Documentation / git.txton commit Merge branch 'mk/unpack-careful' (3c993de)
   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:v1.5.5/git.html[documentation for release 1.5.5]
  47
  48* release notes for
  49  link:RelNotes-1.5.5.txt[1.5.5].
  50
  51* link:v1.5.4.5/git.html[documentation for release 1.5.4.5]
  52
  53* release notes for
  54  link:RelNotes-1.5.4.5.txt[1.5.4.5],
  55  link:RelNotes-1.5.4.4.txt[1.5.4.4],
  56  link:RelNotes-1.5.4.3.txt[1.5.4.3],
  57  link:RelNotes-1.5.4.2.txt[1.5.4.2],
  58  link:RelNotes-1.5.4.1.txt[1.5.4.1],
  59  link:RelNotes-1.5.4.txt[1.5.4].
  60
  61* link:v1.5.3.8/git.html[documentation for release 1.5.3.8]
  62
  63* release notes for
  64  link:RelNotes-1.5.3.8.txt[1.5.3.8],
  65  link:RelNotes-1.5.3.7.txt[1.5.3.7],
  66  link:RelNotes-1.5.3.6.txt[1.5.3.6],
  67  link:RelNotes-1.5.3.5.txt[1.5.3.5],
  68  link:RelNotes-1.5.3.4.txt[1.5.3.4],
  69  link:RelNotes-1.5.3.3.txt[1.5.3.3],
  70  link:RelNotes-1.5.3.2.txt[1.5.3.2],
  71  link:RelNotes-1.5.3.1.txt[1.5.3.1],
  72  link:RelNotes-1.5.3.txt[1.5.3].
  73
  74* release notes for
  75  link:RelNotes-1.5.2.5.txt[1.5.2.5],
  76  link:RelNotes-1.5.2.4.txt[1.5.2.4],
  77  link:RelNotes-1.5.2.3.txt[1.5.2.3],
  78  link:RelNotes-1.5.2.2.txt[1.5.2.2],
  79  link:RelNotes-1.5.2.1.txt[1.5.2.1],
  80  link:RelNotes-1.5.2.txt[1.5.2].
  81
  82* link:v1.5.1.6/git.html[documentation for release 1.5.1.6]
  83
  84* release notes for
  85  link:RelNotes-1.5.1.6.txt[1.5.1.6],
  86  link:RelNotes-1.5.1.5.txt[1.5.1.5],
  87  link:RelNotes-1.5.1.4.txt[1.5.1.4],
  88  link:RelNotes-1.5.1.3.txt[1.5.1.3],
  89  link:RelNotes-1.5.1.2.txt[1.5.1.2],
  90  link:RelNotes-1.5.1.1.txt[1.5.1.1],
  91  link:RelNotes-1.5.1.txt[1.5.1].
  92
  93* link:v1.5.0.7/git.html[documentation for release 1.5.0.7]
  94
  95* release notes for
  96  link:RelNotes-1.5.0.7.txt[1.5.0.7],
  97  link:RelNotes-1.5.0.6.txt[1.5.0.6],
  98  link:RelNotes-1.5.0.5.txt[1.5.0.5],
  99  link:RelNotes-1.5.0.3.txt[1.5.0.3],
 100  link:RelNotes-1.5.0.2.txt[1.5.0.2],
 101  link:RelNotes-1.5.0.1.txt[1.5.0.1],
 102  link:RelNotes-1.5.0.txt[1.5.0].
 103
 104* documentation for release link:v1.4.4.4/git.html[1.4.4.4],
 105  link:v1.3.3/git.html[1.3.3],
 106  link:v1.2.6/git.html[1.2.6],
 107  link:v1.0.13/git.html[1.0.13].
 108
 109============
 110
 111endif::stalenotes[]
 112
 113OPTIONS
 114-------
 115--version::
 116        Prints the git suite version that the 'git' program came from.
 117
 118--help::
 119        Prints the synopsis and a list of the most commonly used
 120        commands. If the option '--all' or '-a' is given then all
 121        available commands are printed. If a git command is named this
 122        option will bring up the manual page for that command.
 123+
 124Other options are available to control how the manual page is
 125displayed. See linkgit:git-help[1] for more information,
 126because 'git --help ...' is converted internally into 'git
 127help ...'.
 128
 129--exec-path::
 130        Path to wherever your core git programs are installed.
 131        This can also be controlled by setting the GIT_EXEC_PATH
 132        environment variable. If no path is given 'git' will print
 133        the current setting and then exit.
 134
 135-p|--paginate::
 136        Pipe all output into 'less' (or if set, $PAGER).
 137
 138--no-pager::
 139        Do not pipe git output into a pager.
 140
 141--git-dir=<path>::
 142        Set the path to the repository. This can also be controlled by
 143        setting the GIT_DIR environment variable.
 144
 145--work-tree=<path>::
 146        Set the path to the working tree.  The value will not be
 147        used in combination with repositories found automatically in
 148        a .git directory (i.e. $GIT_DIR is not set).
 149        This can also be controlled by setting the GIT_WORK_TREE
 150        environment variable and the core.worktree configuration
 151        variable.
 152
 153--bare::
 154        Treat the repository as a bare repository.  If GIT_DIR
 155        environment is not set, it is set to the current working
 156        directory.
 157
 158
 159FURTHER DOCUMENTATION
 160---------------------
 161
 162See the references above to get started using git.  The following is
 163probably more detail than necessary for a first-time user.
 164
 165The link:user-manual.html#git-concepts[git concepts chapter of the
 166user-manual] and the link:core-tutorial.html[Core tutorial] both provide
 167introductions to the underlying git architecture.
 168
 169See also the link:howto-index.html[howto] documents for some useful
 170examples.
 171
 172The internals are documented link:technical/api-index.html[here].
 173
 174GIT COMMANDS
 175------------
 176
 177We divide git into high level ("porcelain") commands and low level
 178("plumbing") commands.
 179
 180High-level commands (porcelain)
 181-------------------------------
 182
 183We separate the porcelain commands into the main commands and some
 184ancillary user utilities.
 185
 186Main porcelain commands
 187~~~~~~~~~~~~~~~~~~~~~~~
 188
 189include::cmds-mainporcelain.txt[]
 190
 191Ancillary Commands
 192~~~~~~~~~~~~~~~~~~
 193Manipulators:
 194
 195include::cmds-ancillarymanipulators.txt[]
 196
 197Interrogators:
 198
 199include::cmds-ancillaryinterrogators.txt[]
 200
 201
 202Interacting with Others
 203~~~~~~~~~~~~~~~~~~~~~~~
 204
 205These commands are to interact with foreign SCM and with other
 206people via patch over e-mail.
 207
 208include::cmds-foreignscminterface.txt[]
 209
 210
 211Low-level commands (plumbing)
 212-----------------------------
 213
 214Although git includes its
 215own porcelain layer, its low-level commands are sufficient to support
 216development of alternative porcelains.  Developers of such porcelains
 217might start by reading about linkgit:git-update-index[1] and
 218linkgit:git-read-tree[1].
 219
 220The interface (input, output, set of options and the semantics)
 221to these low-level commands are meant to be a lot more stable
 222than Porcelain level commands, because these commands are
 223primarily for scripted use.  The interface to Porcelain commands
 224on the other hand are subject to change in order to improve the
 225end user experience.
 226
 227The following description divides
 228the low-level commands into commands that manipulate objects (in
 229the repository, index, and working tree), commands that interrogate and
 230compare objects, and commands that move objects and references between
 231repositories.
 232
 233
 234Manipulation commands
 235~~~~~~~~~~~~~~~~~~~~~
 236
 237include::cmds-plumbingmanipulators.txt[]
 238
 239
 240Interrogation commands
 241~~~~~~~~~~~~~~~~~~~~~~
 242
 243include::cmds-plumbinginterrogators.txt[]
 244
 245In general, the interrogate commands do not touch the files in
 246the working tree.
 247
 248
 249Synching repositories
 250~~~~~~~~~~~~~~~~~~~~~
 251
 252include::cmds-synchingrepositories.txt[]
 253
 254The following are helper programs used by the above; end users
 255typically do not use them directly.
 256
 257include::cmds-synchelpers.txt[]
 258
 259
 260Internal helper commands
 261~~~~~~~~~~~~~~~~~~~~~~~~
 262
 263These are internal helper commands used by other commands; end
 264users typically do not use them directly.
 265
 266include::cmds-purehelpers.txt[]
 267
 268
 269Configuration Mechanism
 270-----------------------
 271
 272Starting from 0.99.9 (actually mid 0.99.8.GIT), `.git/config` file
 273is used to hold per-repository configuration options.  It is a
 274simple text file modeled after `.ini` format familiar to some
 275people.  Here is an example:
 276
 277------------
 278#
 279# A '#' or ';' character indicates a comment.
 280#
 281
 282; core variables
 283[core]
 284        ; Don't trust file modes
 285        filemode = false
 286
 287; user identity
 288[user]
 289        name = "Junio C Hamano"
 290        email = "junkio@twinsun.com"
 291
 292------------
 293
 294Various commands read from the configuration file and adjust
 295their operation accordingly.
 296
 297
 298Identifier Terminology
 299----------------------
 300<object>::
 301        Indicates the object name for any type of object.
 302
 303<blob>::
 304        Indicates a blob object name.
 305
 306<tree>::
 307        Indicates a tree object name.
 308
 309<commit>::
 310        Indicates a commit object name.
 311
 312<tree-ish>::
 313        Indicates a tree, commit or tag object name.  A
 314        command that takes a <tree-ish> argument ultimately wants to
 315        operate on a <tree> object but automatically dereferences
 316        <commit> and <tag> objects that point at a <tree>.
 317
 318<commit-ish>::
 319        Indicates a commit or tag object name.  A
 320        command that takes a <commit-ish> argument ultimately wants to
 321        operate on a <commit> object but automatically dereferences
 322        <tag> objects that point at a <commit>.
 323
 324<type>::
 325        Indicates that an object type is required.
 326        Currently one of: `blob`, `tree`, `commit`, or `tag`.
 327
 328<file>::
 329        Indicates a filename - almost always relative to the
 330        root of the tree structure `GIT_INDEX_FILE` describes.
 331
 332Symbolic Identifiers
 333--------------------
 334Any git command accepting any <object> can also use the following
 335symbolic notation:
 336
 337HEAD::
 338        indicates the head of the current branch (i.e. the
 339        contents of `$GIT_DIR/HEAD`).
 340
 341<tag>::
 342        a valid tag 'name'
 343        (i.e. the contents of `$GIT_DIR/refs/tags/<tag>`).
 344
 345<head>::
 346        a valid head 'name'
 347        (i.e. the contents of `$GIT_DIR/refs/heads/<head>`).
 348
 349For a more complete list of ways to spell object names, see
 350"SPECIFYING REVISIONS" section in linkgit:git-rev-parse[1].
 351
 352
 353File/Directory Structure
 354------------------------
 355
 356Please see the link:repository-layout.html[repository layout] document.
 357
 358Read link:hooks.html[hooks] for more details about each hook.
 359
 360Higher level SCMs may provide and manage additional information in the
 361`$GIT_DIR`.
 362
 363
 364Terminology
 365-----------
 366Please see the link:glossary.html[glossary] document.
 367
 368
 369Environment Variables
 370---------------------
 371Various git commands use the following environment variables:
 372
 373The git Repository
 374~~~~~~~~~~~~~~~~~~
 375These environment variables apply to 'all' core git commands. Nb: it
 376is worth noting that they may be used/overridden by SCMS sitting above
 377git so take care if using Cogito etc.
 378
 379'GIT_INDEX_FILE'::
 380        This environment allows the specification of an alternate
 381        index file. If not specified, the default of `$GIT_DIR/index`
 382        is used.
 383
 384'GIT_OBJECT_DIRECTORY'::
 385        If the object storage directory is specified via this
 386        environment variable then the sha1 directories are created
 387        underneath - otherwise the default `$GIT_DIR/objects`
 388        directory is used.
 389
 390'GIT_ALTERNATE_OBJECT_DIRECTORIES'::
 391        Due to the immutable nature of git objects, old objects can be
 392        archived into shared, read-only directories. This variable
 393        specifies a ":" separated list of git object directories which
 394        can be used to search for git objects. New objects will not be
 395        written to these directories.
 396
 397'GIT_DIR'::
 398        If the 'GIT_DIR' environment variable is set then it
 399        specifies a path to use instead of the default `.git`
 400        for the base of the repository.
 401
 402'GIT_WORK_TREE'::
 403        Set the path to the working tree.  The value will not be
 404        used in combination with repositories found automatically in
 405        a .git directory (i.e. $GIT_DIR is not set).
 406        This can also be controlled by the '--work-tree' command line
 407        option and the core.worktree configuration variable.
 408
 409git Commits
 410~~~~~~~~~~~
 411'GIT_AUTHOR_NAME'::
 412'GIT_AUTHOR_EMAIL'::
 413'GIT_AUTHOR_DATE'::
 414'GIT_COMMITTER_NAME'::
 415'GIT_COMMITTER_EMAIL'::
 416'GIT_COMMITTER_DATE'::
 417'EMAIL'::
 418        see linkgit:git-commit-tree[1]
 419
 420git Diffs
 421~~~~~~~~~
 422'GIT_DIFF_OPTS'::
 423        Only valid setting is "--unified=??" or "-u??" to set the
 424        number of context lines shown when a unified diff is created.
 425        This takes precedence over any "-U" or "--unified" option
 426        value passed on the git diff command line.
 427
 428'GIT_EXTERNAL_DIFF'::
 429        When the environment variable 'GIT_EXTERNAL_DIFF' is set, the
 430        program named by it is called, instead of the diff invocation
 431        described above.  For a path that is added, removed, or modified,
 432        'GIT_EXTERNAL_DIFF' is called with 7 parameters:
 433
 434        path old-file old-hex old-mode new-file new-hex new-mode
 435+
 436where:
 437
 438        <old|new>-file:: are files GIT_EXTERNAL_DIFF can use to read the
 439                         contents of <old|new>,
 440        <old|new>-hex:: are the 40-hexdigit SHA1 hashes,
 441        <old|new>-mode:: are the octal representation of the file modes.
 442
 443+
 444The file parameters can point at the user's working file
 445(e.g. `new-file` in "git-diff-files"), `/dev/null` (e.g. `old-file`
 446when a new file is added), or a temporary file (e.g. `old-file` in the
 447index).  'GIT_EXTERNAL_DIFF' should not worry about unlinking the
 448temporary file --- it is removed when 'GIT_EXTERNAL_DIFF' exits.
 449+
 450For a path that is unmerged, 'GIT_EXTERNAL_DIFF' is called with 1
 451parameter, <path>.
 452
 453other
 454~~~~~
 455'GIT_MERGE_VERBOSITY'::
 456        A number controlling the amount of output shown by
 457        the recursive merge strategy.  Overrides merge.verbosity.
 458        See linkgit:git-merge[1]
 459
 460'GIT_PAGER'::
 461        This environment variable overrides `$PAGER`. If it is set
 462        to an empty string or to the value "cat", git will not launch
 463        a pager.
 464
 465'GIT_SSH'::
 466        If this environment variable is set then linkgit:git-fetch[1]
 467        and linkgit:git-push[1] will use this command instead
 468        of `ssh` when they need to connect to a remote system.
 469        The 'GIT_SSH' command will be given exactly two arguments:
 470        the 'username@host' (or just 'host') from the URL and the
 471        shell command to execute on that remote system.
 472+
 473To pass options to the program that you want to list in GIT_SSH
 474you will need to wrap the program and options into a shell script,
 475then set GIT_SSH to refer to the shell script.
 476+
 477Usually it is easier to configure any desired options through your
 478personal `.ssh/config` file.  Please consult your ssh documentation
 479for further details.
 480
 481'GIT_FLUSH'::
 482        If this environment variable is set to "1", then commands such
 483        as git-blame (in incremental mode), git-rev-list, git-log,
 484        git-whatchanged, etc., will force a flush of the output stream
 485        after each commit-oriented record have been flushed.   If this
 486        variable is set to "0", the output of these commands will be done
 487        using completely buffered I/O.   If this environment variable is
 488        not set, git will choose buffered or record-oriented flushing
 489        based on whether stdout appears to be redirected to a file or not.
 490
 491'GIT_TRACE'::
 492        If this variable is set to "1", "2" or "true" (comparison
 493        is case insensitive), git will print `trace:` messages on
 494        stderr telling about alias expansion, built-in command
 495        execution and external command execution.
 496        If this variable is set to an integer value greater than 1
 497        and lower than 10 (strictly) then git will interpret this
 498        value as an open file descriptor and will try to write the
 499        trace messages into this file descriptor.
 500        Alternatively, if this variable is set to an absolute path
 501        (starting with a '/' character), git will interpret this
 502        as a file path and will try to write the trace messages
 503        into it.
 504
 505Discussion[[Discussion]]
 506------------------------
 507
 508More detail on the following is available from the
 509link:user-manual.html#git-concepts[git concepts chapter of the
 510user-manual] and the link:core-tutorial.html[Core tutorial].
 511
 512A git project normally consists of a working directory with a ".git"
 513subdirectory at the top level.  The .git directory contains, among other
 514things, a compressed object database representing the complete history
 515of the project, an "index" file which links that history to the current
 516contents of the working tree, and named pointers into that history such
 517as tags and branch heads.
 518
 519The object database contains objects of three main types: blobs, which
 520hold file data; trees, which point to blobs and other trees to build up
 521directory hierarchies; and commits, which each reference a single tree
 522and some number of parent commits.
 523
 524The commit, equivalent to what other systems call a "changeset" or
 525"version", represents a step in the project's history, and each parent
 526represents an immediately preceding step.  Commits with more than one
 527parent represent merges of independent lines of development.
 528
 529All objects are named by the SHA1 hash of their contents, normally
 530written as a string of 40 hex digits.  Such names are globally unique.
 531The entire history leading up to a commit can be vouched for by signing
 532just that commit.  A fourth object type, the tag, is provided for this
 533purpose.
 534
 535When first created, objects are stored in individual files, but for
 536efficiency may later be compressed together into "pack files".
 537
 538Named pointers called refs mark interesting points in history.  A ref
 539may contain the SHA1 name of an object or the name of another ref.  Refs
 540with names beginning `ref/head/` contain the SHA1 name of the most
 541recent commit (or "head") of a branch under development.  SHA1 names of
 542tags of interest are stored under `ref/tags/`.  A special ref named
 543`HEAD` contains the name of the currently checked-out branch.
 544
 545The index file is initialized with a list of all paths and, for each
 546path, a blob object and a set of attributes.  The blob object represents
 547the contents of the file as of the head of the current branch.  The
 548attributes (last modified time, size, etc.) are taken from the
 549corresponding file in the working tree.  Subsequent changes to the
 550working tree can be found by comparing these attributes.  The index may
 551be updated with new content, and new commits may be created from the
 552content stored in the index.
 553
 554The index is also capable of storing multiple entries (called "stages")
 555for a given pathname.  These stages are used to hold the various
 556unmerged version of a file when a merge is in progress.
 557
 558Authors
 559-------
 560* git's founding father is Linus Torvalds <torvalds@osdl.org>.
 561* The current git nurse is Junio C Hamano <gitster@pobox.com>.
 562* The git potty was written by Andreas Ericsson <ae@op5.se>.
 563* General upbringing is handled by the git-list <git@vger.kernel.org>.
 564
 565Documentation
 566--------------
 567The documentation for git suite was started by David Greaves
 568<david@dgreaves.com>, and later enhanced greatly by the
 569contributors on the git-list <git@vger.kernel.org>.
 570
 571GIT
 572---
 573Part of the linkgit:git[7] suite