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