Documentation / git.txton commit Merge branch 'ph/describe-match' (3960a95)
   1git(7)
   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 this link:tutorial.html[tutorial] 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 link:cvs-migration.html[CVS migration].  See
  27link: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:v1.5.4/git.html[documentation for release 1.5.4]
  47
  48* release notes for
  49  link:RelNotes-1.5.4.txt[1.5.4].
  50
  51* link:v1.5.3.8/git.html[documentation for release 1.5.3.8]
  52
  53* release notes for
  54  link:RelNotes-1.5.3.8.txt[1.5.3.8],
  55  link:RelNotes-1.5.3.7.txt[1.5.3.7],
  56  link:RelNotes-1.5.3.6.txt[1.5.3.6],
  57  link:RelNotes-1.5.3.5.txt[1.5.3.5],
  58  link:RelNotes-1.5.3.4.txt[1.5.3.4],
  59  link:RelNotes-1.5.3.3.txt[1.5.3.3],
  60  link:RelNotes-1.5.3.2.txt[1.5.3.2],
  61  link:RelNotes-1.5.3.1.txt[1.5.3.1],
  62  link:RelNotes-1.5.3.txt[1.5.3].
  63
  64* release notes for
  65  link:RelNotes-1.5.2.5.txt[1.5.2.5],
  66  link:RelNotes-1.5.2.4.txt[1.5.2.4],
  67  link:RelNotes-1.5.2.3.txt[1.5.2.3],
  68  link:RelNotes-1.5.2.2.txt[1.5.2.2],
  69  link:RelNotes-1.5.2.1.txt[1.5.2.1],
  70  link:RelNotes-1.5.2.txt[1.5.2].
  71
  72* link:v1.5.1.6/git.html[documentation for release 1.5.1.6]
  73
  74* release notes for
  75  link:RelNotes-1.5.1.6.txt[1.5.1.6],
  76  link:RelNotes-1.5.1.5.txt[1.5.1.5],
  77  link:RelNotes-1.5.1.4.txt[1.5.1.4],
  78  link:RelNotes-1.5.1.3.txt[1.5.1.3],
  79  link:RelNotes-1.5.1.2.txt[1.5.1.2],
  80  link:RelNotes-1.5.1.1.txt[1.5.1.1],
  81  link:RelNotes-1.5.1.txt[1.5.1].
  82
  83* link:v1.5.0.7/git.html[documentation for release 1.5.0.7]
  84
  85* release notes for
  86  link:RelNotes-1.5.0.7.txt[1.5.0.7],
  87  link:RelNotes-1.5.0.6.txt[1.5.0.6],
  88  link:RelNotes-1.5.0.5.txt[1.5.0.5],
  89  link:RelNotes-1.5.0.3.txt[1.5.0.3],
  90  link:RelNotes-1.5.0.2.txt[1.5.0.2],
  91  link:RelNotes-1.5.0.1.txt[1.5.0.1],
  92  link:RelNotes-1.5.0.txt[1.5.0].
  93
  94* documentation for release link:v1.4.4.4/git.html[1.4.4.4],
  95  link:v1.3.3/git.html[1.3.3],
  96  link:v1.2.6/git.html[1.2.6],
  97  link:v1.0.13/git.html[1.0.13].
  98
  99============
 100
 101endif::stalenotes[]
 102
 103OPTIONS
 104-------
 105--version::
 106        Prints the git suite version that the 'git' program came from.
 107
 108--help::
 109        Prints the synopsis and a list of the most commonly used
 110        commands. If the option '--all' or '-a' is given then all
 111        available commands are printed. If a git command is named this
 112        option will bring up the manual page for that command.
 113+
 114Other options are available to control how the manual page is
 115displayed. See linkgit:git-help[1] for more information,
 116because 'git --help ...' is converted internally into 'git
 117help ...'.
 118
 119--exec-path::
 120        Path to wherever your core git programs are installed.
 121        This can also be controlled by setting the GIT_EXEC_PATH
 122        environment variable. If no path is given 'git' will print
 123        the current setting and then exit.
 124
 125-p|--paginate::
 126        Pipe all output into 'less' (or if set, $PAGER).
 127
 128--no-pager::
 129        Do not pipe git output into a pager.
 130
 131--git-dir=<path>::
 132        Set the path to the repository. This can also be controlled by
 133        setting the GIT_DIR environment variable.
 134
 135--work-tree=<path>::
 136        Set the path to the working tree.  The value will not be
 137        used in combination with repositories found automatically in
 138        a .git directory (i.e. $GIT_DIR is not set).
 139        This can also be controlled by setting the GIT_WORK_TREE
 140        environment variable and the core.worktree configuration
 141        variable.
 142
 143--bare::
 144        Treat the repository as a bare repository.  If GIT_DIR
 145        environment is not set, it is set to the current working
 146        directory.
 147
 148
 149FURTHER DOCUMENTATION
 150---------------------
 151
 152See the references above to get started using git.  The following is
 153probably more detail than necessary for a first-time user.
 154
 155The link:user-manual.html#git-concepts[git concepts chapter of the
 156user-manual] and the link:core-tutorial.html[Core tutorial] both provide
 157introductions to the underlying git architecture.
 158
 159See also the link:howto-index.html[howto] documents for some useful
 160examples.
 161
 162The internals are documented link:technical/api-index.html[here].
 163
 164GIT COMMANDS
 165------------
 166
 167We divide git into high level ("porcelain") commands and low level
 168("plumbing") commands.
 169
 170High-level commands (porcelain)
 171-------------------------------
 172
 173We separate the porcelain commands into the main commands and some
 174ancillary user utilities.
 175
 176Main porcelain commands
 177~~~~~~~~~~~~~~~~~~~~~~~
 178
 179include::cmds-mainporcelain.txt[]
 180
 181Ancillary Commands
 182~~~~~~~~~~~~~~~~~~
 183Manipulators:
 184
 185include::cmds-ancillarymanipulators.txt[]
 186
 187Interrogators:
 188
 189include::cmds-ancillaryinterrogators.txt[]
 190
 191
 192Interacting with Others
 193~~~~~~~~~~~~~~~~~~~~~~~
 194
 195These commands are to interact with foreign SCM and with other
 196people via patch over e-mail.
 197
 198include::cmds-foreignscminterface.txt[]
 199
 200
 201Low-level commands (plumbing)
 202-----------------------------
 203
 204Although git includes its
 205own porcelain layer, its low-level commands are sufficient to support
 206development of alternative porcelains.  Developers of such porcelains
 207might start by reading about linkgit:git-update-index[1] and
 208linkgit:git-read-tree[1].
 209
 210The interface (input, output, set of options and the semantics)
 211to these low-level commands are meant to be a lot more stable
 212than Porcelain level commands, because these commands are
 213primarily for scripted use.  The interface to Porcelain commands
 214on the other hand are subject to change in order to improve the
 215end user experience.
 216
 217The following description divides
 218the low-level commands into commands that manipulate objects (in
 219the repository, index, and working tree), commands that interrogate and
 220compare objects, and commands that move objects and references between
 221repositories.
 222
 223
 224Manipulation commands
 225~~~~~~~~~~~~~~~~~~~~~
 226
 227include::cmds-plumbingmanipulators.txt[]
 228
 229
 230Interrogation commands
 231~~~~~~~~~~~~~~~~~~~~~~
 232
 233include::cmds-plumbinginterrogators.txt[]
 234
 235In general, the interrogate commands do not touch the files in
 236the working tree.
 237
 238
 239Synching repositories
 240~~~~~~~~~~~~~~~~~~~~~
 241
 242include::cmds-synchingrepositories.txt[]
 243
 244The following are helper programs used by the above; end users
 245typically do not use them directly.
 246
 247include::cmds-synchelpers.txt[]
 248
 249
 250Internal helper commands
 251~~~~~~~~~~~~~~~~~~~~~~~~
 252
 253These are internal helper commands used by other commands; end
 254users typically do not use them directly.
 255
 256include::cmds-purehelpers.txt[]
 257
 258
 259Configuration Mechanism
 260-----------------------
 261
 262Starting from 0.99.9 (actually mid 0.99.8.GIT), `.git/config` file
 263is used to hold per-repository configuration options.  It is a
 264simple text file modeled after `.ini` format familiar to some
 265people.  Here is an example:
 266
 267------------
 268#
 269# A '#' or ';' character indicates a comment.
 270#
 271
 272; core variables
 273[core]
 274        ; Don't trust file modes
 275        filemode = false
 276
 277; user identity
 278[user]
 279        name = "Junio C Hamano"
 280        email = "junkio@twinsun.com"
 281
 282------------
 283
 284Various commands read from the configuration file and adjust
 285their operation accordingly.
 286
 287
 288Identifier Terminology
 289----------------------
 290<object>::
 291        Indicates the object name for any type of object.
 292
 293<blob>::
 294        Indicates a blob object name.
 295
 296<tree>::
 297        Indicates a tree object name.
 298
 299<commit>::
 300        Indicates a commit object name.
 301
 302<tree-ish>::
 303        Indicates a tree, commit or tag object name.  A
 304        command that takes a <tree-ish> argument ultimately wants to
 305        operate on a <tree> object but automatically dereferences
 306        <commit> and <tag> objects that point at a <tree>.
 307
 308<commit-ish>::
 309        Indicates a commit or tag object name.  A
 310        command that takes a <commit-ish> argument ultimately wants to
 311        operate on a <commit> object but automatically dereferences
 312        <tag> objects that point at a <commit>.
 313
 314<type>::
 315        Indicates that an object type is required.
 316        Currently one of: `blob`, `tree`, `commit`, or `tag`.
 317
 318<file>::
 319        Indicates a filename - almost always relative to the
 320        root of the tree structure `GIT_INDEX_FILE` describes.
 321
 322Symbolic Identifiers
 323--------------------
 324Any git command accepting any <object> can also use the following
 325symbolic notation:
 326
 327HEAD::
 328        indicates the head of the current branch (i.e. the
 329        contents of `$GIT_DIR/HEAD`).
 330
 331<tag>::
 332        a valid tag 'name'
 333        (i.e. the contents of `$GIT_DIR/refs/tags/<tag>`).
 334
 335<head>::
 336        a valid head 'name'
 337        (i.e. the contents of `$GIT_DIR/refs/heads/<head>`).
 338
 339For a more complete list of ways to spell object names, see
 340"SPECIFYING REVISIONS" section in linkgit:git-rev-parse[1].
 341
 342
 343File/Directory Structure
 344------------------------
 345
 346Please see the link:repository-layout.html[repository layout] document.
 347
 348Read link:hooks.html[hooks] for more details about each hook.
 349
 350Higher level SCMs may provide and manage additional information in the
 351`$GIT_DIR`.
 352
 353
 354Terminology
 355-----------
 356Please see the link:glossary.html[glossary] document.
 357
 358
 359Environment Variables
 360---------------------
 361Various git commands use the following environment variables:
 362
 363The git Repository
 364~~~~~~~~~~~~~~~~~~
 365These environment variables apply to 'all' core git commands. Nb: it
 366is worth noting that they may be used/overridden by SCMS sitting above
 367git so take care if using Cogito etc.
 368
 369'GIT_INDEX_FILE'::
 370        This environment allows the specification of an alternate
 371        index file. If not specified, the default of `$GIT_DIR/index`
 372        is used.
 373
 374'GIT_OBJECT_DIRECTORY'::
 375        If the object storage directory is specified via this
 376        environment variable then the sha1 directories are created
 377        underneath - otherwise the default `$GIT_DIR/objects`
 378        directory is used.
 379
 380'GIT_ALTERNATE_OBJECT_DIRECTORIES'::
 381        Due to the immutable nature of git objects, old objects can be
 382        archived into shared, read-only directories. This variable
 383        specifies a ":" separated list of git object directories which
 384        can be used to search for git objects. New objects will not be
 385        written to these directories.
 386
 387'GIT_DIR'::
 388        If the 'GIT_DIR' environment variable is set then it
 389        specifies a path to use instead of the default `.git`
 390        for the base of the repository.
 391
 392'GIT_WORK_TREE'::
 393        Set the path to the working tree.  The value will not be
 394        used in combination with repositories found automatically in
 395        a .git directory (i.e. $GIT_DIR is not set).
 396        This can also be controlled by the '--work-tree' command line
 397        option and the core.worktree configuration variable.
 398
 399git Commits
 400~~~~~~~~~~~
 401'GIT_AUTHOR_NAME'::
 402'GIT_AUTHOR_EMAIL'::
 403'GIT_AUTHOR_DATE'::
 404'GIT_COMMITTER_NAME'::
 405'GIT_COMMITTER_EMAIL'::
 406'GIT_COMMITTER_DATE'::
 407'EMAIL'::
 408        see linkgit:git-commit-tree[1]
 409
 410git Diffs
 411~~~~~~~~~
 412'GIT_DIFF_OPTS'::
 413        Only valid setting is "--unified=??" or "-u??" to set the
 414        number of context lines shown when a unified diff is created.
 415        This takes precedence over any "-U" or "--unified" option
 416        value passed on the git diff command line.
 417
 418'GIT_EXTERNAL_DIFF'::
 419        When the environment variable 'GIT_EXTERNAL_DIFF' is set, the
 420        program named by it is called, instead of the diff invocation
 421        described above.  For a path that is added, removed, or modified,
 422        'GIT_EXTERNAL_DIFF' is called with 7 parameters:
 423
 424        path old-file old-hex old-mode new-file new-hex new-mode
 425+
 426where:
 427
 428        <old|new>-file:: are files GIT_EXTERNAL_DIFF can use to read the
 429                         contents of <old|new>,
 430        <old|new>-hex:: are the 40-hexdigit SHA1 hashes,
 431        <old|new>-mode:: are the octal representation of the file modes.
 432
 433+
 434The file parameters can point at the user's working file
 435(e.g. `new-file` in "git-diff-files"), `/dev/null` (e.g. `old-file`
 436when a new file is added), or a temporary file (e.g. `old-file` in the
 437index).  'GIT_EXTERNAL_DIFF' should not worry about unlinking the
 438temporary file --- it is removed when 'GIT_EXTERNAL_DIFF' exits.
 439+
 440For a path that is unmerged, 'GIT_EXTERNAL_DIFF' is called with 1
 441parameter, <path>.
 442
 443other
 444~~~~~
 445'GIT_MERGE_VERBOSITY'::
 446        A number controlling the amount of output shown by
 447        the recursive merge strategy.  Overrides merge.verbosity.
 448        See linkgit:git-merge[1]
 449
 450'GIT_PAGER'::
 451        This environment variable overrides `$PAGER`. If it is set
 452        to an empty string or to the value "cat", git will not launch
 453        a pager.
 454
 455'GIT_SSH'::
 456        If this environment variable is set then linkgit:git-fetch[1]
 457        and linkgit:git-push[1] will use this command instead
 458        of `ssh` when they need to connect to a remote system.
 459        The 'GIT_SSH' command will be given exactly two arguments:
 460        the 'username@host' (or just 'host') from the URL and the
 461        shell command to execute on that remote system.
 462+
 463To pass options to the program that you want to list in GIT_SSH
 464you will need to wrap the program and options into a shell script,
 465then set GIT_SSH to refer to the shell script.
 466+
 467Usually it is easier to configure any desired options through your
 468personal `.ssh/config` file.  Please consult your ssh documentation
 469for further details.
 470
 471'GIT_FLUSH'::
 472        If this environment variable is set to "1", then commands such
 473        as git-blame (in incremental mode), git-rev-list, git-log,
 474        git-whatchanged, etc., will force a flush of the output stream
 475        after each commit-oriented record have been flushed.   If this
 476        variable is set to "0", the output of these commands will be done
 477        using completely buffered I/O.   If this environment variable is
 478        not set, git will choose buffered or record-oriented flushing
 479        based on whether stdout appears to be redirected to a file or not.
 480
 481'GIT_TRACE'::
 482        If this variable is set to "1", "2" or "true" (comparison
 483        is case insensitive), git will print `trace:` messages on
 484        stderr telling about alias expansion, built-in command
 485        execution and external command execution.
 486        If this variable is set to an integer value greater than 1
 487        and lower than 10 (strictly) then git will interpret this
 488        value as an open file descriptor and will try to write the
 489        trace messages into this file descriptor.
 490        Alternatively, if this variable is set to an absolute path
 491        (starting with a '/' character), git will interpret this
 492        as a file path and will try to write the trace messages
 493        into it.
 494
 495Discussion[[Discussion]]
 496------------------------
 497
 498More detail on the following is available from the
 499link:user-manual.html#git-concepts[git concepts chapter of the
 500user-manual] and the link:core-tutorial.html[Core tutorial].
 501
 502A git project normally consists of a working directory with a ".git"
 503subdirectory at the top level.  The .git directory contains, among other
 504things, a compressed object database representing the complete history
 505of the project, an "index" file which links that history to the current
 506contents of the working tree, and named pointers into that history such
 507as tags and branch heads.
 508
 509The object database contains objects of three main types: blobs, which
 510hold file data; trees, which point to blobs and other trees to build up
 511directory hierarchies; and commits, which each reference a single tree
 512and some number of parent commits.
 513
 514The commit, equivalent to what other systems call a "changeset" or
 515"version", represents a step in the project's history, and each parent
 516represents an immediately preceding step.  Commits with more than one
 517parent represent merges of independent lines of development.
 518
 519All objects are named by the SHA1 hash of their contents, normally
 520written as a string of 40 hex digits.  Such names are globally unique.
 521The entire history leading up to a commit can be vouched for by signing
 522just that commit.  A fourth object type, the tag, is provided for this
 523purpose.
 524
 525When first created, objects are stored in individual files, but for
 526efficiency may later be compressed together into "pack files".
 527
 528Named pointers called refs mark interesting points in history.  A ref
 529may contain the SHA1 name of an object or the name of another ref.  Refs
 530with names beginning `ref/head/` contain the SHA1 name of the most
 531recent commit (or "head") of a branch under development.  SHA1 names of
 532tags of interest are stored under `ref/tags/`.  A special ref named
 533`HEAD` contains the name of the currently checked-out branch.
 534
 535The index file is initialized with a list of all paths and, for each
 536path, a blob object and a set of attributes.  The blob object represents
 537the contents of the file as of the head of the current branch.  The
 538attributes (last modified time, size, etc.) are taken from the
 539corresponding file in the working tree.  Subsequent changes to the
 540working tree can be found by comparing these attributes.  The index may
 541be updated with new content, and new commits may be created from the
 542content stored in the index.
 543
 544The index is also capable of storing multiple entries (called "stages")
 545for a given pathname.  These stages are used to hold the various
 546unmerged version of a file when a merge is in progress.
 547
 548Authors
 549-------
 550* git's founding father is Linus Torvalds <torvalds@osdl.org>.
 551* The current git nurse is Junio C Hamano <gitster@pobox.com>.
 552* The git potty was written by Andreas Ericsson <ae@op5.se>.
 553* General upbringing is handled by the git-list <git@vger.kernel.org>.
 554
 555Documentation
 556--------------
 557The documentation for git suite was started by David Greaves
 558<david@dgreaves.com>, and later enhanced greatly by the
 559contributors on the git-list <git@vger.kernel.org>.
 560
 561GIT
 562---
 563Part of the linkgit:git[7] suite