`). 530 531<head>:: 532 a valid head 'name' 533 (i.e. the contents of `$GIT_DIR/refs/heads/<head>`). 534 535For a more complete list of ways to spell object names, see 536"SPECIFYING REVISIONS" section in linkgit:gitrevisions[7]. 537 538 539File/Directory Structure 540------------------------ 541 542Please see the linkgit:gitrepository-layout[5] document. 543 544Read linkgit:githooks[5] for more details about each hook. 545 546Higher level SCMs may provide and manage additional information in the 547`$GIT_DIR`. 548 549 550Terminology 551----------- 552Please see linkgit:gitglossary[7]. 553 554 555Environment Variables 556--------------------- 557Various git commands use the following environment variables: 558 559The git Repository 560~~~~~~~~~~~~~~~~~~ 561These environment variables apply to 'all' core git commands. Nb: it 562is worth noting that they may be used/overridden by SCMS sitting above 563git so take care if using Cogito etc. 564 565'GIT_INDEX_FILE':: 566 This environment allows the specification of an alternate 567 index file. If not specified, the default of `$GIT_DIR/index` 568 is used. 569 570'GIT_OBJECT_DIRECTORY':: 571 If the object storage directory is specified via this 572 environment variable then the sha1 directories are created 573 underneath - otherwise the default `$GIT_DIR/objects` 574 directory is used. 575 576'GIT_ALTERNATE_OBJECT_DIRECTORIES':: 577 Due to the immutable nature of git objects, old objects can be 578 archived into shared, read-only directories. This variable 579 specifies a ":" separated (on Windows ";" separated) list 580 of git object directories which can be used to search for git 581 objects. New objects will not be written to these directories. 582 583'GIT_DIR':: 584 If the 'GIT_DIR' environment variable is set then it 585 specifies a path to use instead of the default `.git` 586 for the base of the repository. 587 588'GIT_WORK_TREE':: 589 Set the path to the working tree. The value will not be 590 used in combination with repositories found automatically in 591 a .git directory (i.e. $GIT_DIR is not set). 592 This can also be controlled by the '--work-tree' command line 593 option and the core.worktree configuration variable. 594 595'GIT_NAMESPACE':: 596 Set the git namespace; see linkgit:gitnamespaces[7] for details. 597 The '--namespace' command-line option also sets this value. 598 599'GIT_CEILING_DIRECTORIES':: 600 This should be a colon-separated list of absolute paths. 601 If set, it is a list of directories that git should not chdir 602 up into while looking for a repository directory. 603 It will not exclude the current working directory or 604 a GIT_DIR set on the command line or in the environment. 605 (Useful for excluding slow-loading network directories.) 606 607'GIT_DISCOVERY_ACROSS_FILESYSTEM':: 608 When run in a directory that does not have ".git" repository 609 directory, git tries to find such a directory in the parent 610 directories to find the top of the working tree, but by default it 611 does not cross filesystem boundaries. This environment variable 612 can be set to true to tell git not to stop at filesystem 613 boundaries. Like 'GIT_CEILING_DIRECTORIES', this will not affect 614 an explicit repository directory set via 'GIT_DIR' or on the 615 command line. 616 617git Commits 618~~~~~~~~~~~ 619'GIT_AUTHOR_NAME':: 620'GIT_AUTHOR_EMAIL':: 621'GIT_AUTHOR_DATE':: 622'GIT_COMMITTER_NAME':: 623'GIT_COMMITTER_EMAIL':: 624'GIT_COMMITTER_DATE':: 625'EMAIL':: 626 see linkgit:git-commit-tree[1] 627 628git Diffs 629~~~~~~~~~ 630'GIT_DIFF_OPTS':: 631 Only valid setting is "--unified=??" or "-u??" to set the 632 number of context lines shown when a unified diff is created. 633 This takes precedence over any "-U" or "--unified" option 634 value passed on the git diff command line. 635 636'GIT_EXTERNAL_DIFF':: 637 When the environment variable 'GIT_EXTERNAL_DIFF' is set, the 638 program named by it is called, instead of the diff invocation 639 described above. For a path that is added, removed, or modified, 640 'GIT_EXTERNAL_DIFF' is called with 7 parameters: 641 642 path old-file old-hex old-mode new-file new-hex new-mode 643+ 644where: 645 646 <old|new>-file:: are files GIT_EXTERNAL_DIFF can use to read the 647 contents of <old|new>, 648 <old|new>-hex:: are the 40-hexdigit SHA1 hashes, 649 <old|new>-mode:: are the octal representation of the file modes. 650+ 651The file parameters can point at the user's working file 652(e.g. `new-file` in "git-diff-files"), `/dev/null` (e.g. `old-file` 653when a new file is added), or a temporary file (e.g. `old-file` in the 654index). 'GIT_EXTERNAL_DIFF' should not worry about unlinking the 655temporary file --- it is removed when 'GIT_EXTERNAL_DIFF' exits. 656+ 657For a path that is unmerged, 'GIT_EXTERNAL_DIFF' is called with 1 658parameter, <path>. 659 660other 661~~~~~ 662'GIT_MERGE_VERBOSITY':: 663 A number controlling the amount of output shown by 664 the recursive merge strategy. Overrides merge.verbosity. 665 See linkgit:git-merge[1] 666 667'GIT_PAGER':: 668 This environment variable overrides `$PAGER`. If it is set 669 to an empty string or to the value "cat", git will not launch 670 a pager. See also the `core.pager` option in 671 linkgit:git-config[1]. 672 673'GIT_SSH':: 674 If this environment variable is set then 'git fetch' 675 and 'git push' will use this command instead 676 of 'ssh' when they need to connect to a remote system. 677 The '$GIT_SSH' command will be given exactly two arguments: 678 the 'username@host' (or just 'host') from the URL and the 679 shell command to execute on that remote system. 680+ 681To pass options to the program that you want to list in GIT_SSH 682you will need to wrap the program and options into a shell script, 683then set GIT_SSH to refer to the shell script. 684+ 685Usually it is easier to configure any desired options through your 686personal `.ssh/config` file. Please consult your ssh documentation 687for further details. 688 689'GIT_ASKPASS':: 690 If this environment variable is set, then git commands which need to 691 acquire passwords or passphrases (e.g. for HTTP or IMAP authentication) 692 will call this program with a suitable prompt as command line argument 693 and read the password from its STDOUT. See also the 'core.askpass' 694 option in linkgit:git-config[1]. 695 696'GIT_FLUSH':: 697 If this environment variable is set to "1", then commands such 698 as 'git blame' (in incremental mode), 'git rev-list', 'git log', 699 and 'git whatchanged' will force a flush of the output stream 700 after each commit-oriented record have been flushed. If this 701 variable is set to "0", the output of these commands will be done 702 using completely buffered I/O. If this environment variable is 703 not set, git will choose buffered or record-oriented flushing 704 based on whether stdout appears to be redirected to a file or not. 705 706'GIT_TRACE':: 707 If this variable is set to "1", "2" or "true" (comparison 708 is case insensitive), git will print `trace:` messages on 709 stderr telling about alias expansion, built-in command 710 execution and external command execution. 711 If this variable is set to an integer value greater than 1 712 and lower than 10 (strictly) then git will interpret this 713 value as an open file descriptor and will try to write the 714 trace messages into this file descriptor. 715 Alternatively, if this variable is set to an absolute path 716 (starting with a '/' character), git will interpret this 717 as a file path and will try to write the trace messages 718 into it. 719 720Discussion[[Discussion]] 721------------------------ 722 723More detail on the following is available from the 724link:user-manual.html#git-concepts[git concepts chapter of the 725user-manual] and linkgit:gitcore-tutorial[7]. 726 727A git project normally consists of a working directory with a ".git" 728subdirectory at the top level. The .git directory contains, among other 729things, a compressed object database representing the complete history 730of the project, an "index" file which links that history to the current 731contents of the working tree, and named pointers into that history such 732as tags and branch heads. 733 734The object database contains objects of three main types: blobs, which 735hold file data; trees, which point to blobs and other trees to build up 736directory hierarchies; and commits, which each reference a single tree 737and some number of parent commits. 738 739The commit, equivalent to what other systems call a "changeset" or 740"version", represents a step in the project's history, and each parent 741represents an immediately preceding step. Commits with more than one 742parent represent merges of independent lines of development. 743 744All objects are named by the SHA1 hash of their contents, normally 745written as a string of 40 hex digits. Such names are globally unique. 746The entire history leading up to a commit can be vouched for by signing 747just that commit. A fourth object type, the tag, is provided for this 748purpose. 749 750When first created, objects are stored in individual files, but for 751efficiency may later be compressed together into "pack files". 752 753Named pointers called refs mark interesting points in history. A ref 754may contain the SHA1 name of an object or the name of another ref. Refs 755with names beginning `ref/head/` contain the SHA1 name of the most 756recent commit (or "head") of a branch under development. SHA1 names of 757tags of interest are stored under `ref/tags/`. A special ref named 758`HEAD` contains the name of the currently checked-out branch. 759 760The index file is initialized with a list of all paths and, for each 761path, a blob object and a set of attributes. The blob object represents 762the contents of the file as of the head of the current branch. The 763attributes (last modified time, size, etc.) are taken from the 764corresponding file in the working tree. Subsequent changes to the 765working tree can be found by comparing these attributes. The index may 766be updated with new content, and new commits may be created from the 767content stored in the index. 768 769The index is also capable of storing multiple entries (called "stages") 770for a given pathname. These stages are used to hold the various 771unmerged version of a file when a merge is in progress. 772 773Authors 774------- 775Git was started by Linus Torvalds, and is currently maintained by Junio 776C Hamano. Numerous contributions have come from the git mailing list 777<git@vger.kernel.org>. For a more complete list of contributors, see 778http://git-scm.com/about. If you have a clone of git.git itself, the 779output of linkgit:git-shortlog[1] and linkgit:git-blame[1] can show you 780the authors for specific parts of the project. 781 782Reporting Bugs 783-------------- 784 785Report bugs to the Git mailing list <git@vger.kernel.org> where the 786development and maintenance is primarily done. You do not have to be 787subscribed to the list to send a message there. 788 789SEE ALSO 790-------- 791linkgit:gittutorial[7], linkgit:gittutorial-2[7], 792link:everyday.html[Everyday Git], linkgit:gitcvs-migration[7], 793linkgit:gitglossary[7], linkgit:gitcore-tutorial[7], 794linkgit:gitcli[7], link:user-manual.html[The Git User's Manual], 795linkgit:gitworkflows[7] 796 797GIT 798--- 799Part of the linkgit:git[1] suite