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:v1.7.6/git.html[documentation for release 1.7.6] 48 49* release notes for 50 link:RelNotes/1.7.6.txt[1.7.6]. 51 52* link:v1.7.5.4/git.html[documentation for release 1.7.5.4] 53 54* release notes for 55 link:RelNotes/1.7.5.4.txt[1.7.5.4], 56 link:RelNotes/1.7.5.3.txt[1.7.5.3], 57 link:RelNotes/1.7.5.2.txt[1.7.5.2], 58 link:RelNotes/1.7.5.1.txt[1.7.5.1], 59 link:RelNotes/1.7.5.txt[1.7.5]. 60 61* link:v1.7.4.5/git.html[documentation for release 1.7.4.5] 62 63* release notes for 64 link:RelNotes/1.7.4.5.txt[1.7.4.5], 65 link:RelNotes/1.7.4.4.txt[1.7.4.4], 66 link:RelNotes/1.7.4.3.txt[1.7.4.3], 67 link:RelNotes/1.7.4.2.txt[1.7.4.2], 68 link:RelNotes/1.7.4.1.txt[1.7.4.1], 69 link:RelNotes/1.7.4.txt[1.7.4]. 70 71* link:v1.7.3.5/git.html[documentation for release 1.7.3.5] 72 73* release notes for 74 link:RelNotes/1.7.3.5.txt[1.7.3.5], 75 link:RelNotes/1.7.3.4.txt[1.7.3.4], 76 link:RelNotes/1.7.3.3.txt[1.7.3.3], 77 link:RelNotes/1.7.3.2.txt[1.7.3.2], 78 link:RelNotes/1.7.3.1.txt[1.7.3.1], 79 link:RelNotes/1.7.3.txt[1.7.3]. 80 81* link:v1.7.2.5/git.html[documentation for release 1.7.2.5] 82 83* release notes for 84 link:RelNotes/1.7.2.5.txt[1.7.2.5], 85 link:RelNotes/1.7.2.4.txt[1.7.2.4], 86 link:RelNotes/1.7.2.3.txt[1.7.2.3], 87 link:RelNotes/1.7.2.2.txt[1.7.2.2], 88 link:RelNotes/1.7.2.1.txt[1.7.2.1], 89 link:RelNotes/1.7.2.txt[1.7.2]. 90 91* link:v1.7.1.4/git.html[documentation for release 1.7.1.4] 92 93* release notes for 94 link:RelNotes/1.7.1.4.txt[1.7.1.4], 95 link:RelNotes/1.7.1.3.txt[1.7.1.3], 96 link:RelNotes/1.7.1.2.txt[1.7.1.2], 97 link:RelNotes/1.7.1.1.txt[1.7.1.1], 98 link:RelNotes/1.7.1.txt[1.7.1]. 99 100* link:v1.7.0.9/git.html[documentation for release 1.7.0.9] 101 102* release notes for 103 link:RelNotes/1.7.0.9.txt[1.7.0.9], 104 link:RelNotes/1.7.0.8.txt[1.7.0.8], 105 link:RelNotes/1.7.0.7.txt[1.7.0.7], 106 link:RelNotes/1.7.0.6.txt[1.7.0.6], 107 link:RelNotes/1.7.0.5.txt[1.7.0.5], 108 link:RelNotes/1.7.0.4.txt[1.7.0.4], 109 link:RelNotes/1.7.0.3.txt[1.7.0.3], 110 link:RelNotes/1.7.0.2.txt[1.7.0.2], 111 link:RelNotes/1.7.0.1.txt[1.7.0.1], 112 link:RelNotes/1.7.0.txt[1.7.0]. 113 114* link:v1.6.6.3/git.html[documentation for release 1.6.6.3] 115 116* release notes for 117 link:RelNotes/1.6.6.3.txt[1.6.6.3], 118 link:RelNotes/1.6.6.2.txt[1.6.6.2], 119 link:RelNotes/1.6.6.1.txt[1.6.6.1], 120 link:RelNotes/1.6.6.txt[1.6.6]. 121 122* link:v1.6.5.9/git.html[documentation for release 1.6.5.9] 123 124* release notes for 125 link:RelNotes/1.6.5.9.txt[1.6.5.9], 126 link:RelNotes/1.6.5.8.txt[1.6.5.8], 127 link:RelNotes/1.6.5.7.txt[1.6.5.7], 128 link:RelNotes/1.6.5.6.txt[1.6.5.6], 129 link:RelNotes/1.6.5.5.txt[1.6.5.5], 130 link:RelNotes/1.6.5.4.txt[1.6.5.4], 131 link:RelNotes/1.6.5.3.txt[1.6.5.3], 132 link:RelNotes/1.6.5.2.txt[1.6.5.2], 133 link:RelNotes/1.6.5.1.txt[1.6.5.1], 134 link:RelNotes/1.6.5.txt[1.6.5]. 135 136* link:v1.6.4.5/git.html[documentation for release 1.6.4.5] 137 138* release notes for 139 link:RelNotes/1.6.4.5.txt[1.6.4.5], 140 link:RelNotes/1.6.4.4.txt[1.6.4.4], 141 link:RelNotes/1.6.4.3.txt[1.6.4.3], 142 link:RelNotes/1.6.4.2.txt[1.6.4.2], 143 link:RelNotes/1.6.4.1.txt[1.6.4.1], 144 link:RelNotes/1.6.4.txt[1.6.4]. 145 146* link:v1.6.3.4/git.html[documentation for release 1.6.3.4] 147 148* release notes for 149 link:RelNotes/1.6.3.4.txt[1.6.3.4], 150 link:RelNotes/1.6.3.3.txt[1.6.3.3], 151 link:RelNotes/1.6.3.2.txt[1.6.3.2], 152 link:RelNotes/1.6.3.1.txt[1.6.3.1], 153 link:RelNotes/1.6.3.txt[1.6.3]. 154 155* release notes for 156 link:RelNotes/1.6.2.5.txt[1.6.2.5], 157 link:RelNotes/1.6.2.4.txt[1.6.2.4], 158 link:RelNotes/1.6.2.3.txt[1.6.2.3], 159 link:RelNotes/1.6.2.2.txt[1.6.2.2], 160 link:RelNotes/1.6.2.1.txt[1.6.2.1], 161 link:RelNotes/1.6.2.txt[1.6.2]. 162 163* link:v1.6.1.3/git.html[documentation for release 1.6.1.3] 164 165* release notes for 166 link:RelNotes/1.6.1.3.txt[1.6.1.3], 167 link:RelNotes/1.6.1.2.txt[1.6.1.2], 168 link:RelNotes/1.6.1.1.txt[1.6.1.1], 169 link:RelNotes/1.6.1.txt[1.6.1]. 170 171* link:v1.6.0.6/git.html[documentation for release 1.6.0.6] 172 173* release notes for 174 link:RelNotes/1.6.0.6.txt[1.6.0.6], 175 link:RelNotes/1.6.0.5.txt[1.6.0.5], 176 link:RelNotes/1.6.0.4.txt[1.6.0.4], 177 link:RelNotes/1.6.0.3.txt[1.6.0.3], 178 link:RelNotes/1.6.0.2.txt[1.6.0.2], 179 link:RelNotes/1.6.0.1.txt[1.6.0.1], 180 link:RelNotes/1.6.0.txt[1.6.0]. 181 182* link:v1.5.6.6/git.html[documentation for release 1.5.6.6] 183 184* release notes for 185 link:RelNotes/1.5.6.6.txt[1.5.6.6], 186 link:RelNotes/1.5.6.5.txt[1.5.6.5], 187 link:RelNotes/1.5.6.4.txt[1.5.6.4], 188 link:RelNotes/1.5.6.3.txt[1.5.6.3], 189 link:RelNotes/1.5.6.2.txt[1.5.6.2], 190 link:RelNotes/1.5.6.1.txt[1.5.6.1], 191 link:RelNotes/1.5.6.txt[1.5.6]. 192 193* link:v1.5.5.6/git.html[documentation for release 1.5.5.6] 194 195* release notes for 196 link:RelNotes/1.5.5.6.txt[1.5.5.6], 197 link:RelNotes/1.5.5.5.txt[1.5.5.5], 198 link:RelNotes/1.5.5.4.txt[1.5.5.4], 199 link:RelNotes/1.5.5.3.txt[1.5.5.3], 200 link:RelNotes/1.5.5.2.txt[1.5.5.2], 201 link:RelNotes/1.5.5.1.txt[1.5.5.1], 202 link:RelNotes/1.5.5.txt[1.5.5]. 203 204* link:v1.5.4.7/git.html[documentation for release 1.5.4.7] 205 206* release notes for 207 link:RelNotes/1.5.4.7.txt[1.5.4.7], 208 link:RelNotes/1.5.4.6.txt[1.5.4.6], 209 link:RelNotes/1.5.4.5.txt[1.5.4.5], 210 link:RelNotes/1.5.4.4.txt[1.5.4.4], 211 link:RelNotes/1.5.4.3.txt[1.5.4.3], 212 link:RelNotes/1.5.4.2.txt[1.5.4.2], 213 link:RelNotes/1.5.4.1.txt[1.5.4.1], 214 link:RelNotes/1.5.4.txt[1.5.4]. 215 216* link:v1.5.3.8/git.html[documentation for release 1.5.3.8] 217 218* release notes for 219 link:RelNotes/1.5.3.8.txt[1.5.3.8], 220 link:RelNotes/1.5.3.7.txt[1.5.3.7], 221 link:RelNotes/1.5.3.6.txt[1.5.3.6], 222 link:RelNotes/1.5.3.5.txt[1.5.3.5], 223 link:RelNotes/1.5.3.4.txt[1.5.3.4], 224 link:RelNotes/1.5.3.3.txt[1.5.3.3], 225 link:RelNotes/1.5.3.2.txt[1.5.3.2], 226 link:RelNotes/1.5.3.1.txt[1.5.3.1], 227 link:RelNotes/1.5.3.txt[1.5.3]. 228 229* link:v1.5.2.5/git.html[documentation for release 1.5.2.5] 230 231* release notes for 232 link:RelNotes/1.5.2.5.txt[1.5.2.5], 233 link:RelNotes/1.5.2.4.txt[1.5.2.4], 234 link:RelNotes/1.5.2.3.txt[1.5.2.3], 235 link:RelNotes/1.5.2.2.txt[1.5.2.2], 236 link:RelNotes/1.5.2.1.txt[1.5.2.1], 237 link:RelNotes/1.5.2.txt[1.5.2]. 238 239* link:v1.5.1.6/git.html[documentation for release 1.5.1.6] 240 241* release notes for 242 link:RelNotes/1.5.1.6.txt[1.5.1.6], 243 link:RelNotes/1.5.1.5.txt[1.5.1.5], 244 link:RelNotes/1.5.1.4.txt[1.5.1.4], 245 link:RelNotes/1.5.1.3.txt[1.5.1.3], 246 link:RelNotes/1.5.1.2.txt[1.5.1.2], 247 link:RelNotes/1.5.1.1.txt[1.5.1.1], 248 link:RelNotes/1.5.1.txt[1.5.1]. 249 250* link:v1.5.0.7/git.html[documentation for release 1.5.0.7] 251 252* release notes for 253 link:RelNotes/1.5.0.7.txt[1.5.0.7], 254 link:RelNotes/1.5.0.6.txt[1.5.0.6], 255 link:RelNotes/1.5.0.5.txt[1.5.0.5], 256 link:RelNotes/1.5.0.3.txt[1.5.0.3], 257 link:RelNotes/1.5.0.2.txt[1.5.0.2], 258 link:RelNotes/1.5.0.1.txt[1.5.0.1], 259 link:RelNotes/1.5.0.txt[1.5.0]. 260 261* documentation for release link:v1.4.4.4/git.html[1.4.4.4], 262 link:v1.3.3/git.html[1.3.3], 263 link:v1.2.6/git.html[1.2.6], 264 link:v1.0.13/git.html[1.0.13]. 265 266============ 267 268endif::stalenotes[] 269 270OPTIONS 271------- 272--version:: 273 Prints the git suite version that the 'git' program came from. 274 275--help:: 276 Prints the synopsis and a list of the most commonly used 277 commands. If the option '--all' or '-a' is given then all 278 available commands are printed. If a git command is named this 279 option will bring up the manual page for that command. 280+ 281Other options are available to control how the manual page is 282displayed. See linkgit:git-help[1] for more information, 283because `git --help ...` is converted internally into `git 284help ...`. 285 286-c <name>=<value>:: 287 Pass a configuration parameter to the command. The value 288 given will override values from configuration files. 289 The <name> is expected in the same format as listed by 290 'git config' (subkeys separated by dots). 291 292--exec-path[=<path>]:: 293 Path to wherever your core git programs are installed. 294 This can also be controlled by setting the GIT_EXEC_PATH 295 environment variable. If no path is given, 'git' will print 296 the current setting and then exit. 297 298--html-path:: 299 Print the path, without trailing slash, where git's HTML 300 documentation is installed and exit. 301 302--man-path:: 303 Print the manpath (see `man(1)`) for the man pages for 304 this version of git and exit. 305 306--info-path:: 307 Print the path where the Info files documenting this 308 version of git are installed and exit. 309 310-p:: 311--paginate:: 312 Pipe all output into 'less' (or if set, $PAGER) if standard 313 output is a terminal. This overrides the `pager.<cmd>` 314 configuration options (see the "Configuration Mechanism" section 315 below). 316 317--no-pager:: 318 Do not pipe git output into a pager. 319 320--git-dir=<path>:: 321 Set the path to the repository. This can also be controlled by 322 setting the GIT_DIR environment variable. It can be an absolute 323 path or relative path to current working directory. 324 325--work-tree=<path>:: 326 Set the path to the working tree. It can be an absolute path 327 or a path relative to the current working directory. 328 This can also be controlled by setting the GIT_WORK_TREE 329 environment variable and the core.worktree configuration 330 variable (see core.worktree in linkgit:git-config[1] for a 331 more detailed discussion). 332 333--namespace=<path>:: 334 Set the git namespace. See linkgit:gitnamespaces[7] for more 335 details. Equivalent to setting the `GIT_NAMESPACE` environment 336 variable. 337 338--bare:: 339 Treat the repository as a bare repository. If GIT_DIR 340 environment is not set, it is set to the current working 341 directory. 342 343--no-replace-objects:: 344 Do not use replacement refs to replace git objects. See 345 linkgit:git-replace[1] for more information. 346 347 348FURTHER DOCUMENTATION 349--------------------- 350 351See the references above to get started using git. The following is 352probably more detail than necessary for a first-time user. 353 354The link:user-manual.html#git-concepts[git concepts chapter of the 355user-manual] and linkgit:gitcore-tutorial[7] both provide 356introductions to the underlying git architecture. 357 358See linkgit:gitworkflows[7] for an overview of recommended workflows. 359 360See also the link:howto-index.html[howto] documents for some useful 361examples. 362 363The internals are documented in the 364link:technical/api-index.html[GIT API documentation]. 365 366GIT COMMANDS 367------------ 368 369We divide git into high level ("porcelain") commands and low level 370("plumbing") commands. 371 372High-level commands (porcelain) 373------------------------------- 374 375We separate the porcelain commands into the main commands and some 376ancillary user utilities. 377 378Main porcelain commands 379~~~~~~~~~~~~~~~~~~~~~~~ 380 381include::cmds-mainporcelain.txt[] 382 383Ancillary Commands 384~~~~~~~~~~~~~~~~~~ 385Manipulators: 386 387include::cmds-ancillarymanipulators.txt[] 388 389Interrogators: 390 391include::cmds-ancillaryinterrogators.txt[] 392 393 394Interacting with Others 395~~~~~~~~~~~~~~~~~~~~~~~ 396 397These commands are to interact with foreign SCM and with other 398people via patch over e-mail. 399 400include::cmds-foreignscminterface.txt[] 401 402 403Low-level commands (plumbing) 404----------------------------- 405 406Although git includes its 407own porcelain layer, its low-level commands are sufficient to support 408development of alternative porcelains. Developers of such porcelains 409might start by reading about linkgit:git-update-index[1] and 410linkgit:git-read-tree[1]. 411 412The interface (input, output, set of options and the semantics) 413to these low-level commands are meant to be a lot more stable 414than Porcelain level commands, because these commands are 415primarily for scripted use. The interface to Porcelain commands 416on the other hand are subject to change in order to improve the 417end user experience. 418 419The following description divides 420the low-level commands into commands that manipulate objects (in 421the repository, index, and working tree), commands that interrogate and 422compare objects, and commands that move objects and references between 423repositories. 424 425 426Manipulation commands 427~~~~~~~~~~~~~~~~~~~~~ 428 429include::cmds-plumbingmanipulators.txt[] 430 431 432Interrogation commands 433~~~~~~~~~~~~~~~~~~~~~~ 434 435include::cmds-plumbinginterrogators.txt[] 436 437In general, the interrogate commands do not touch the files in 438the working tree. 439 440 441Synching repositories 442~~~~~~~~~~~~~~~~~~~~~ 443 444include::cmds-synchingrepositories.txt[] 445 446The following are helper commands used by the above; end users 447typically do not use them directly. 448 449include::cmds-synchelpers.txt[] 450 451 452Internal helper commands 453~~~~~~~~~~~~~~~~~~~~~~~~ 454 455These are internal helper commands used by other commands; end 456users typically do not use them directly. 457 458include::cmds-purehelpers.txt[] 459 460 461Configuration Mechanism 462----------------------- 463 464Starting from 0.99.9 (actually mid 0.99.8.GIT), `.git/config` file 465is used to hold per-repository configuration options. It is a 466simple text file modeled after `.ini` format familiar to some 467people. Here is an example: 468 469------------ 470# 471# A '#' or ';' character indicates a comment. 472# 473 474; core variables 475[core] 476 ; Don't trust file modes 477 filemode = false 478 479; user identity 480[user] 481 name = "Junio C Hamano" 482 email = "junkio@twinsun.com" 483 484------------ 485 486Various commands read from the configuration file and adjust 487their operation accordingly. See linkgit:git-config[1] for a 488list. 489 490 491Identifier Terminology 492---------------------- 493<object>:: 494 Indicates the object name for any type of object. 495 496<blob>:: 497 Indicates a blob object name. 498 499<tree>:: 500 Indicates a tree object name. 501 502<commit>:: 503 Indicates a commit object name. 504 505<tree-ish>:: 506 Indicates a tree, commit or tag object name. A 507 command that takes a <tree-ish> argument ultimately wants to 508 operate on a <tree> object but automatically dereferences 509 <commit> and <tag> objects that point at a <tree>. 510 511<commit-ish>:: 512 Indicates a commit or tag object name. A 513 command that takes a <commit-ish> argument ultimately wants to 514 operate on a <commit> object but automatically dereferences 515 <tag> objects that point at a <commit>. 516 517<type>:: 518 Indicates that an object type is required. 519 Currently one of: `blob`, `tree`, `commit`, or `tag`. 520 521<file>:: 522 Indicates a filename - almost always relative to the 523 root of the tree structure `GIT_INDEX_FILE` describes. 524 525Symbolic Identifiers 526-------------------- 527Any git command accepting any <object> can also use the following 528symbolic notation: 529 530HEAD:: 531 indicates the head of the current branch. 532 533<tag>:: 534 a valid tag 'name' 535 (i.e. a `refs/tags/<tag>` reference). 536 537<head>:: 538 a valid head 'name' 539 (i.e. a `refs/heads/<head>` reference). 540 541For a more complete list of ways to spell object names, see 542"SPECIFYING REVISIONS" section in linkgit:gitrevisions[7]. 543 544 545File/Directory Structure 546------------------------ 547 548Please see the linkgit:gitrepository-layout[5] document. 549 550Read linkgit:githooks[5] for more details about each hook. 551 552Higher level SCMs may provide and manage additional information in the 553`$GIT_DIR`. 554 555 556Terminology 557----------- 558Please see linkgit:gitglossary[7]. 559 560 561Environment Variables 562--------------------- 563Various git commands use the following environment variables: 564 565The git Repository 566~~~~~~~~~~~~~~~~~~ 567These environment variables apply to 'all' core git commands. Nb: it 568is worth noting that they may be used/overridden by SCMS sitting above 569git so take care if using Cogito etc. 570 571'GIT_INDEX_FILE':: 572 This environment allows the specification of an alternate 573 index file. If not specified, the default of `$GIT_DIR/index` 574 is used. 575 576'GIT_OBJECT_DIRECTORY':: 577 If the object storage directory is specified via this 578 environment variable then the sha1 directories are created 579 underneath - otherwise the default `$GIT_DIR/objects` 580 directory is used. 581 582'GIT_ALTERNATE_OBJECT_DIRECTORIES':: 583 Due to the immutable nature of git objects, old objects can be 584 archived into shared, read-only directories. This variable 585 specifies a ":" separated (on Windows ";" separated) list 586 of git object directories which can be used to search for git 587 objects. New objects will not be written to these directories. 588 589'GIT_DIR':: 590 If the 'GIT_DIR' environment variable is set then it 591 specifies a path to use instead of the default `.git` 592 for the base of the repository. 593 594'GIT_WORK_TREE':: 595 Set the path to the working tree. The value will not be 596 used in combination with repositories found automatically in 597 a .git directory (i.e. $GIT_DIR is not set). 598 This can also be controlled by the '--work-tree' command line 599 option and the core.worktree configuration variable. 600 601'GIT_NAMESPACE':: 602 Set the git namespace; see linkgit:gitnamespaces[7] for details. 603 The '--namespace' command-line option also sets this value. 604 605'GIT_CEILING_DIRECTORIES':: 606 This should be a colon-separated list of absolute paths. 607 If set, it is a list of directories that git should not chdir 608 up into while looking for a repository directory. 609 It will not exclude the current working directory or 610 a GIT_DIR set on the command line or in the environment. 611 (Useful for excluding slow-loading network directories.) 612 613'GIT_DISCOVERY_ACROSS_FILESYSTEM':: 614 When run in a directory that does not have ".git" repository 615 directory, git tries to find such a directory in the parent 616 directories to find the top of the working tree, but by default it 617 does not cross filesystem boundaries. This environment variable 618 can be set to true to tell git not to stop at filesystem 619 boundaries. Like 'GIT_CEILING_DIRECTORIES', this will not affect 620 an explicit repository directory set via 'GIT_DIR' or on the 621 command line. 622 623git Commits 624~~~~~~~~~~~ 625'GIT_AUTHOR_NAME':: 626'GIT_AUTHOR_EMAIL':: 627'GIT_AUTHOR_DATE':: 628'GIT_COMMITTER_NAME':: 629'GIT_COMMITTER_EMAIL':: 630'GIT_COMMITTER_DATE':: 631'EMAIL':: 632 see linkgit:git-commit-tree[1] 633 634git Diffs 635~~~~~~~~~ 636'GIT_DIFF_OPTS':: 637 Only valid setting is "--unified=??" or "-u??" to set the 638 number of context lines shown when a unified diff is created. 639 This takes precedence over any "-U" or "--unified" option 640 value passed on the git diff command line. 641 642'GIT_EXTERNAL_DIFF':: 643 When the environment variable 'GIT_EXTERNAL_DIFF' is set, the 644 program named by it is called, instead of the diff invocation 645 described above. For a path that is added, removed, or modified, 646 'GIT_EXTERNAL_DIFF' is called with 7 parameters: 647 648 path old-file old-hex old-mode new-file new-hex new-mode 649+ 650where: 651 652 <old|new>-file:: are files GIT_EXTERNAL_DIFF can use to read the 653 contents of <old|new>, 654 <old|new>-hex:: are the 40-hexdigit SHA1 hashes, 655 <old|new>-mode:: are the octal representation of the file modes. 656+ 657The file parameters can point at the user's working file 658(e.g. `new-file` in "git-diff-files"), `/dev/null` (e.g. `old-file` 659when a new file is added), or a temporary file (e.g. `old-file` in the 660index). 'GIT_EXTERNAL_DIFF' should not worry about unlinking the 661temporary file --- it is removed when 'GIT_EXTERNAL_DIFF' exits. 662+ 663For a path that is unmerged, 'GIT_EXTERNAL_DIFF' is called with 1 664parameter, <path>. 665 666other 667~~~~~ 668'GIT_MERGE_VERBOSITY':: 669 A number controlling the amount of output shown by 670 the recursive merge strategy. Overrides merge.verbosity. 671 See linkgit:git-merge[1] 672 673'GIT_PAGER':: 674 This environment variable overrides `$PAGER`. If it is set 675 to an empty string or to the value "cat", git will not launch 676 a pager. See also the `core.pager` option in 677 linkgit:git-config[1]. 678 679'GIT_SSH':: 680 If this environment variable is set then 'git fetch' 681 and 'git push' will use this command instead 682 of 'ssh' when they need to connect to a remote system. 683 The '$GIT_SSH' command will be given exactly two arguments: 684 the 'username@host' (or just 'host') from the URL and the 685 shell command to execute on that remote system. 686+ 687To pass options to the program that you want to list in GIT_SSH 688you will need to wrap the program and options into a shell script, 689then set GIT_SSH to refer to the shell script. 690+ 691Usually it is easier to configure any desired options through your 692personal `.ssh/config` file. Please consult your ssh documentation 693for further details. 694 695'GIT_ASKPASS':: 696 If this environment variable is set, then git commands which need to 697 acquire passwords or passphrases (e.g. for HTTP or IMAP authentication) 698 will call this program with a suitable prompt as command line argument 699 and read the password from its STDOUT. See also the 'core.askpass' 700 option in linkgit:git-config[1]. 701 702'GIT_FLUSH':: 703 If this environment variable is set to "1", then commands such 704 as 'git blame' (in incremental mode), 'git rev-list', 'git log', 705 and 'git whatchanged' will force a flush of the output stream 706 after each commit-oriented record have been flushed. If this 707 variable is set to "0", the output of these commands will be done 708 using completely buffered I/O. If this environment variable is 709 not set, git will choose buffered or record-oriented flushing 710 based on whether stdout appears to be redirected to a file or not. 711 712'GIT_TRACE':: 713 If this variable is set to "1", "2" or "true" (comparison 714 is case insensitive), git will print `trace:` messages on 715 stderr telling about alias expansion, built-in command 716 execution and external command execution. 717 If this variable is set to an integer value greater than 1 718 and lower than 10 (strictly) then git will interpret this 719 value as an open file descriptor and will try to write the 720 trace messages into this file descriptor. 721 Alternatively, if this variable is set to an absolute path 722 (starting with a '/' character), git will interpret this 723 as a file path and will try to write the trace messages 724 into it. 725 726Discussion[[Discussion]] 727------------------------ 728 729More detail on the following is available from the 730link:user-manual.html#git-concepts[git concepts chapter of the 731user-manual] and linkgit:gitcore-tutorial[7]. 732 733A git project normally consists of a working directory with a ".git" 734subdirectory at the top level. The .git directory contains, among other 735things, a compressed object database representing the complete history 736of the project, an "index" file which links that history to the current 737contents of the working tree, and named pointers into that history such 738as tags and branch heads. 739 740The object database contains objects of three main types: blobs, which 741hold file data; trees, which point to blobs and other trees to build up 742directory hierarchies; and commits, which each reference a single tree 743and some number of parent commits. 744 745The commit, equivalent to what other systems call a "changeset" or 746"version", represents a step in the project's history, and each parent 747represents an immediately preceding step. Commits with more than one 748parent represent merges of independent lines of development. 749 750All objects are named by the SHA1 hash of their contents, normally 751written as a string of 40 hex digits. Such names are globally unique. 752The entire history leading up to a commit can be vouched for by signing 753just that commit. A fourth object type, the tag, is provided for this 754purpose. 755 756When first created, objects are stored in individual files, but for 757efficiency may later be compressed together into "pack files". 758 759Named pointers called refs mark interesting points in history. A ref 760may contain the SHA1 name of an object or the name of another ref. Refs 761with names beginning `ref/head/` contain the SHA1 name of the most 762recent commit (or "head") of a branch under development. SHA1 names of 763tags of interest are stored under `ref/tags/`. A special ref named 764`HEAD` contains the name of the currently checked-out branch. 765 766The index file is initialized with a list of all paths and, for each 767path, a blob object and a set of attributes. The blob object represents 768the contents of the file as of the head of the current branch. The 769attributes (last modified time, size, etc.) are taken from the 770corresponding file in the working tree. Subsequent changes to the 771working tree can be found by comparing these attributes. The index may 772be updated with new content, and new commits may be created from the 773content stored in the index. 774 775The index is also capable of storing multiple entries (called "stages") 776for a given pathname. These stages are used to hold the various 777unmerged version of a file when a merge is in progress. 778 779Authors 780------- 781Git was started by Linus Torvalds, and is currently maintained by Junio 782C Hamano. Numerous contributions have come from the git mailing list 783<git@vger.kernel.org>. For a more complete list of contributors, see 784http://git-scm.com/about. If you have a clone of git.git itself, the 785output of linkgit:git-shortlog[1] and linkgit:git-blame[1] can show you 786the authors for specific parts of the project. 787 788Reporting Bugs 789-------------- 790 791Report bugs to the Git mailing list <git@vger.kernel.org> where the 792development and maintenance is primarily done. You do not have to be 793subscribed to the list to send a message there. 794 795SEE ALSO 796-------- 797linkgit:gittutorial[7], linkgit:gittutorial-2[7], 798link:everyday.html[Everyday Git], linkgit:gitcvs-migration[7], 799linkgit:gitglossary[7], linkgit:gitcore-tutorial[7], 800linkgit:gitcli[7], link:user-manual.html[The Git User's Manual], 801linkgit:gitworkflows[7] 802 803GIT 804--- 805Part of the linkgit:git[1] suite