Documentation / git.txton commit git grep: Add "-z/--null" option as in GNU's grep. (83caecc)
   1git(1)
   2======
   3
   4NAME
   5----
   6git - the stupid content tracker
   7
   8
   9SYNOPSIS
  10--------
  11[verse]
  12'git' [--version] [--exec-path[=GIT_EXEC_PATH]]
  13    [-p|--paginate|--no-pager]
  14    [--bare] [--git-dir=GIT_DIR] [--work-tree=GIT_WORK_TREE]
  15    [--help] COMMAND [ARGS]
  16
  17DESCRIPTION
  18-----------
  19Git is a fast, scalable, distributed revision control system with an
  20unusually rich command set that provides both high-level operations
  21and full access to internals.
  22
  23See linkgit:gittutorial[7] to get started, then see
  24link:everyday.html[Everyday Git] for a useful minimum set of commands, and
  25"man git-commandname" for documentation of each command.  CVS users may
  26also want to read linkgit:gitcvs-migration[7].  See
  27the link:user-manual.html[Git User's Manual] for a more in-depth
  28introduction.
  29
  30The COMMAND is either a name of a Git command (see below) or an alias
  31as defined in the configuration file (see linkgit:git-config[1]).
  32
  33Formatted and hyperlinked version of the latest git
  34documentation can be viewed at
  35`http://www.kernel.org/pub/software/scm/git/docs/`.
  36
  37ifdef::stalenotes[]
  38[NOTE]
  39============
  40
  41You are reading the documentation for the latest (possibly
  42unreleased) version of git, that is available from 'master'
  43branch of the `git.git` repository.
  44Documentation for older releases are available here:
  45
  46* link:v1.6.0.2/git.html[documentation for release 1.6.0.2]
  47
  48* release notes for
  49  link:RelNotes-1.6.0.2.txt[1.6.0.2],
  50  link:RelNotes-1.6.0.1.txt[1.6.0.1],
  51  link:RelNotes-1.6.0.txt[1.6.0].
  52
  53* link:v1.5.6.5/git.html[documentation for release 1.5.6.5]
  54
  55* release notes for
  56  link:RelNotes-1.5.6.5.txt[1.5.6.5],
  57  link:RelNotes-1.5.6.4.txt[1.5.6.4],
  58  link:RelNotes-1.5.6.3.txt[1.5.6.3],
  59  link:RelNotes-1.5.6.2.txt[1.5.6.2],
  60  link:RelNotes-1.5.6.1.txt[1.5.6.1],
  61  link:RelNotes-1.5.6.txt[1.5.6].
  62
  63* link:v1.5.5.4/git.html[documentation for release 1.5.5.4]
  64
  65* release notes for
  66  link:RelNotes-1.5.5.4.txt[1.5.5.4],
  67  link:RelNotes-1.5.5.3.txt[1.5.5.3],
  68  link:RelNotes-1.5.5.2.txt[1.5.5.2],
  69  link:RelNotes-1.5.5.1.txt[1.5.5.1],
  70  link:RelNotes-1.5.5.txt[1.5.5].
  71
  72* link:v1.5.4.5/git.html[documentation for release 1.5.4.5]
  73
  74* release notes for
  75  link:RelNotes-1.5.4.5.txt[1.5.4.5],
  76  link:RelNotes-1.5.4.4.txt[1.5.4.4],
  77  link:RelNotes-1.5.4.3.txt[1.5.4.3],
  78  link:RelNotes-1.5.4.2.txt[1.5.4.2],
  79  link:RelNotes-1.5.4.1.txt[1.5.4.1],
  80  link:RelNotes-1.5.4.txt[1.5.4].
  81
  82* link:v1.5.3.8/git.html[documentation for release 1.5.3.8]
  83
  84* release notes for
  85  link:RelNotes-1.5.3.8.txt[1.5.3.8],
  86  link:RelNotes-1.5.3.7.txt[1.5.3.7],
  87  link:RelNotes-1.5.3.6.txt[1.5.3.6],
  88  link:RelNotes-1.5.3.5.txt[1.5.3.5],
  89  link:RelNotes-1.5.3.4.txt[1.5.3.4],
  90  link:RelNotes-1.5.3.3.txt[1.5.3.3],
  91  link:RelNotes-1.5.3.2.txt[1.5.3.2],
  92  link:RelNotes-1.5.3.1.txt[1.5.3.1],
  93  link:RelNotes-1.5.3.txt[1.5.3].
  94
  95* link:v1.5.2.5/git.html[documentation for release 1.5.2.5]
  96
  97* release notes for
  98  link:RelNotes-1.5.2.5.txt[1.5.2.5],
  99  link:RelNotes-1.5.2.4.txt[1.5.2.4],
 100  link:RelNotes-1.5.2.3.txt[1.5.2.3],
 101  link:RelNotes-1.5.2.2.txt[1.5.2.2],
 102  link:RelNotes-1.5.2.1.txt[1.5.2.1],
 103  link:RelNotes-1.5.2.txt[1.5.2].
 104
 105* link:v1.5.1.6/git.html[documentation for release 1.5.1.6]
 106
 107* release notes for
 108  link:RelNotes-1.5.1.6.txt[1.5.1.6],
 109  link:RelNotes-1.5.1.5.txt[1.5.1.5],
 110  link:RelNotes-1.5.1.4.txt[1.5.1.4],
 111  link:RelNotes-1.5.1.3.txt[1.5.1.3],
 112  link:RelNotes-1.5.1.2.txt[1.5.1.2],
 113  link:RelNotes-1.5.1.1.txt[1.5.1.1],
 114  link:RelNotes-1.5.1.txt[1.5.1].
 115
 116* link:v1.5.0.7/git.html[documentation for release 1.5.0.7]
 117
 118* release notes for
 119  link:RelNotes-1.5.0.7.txt[1.5.0.7],
 120  link:RelNotes-1.5.0.6.txt[1.5.0.6],
 121  link:RelNotes-1.5.0.5.txt[1.5.0.5],
 122  link:RelNotes-1.5.0.3.txt[1.5.0.3],
 123  link:RelNotes-1.5.0.2.txt[1.5.0.2],
 124  link:RelNotes-1.5.0.1.txt[1.5.0.1],
 125  link:RelNotes-1.5.0.txt[1.5.0].
 126
 127* documentation for release link:v1.4.4.4/git.html[1.4.4.4],
 128  link:v1.3.3/git.html[1.3.3],
 129  link:v1.2.6/git.html[1.2.6],
 130  link:v1.0.13/git.html[1.0.13].
 131
 132============
 133
 134endif::stalenotes[]
 135
 136OPTIONS
 137-------
 138--version::
 139        Prints the git suite version that the 'git' program came from.
 140
 141--help::
 142        Prints the synopsis and a list of the most commonly used
 143        commands. If the option '--all' or '-a' is given then all
 144        available commands are printed. If a git command is named this
 145        option will bring up the manual page for that command.
 146+
 147Other options are available to control how the manual page is
 148displayed. See linkgit:git-help[1] for more information,
 149because `git --help ...` is converted internally into `git
 150help ...`.
 151
 152--exec-path::
 153        Path to wherever your core git programs are installed.
 154        This can also be controlled by setting the GIT_EXEC_PATH
 155        environment variable. If no path is given, 'git' will print
 156        the current setting and then exit.
 157
 158-p::
 159--paginate::
 160        Pipe all output into 'less' (or if set, $PAGER).
 161
 162--no-pager::
 163        Do not pipe git output into a pager.
 164
 165--git-dir=<path>::
 166        Set the path to the repository. This can also be controlled by
 167        setting the GIT_DIR environment variable. It can be an absolute
 168        path or relative path to current working directory.
 169
 170--work-tree=<path>::
 171        Set the path to the working tree.  The value will not be
 172        used in combination with repositories found automatically in
 173        a .git directory (i.e. $GIT_DIR is not set).
 174        This can also be controlled by setting the GIT_WORK_TREE
 175        environment variable and the core.worktree configuration
 176        variable. It can be an absolute path or relative path to
 177        the directory specified by --git-dir or GIT_DIR.
 178        Note: If --git-dir or GIT_DIR are specified but none of
 179        --work-tree, GIT_WORK_TREE and core.worktree is specified,
 180        the current working directory is regarded as the top directory
 181        of your working tree.
 182
 183--bare::
 184        Treat the repository as a bare repository.  If GIT_DIR
 185        environment is not set, it is set to the current working
 186        directory.
 187
 188
 189FURTHER DOCUMENTATION
 190---------------------
 191
 192See the references above to get started using git.  The following is
 193probably more detail than necessary for a first-time user.
 194
 195The link:user-manual.html#git-concepts[git concepts chapter of the
 196user-manual] and linkgit:gitcore-tutorial[7] both provide
 197introductions to the underlying git architecture.
 198
 199See also the link:howto-index.html[howto] documents for some useful
 200examples.
 201
 202The internals are documented in the
 203link:technical/api-index.html[GIT API documentation].
 204
 205GIT COMMANDS
 206------------
 207
 208We divide git into high level ("porcelain") commands and low level
 209("plumbing") commands.
 210
 211High-level commands (porcelain)
 212-------------------------------
 213
 214We separate the porcelain commands into the main commands and some
 215ancillary user utilities.
 216
 217Main porcelain commands
 218~~~~~~~~~~~~~~~~~~~~~~~
 219
 220include::cmds-mainporcelain.txt[]
 221
 222Ancillary Commands
 223~~~~~~~~~~~~~~~~~~
 224Manipulators:
 225
 226include::cmds-ancillarymanipulators.txt[]
 227
 228Interrogators:
 229
 230include::cmds-ancillaryinterrogators.txt[]
 231
 232
 233Interacting with Others
 234~~~~~~~~~~~~~~~~~~~~~~~
 235
 236These commands are to interact with foreign SCM and with other
 237people via patch over e-mail.
 238
 239include::cmds-foreignscminterface.txt[]
 240
 241
 242Low-level commands (plumbing)
 243-----------------------------
 244
 245Although git includes its
 246own porcelain layer, its low-level commands are sufficient to support
 247development of alternative porcelains.  Developers of such porcelains
 248might start by reading about linkgit:git-update-index[1] and
 249linkgit:git-read-tree[1].
 250
 251The interface (input, output, set of options and the semantics)
 252to these low-level commands are meant to be a lot more stable
 253than Porcelain level commands, because these commands are
 254primarily for scripted use.  The interface to Porcelain commands
 255on the other hand are subject to change in order to improve the
 256end user experience.
 257
 258The following description divides
 259the low-level commands into commands that manipulate objects (in
 260the repository, index, and working tree), commands that interrogate and
 261compare objects, and commands that move objects and references between
 262repositories.
 263
 264
 265Manipulation commands
 266~~~~~~~~~~~~~~~~~~~~~
 267
 268include::cmds-plumbingmanipulators.txt[]
 269
 270
 271Interrogation commands
 272~~~~~~~~~~~~~~~~~~~~~~
 273
 274include::cmds-plumbinginterrogators.txt[]
 275
 276In general, the interrogate commands do not touch the files in
 277the working tree.
 278
 279
 280Synching repositories
 281~~~~~~~~~~~~~~~~~~~~~
 282
 283include::cmds-synchingrepositories.txt[]
 284
 285The following are helper programs used by the above; end users
 286typically do not use them directly.
 287
 288include::cmds-synchelpers.txt[]
 289
 290
 291Internal helper commands
 292~~~~~~~~~~~~~~~~~~~~~~~~
 293
 294These are internal helper commands used by other commands; end
 295users typically do not use them directly.
 296
 297include::cmds-purehelpers.txt[]
 298
 299
 300Configuration Mechanism
 301-----------------------
 302
 303Starting from 0.99.9 (actually mid 0.99.8.GIT), `.git/config` file
 304is used to hold per-repository configuration options.  It is a
 305simple text file modeled after `.ini` format familiar to some
 306people.  Here is an example:
 307
 308------------
 309#
 310# A '#' or ';' character indicates a comment.
 311#
 312
 313; core variables
 314[core]
 315        ; Don't trust file modes
 316        filemode = false
 317
 318; user identity
 319[user]
 320        name = "Junio C Hamano"
 321        email = "junkio@twinsun.com"
 322
 323------------
 324
 325Various commands read from the configuration file and adjust
 326their operation accordingly.
 327
 328
 329Identifier Terminology
 330----------------------
 331<object>::
 332        Indicates the object name for any type of object.
 333
 334<blob>::
 335        Indicates a blob object name.
 336
 337<tree>::
 338        Indicates a tree object name.
 339
 340<commit>::
 341        Indicates a commit object name.
 342
 343<tree-ish>::
 344        Indicates a tree, commit or tag object name.  A
 345        command that takes a <tree-ish> argument ultimately wants to
 346        operate on a <tree> object but automatically dereferences
 347        <commit> and <tag> objects that point at a <tree>.
 348
 349<commit-ish>::
 350        Indicates a commit or tag object name.  A
 351        command that takes a <commit-ish> argument ultimately wants to
 352        operate on a <commit> object but automatically dereferences
 353        <tag> objects that point at a <commit>.
 354
 355<type>::
 356        Indicates that an object type is required.
 357        Currently one of: `blob`, `tree`, `commit`, or `tag`.
 358
 359<file>::
 360        Indicates a filename - almost always relative to the
 361        root of the tree structure `GIT_INDEX_FILE` describes.
 362
 363Symbolic Identifiers
 364--------------------
 365Any git command accepting any <object> can also use the following
 366symbolic notation:
 367
 368HEAD::
 369        indicates the head of the current branch (i.e. the
 370        contents of `$GIT_DIR/HEAD`).
 371
 372<tag>::
 373        a valid tag 'name'
 374        (i.e. the contents of `$GIT_DIR/refs/tags/<tag>`).
 375
 376<head>::
 377        a valid head 'name'
 378        (i.e. the contents of `$GIT_DIR/refs/heads/<head>`).
 379
 380For a more complete list of ways to spell object names, see
 381"SPECIFYING REVISIONS" section in linkgit:git-rev-parse[1].
 382
 383
 384File/Directory Structure
 385------------------------
 386
 387Please see the linkgit:gitrepository-layout[5] document.
 388
 389Read linkgit:githooks[5] for more details about each hook.
 390
 391Higher level SCMs may provide and manage additional information in the
 392`$GIT_DIR`.
 393
 394
 395Terminology
 396-----------
 397Please see linkgit:gitglossary[7].
 398
 399
 400Environment Variables
 401---------------------
 402Various git commands use the following environment variables:
 403
 404The git Repository
 405~~~~~~~~~~~~~~~~~~
 406These environment variables apply to 'all' core git commands. Nb: it
 407is worth noting that they may be used/overridden by SCMS sitting above
 408git so take care if using Cogito etc.
 409
 410'GIT_INDEX_FILE'::
 411        This environment allows the specification of an alternate
 412        index file. If not specified, the default of `$GIT_DIR/index`
 413        is used.
 414
 415'GIT_OBJECT_DIRECTORY'::
 416        If the object storage directory is specified via this
 417        environment variable then the sha1 directories are created
 418        underneath - otherwise the default `$GIT_DIR/objects`
 419        directory is used.
 420
 421'GIT_ALTERNATE_OBJECT_DIRECTORIES'::
 422        Due to the immutable nature of git objects, old objects can be
 423        archived into shared, read-only directories. This variable
 424        specifies a ":" separated (on Windows ";" separated) list
 425        of git object directories which can be used to search for git
 426        objects. New objects will not be written to these directories.
 427
 428'GIT_DIR'::
 429        If the 'GIT_DIR' environment variable is set then it
 430        specifies a path to use instead of the default `.git`
 431        for the base of the repository.
 432
 433'GIT_WORK_TREE'::
 434        Set the path to the working tree.  The value will not be
 435        used in combination with repositories found automatically in
 436        a .git directory (i.e. $GIT_DIR is not set).
 437        This can also be controlled by the '--work-tree' command line
 438        option and the core.worktree configuration variable.
 439
 440'GIT_CEILING_DIRECTORIES'::
 441        This should be a colon-separated list of absolute paths.
 442        If set, it is a list of directories that git should not chdir
 443        up into while looking for a repository directory.
 444        It will not exclude the current working directory or
 445        a GIT_DIR set on the command line or in the environment.
 446        (Useful for excluding slow-loading network directories.)
 447
 448git Commits
 449~~~~~~~~~~~
 450'GIT_AUTHOR_NAME'::
 451'GIT_AUTHOR_EMAIL'::
 452'GIT_AUTHOR_DATE'::
 453'GIT_COMMITTER_NAME'::
 454'GIT_COMMITTER_EMAIL'::
 455'GIT_COMMITTER_DATE'::
 456'EMAIL'::
 457        see linkgit:git-commit-tree[1]
 458
 459git Diffs
 460~~~~~~~~~
 461'GIT_DIFF_OPTS'::
 462        Only valid setting is "--unified=??" or "-u??" to set the
 463        number of context lines shown when a unified diff is created.
 464        This takes precedence over any "-U" or "--unified" option
 465        value passed on the git diff command line.
 466
 467'GIT_EXTERNAL_DIFF'::
 468        When the environment variable 'GIT_EXTERNAL_DIFF' is set, the
 469        program named by it is called, instead of the diff invocation
 470        described above.  For a path that is added, removed, or modified,
 471        'GIT_EXTERNAL_DIFF' is called with 7 parameters:
 472
 473        path old-file old-hex old-mode new-file new-hex new-mode
 474+
 475where:
 476
 477        <old|new>-file:: are files GIT_EXTERNAL_DIFF can use to read the
 478                         contents of <old|new>,
 479        <old|new>-hex:: are the 40-hexdigit SHA1 hashes,
 480        <old|new>-mode:: are the octal representation of the file modes.
 481
 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
 492other
 493~~~~~
 494'GIT_MERGE_VERBOSITY'::
 495        A number controlling the amount of output shown by
 496        the recursive merge strategy.  Overrides merge.verbosity.
 497        See linkgit:git-merge[1]
 498
 499'GIT_PAGER'::
 500        This environment variable overrides `$PAGER`. If it is set
 501        to an empty string or to the value "cat", git will not launch
 502        a pager.  See also the `core.pager` option in
 503        linkgit:git-config[1].
 504
 505'GIT_SSH'::
 506        If this environment variable is set then 'git-fetch'
 507        and 'git-push' will use this command instead
 508        of 'ssh' when they need to connect to a remote system.
 509        The '$GIT_SSH' command will be given exactly two arguments:
 510        the 'username@host' (or just 'host') from the URL and the
 511        shell command to execute on that remote system.
 512+
 513To pass options to the program that you want to list in GIT_SSH
 514you will need to wrap the program and options into a shell script,
 515then set GIT_SSH to refer to the shell script.
 516+
 517Usually it is easier to configure any desired options through your
 518personal `.ssh/config` file.  Please consult your ssh documentation
 519for further details.
 520
 521'GIT_FLUSH'::
 522        If this environment variable is set to "1", then commands such
 523        as 'git-blame' (in incremental mode), 'git-rev-list', 'git-log',
 524        and 'git-whatchanged' will force a flush of the output stream
 525        after each commit-oriented record have been flushed.   If this
 526        variable is set to "0", the output of these commands will be done
 527        using completely buffered I/O.   If this environment variable is
 528        not set, git will choose buffered or record-oriented flushing
 529        based on whether stdout appears to be redirected to a file or not.
 530
 531'GIT_TRACE'::
 532        If this variable is set to "1", "2" or "true" (comparison
 533        is case insensitive), git will print `trace:` messages on
 534        stderr telling about alias expansion, built-in command
 535        execution and external command execution.
 536        If this variable is set to an integer value greater than 1
 537        and lower than 10 (strictly) then git will interpret this
 538        value as an open file descriptor and will try to write the
 539        trace messages into this file descriptor.
 540        Alternatively, if this variable is set to an absolute path
 541        (starting with a '/' character), git will interpret this
 542        as a file path and will try to write the trace messages
 543        into it.
 544
 545Discussion[[Discussion]]
 546------------------------
 547
 548More detail on the following is available from the
 549link:user-manual.html#git-concepts[git concepts chapter of the
 550user-manual] and linkgit:gitcore-tutorial[7].
 551
 552A git project normally consists of a working directory with a ".git"
 553subdirectory at the top level.  The .git directory contains, among other
 554things, a compressed object database representing the complete history
 555of the project, an "index" file which links that history to the current
 556contents of the working tree, and named pointers into that history such
 557as tags and branch heads.
 558
 559The object database contains objects of three main types: blobs, which
 560hold file data; trees, which point to blobs and other trees to build up
 561directory hierarchies; and commits, which each reference a single tree
 562and some number of parent commits.
 563
 564The commit, equivalent to what other systems call a "changeset" or
 565"version", represents a step in the project's history, and each parent
 566represents an immediately preceding step.  Commits with more than one
 567parent represent merges of independent lines of development.
 568
 569All objects are named by the SHA1 hash of their contents, normally
 570written as a string of 40 hex digits.  Such names are globally unique.
 571The entire history leading up to a commit can be vouched for by signing
 572just that commit.  A fourth object type, the tag, is provided for this
 573purpose.
 574
 575When first created, objects are stored in individual files, but for
 576efficiency may later be compressed together into "pack files".
 577
 578Named pointers called refs mark interesting points in history.  A ref
 579may contain the SHA1 name of an object or the name of another ref.  Refs
 580with names beginning `ref/head/` contain the SHA1 name of the most
 581recent commit (or "head") of a branch under development.  SHA1 names of
 582tags of interest are stored under `ref/tags/`.  A special ref named
 583`HEAD` contains the name of the currently checked-out branch.
 584
 585The index file is initialized with a list of all paths and, for each
 586path, a blob object and a set of attributes.  The blob object represents
 587the contents of the file as of the head of the current branch.  The
 588attributes (last modified time, size, etc.) are taken from the
 589corresponding file in the working tree.  Subsequent changes to the
 590working tree can be found by comparing these attributes.  The index may
 591be updated with new content, and new commits may be created from the
 592content stored in the index.
 593
 594The index is also capable of storing multiple entries (called "stages")
 595for a given pathname.  These stages are used to hold the various
 596unmerged version of a file when a merge is in progress.
 597
 598Authors
 599-------
 600* git's founding father is Linus Torvalds <torvalds@osdl.org>.
 601* The current git nurse is Junio C Hamano <gitster@pobox.com>.
 602* The git potty was written by Andreas Ericsson <ae@op5.se>.
 603* General upbringing is handled by the git-list <git@vger.kernel.org>.
 604
 605Documentation
 606--------------
 607The documentation for git suite was started by David Greaves
 608<david@dgreaves.com>, and later enhanced greatly by the
 609contributors on the git-list <git@vger.kernel.org>.
 610
 611SEE ALSO
 612--------
 613linkgit:gittutorial[7], linkgit:gittutorial-2[7],
 614link:everyday.html[Everyday Git], linkgit:gitcvs-migration[7],
 615linkgit:gitglossary[7], linkgit:gitcore-tutorial[7],
 616linkgit:gitcli[7], link:user-manual.html[The Git User's Manual]
 617
 618GIT
 619---
 620Part of the linkgit:git[1] suite