Documentation / git.txton commit diff-delta: set size out-parameter to 0 for NULL delta (e4b3690)
   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|-P|--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
  37or https://git-scm.com/docs.
  38
  39
  40OPTIONS
  41-------
  42--version::
  43        Prints the Git suite version that the 'git' program came from.
  44
  45--help::
  46        Prints the synopsis and a list of the most commonly used
  47        commands. If the option `--all` or `-a` is given then all
  48        available commands are printed. If a Git command is named this
  49        option will bring up the manual page for that command.
  50+
  51Other options are available to control how the manual page is
  52displayed. See linkgit:git-help[1] for more information,
  53because `git --help ...` is converted internally into `git
  54help ...`.
  55
  56-C <path>::
  57        Run as if git was started in '<path>' instead of the current working
  58        directory.  When multiple `-C` options are given, each subsequent
  59        non-absolute `-C <path>` is interpreted relative to the preceding `-C
  60        <path>`.  If '<path>' is present but empty, e.g. `-C ""`, then the
  61        current working directory is left unchanged.
  62+
  63This option affects options that expect path name like `--git-dir` and
  64`--work-tree` in that their interpretations of the path names would be
  65made relative to the working directory caused by the `-C` option. For
  66example the following invocations are equivalent:
  67
  68    git --git-dir=a.git --work-tree=b -C c status
  69    git --git-dir=c/a.git --work-tree=c/b status
  70
  71-c <name>=<value>::
  72        Pass a configuration parameter to the command. The value
  73        given will override values from configuration files.
  74        The <name> is expected in the same format as listed by
  75        'git config' (subkeys separated by dots).
  76+
  77Note that omitting the `=` in `git -c foo.bar ...` is allowed and sets
  78`foo.bar` to the boolean true value (just like `[foo]bar` would in a
  79config file). Including the equals but with an empty value (like `git -c
  80foo.bar= ...`) sets `foo.bar` to the empty string which `git config
  81--type=bool` will convert to `false`.
  82
  83--exec-path[=<path>]::
  84        Path to wherever your core Git programs are installed.
  85        This can also be controlled by setting the GIT_EXEC_PATH
  86        environment variable. If no path is given, 'git' will print
  87        the current setting and then exit.
  88
  89--html-path::
  90        Print the path, without trailing slash, where Git's HTML
  91        documentation is installed and exit.
  92
  93--man-path::
  94        Print the manpath (see `man(1)`) for the man pages for
  95        this version of Git and exit.
  96
  97--info-path::
  98        Print the path where the Info files documenting this
  99        version of Git are installed and exit.
 100
 101-p::
 102--paginate::
 103        Pipe all output into 'less' (or if set, $PAGER) if standard
 104        output is a terminal.  This overrides the `pager.<cmd>`
 105        configuration options (see the "Configuration Mechanism" section
 106        below).
 107
 108-P::
 109--no-pager::
 110        Do not pipe Git output into a pager.
 111
 112--git-dir=<path>::
 113        Set the path to the repository. This can also be controlled by
 114        setting the `GIT_DIR` environment variable. It can be an absolute
 115        path or relative path to current working directory.
 116
 117--work-tree=<path>::
 118        Set the path to the working tree. It can be an absolute path
 119        or a path relative to the current working directory.
 120        This can also be controlled by setting the GIT_WORK_TREE
 121        environment variable and the core.worktree configuration
 122        variable (see core.worktree in linkgit:git-config[1] for a
 123        more detailed discussion).
 124
 125--namespace=<path>::
 126        Set the Git namespace.  See linkgit:gitnamespaces[7] for more
 127        details.  Equivalent to setting the `GIT_NAMESPACE` environment
 128        variable.
 129
 130--super-prefix=<path>::
 131        Currently for internal use only.  Set a prefix which gives a path from
 132        above a repository down to its root.  One use is to give submodules
 133        context about the superproject that invoked it.
 134
 135--bare::
 136        Treat the repository as a bare repository.  If GIT_DIR
 137        environment is not set, it is set to the current working
 138        directory.
 139
 140--no-replace-objects::
 141        Do not use replacement refs to replace Git objects. See
 142        linkgit:git-replace[1] for more information.
 143
 144--literal-pathspecs::
 145        Treat pathspecs literally (i.e. no globbing, no pathspec magic).
 146        This is equivalent to setting the `GIT_LITERAL_PATHSPECS` environment
 147        variable to `1`.
 148
 149--glob-pathspecs::
 150        Add "glob" magic to all pathspec. This is equivalent to setting
 151        the `GIT_GLOB_PATHSPECS` environment variable to `1`. Disabling
 152        globbing on individual pathspecs can be done using pathspec
 153        magic ":(literal)"
 154
 155--noglob-pathspecs::
 156        Add "literal" magic to all pathspec. This is equivalent to setting
 157        the `GIT_NOGLOB_PATHSPECS` environment variable to `1`. Enabling
 158        globbing on individual pathspecs can be done using pathspec
 159        magic ":(glob)"
 160
 161--icase-pathspecs::
 162        Add "icase" magic to all pathspec. This is equivalent to setting
 163        the `GIT_ICASE_PATHSPECS` environment variable to `1`.
 164
 165--no-optional-locks::
 166        Do not perform optional operations that require locks. This is
 167        equivalent to setting the `GIT_OPTIONAL_LOCKS` to `0`.
 168
 169--list-cmds=group[,group...]::
 170        List commands by group. This is an internal/experimental
 171        option and may change or be removed in the future. Supported
 172        groups are: builtins, parseopt (builtin commands that use
 173        parse-options), main (all commands in libexec directory),
 174        others (all other commands in `$PATH` that have git- prefix),
 175        list-<category> (see categories in command-list.txt),
 176        nohelpers (exclude helper commands), alias and config
 177        (retrieve command list from config variable completion.commands)
 178
 179GIT COMMANDS
 180------------
 181
 182We divide Git into high level ("porcelain") commands and low level
 183("plumbing") commands.
 184
 185High-level commands (porcelain)
 186-------------------------------
 187
 188We separate the porcelain commands into the main commands and some
 189ancillary user utilities.
 190
 191Main porcelain commands
 192~~~~~~~~~~~~~~~~~~~~~~~
 193
 194include::cmds-mainporcelain.txt[]
 195
 196Ancillary Commands
 197~~~~~~~~~~~~~~~~~~
 198Manipulators:
 199
 200include::cmds-ancillarymanipulators.txt[]
 201
 202Interrogators:
 203
 204include::cmds-ancillaryinterrogators.txt[]
 205
 206
 207Interacting with Others
 208~~~~~~~~~~~~~~~~~~~~~~~
 209
 210These commands are to interact with foreign SCM and with other
 211people via patch over e-mail.
 212
 213include::cmds-foreignscminterface.txt[]
 214
 215Reset, restore and revert
 216~~~~~~~~~~~~~~~~~~~~~~~~~
 217There are three commands with similar names: `git reset`,
 218`git restore` and `git revert`.
 219
 220* linkgit:git-revert[1] is about making a new commit that reverts the
 221  changes made by other commits.
 222
 223* linkgit:git-restore[1] is about restoring files in the working tree
 224  from either the index or another commit. This command does not
 225  update your branch. The command can also be used to restore files in
 226  the index from another commit.
 227
 228* linkgit:git-reset[1] is about updating your branch, moving the tip
 229  in order to add or remove commits from the branch. This operation
 230  changes the commit history.
 231+
 232`git reset` can also be used to restore the index, overlapping with
 233`git restore`.
 234
 235
 236Low-level commands (plumbing)
 237-----------------------------
 238
 239Although Git includes its
 240own porcelain layer, its low-level commands are sufficient to support
 241development of alternative porcelains.  Developers of such porcelains
 242might start by reading about linkgit:git-update-index[1] and
 243linkgit:git-read-tree[1].
 244
 245The interface (input, output, set of options and the semantics)
 246to these low-level commands are meant to be a lot more stable
 247than Porcelain level commands, because these commands are
 248primarily for scripted use.  The interface to Porcelain commands
 249on the other hand are subject to change in order to improve the
 250end user experience.
 251
 252The following description divides
 253the low-level commands into commands that manipulate objects (in
 254the repository, index, and working tree), commands that interrogate and
 255compare objects, and commands that move objects and references between
 256repositories.
 257
 258
 259Manipulation commands
 260~~~~~~~~~~~~~~~~~~~~~
 261
 262include::cmds-plumbingmanipulators.txt[]
 263
 264
 265Interrogation commands
 266~~~~~~~~~~~~~~~~~~~~~~
 267
 268include::cmds-plumbinginterrogators.txt[]
 269
 270In general, the interrogate commands do not touch the files in
 271the working tree.
 272
 273
 274Synching repositories
 275~~~~~~~~~~~~~~~~~~~~~
 276
 277include::cmds-synchingrepositories.txt[]
 278
 279The following are helper commands used by the above; end users
 280typically do not use them directly.
 281
 282include::cmds-synchelpers.txt[]
 283
 284
 285Internal helper commands
 286~~~~~~~~~~~~~~~~~~~~~~~~
 287
 288These are internal helper commands used by other commands; end
 289users typically do not use them directly.
 290
 291include::cmds-purehelpers.txt[]
 292
 293
 294Configuration Mechanism
 295-----------------------
 296
 297Git uses a simple text format to store customizations that are per
 298repository and are per user.  Such a configuration file may look
 299like this:
 300
 301------------
 302#
 303# A '#' or ';' character indicates a comment.
 304#
 305
 306; core variables
 307[core]
 308        ; Don't trust file modes
 309        filemode = false
 310
 311; user identity
 312[user]
 313        name = "Junio C Hamano"
 314        email = "gitster@pobox.com"
 315
 316------------
 317
 318Various commands read from the configuration file and adjust
 319their operation accordingly.  See linkgit:git-config[1] for a
 320list and more details about the configuration mechanism.
 321
 322
 323Identifier Terminology
 324----------------------
 325<object>::
 326        Indicates the object name for any type of object.
 327
 328<blob>::
 329        Indicates a blob object name.
 330
 331<tree>::
 332        Indicates a tree object name.
 333
 334<commit>::
 335        Indicates a commit object name.
 336
 337<tree-ish>::
 338        Indicates a tree, commit or tag object name.  A
 339        command that takes a <tree-ish> argument ultimately wants to
 340        operate on a <tree> object but automatically dereferences
 341        <commit> and <tag> objects that point at a <tree>.
 342
 343<commit-ish>::
 344        Indicates a commit or tag object name.  A
 345        command that takes a <commit-ish> argument ultimately wants to
 346        operate on a <commit> object but automatically dereferences
 347        <tag> objects that point at a <commit>.
 348
 349<type>::
 350        Indicates that an object type is required.
 351        Currently one of: `blob`, `tree`, `commit`, or `tag`.
 352
 353<file>::
 354        Indicates a filename - almost always relative to the
 355        root of the tree structure `GIT_INDEX_FILE` describes.
 356
 357Symbolic Identifiers
 358--------------------
 359Any Git command accepting any <object> can also use the following
 360symbolic notation:
 361
 362HEAD::
 363        indicates the head of the current branch.
 364
 365<tag>::
 366        a valid tag 'name'
 367        (i.e. a `refs/tags/<tag>` reference).
 368
 369<head>::
 370        a valid head 'name'
 371        (i.e. a `refs/heads/<head>` reference).
 372
 373For a more complete list of ways to spell object names, see
 374"SPECIFYING REVISIONS" section in linkgit:gitrevisions[7].
 375
 376
 377File/Directory Structure
 378------------------------
 379
 380Please see the linkgit:gitrepository-layout[5] document.
 381
 382Read linkgit:githooks[5] for more details about each hook.
 383
 384Higher level SCMs may provide and manage additional information in the
 385`$GIT_DIR`.
 386
 387
 388Terminology
 389-----------
 390Please see linkgit:gitglossary[7].
 391
 392
 393Environment Variables
 394---------------------
 395Various Git commands use the following environment variables:
 396
 397The Git Repository
 398~~~~~~~~~~~~~~~~~~
 399These environment variables apply to 'all' core Git commands. Nb: it
 400is worth noting that they may be used/overridden by SCMS sitting above
 401Git so take care if using a foreign front-end.
 402
 403`GIT_INDEX_FILE`::
 404        This environment allows the specification of an alternate
 405        index file. If not specified, the default of `$GIT_DIR/index`
 406        is used.
 407
 408`GIT_INDEX_VERSION`::
 409        This environment variable allows the specification of an index
 410        version for new repositories.  It won't affect existing index
 411        files.  By default index file version 2 or 3 is used. See
 412        linkgit:git-update-index[1] for more information.
 413
 414`GIT_OBJECT_DIRECTORY`::
 415        If the object storage directory is specified via this
 416        environment variable then the sha1 directories are created
 417        underneath - otherwise the default `$GIT_DIR/objects`
 418        directory is used.
 419
 420`GIT_ALTERNATE_OBJECT_DIRECTORIES`::
 421        Due to the immutable nature of Git objects, old objects can be
 422        archived into shared, read-only directories. This variable
 423        specifies a ":" separated (on Windows ";" separated) list
 424        of Git object directories which can be used to search for Git
 425        objects. New objects will not be written to these directories.
 426+
 427Entries that begin with `"` (double-quote) will be interpreted
 428as C-style quoted paths, removing leading and trailing
 429double-quotes and respecting backslash escapes. E.g., the value
 430`"path-with-\"-and-:-in-it":vanilla-path` has two paths:
 431`path-with-"-and-:-in-it` and `vanilla-path`.
 432
 433`GIT_DIR`::
 434        If the `GIT_DIR` environment variable is set then it
 435        specifies a path to use instead of the default `.git`
 436        for the base of the repository.
 437        The `--git-dir` command-line option also sets this value.
 438
 439`GIT_WORK_TREE`::
 440        Set the path to the root of the working tree.
 441        This can also be controlled by the `--work-tree` command-line
 442        option and the core.worktree configuration variable.
 443
 444`GIT_NAMESPACE`::
 445        Set the Git namespace; see linkgit:gitnamespaces[7] for details.
 446        The `--namespace` command-line option also sets this value.
 447
 448`GIT_CEILING_DIRECTORIES`::
 449        This should be a colon-separated list of absolute paths.  If
 450        set, it is a list of directories that Git should not chdir up
 451        into while looking for a repository directory (useful for
 452        excluding slow-loading network directories).  It will not
 453        exclude the current working directory or a GIT_DIR set on the
 454        command line or in the environment.  Normally, Git has to read
 455        the entries in this list and resolve any symlink that
 456        might be present in order to compare them with the current
 457        directory.  However, if even this access is slow, you
 458        can add an empty entry to the list to tell Git that the
 459        subsequent entries are not symlinks and needn't be resolved;
 460        e.g.,
 461        `GIT_CEILING_DIRECTORIES=/maybe/symlink::/very/slow/non/symlink`.
 462
 463`GIT_DISCOVERY_ACROSS_FILESYSTEM`::
 464        When run in a directory that does not have ".git" repository
 465        directory, Git tries to find such a directory in the parent
 466        directories to find the top of the working tree, but by default it
 467        does not cross filesystem boundaries.  This environment variable
 468        can be set to true to tell Git not to stop at filesystem
 469        boundaries.  Like `GIT_CEILING_DIRECTORIES`, this will not affect
 470        an explicit repository directory set via `GIT_DIR` or on the
 471        command line.
 472
 473`GIT_COMMON_DIR`::
 474        If this variable is set to a path, non-worktree files that are
 475        normally in $GIT_DIR will be taken from this path
 476        instead. Worktree-specific files such as HEAD or index are
 477        taken from $GIT_DIR. See linkgit:gitrepository-layout[5] and
 478        linkgit:git-worktree[1] for
 479        details. This variable has lower precedence than other path
 480        variables such as GIT_INDEX_FILE, GIT_OBJECT_DIRECTORY...
 481
 482Git Commits
 483~~~~~~~~~~~
 484`GIT_AUTHOR_NAME`::
 485`GIT_AUTHOR_EMAIL`::
 486`GIT_AUTHOR_DATE`::
 487`GIT_COMMITTER_NAME`::
 488`GIT_COMMITTER_EMAIL`::
 489`GIT_COMMITTER_DATE`::
 490'EMAIL'::
 491        see linkgit:git-commit-tree[1]
 492
 493Git Diffs
 494~~~~~~~~~
 495`GIT_DIFF_OPTS`::
 496        Only valid setting is "--unified=??" or "-u??" to set the
 497        number of context lines shown when a unified diff is created.
 498        This takes precedence over any "-U" or "--unified" option
 499        value passed on the Git diff command line.
 500
 501`GIT_EXTERNAL_DIFF`::
 502        When the environment variable `GIT_EXTERNAL_DIFF` is set, the
 503        program named by it is called, instead of the diff invocation
 504        described above.  For a path that is added, removed, or modified,
 505        `GIT_EXTERNAL_DIFF` is called with 7 parameters:
 506
 507        path old-file old-hex old-mode new-file new-hex new-mode
 508+
 509where:
 510
 511        <old|new>-file:: are files GIT_EXTERNAL_DIFF can use to read the
 512                         contents of <old|new>,
 513        <old|new>-hex:: are the 40-hexdigit SHA-1 hashes,
 514        <old|new>-mode:: are the octal representation of the file modes.
 515+
 516The file parameters can point at the user's working file
 517(e.g. `new-file` in "git-diff-files"), `/dev/null` (e.g. `old-file`
 518when a new file is added), or a temporary file (e.g. `old-file` in the
 519index).  `GIT_EXTERNAL_DIFF` should not worry about unlinking the
 520temporary file --- it is removed when `GIT_EXTERNAL_DIFF` exits.
 521+
 522For a path that is unmerged, `GIT_EXTERNAL_DIFF` is called with 1
 523parameter, <path>.
 524+
 525For each path `GIT_EXTERNAL_DIFF` is called, two environment variables,
 526`GIT_DIFF_PATH_COUNTER` and `GIT_DIFF_PATH_TOTAL` are set.
 527
 528`GIT_DIFF_PATH_COUNTER`::
 529        A 1-based counter incremented by one for every path.
 530
 531`GIT_DIFF_PATH_TOTAL`::
 532        The total number of paths.
 533
 534other
 535~~~~~
 536`GIT_MERGE_VERBOSITY`::
 537        A number controlling the amount of output shown by
 538        the recursive merge strategy.  Overrides merge.verbosity.
 539        See linkgit:git-merge[1]
 540
 541`GIT_PAGER`::
 542        This environment variable overrides `$PAGER`. If it is set
 543        to an empty string or to the value "cat", Git will not launch
 544        a pager.  See also the `core.pager` option in
 545        linkgit:git-config[1].
 546
 547`GIT_EDITOR`::
 548        This environment variable overrides `$EDITOR` and `$VISUAL`.
 549        It is used by several Git commands when, on interactive mode,
 550        an editor is to be launched. See also linkgit:git-var[1]
 551        and the `core.editor` option in linkgit:git-config[1].
 552
 553`GIT_SSH`::
 554`GIT_SSH_COMMAND`::
 555        If either of these environment variables is set then 'git fetch'
 556        and 'git push' will use the specified command instead of 'ssh'
 557        when they need to connect to a remote system.
 558        The command-line parameters passed to the configured command are
 559        determined by the ssh variant.  See `ssh.variant` option in
 560        linkgit:git-config[1] for details.
 561+
 562`$GIT_SSH_COMMAND` takes precedence over `$GIT_SSH`, and is interpreted
 563by the shell, which allows additional arguments to be included.
 564`$GIT_SSH` on the other hand must be just the path to a program
 565(which can be a wrapper shell script, if additional arguments are
 566needed).
 567+
 568Usually it is easier to configure any desired options through your
 569personal `.ssh/config` file.  Please consult your ssh documentation
 570for further details.
 571
 572`GIT_SSH_VARIANT`::
 573        If this environment variable is set, it overrides Git's autodetection
 574        whether `GIT_SSH`/`GIT_SSH_COMMAND`/`core.sshCommand` refer to OpenSSH,
 575        plink or tortoiseplink. This variable overrides the config setting
 576        `ssh.variant` that serves the same purpose.
 577
 578`GIT_ASKPASS`::
 579        If this environment variable is set, then Git commands which need to
 580        acquire passwords or passphrases (e.g. for HTTP or IMAP authentication)
 581        will call this program with a suitable prompt as command-line argument
 582        and read the password from its STDOUT. See also the `core.askPass`
 583        option in linkgit:git-config[1].
 584
 585`GIT_TERMINAL_PROMPT`::
 586        If this environment variable is set to `0`, git will not prompt
 587        on the terminal (e.g., when asking for HTTP authentication).
 588
 589`GIT_CONFIG_NOSYSTEM`::
 590        Whether to skip reading settings from the system-wide
 591        `$(prefix)/etc/gitconfig` file.  This environment variable can
 592        be used along with `$HOME` and `$XDG_CONFIG_HOME` to create a
 593        predictable environment for a picky script, or you can set it
 594        temporarily to avoid using a buggy `/etc/gitconfig` file while
 595        waiting for someone with sufficient permissions to fix it.
 596
 597`GIT_FLUSH`::
 598        If this environment variable is set to "1", then commands such
 599        as 'git blame' (in incremental mode), 'git rev-list', 'git log',
 600        'git check-attr' and 'git check-ignore' will
 601        force a flush of the output stream after each record have been
 602        flushed. If this
 603        variable is set to "0", the output of these commands will be done
 604        using completely buffered I/O.   If this environment variable is
 605        not set, Git will choose buffered or record-oriented flushing
 606        based on whether stdout appears to be redirected to a file or not.
 607
 608`GIT_TRACE`::
 609        Enables general trace messages, e.g. alias expansion, built-in
 610        command execution and external command execution.
 611+
 612If this variable is set to "1", "2" or "true" (comparison
 613is case insensitive), trace messages will be printed to
 614stderr.
 615+
 616If the variable is set to an integer value greater than 2
 617and lower than 10 (strictly) then Git will interpret this
 618value as an open file descriptor and will try to write the
 619trace messages into this file descriptor.
 620+
 621Alternatively, if the variable is set to an absolute path
 622(starting with a '/' character), Git will interpret this
 623as a file path and will try to append the trace messages
 624to it.
 625+
 626Unsetting the variable, or setting it to empty, "0" or
 627"false" (case insensitive) disables trace messages.
 628
 629`GIT_TRACE_FSMONITOR`::
 630        Enables trace messages for the filesystem monitor extension.
 631        See `GIT_TRACE` for available trace output options.
 632
 633`GIT_TRACE_PACK_ACCESS`::
 634        Enables trace messages for all accesses to any packs. For each
 635        access, the pack file name and an offset in the pack is
 636        recorded. This may be helpful for troubleshooting some
 637        pack-related performance problems.
 638        See `GIT_TRACE` for available trace output options.
 639
 640`GIT_TRACE_PACKET`::
 641        Enables trace messages for all packets coming in or out of a
 642        given program. This can help with debugging object negotiation
 643        or other protocol issues. Tracing is turned off at a packet
 644        starting with "PACK" (but see `GIT_TRACE_PACKFILE` below).
 645        See `GIT_TRACE` for available trace output options.
 646
 647`GIT_TRACE_PACKFILE`::
 648        Enables tracing of packfiles sent or received by a
 649        given program. Unlike other trace output, this trace is
 650        verbatim: no headers, and no quoting of binary data. You almost
 651        certainly want to direct into a file (e.g.,
 652        `GIT_TRACE_PACKFILE=/tmp/my.pack`) rather than displaying it on
 653        the terminal or mixing it with other trace output.
 654+
 655Note that this is currently only implemented for the client side
 656of clones and fetches.
 657
 658`GIT_TRACE_PERFORMANCE`::
 659        Enables performance related trace messages, e.g. total execution
 660        time of each Git command.
 661        See `GIT_TRACE` for available trace output options.
 662
 663`GIT_TRACE_SETUP`::
 664        Enables trace messages printing the .git, working tree and current
 665        working directory after Git has completed its setup phase.
 666        See `GIT_TRACE` for available trace output options.
 667
 668`GIT_TRACE_SHALLOW`::
 669        Enables trace messages that can help debugging fetching /
 670        cloning of shallow repositories.
 671        See `GIT_TRACE` for available trace output options.
 672
 673`GIT_TRACE_CURL`::
 674        Enables a curl full trace dump of all incoming and outgoing data,
 675        including descriptive information, of the git transport protocol.
 676        This is similar to doing curl `--trace-ascii` on the command line.
 677        This option overrides setting the `GIT_CURL_VERBOSE` environment
 678        variable.
 679        See `GIT_TRACE` for available trace output options.
 680
 681`GIT_TRACE_CURL_NO_DATA`::
 682        When a curl trace is enabled (see `GIT_TRACE_CURL` above), do not dump
 683        data (that is, only dump info lines and headers).
 684
 685`GIT_TRACE2`::
 686        Enables more detailed trace messages from the "trace2" library.
 687        Output from `GIT_TRACE2` is a simple text-based format for human
 688        readability.
 689+
 690If this variable is set to "1", "2" or "true" (comparison
 691is case insensitive), trace messages will be printed to
 692stderr.
 693+
 694If the variable is set to an integer value greater than 2
 695and lower than 10 (strictly) then Git will interpret this
 696value as an open file descriptor and will try to write the
 697trace messages into this file descriptor.
 698+
 699Alternatively, if the variable is set to an absolute path
 700(starting with a '/' character), Git will interpret this
 701as a file path and will try to append the trace messages
 702to it.  If the path already exists and is a directory, the
 703trace messages will be written to files (one per process)
 704in that directory, named according to the last component
 705of the SID and an optional counter (to avoid filename
 706collisions).
 707+
 708In addition, if the variable is set to
 709`af_unix:[<socket_type>:]<absolute-pathname>`, Git will try
 710to open the path as a Unix Domain Socket.  The socket type
 711can be either `stream` or `dgram`.
 712+
 713Unsetting the variable, or setting it to empty, "0" or
 714"false" (case insensitive) disables trace messages.
 715+
 716See link:technical/api-trace2.html[Trace2 documentation]
 717for full details.
 718
 719
 720`GIT_TRACE2_EVENT`::
 721        This setting writes a JSON-based format that is suited for machine
 722        interpretation.
 723        See `GIT_TRACE2` for available trace output options and
 724        link:technical/api-trace2.html[Trace2 documentation] for full details.
 725
 726`GIT_TRACE2_PERF`::
 727        In addition to the text-based messages available in `GIT_TRACE2`, this
 728        setting writes a column-based format for understanding nesting
 729        regions.
 730        See `GIT_TRACE2` for available trace output options and
 731        link:technical/api-trace2.html[Trace2 documentation] for full details.
 732
 733`GIT_REDACT_COOKIES`::
 734        This can be set to a comma-separated list of strings. When a curl trace
 735        is enabled (see `GIT_TRACE_CURL` above), whenever a "Cookies:" header
 736        sent by the client is dumped, values of cookies whose key is in that
 737        list (case-sensitive) are redacted.
 738
 739`GIT_LITERAL_PATHSPECS`::
 740        Setting this variable to `1` will cause Git to treat all
 741        pathspecs literally, rather than as glob patterns. For example,
 742        running `GIT_LITERAL_PATHSPECS=1 git log -- '*.c'` will search
 743        for commits that touch the path `*.c`, not any paths that the
 744        glob `*.c` matches. You might want this if you are feeding
 745        literal paths to Git (e.g., paths previously given to you by
 746        `git ls-tree`, `--raw` diff output, etc).
 747
 748`GIT_GLOB_PATHSPECS`::
 749        Setting this variable to `1` will cause Git to treat all
 750        pathspecs as glob patterns (aka "glob" magic).
 751
 752`GIT_NOGLOB_PATHSPECS`::
 753        Setting this variable to `1` will cause Git to treat all
 754        pathspecs as literal (aka "literal" magic).
 755
 756`GIT_ICASE_PATHSPECS`::
 757        Setting this variable to `1` will cause Git to treat all
 758        pathspecs as case-insensitive.
 759
 760`GIT_REFLOG_ACTION`::
 761        When a ref is updated, reflog entries are created to keep
 762        track of the reason why the ref was updated (which is
 763        typically the name of the high-level command that updated
 764        the ref), in addition to the old and new values of the ref.
 765        A scripted Porcelain command can use set_reflog_action
 766        helper function in `git-sh-setup` to set its name to this
 767        variable when it is invoked as the top level command by the
 768        end user, to be recorded in the body of the reflog.
 769
 770`GIT_REF_PARANOIA`::
 771        If set to `1`, include broken or badly named refs when iterating
 772        over lists of refs. In a normal, non-corrupted repository, this
 773        does nothing. However, enabling it may help git to detect and
 774        abort some operations in the presence of broken refs. Git sets
 775        this variable automatically when performing destructive
 776        operations like linkgit:git-prune[1]. You should not need to set
 777        it yourself unless you want to be paranoid about making sure
 778        an operation has touched every ref (e.g., because you are
 779        cloning a repository to make a backup).
 780
 781`GIT_ALLOW_PROTOCOL`::
 782        If set to a colon-separated list of protocols, behave as if
 783        `protocol.allow` is set to `never`, and each of the listed
 784        protocols has `protocol.<name>.allow` set to `always`
 785        (overriding any existing configuration). In other words, any
 786        protocol not mentioned will be disallowed (i.e., this is a
 787        whitelist, not a blacklist). See the description of
 788        `protocol.allow` in linkgit:git-config[1] for more details.
 789
 790`GIT_PROTOCOL_FROM_USER`::
 791        Set to 0 to prevent protocols used by fetch/push/clone which are
 792        configured to the `user` state.  This is useful to restrict recursive
 793        submodule initialization from an untrusted repository or for programs
 794        which feed potentially-untrusted URLS to git commands.  See
 795        linkgit:git-config[1] for more details.
 796
 797`GIT_PROTOCOL`::
 798        For internal use only.  Used in handshaking the wire protocol.
 799        Contains a colon ':' separated list of keys with optional values
 800        'key[=value]'.  Presence of unknown keys and values must be
 801        ignored.
 802
 803`GIT_OPTIONAL_LOCKS`::
 804        If set to `0`, Git will complete any requested operation without
 805        performing any optional sub-operations that require taking a lock.
 806        For example, this will prevent `git status` from refreshing the
 807        index as a side effect. This is useful for processes running in
 808        the background which do not want to cause lock contention with
 809        other operations on the repository.  Defaults to `1`.
 810
 811`GIT_REDIRECT_STDIN`::
 812`GIT_REDIRECT_STDOUT`::
 813`GIT_REDIRECT_STDERR`::
 814        Windows-only: allow redirecting the standard input/output/error
 815        handles to paths specified by the environment variables. This is
 816        particularly useful in multi-threaded applications where the
 817        canonical way to pass standard handles via `CreateProcess()` is
 818        not an option because it would require the handles to be marked
 819        inheritable (and consequently *every* spawned process would
 820        inherit them, possibly blocking regular Git operations). The
 821        primary intended use case is to use named pipes for communication
 822        (e.g. `\\.\pipe\my-git-stdin-123`).
 823+
 824Two special values are supported: `off` will simply close the
 825corresponding standard handle, and if `GIT_REDIRECT_STDERR` is
 826`2>&1`, standard error will be redirected to the same handle as
 827standard output.
 828
 829`GIT_PRINT_SHA1_ELLIPSIS` (deprecated)::
 830        If set to `yes`, print an ellipsis following an
 831        (abbreviated) SHA-1 value.  This affects indications of
 832        detached HEADs (linkgit:git-checkout[1]) and the raw
 833        diff output (linkgit:git-diff[1]).  Printing an
 834        ellipsis in the cases mentioned is no longer considered
 835        adequate and support for it is likely to be removed in the
 836        foreseeable future (along with the variable).
 837
 838Discussion[[Discussion]]
 839------------------------
 840
 841More detail on the following is available from the
 842link:user-manual.html#git-concepts[Git concepts chapter of the
 843user-manual] and linkgit:gitcore-tutorial[7].
 844
 845A Git project normally consists of a working directory with a ".git"
 846subdirectory at the top level.  The .git directory contains, among other
 847things, a compressed object database representing the complete history
 848of the project, an "index" file which links that history to the current
 849contents of the working tree, and named pointers into that history such
 850as tags and branch heads.
 851
 852The object database contains objects of three main types: blobs, which
 853hold file data; trees, which point to blobs and other trees to build up
 854directory hierarchies; and commits, which each reference a single tree
 855and some number of parent commits.
 856
 857The commit, equivalent to what other systems call a "changeset" or
 858"version", represents a step in the project's history, and each parent
 859represents an immediately preceding step.  Commits with more than one
 860parent represent merges of independent lines of development.
 861
 862All objects are named by the SHA-1 hash of their contents, normally
 863written as a string of 40 hex digits.  Such names are globally unique.
 864The entire history leading up to a commit can be vouched for by signing
 865just that commit.  A fourth object type, the tag, is provided for this
 866purpose.
 867
 868When first created, objects are stored in individual files, but for
 869efficiency may later be compressed together into "pack files".
 870
 871Named pointers called refs mark interesting points in history.  A ref
 872may contain the SHA-1 name of an object or the name of another ref.  Refs
 873with names beginning `ref/head/` contain the SHA-1 name of the most
 874recent commit (or "head") of a branch under development.  SHA-1 names of
 875tags of interest are stored under `ref/tags/`.  A special ref named
 876`HEAD` contains the name of the currently checked-out branch.
 877
 878The index file is initialized with a list of all paths and, for each
 879path, a blob object and a set of attributes.  The blob object represents
 880the contents of the file as of the head of the current branch.  The
 881attributes (last modified time, size, etc.) are taken from the
 882corresponding file in the working tree.  Subsequent changes to the
 883working tree can be found by comparing these attributes.  The index may
 884be updated with new content, and new commits may be created from the
 885content stored in the index.
 886
 887The index is also capable of storing multiple entries (called "stages")
 888for a given pathname.  These stages are used to hold the various
 889unmerged version of a file when a merge is in progress.
 890
 891FURTHER DOCUMENTATION
 892---------------------
 893
 894See the references in the "description" section to get started
 895using Git.  The following is probably more detail than necessary
 896for a first-time user.
 897
 898The link:user-manual.html#git-concepts[Git concepts chapter of the
 899user-manual] and linkgit:gitcore-tutorial[7] both provide
 900introductions to the underlying Git architecture.
 901
 902See linkgit:gitworkflows[7] for an overview of recommended workflows.
 903
 904See also the link:howto-index.html[howto] documents for some useful
 905examples.
 906
 907The internals are documented in the
 908link:technical/api-index.html[Git API documentation].
 909
 910Users migrating from CVS may also want to
 911read linkgit:gitcvs-migration[7].
 912
 913
 914Authors
 915-------
 916Git was started by Linus Torvalds, and is currently maintained by Junio
 917C Hamano. Numerous contributions have come from the Git mailing list
 918<git@vger.kernel.org>.  http://www.openhub.net/p/git/contributors/summary
 919gives you a more complete list of contributors.
 920
 921If you have a clone of git.git itself, the
 922output of linkgit:git-shortlog[1] and linkgit:git-blame[1] can show you
 923the authors for specific parts of the project.
 924
 925Reporting Bugs
 926--------------
 927
 928Report bugs to the Git mailing list <git@vger.kernel.org> where the
 929development and maintenance is primarily done.  You do not have to be
 930subscribed to the list to send a message there.  See the list archive
 931at https://public-inbox.org/git for previous bug reports and other
 932discussions.
 933
 934Issues which are security relevant should be disclosed privately to
 935the Git Security mailing list <git-security@googlegroups.com>.
 936
 937SEE ALSO
 938--------
 939linkgit:gittutorial[7], linkgit:gittutorial-2[7],
 940linkgit:giteveryday[7], linkgit:gitcvs-migration[7],
 941linkgit:gitglossary[7], linkgit:gitcore-tutorial[7],
 942linkgit:gitcli[7], link:user-manual.html[The Git User's Manual],
 943linkgit:gitworkflows[7]
 944
 945GIT
 946---
 947Part of the linkgit:git[1] suite