Documentation / git.txton commit graph: add commit graph design document (ae30d7b)
   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_TRACE_CURL_NO_DATA`::
 650        When a curl trace is enabled (see `GIT_TRACE_CURL` above), do not dump
 651        data (that is, only dump info lines and headers).
 652
 653`GIT_REDACT_COOKIES`::
 654        This can be set to a comma-separated list of strings. When a curl trace
 655        is enabled (see `GIT_TRACE_CURL` above), whenever a "Cookies:" header
 656        sent by the client is dumped, values of cookies whose key is in that
 657        list (case-sensitive) are redacted.
 658
 659`GIT_LITERAL_PATHSPECS`::
 660        Setting this variable to `1` will cause Git to treat all
 661        pathspecs literally, rather than as glob patterns. For example,
 662        running `GIT_LITERAL_PATHSPECS=1 git log -- '*.c'` will search
 663        for commits that touch the path `*.c`, not any paths that the
 664        glob `*.c` matches. You might want this if you are feeding
 665        literal paths to Git (e.g., paths previously given to you by
 666        `git ls-tree`, `--raw` diff output, etc).
 667
 668`GIT_GLOB_PATHSPECS`::
 669        Setting this variable to `1` will cause Git to treat all
 670        pathspecs as glob patterns (aka "glob" magic).
 671
 672`GIT_NOGLOB_PATHSPECS`::
 673        Setting this variable to `1` will cause Git to treat all
 674        pathspecs as literal (aka "literal" magic).
 675
 676`GIT_ICASE_PATHSPECS`::
 677        Setting this variable to `1` will cause Git to treat all
 678        pathspecs as case-insensitive.
 679
 680`GIT_REFLOG_ACTION`::
 681        When a ref is updated, reflog entries are created to keep
 682        track of the reason why the ref was updated (which is
 683        typically the name of the high-level command that updated
 684        the ref), in addition to the old and new values of the ref.
 685        A scripted Porcelain command can use set_reflog_action
 686        helper function in `git-sh-setup` to set its name to this
 687        variable when it is invoked as the top level command by the
 688        end user, to be recorded in the body of the reflog.
 689
 690`GIT_REF_PARANOIA`::
 691        If set to `1`, include broken or badly named refs when iterating
 692        over lists of refs. In a normal, non-corrupted repository, this
 693        does nothing. However, enabling it may help git to detect and
 694        abort some operations in the presence of broken refs. Git sets
 695        this variable automatically when performing destructive
 696        operations like linkgit:git-prune[1]. You should not need to set
 697        it yourself unless you want to be paranoid about making sure
 698        an operation has touched every ref (e.g., because you are
 699        cloning a repository to make a backup).
 700
 701`GIT_ALLOW_PROTOCOL`::
 702        If set to a colon-separated list of protocols, behave as if
 703        `protocol.allow` is set to `never`, and each of the listed
 704        protocols has `protocol.<name>.allow` set to `always`
 705        (overriding any existing configuration). In other words, any
 706        protocol not mentioned will be disallowed (i.e., this is a
 707        whitelist, not a blacklist). See the description of
 708        `protocol.allow` in linkgit:git-config[1] for more details.
 709
 710`GIT_PROTOCOL_FROM_USER`::
 711        Set to 0 to prevent protocols used by fetch/push/clone which are
 712        configured to the `user` state.  This is useful to restrict recursive
 713        submodule initialization from an untrusted repository or for programs
 714        which feed potentially-untrusted URLS to git commands.  See
 715        linkgit:git-config[1] for more details.
 716
 717`GIT_PROTOCOL`::
 718        For internal use only.  Used in handshaking the wire protocol.
 719        Contains a colon ':' separated list of keys with optional values
 720        'key[=value]'.  Presence of unknown keys and values must be
 721        ignored.
 722
 723`GIT_OPTIONAL_LOCKS`::
 724        If set to `0`, Git will complete any requested operation without
 725        performing any optional sub-operations that require taking a lock.
 726        For example, this will prevent `git status` from refreshing the
 727        index as a side effect. This is useful for processes running in
 728        the background which do not want to cause lock contention with
 729        other operations on the repository.  Defaults to `1`.
 730
 731`GIT_REDIRECT_STDIN`::
 732`GIT_REDIRECT_STDOUT`::
 733`GIT_REDIRECT_STDERR`::
 734        Windows-only: allow redirecting the standard input/output/error
 735        handles to paths specified by the environment variables. This is
 736        particularly useful in multi-threaded applications where the
 737        canonical way to pass standard handles via `CreateProcess()` is
 738        not an option because it would require the handles to be marked
 739        inheritable (and consequently *every* spawned process would
 740        inherit them, possibly blocking regular Git operations). The
 741        primary intended use case is to use named pipes for communication
 742        (e.g. `\\.\pipe\my-git-stdin-123`).
 743+
 744Two special values are supported: `off` will simply close the
 745corresponding standard handle, and if `GIT_REDIRECT_STDERR` is
 746`2>&1`, standard error will be redirected to the same handle as
 747standard output.
 748
 749`GIT_PRINT_SHA1_ELLIPSIS` (deprecated)::
 750        If set to `yes`, print an ellipsis following an
 751        (abbreviated) SHA-1 value.  This affects indications of
 752        detached HEADs (linkgit:git-checkout[1]) and the raw
 753        diff output (linkgit:git-diff[1]).  Printing an
 754        ellipsis in the cases mentioned is no longer considered
 755        adequate and support for it is likely to be removed in the
 756        foreseeable future (along with the variable).
 757
 758Discussion[[Discussion]]
 759------------------------
 760
 761More detail on the following is available from the
 762link:user-manual.html#git-concepts[Git concepts chapter of the
 763user-manual] and linkgit:gitcore-tutorial[7].
 764
 765A Git project normally consists of a working directory with a ".git"
 766subdirectory at the top level.  The .git directory contains, among other
 767things, a compressed object database representing the complete history
 768of the project, an "index" file which links that history to the current
 769contents of the working tree, and named pointers into that history such
 770as tags and branch heads.
 771
 772The object database contains objects of three main types: blobs, which
 773hold file data; trees, which point to blobs and other trees to build up
 774directory hierarchies; and commits, which each reference a single tree
 775and some number of parent commits.
 776
 777The commit, equivalent to what other systems call a "changeset" or
 778"version", represents a step in the project's history, and each parent
 779represents an immediately preceding step.  Commits with more than one
 780parent represent merges of independent lines of development.
 781
 782All objects are named by the SHA-1 hash of their contents, normally
 783written as a string of 40 hex digits.  Such names are globally unique.
 784The entire history leading up to a commit can be vouched for by signing
 785just that commit.  A fourth object type, the tag, is provided for this
 786purpose.
 787
 788When first created, objects are stored in individual files, but for
 789efficiency may later be compressed together into "pack files".
 790
 791Named pointers called refs mark interesting points in history.  A ref
 792may contain the SHA-1 name of an object or the name of another ref.  Refs
 793with names beginning `ref/head/` contain the SHA-1 name of the most
 794recent commit (or "head") of a branch under development.  SHA-1 names of
 795tags of interest are stored under `ref/tags/`.  A special ref named
 796`HEAD` contains the name of the currently checked-out branch.
 797
 798The index file is initialized with a list of all paths and, for each
 799path, a blob object and a set of attributes.  The blob object represents
 800the contents of the file as of the head of the current branch.  The
 801attributes (last modified time, size, etc.) are taken from the
 802corresponding file in the working tree.  Subsequent changes to the
 803working tree can be found by comparing these attributes.  The index may
 804be updated with new content, and new commits may be created from the
 805content stored in the index.
 806
 807The index is also capable of storing multiple entries (called "stages")
 808for a given pathname.  These stages are used to hold the various
 809unmerged version of a file when a merge is in progress.
 810
 811FURTHER DOCUMENTATION
 812---------------------
 813
 814See the references in the "description" section to get started
 815using Git.  The following is probably more detail than necessary
 816for a first-time user.
 817
 818The link:user-manual.html#git-concepts[Git concepts chapter of the
 819user-manual] and linkgit:gitcore-tutorial[7] both provide
 820introductions to the underlying Git architecture.
 821
 822See linkgit:gitworkflows[7] for an overview of recommended workflows.
 823
 824See also the link:howto-index.html[howto] documents for some useful
 825examples.
 826
 827The internals are documented in the
 828link:technical/api-index.html[Git API documentation].
 829
 830Users migrating from CVS may also want to
 831read linkgit:gitcvs-migration[7].
 832
 833
 834Authors
 835-------
 836Git was started by Linus Torvalds, and is currently maintained by Junio
 837C Hamano. Numerous contributions have come from the Git mailing list
 838<git@vger.kernel.org>.  http://www.openhub.net/p/git/contributors/summary
 839gives you a more complete list of contributors.
 840
 841If you have a clone of git.git itself, the
 842output of linkgit:git-shortlog[1] and linkgit:git-blame[1] can show you
 843the authors for specific parts of the project.
 844
 845Reporting Bugs
 846--------------
 847
 848Report bugs to the Git mailing list <git@vger.kernel.org> where the
 849development and maintenance is primarily done.  You do not have to be
 850subscribed to the list to send a message there.
 851
 852SEE ALSO
 853--------
 854linkgit:gittutorial[7], linkgit:gittutorial-2[7],
 855linkgit:giteveryday[7], linkgit:gitcvs-migration[7],
 856linkgit:gitglossary[7], linkgit:gitcore-tutorial[7],
 857linkgit:gitcli[7], link:user-manual.html[The Git User's Manual],
 858linkgit:gitworkflows[7]
 859
 860GIT
 861---
 862Part of the linkgit:git[1] suite