1git(1) 2====== 3 4NAME 5---- 6git - the stupid content tracker 7 8 9SYNOPSIS 10-------- 11[verse] 12'git' [--version] [--help] [-C <path>] [-c <name>=<value>] 13 [--exec-path[=<path>]] [--html-path] [--man-path] [--info-path] 14 [-p|--paginate|--no-pager] [--no-replace-objects] [--bare] 15 [--git-dir=<path>] [--work-tree=<path>] [--namespace=<name>] 16 [--super-prefix=<path>] 17 <command> [<args>] 18 19DESCRIPTION 20----------- 21Git is a fast, scalable, distributed revision control system with an 22unusually rich command set that provides both high-level operations 23and full access to internals. 24 25See linkgit:gittutorial[7] to get started, then see 26linkgit:giteveryday[7] for a useful minimum set of 27commands. The link:user-manual.html[Git User's Manual] has a more 28in-depth introduction. 29 30After you mastered the basic concepts, you can come back to this 31page to learn what commands Git offers. You can learn more about 32individual Git commands with "git help command". linkgit:gitcli[7] 33manual page gives you an overview of the command-line command syntax. 34 35A formatted and hyperlinked copy of the latest Git documentation 36can be viewed at `https://git.github.io/htmldocs/git.html`. 37 38 39OPTIONS 40------- 41--version:: 42 Prints the Git suite version that the 'git' program came from. 43 44--help:: 45 Prints the synopsis and a list of the most commonly used 46 commands. If the option `--all` or `-a` is given then all 47 available commands are printed. If a Git command is named this 48 option will bring up the manual page for that command. 49+ 50Other options are available to control how the manual page is 51displayed. See linkgit:git-help[1] for more information, 52because `git --help ...` is converted internally into `git 53help ...`. 54 55-C <path>:: 56 Run as if git was started in '<path>' instead of the current working 57 directory. When multiple `-C` options are given, each subsequent 58 non-absolute `-C <path>` is interpreted relative to the preceding `-C 59 <path>`. 60+ 61This option affects options that expect path name like `--git-dir` and 62`--work-tree` in that their interpretations of the path names would be 63made relative to the working directory caused by the `-C` option. For 64example the following invocations are equivalent: 65 66 git --git-dir=a.git --work-tree=b -C c status 67 git --git-dir=c/a.git --work-tree=c/b status 68 69-c <name>=<value>:: 70 Pass a configuration parameter to the command. The value 71 given will override values from configuration files. 72 The <name> is expected in the same format as listed by 73 'git config' (subkeys separated by dots). 74+ 75Note that omitting the `=` in `git -c foo.bar ...` is allowed and sets 76`foo.bar` to the boolean true value (just like `[foo]bar` would in a 77config file). Including the equals but with an empty value (like `git -c 78foo.bar= ...`) sets `foo.bar` to the empty string which `git config 79--bool` will convert to `false`. 80 81--exec-path[=<path>]:: 82 Path to wherever your core Git programs are installed. 83 This can also be controlled by setting the GIT_EXEC_PATH 84 environment variable. If no path is given, 'git' will print 85 the current setting and then exit. 86 87--html-path:: 88 Print the path, without trailing slash, where Git's HTML 89 documentation is installed and exit. 90 91--man-path:: 92 Print the manpath (see `man(1)`) for the man pages for 93 this version of Git and exit. 94 95--info-path:: 96 Print the path where the Info files documenting this 97 version of Git are installed and exit. 98 99-p:: 100--paginate:: 101 Pipe all output into 'less' (or if set, $PAGER) if standard 102 output is a terminal. This overrides the `pager.<cmd>` 103 configuration options (see the "Configuration Mechanism" section 104 below). 105 106--no-pager:: 107 Do not pipe Git output into a pager. 108 109--git-dir=<path>:: 110 Set the path to the repository. This can also be controlled by 111 setting the `GIT_DIR` environment variable. It can be an absolute 112 path or relative path to current working directory. 113 114--work-tree=<path>:: 115 Set the path to the working tree. It can be an absolute path 116 or a path relative to the current working directory. 117 This can also be controlled by setting the GIT_WORK_TREE 118 environment variable and the core.worktree configuration 119 variable (see core.worktree in linkgit:git-config[1] for a 120 more detailed discussion). 121 122--namespace=<path>:: 123 Set the Git namespace. See linkgit:gitnamespaces[7] for more 124 details. Equivalent to setting the `GIT_NAMESPACE` environment 125 variable. 126 127--super-prefix=<path>:: 128 Currently for internal use only. Set a prefix which gives a path from 129 above a repository down to its root. One use is to give submodules 130 context about the superproject that invoked it. 131 132--bare:: 133 Treat the repository as a bare repository. If GIT_DIR 134 environment is not set, it is set to the current working 135 directory. 136 137--no-replace-objects:: 138 Do not use replacement refs to replace Git objects. See 139 linkgit:git-replace[1] for more information. 140 141--literal-pathspecs:: 142 Treat pathspecs literally (i.e. no globbing, no pathspec magic). 143 This is equivalent to setting the `GIT_LITERAL_PATHSPECS` environment 144 variable to `1`. 145 146--glob-pathspecs:: 147 Add "glob" magic to all pathspec. This is equivalent to setting 148 the `GIT_GLOB_PATHSPECS` environment variable to `1`. Disabling 149 globbing on individual pathspecs can be done using pathspec 150 magic ":(literal)" 151 152--noglob-pathspecs:: 153 Add "literal" magic to all pathspec. This is equivalent to setting 154 the `GIT_NOGLOB_PATHSPECS` environment variable to `1`. Enabling 155 globbing on individual pathspecs can be done using pathspec 156 magic ":(glob)" 157 158--icase-pathspecs:: 159 Add "icase" magic to all pathspec. This is equivalent to setting 160 the `GIT_ICASE_PATHSPECS` environment variable to `1`. 161 162--no-optional-locks:: 163 Do not perform optional operations that require locks. This is 164 equivalent to setting the `GIT_OPTIONAL_LOCKS` to `0`. 165 166GIT COMMANDS 167------------ 168 169We divide Git into high level ("porcelain") commands and low level 170("plumbing") commands. 171 172High-level commands (porcelain) 173------------------------------- 174 175We separate the porcelain commands into the main commands and some 176ancillary user utilities. 177 178Main porcelain commands 179~~~~~~~~~~~~~~~~~~~~~~~ 180 181include::cmds-mainporcelain.txt[] 182 183Ancillary Commands 184~~~~~~~~~~~~~~~~~~ 185Manipulators: 186 187include::cmds-ancillarymanipulators.txt[] 188 189Interrogators: 190 191include::cmds-ancillaryinterrogators.txt[] 192 193 194Interacting with Others 195~~~~~~~~~~~~~~~~~~~~~~~ 196 197These commands are to interact with foreign SCM and with other 198people via patch over e-mail. 199 200include::cmds-foreignscminterface.txt[] 201 202 203Low-level commands (plumbing) 204----------------------------- 205 206Although Git includes its 207own porcelain layer, its low-level commands are sufficient to support 208development of alternative porcelains. Developers of such porcelains 209might start by reading about linkgit:git-update-index[1] and 210linkgit:git-read-tree[1]. 211 212The interface (input, output, set of options and the semantics) 213to these low-level commands are meant to be a lot more stable 214than Porcelain level commands, because these commands are 215primarily for scripted use. The interface to Porcelain commands 216on the other hand are subject to change in order to improve the 217end user experience. 218 219The following description divides 220the low-level commands into commands that manipulate objects (in 221the repository, index, and working tree), commands that interrogate and 222compare objects, and commands that move objects and references between 223repositories. 224 225 226Manipulation commands 227~~~~~~~~~~~~~~~~~~~~~ 228 229include::cmds-plumbingmanipulators.txt[] 230 231 232Interrogation commands 233~~~~~~~~~~~~~~~~~~~~~~ 234 235include::cmds-plumbinginterrogators.txt[] 236 237In general, the interrogate commands do not touch the files in 238the working tree. 239 240 241Synching repositories 242~~~~~~~~~~~~~~~~~~~~~ 243 244include::cmds-synchingrepositories.txt[] 245 246The following are helper commands used by the above; end users 247typically do not use them directly. 248 249include::cmds-synchelpers.txt[] 250 251 252Internal helper commands 253~~~~~~~~~~~~~~~~~~~~~~~~ 254 255These are internal helper commands used by other commands; end 256users typically do not use them directly. 257 258include::cmds-purehelpers.txt[] 259 260 261Configuration Mechanism 262----------------------- 263 264Git uses a simple text format to store customizations that are per 265repository and are per user. Such a configuration file may look 266like this: 267 268------------ 269# 270# A '#' or ';' character indicates a comment. 271# 272 273; core variables 274[core] 275 ; Don't trust file modes 276 filemode = false 277 278; user identity 279[user] 280 name = "Junio C Hamano" 281 email = "gitster@pobox.com" 282 283------------ 284 285Various commands read from the configuration file and adjust 286their operation accordingly. See linkgit:git-config[1] for a 287list and more details about the configuration mechanism. 288 289 290Identifier Terminology 291---------------------- 292<object>:: 293 Indicates the object name for any type of object. 294 295<blob>:: 296 Indicates a blob object name. 297 298<tree>:: 299 Indicates a tree object name. 300 301<commit>:: 302 Indicates a commit object name. 303 304<tree-ish>:: 305 Indicates a tree, commit or tag object name. A 306 command that takes a <tree-ish> argument ultimately wants to 307 operate on a <tree> object but automatically dereferences 308 <commit> and <tag> objects that point at a <tree>. 309 310<commit-ish>:: 311 Indicates a commit or tag object name. A 312 command that takes a <commit-ish> argument ultimately wants to 313 operate on a <commit> object but automatically dereferences 314 <tag> objects that point at a <commit>. 315 316<type>:: 317 Indicates that an object type is required. 318 Currently one of: `blob`, `tree`, `commit`, or `tag`. 319 320<file>:: 321 Indicates a filename - almost always relative to the 322 root of the tree structure `GIT_INDEX_FILE` describes. 323 324Symbolic Identifiers 325-------------------- 326Any Git command accepting any <object> can also use the following 327symbolic notation: 328 329HEAD:: 330 indicates the head of the current branch. 331 332<tag>:: 333 a valid tag 'name' 334 (i.e. a `refs/tags/<tag>` reference). 335 336<head>:: 337 a valid head 'name' 338 (i.e. a `refs/heads/<head>` reference). 339 340For a more complete list of ways to spell object names, see 341"SPECIFYING REVISIONS" section in linkgit:gitrevisions[7]. 342 343 344File/Directory Structure 345------------------------ 346 347Please see the linkgit:gitrepository-layout[5] document. 348 349Read linkgit:githooks[5] for more details about each hook. 350 351Higher level SCMs may provide and manage additional information in the 352`$GIT_DIR`. 353 354 355Terminology 356----------- 357Please see linkgit:gitglossary[7]. 358 359 360Environment Variables 361--------------------- 362Various Git commands use the following environment variables: 363 364The Git Repository 365~~~~~~~~~~~~~~~~~~ 366These environment variables apply to 'all' core Git commands. Nb: it 367is worth noting that they may be used/overridden by SCMS sitting above 368Git so take care if using a foreign front-end. 369 370`GIT_INDEX_FILE`:: 371 This environment allows the specification of an alternate 372 index file. If not specified, the default of `$GIT_DIR/index` 373 is used. 374 375`GIT_INDEX_VERSION`:: 376 This environment variable allows the specification of an index 377 version for new repositories. It won't affect existing index 378 files. By default index file version 2 or 3 is used. See 379 linkgit:git-update-index[1] for more information. 380 381`GIT_OBJECT_DIRECTORY`:: 382 If the object storage directory is specified via this 383 environment variable then the sha1 directories are created 384 underneath - otherwise the default `$GIT_DIR/objects` 385 directory is used. 386 387`GIT_ALTERNATE_OBJECT_DIRECTORIES`:: 388 Due to the immutable nature of Git objects, old objects can be 389 archived into shared, read-only directories. This variable 390 specifies a ":" separated (on Windows ";" separated) list 391 of Git object directories which can be used to search for Git 392 objects. New objects will not be written to these directories. 393+ 394 Entries that begin with `"` (double-quote) will be interpreted 395 as C-style quoted paths, removing leading and trailing 396 double-quotes and respecting backslash escapes. E.g., the value 397 `"path-with-\"-and-:-in-it":vanilla-path` has two paths: 398 `path-with-"-and-:-in-it` and `vanilla-path`. 399 400`GIT_DIR`:: 401 If the `GIT_DIR` environment variable is set then it 402 specifies a path to use instead of the default `.git` 403 for the base of the repository. 404 The `--git-dir` command-line option also sets this value. 405 406`GIT_WORK_TREE`:: 407 Set the path to the root of the working tree. 408 This can also be controlled by the `--work-tree` command-line 409 option and the core.worktree configuration variable. 410 411`GIT_NAMESPACE`:: 412 Set the Git namespace; see linkgit:gitnamespaces[7] for details. 413 The `--namespace` command-line option also sets this value. 414 415`GIT_CEILING_DIRECTORIES`:: 416 This should be a colon-separated list of absolute paths. If 417 set, it is a list of directories that Git should not chdir up 418 into while looking for a repository directory (useful for 419 excluding slow-loading network directories). It will not 420 exclude the current working directory or a GIT_DIR set on the 421 command line or in the environment. Normally, Git has to read 422 the entries in this list and resolve any symlink that 423 might be present in order to compare them with the current 424 directory. However, if even this access is slow, you 425 can add an empty entry to the list to tell Git that the 426 subsequent entries are not symlinks and needn't be resolved; 427 e.g., 428 `GIT_CEILING_DIRECTORIES=/maybe/symlink::/very/slow/non/symlink`. 429 430`GIT_DISCOVERY_ACROSS_FILESYSTEM`:: 431 When run in a directory that does not have ".git" repository 432 directory, Git tries to find such a directory in the parent 433 directories to find the top of the working tree, but by default it 434 does not cross filesystem boundaries. This environment variable 435 can be set to true to tell Git not to stop at filesystem 436 boundaries. Like `GIT_CEILING_DIRECTORIES`, this will not affect 437 an explicit repository directory set via `GIT_DIR` or on the 438 command line. 439 440`GIT_COMMON_DIR`:: 441 If this variable is set to a path, non-worktree files that are 442 normally in $GIT_DIR will be taken from this path 443 instead. Worktree-specific files such as HEAD or index are 444 taken from $GIT_DIR. See linkgit:gitrepository-layout[5] and 445 linkgit:git-worktree[1] for 446 details. This variable has lower precedence than other path 447 variables such as GIT_INDEX_FILE, GIT_OBJECT_DIRECTORY... 448 449Git Commits 450~~~~~~~~~~~ 451`GIT_AUTHOR_NAME`:: 452`GIT_AUTHOR_EMAIL`:: 453`GIT_AUTHOR_DATE`:: 454`GIT_COMMITTER_NAME`:: 455`GIT_COMMITTER_EMAIL`:: 456`GIT_COMMITTER_DATE`:: 457'EMAIL':: 458 see linkgit:git-commit-tree[1] 459 460Git Diffs 461~~~~~~~~~ 462`GIT_DIFF_OPTS`:: 463 Only valid setting is "--unified=??" or "-u??" to set the 464 number of context lines shown when a unified diff is created. 465 This takes precedence over any "-U" or "--unified" option 466 value passed on the Git diff command line. 467 468`GIT_EXTERNAL_DIFF`:: 469 When the environment variable `GIT_EXTERNAL_DIFF` is set, the 470 program named by it is called, instead of the diff invocation 471 described above. For a path that is added, removed, or modified, 472 `GIT_EXTERNAL_DIFF` is called with 7 parameters: 473 474 path old-file old-hex old-mode new-file new-hex new-mode 475+ 476where: 477 478 <old|new>-file:: are files GIT_EXTERNAL_DIFF can use to read the 479 contents of <old|new>, 480 <old|new>-hex:: are the 40-hexdigit SHA-1 hashes, 481 <old|new>-mode:: are the octal representation of the file modes. 482+ 483The file parameters can point at the user's working file 484(e.g. `new-file` in "git-diff-files"), `/dev/null` (e.g. `old-file` 485when a new file is added), or a temporary file (e.g. `old-file` in the 486index). `GIT_EXTERNAL_DIFF` should not worry about unlinking the 487temporary file --- it is removed when `GIT_EXTERNAL_DIFF` exits. 488+ 489For a path that is unmerged, `GIT_EXTERNAL_DIFF` is called with 1 490parameter, <path>. 491+ 492For each path `GIT_EXTERNAL_DIFF` is called, two environment variables, 493`GIT_DIFF_PATH_COUNTER` and `GIT_DIFF_PATH_TOTAL` are set. 494 495`GIT_DIFF_PATH_COUNTER`:: 496 A 1-based counter incremented by one for every path. 497 498`GIT_DIFF_PATH_TOTAL`:: 499 The total number of paths. 500 501other 502~~~~~ 503`GIT_MERGE_VERBOSITY`:: 504 A number controlling the amount of output shown by 505 the recursive merge strategy. Overrides merge.verbosity. 506 See linkgit:git-merge[1] 507 508`GIT_PAGER`:: 509 This environment variable overrides `$PAGER`. If it is set 510 to an empty string or to the value "cat", Git will not launch 511 a pager. See also the `core.pager` option in 512 linkgit:git-config[1]. 513 514`GIT_EDITOR`:: 515 This environment variable overrides `$EDITOR` and `$VISUAL`. 516 It is used by several Git commands when, on interactive mode, 517 an editor is to be launched. See also linkgit:git-var[1] 518 and the `core.editor` option in linkgit:git-config[1]. 519 520`GIT_SSH`:: 521`GIT_SSH_COMMAND`:: 522 If either of these environment variables is set then 'git fetch' 523 and 'git push' will use the specified command instead of 'ssh' 524 when they need to connect to a remote system. 525 The command-line parameters passed to the configured command are 526 determined by the ssh variant. See `ssh.variant` option in 527 linkgit:git-config[1] for details. 528 529+ 530`$GIT_SSH_COMMAND` takes precedence over `$GIT_SSH`, and is interpreted 531by the shell, which allows additional arguments to be included. 532`$GIT_SSH` on the other hand must be just the path to a program 533(which can be a wrapper shell script, if additional arguments are 534needed). 535+ 536Usually it is easier to configure any desired options through your 537personal `.ssh/config` file. Please consult your ssh documentation 538for further details. 539 540`GIT_SSH_VARIANT`:: 541 If this environment variable is set, it overrides Git's autodetection 542 whether `GIT_SSH`/`GIT_SSH_COMMAND`/`core.sshCommand` refer to OpenSSH, 543 plink or tortoiseplink. This variable overrides the config setting 544 `ssh.variant` that serves the same purpose. 545 546`GIT_ASKPASS`:: 547 If this environment variable is set, then Git commands which need to 548 acquire passwords or passphrases (e.g. for HTTP or IMAP authentication) 549 will call this program with a suitable prompt as command-line argument 550 and read the password from its STDOUT. See also the `core.askPass` 551 option in linkgit:git-config[1]. 552 553`GIT_TERMINAL_PROMPT`:: 554 If this environment variable is set to `0`, git will not prompt 555 on the terminal (e.g., when asking for HTTP authentication). 556 557`GIT_CONFIG_NOSYSTEM`:: 558 Whether to skip reading settings from the system-wide 559 `$(prefix)/etc/gitconfig` file. This environment variable can 560 be used along with `$HOME` and `$XDG_CONFIG_HOME` to create a 561 predictable environment for a picky script, or you can set it 562 temporarily to avoid using a buggy `/etc/gitconfig` file while 563 waiting for someone with sufficient permissions to fix it. 564 565`GIT_FLUSH`:: 566 If this environment variable is set to "1", then commands such 567 as 'git blame' (in incremental mode), 'git rev-list', 'git log', 568 'git check-attr' and 'git check-ignore' will 569 force a flush of the output stream after each record have been 570 flushed. If this 571 variable is set to "0", the output of these commands will be done 572 using completely buffered I/O. If this environment variable is 573 not set, Git will choose buffered or record-oriented flushing 574 based on whether stdout appears to be redirected to a file or not. 575 576`GIT_TRACE`:: 577 Enables general trace messages, e.g. alias expansion, built-in 578 command execution and external command execution. 579+ 580If this variable is set to "1", "2" or "true" (comparison 581is case insensitive), trace messages will be printed to 582stderr. 583+ 584If the variable is set to an integer value greater than 2 585and lower than 10 (strictly) then Git will interpret this 586value as an open file descriptor and will try to write the 587trace messages into this file descriptor. 588+ 589Alternatively, if the variable is set to an absolute path 590(starting with a '/' character), Git will interpret this 591as a file path and will try to write the trace messages 592into it. 593+ 594Unsetting the variable, or setting it to empty, "0" or 595"false" (case insensitive) disables trace messages. 596 597`GIT_TRACE_FSMONITOR`:: 598 Enables trace messages for the filesystem monitor extension. 599 See `GIT_TRACE` for available trace output options. 600 601`GIT_TRACE_PACK_ACCESS`:: 602 Enables trace messages for all accesses to any packs. For each 603 access, the pack file name and an offset in the pack is 604 recorded. This may be helpful for troubleshooting some 605 pack-related performance problems. 606 See `GIT_TRACE` for available trace output options. 607 608`GIT_TRACE_PACKET`:: 609 Enables trace messages for all packets coming in or out of a 610 given program. This can help with debugging object negotiation 611 or other protocol issues. Tracing is turned off at a packet 612 starting with "PACK" (but see `GIT_TRACE_PACKFILE` below). 613 See `GIT_TRACE` for available trace output options. 614 615`GIT_TRACE_PACKFILE`:: 616 Enables tracing of packfiles sent or received by a 617 given program. Unlike other trace output, this trace is 618 verbatim: no headers, and no quoting of binary data. You almost 619 certainly want to direct into a file (e.g., 620 `GIT_TRACE_PACKFILE=/tmp/my.pack`) rather than displaying it on 621 the terminal or mixing it with other trace output. 622+ 623Note that this is currently only implemented for the client side 624of clones and fetches. 625 626`GIT_TRACE_PERFORMANCE`:: 627 Enables performance related trace messages, e.g. total execution 628 time of each Git command. 629 See `GIT_TRACE` for available trace output options. 630 631`GIT_TRACE_SETUP`:: 632 Enables trace messages printing the .git, working tree and current 633 working directory after Git has completed its setup phase. 634 See `GIT_TRACE` for available trace output options. 635 636`GIT_TRACE_SHALLOW`:: 637 Enables trace messages that can help debugging fetching / 638 cloning of shallow repositories. 639 See `GIT_TRACE` for available trace output options. 640 641`GIT_TRACE_CURL`:: 642 Enables a curl full trace dump of all incoming and outgoing data, 643 including descriptive information, of the git transport protocol. 644 This is similar to doing curl `--trace-ascii` on the command line. 645 This option overrides setting the `GIT_CURL_VERBOSE` environment 646 variable. 647 See `GIT_TRACE` for available trace output options. 648 649`GIT_LITERAL_PATHSPECS`:: 650 Setting this variable to `1` will cause Git to treat all 651 pathspecs literally, rather than as glob patterns. For example, 652 running `GIT_LITERAL_PATHSPECS=1 git log -- '*.c'` will search 653 for commits that touch the path `*.c`, not any paths that the 654 glob `*.c` matches. You might want this if you are feeding 655 literal paths to Git (e.g., paths previously given to you by 656 `git ls-tree`, `--raw` diff output, etc). 657 658`GIT_GLOB_PATHSPECS`:: 659 Setting this variable to `1` will cause Git to treat all 660 pathspecs as glob patterns (aka "glob" magic). 661 662`GIT_NOGLOB_PATHSPECS`:: 663 Setting this variable to `1` will cause Git to treat all 664 pathspecs as literal (aka "literal" magic). 665 666`GIT_ICASE_PATHSPECS`:: 667 Setting this variable to `1` will cause Git to treat all 668 pathspecs as case-insensitive. 669 670`GIT_REFLOG_ACTION`:: 671 When a ref is updated, reflog entries are created to keep 672 track of the reason why the ref was updated (which is 673 typically the name of the high-level command that updated 674 the ref), in addition to the old and new values of the ref. 675 A scripted Porcelain command can use set_reflog_action 676 helper function in `git-sh-setup` to set its name to this 677 variable when it is invoked as the top level command by the 678 end user, to be recorded in the body of the reflog. 679 680`GIT_REF_PARANOIA`:: 681 If set to `1`, include broken or badly named refs when iterating 682 over lists of refs. In a normal, non-corrupted repository, this 683 does nothing. However, enabling it may help git to detect and 684 abort some operations in the presence of broken refs. Git sets 685 this variable automatically when performing destructive 686 operations like linkgit:git-prune[1]. You should not need to set 687 it yourself unless you want to be paranoid about making sure 688 an operation has touched every ref (e.g., because you are 689 cloning a repository to make a backup). 690 691`GIT_ALLOW_PROTOCOL`:: 692 If set to a colon-separated list of protocols, behave as if 693 `protocol.allow` is set to `never`, and each of the listed 694 protocols has `protocol.<name>.allow` set to `always` 695 (overriding any existing configuration). In other words, any 696 protocol not mentioned will be disallowed (i.e., this is a 697 whitelist, not a blacklist). See the description of 698 `protocol.allow` in linkgit:git-config[1] for more details. 699 700`GIT_PROTOCOL_FROM_USER`:: 701 Set to 0 to prevent protocols used by fetch/push/clone which are 702 configured to the `user` state. This is useful to restrict recursive 703 submodule initialization from an untrusted repository or for programs 704 which feed potentially-untrusted URLS to git commands. See 705 linkgit:git-config[1] for more details. 706 707`GIT_PROTOCOL`:: 708 For internal use only. Used in handshaking the wire protocol. 709 Contains a colon ':' separated list of keys with optional values 710 'key[=value]'. Presence of unknown keys and values must be 711 ignored. 712 713`GIT_OPTIONAL_LOCKS`:: 714 If set to `0`, Git will complete any requested operation without 715 performing any optional sub-operations that require taking a lock. 716 For example, this will prevent `git status` from refreshing the 717 index as a side effect. This is useful for processes running in 718 the background which do not want to cause lock contention with 719 other operations on the repository. Defaults to `1`. 720 721`GIT_REDIRECT_STDIN`:: 722`GIT_REDIRECT_STDOUT`:: 723`GIT_REDIRECT_STDERR`:: 724 Windows-only: allow redirecting the standard input/output/error 725 handles to paths specified by the environment variables. This is 726 particularly useful in multi-threaded applications where the 727 canonical way to pass standard handles via `CreateProcess()` is 728 not an option because it would require the handles to be marked 729 inheritable (and consequently *every* spawned process would 730 inherit them, possibly blocking regular Git operations). The 731 primary intended use case is to use named pipes for communication 732 (e.g. `\\.\pipe\my-git-stdin-123`). 733+ 734Two special values are supported: `off` will simply close the 735corresponding standard handle, and if `GIT_REDIRECT_STDERR` is 736`2>&1`, standard error will be redirected to the same handle as 737standard output. 738 739`GIT_PRINT_SHA1_ELLIPSIS` (deprecated):: 740 If set to `yes`, print an ellipsis following an 741 (abbreviated) SHA-1 value. This affects indications of 742 detached HEADs (linkgit:git-checkout[1]) and the raw 743 diff output (linkgit:git-diff[1]). Printing an 744 ellipsis in the cases mentioned is no longer considered 745 adequate and support for it is likely to be removed in the 746 foreseeable future (along with the variable). 747 748Discussion[[Discussion]] 749------------------------ 750 751More detail on the following is available from the 752link:user-manual.html#git-concepts[Git concepts chapter of the 753user-manual] and linkgit:gitcore-tutorial[7]. 754 755A Git project normally consists of a working directory with a ".git" 756subdirectory at the top level. The .git directory contains, among other 757things, a compressed object database representing the complete history 758of the project, an "index" file which links that history to the current 759contents of the working tree, and named pointers into that history such 760as tags and branch heads. 761 762The object database contains objects of three main types: blobs, which 763hold file data; trees, which point to blobs and other trees to build up 764directory hierarchies; and commits, which each reference a single tree 765and some number of parent commits. 766 767The commit, equivalent to what other systems call a "changeset" or 768"version", represents a step in the project's history, and each parent 769represents an immediately preceding step. Commits with more than one 770parent represent merges of independent lines of development. 771 772All objects are named by the SHA-1 hash of their contents, normally 773written as a string of 40 hex digits. Such names are globally unique. 774The entire history leading up to a commit can be vouched for by signing 775just that commit. A fourth object type, the tag, is provided for this 776purpose. 777 778When first created, objects are stored in individual files, but for 779efficiency may later be compressed together into "pack files". 780 781Named pointers called refs mark interesting points in history. A ref 782may contain the SHA-1 name of an object or the name of another ref. Refs 783with names beginning `ref/head/` contain the SHA-1 name of the most 784recent commit (or "head") of a branch under development. SHA-1 names of 785tags of interest are stored under `ref/tags/`. A special ref named 786`HEAD` contains the name of the currently checked-out branch. 787 788The index file is initialized with a list of all paths and, for each 789path, a blob object and a set of attributes. The blob object represents 790the contents of the file as of the head of the current branch. The 791attributes (last modified time, size, etc.) are taken from the 792corresponding file in the working tree. Subsequent changes to the 793working tree can be found by comparing these attributes. The index may 794be updated with new content, and new commits may be created from the 795content stored in the index. 796 797The index is also capable of storing multiple entries (called "stages") 798for a given pathname. These stages are used to hold the various 799unmerged version of a file when a merge is in progress. 800 801FURTHER DOCUMENTATION 802--------------------- 803 804See the references in the "description" section to get started 805using Git. The following is probably more detail than necessary 806for a first-time user. 807 808The link:user-manual.html#git-concepts[Git concepts chapter of the 809user-manual] and linkgit:gitcore-tutorial[7] both provide 810introductions to the underlying Git architecture. 811 812See linkgit:gitworkflows[7] for an overview of recommended workflows. 813 814See also the link:howto-index.html[howto] documents for some useful 815examples. 816 817The internals are documented in the 818link:technical/api-index.html[Git API documentation]. 819 820Users migrating from CVS may also want to 821read linkgit:gitcvs-migration[7]. 822 823 824Authors 825------- 826Git was started by Linus Torvalds, and is currently maintained by Junio 827C Hamano. Numerous contributions have come from the Git mailing list 828<git@vger.kernel.org>. http://www.openhub.net/p/git/contributors/summary 829gives you a more complete list of contributors. 830 831If you have a clone of git.git itself, the 832output of linkgit:git-shortlog[1] and linkgit:git-blame[1] can show you 833the authors for specific parts of the project. 834 835Reporting Bugs 836-------------- 837 838Report bugs to the Git mailing list <git@vger.kernel.org> where the 839development and maintenance is primarily done. You do not have to be 840subscribed to the list to send a message there. 841 842SEE ALSO 843-------- 844linkgit:gittutorial[7], linkgit:gittutorial-2[7], 845linkgit:giteveryday[7], linkgit:gitcvs-migration[7], 846linkgit:gitglossary[7], linkgit:gitcore-tutorial[7], 847linkgit:gitcli[7], link:user-manual.html[The Git User's Manual], 848linkgit:gitworkflows[7] 849 850GIT 851--- 852Part of the linkgit:git[1] suite