Documentation / git.txton commit diff-files: careful when inspecting work tree items (f58dbf2)
   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:v1.5.4.5/git.html[documentation for release 1.5.4.5]
  47
  48* release notes for
  49  link:RelNotes-1.5.4.5.txt[1.5.4.5],
  50  link:RelNotes-1.5.4.4.txt[1.5.4.4],
  51  link:RelNotes-1.5.4.3.txt[1.5.4.3],
  52  link:RelNotes-1.5.4.2.txt[1.5.4.2],
  53  link:RelNotes-1.5.4.1.txt[1.5.4.1],
  54  link:RelNotes-1.5.4.txt[1.5.4].
  55
  56* link:v1.5.3.8/git.html[documentation for release 1.5.3.8]
  57
  58* release notes for
  59  link:RelNotes-1.5.3.8.txt[1.5.3.8],
  60  link:RelNotes-1.5.3.7.txt[1.5.3.7],
  61  link:RelNotes-1.5.3.6.txt[1.5.3.6],
  62  link:RelNotes-1.5.3.5.txt[1.5.3.5],
  63  link:RelNotes-1.5.3.4.txt[1.5.3.4],
  64  link:RelNotes-1.5.3.3.txt[1.5.3.3],
  65  link:RelNotes-1.5.3.2.txt[1.5.3.2],
  66  link:RelNotes-1.5.3.1.txt[1.5.3.1],
  67  link:RelNotes-1.5.3.txt[1.5.3].
  68
  69* release notes for
  70  link:RelNotes-1.5.2.5.txt[1.5.2.5],
  71  link:RelNotes-1.5.2.4.txt[1.5.2.4],
  72  link:RelNotes-1.5.2.3.txt[1.5.2.3],
  73  link:RelNotes-1.5.2.2.txt[1.5.2.2],
  74  link:RelNotes-1.5.2.1.txt[1.5.2.1],
  75  link:RelNotes-1.5.2.txt[1.5.2].
  76
  77* link:v1.5.1.6/git.html[documentation for release 1.5.1.6]
  78
  79* release notes for
  80  link:RelNotes-1.5.1.6.txt[1.5.1.6],
  81  link:RelNotes-1.5.1.5.txt[1.5.1.5],
  82  link:RelNotes-1.5.1.4.txt[1.5.1.4],
  83  link:RelNotes-1.5.1.3.txt[1.5.1.3],
  84  link:RelNotes-1.5.1.2.txt[1.5.1.2],
  85  link:RelNotes-1.5.1.1.txt[1.5.1.1],
  86  link:RelNotes-1.5.1.txt[1.5.1].
  87
  88* link:v1.5.0.7/git.html[documentation for release 1.5.0.7]
  89
  90* release notes for
  91  link:RelNotes-1.5.0.7.txt[1.5.0.7],
  92  link:RelNotes-1.5.0.6.txt[1.5.0.6],
  93  link:RelNotes-1.5.0.5.txt[1.5.0.5],
  94  link:RelNotes-1.5.0.3.txt[1.5.0.3],
  95  link:RelNotes-1.5.0.2.txt[1.5.0.2],
  96  link:RelNotes-1.5.0.1.txt[1.5.0.1],
  97  link:RelNotes-1.5.0.txt[1.5.0].
  98
  99* documentation for release link:v1.4.4.4/git.html[1.4.4.4],
 100  link:v1.3.3/git.html[1.3.3],
 101  link:v1.2.6/git.html[1.2.6],
 102  link:v1.0.13/git.html[1.0.13].
 103
 104============
 105
 106endif::stalenotes[]
 107
 108OPTIONS
 109-------
 110--version::
 111        Prints the git suite version that the 'git' program came from.
 112
 113--help::
 114        Prints the synopsis and a list of the most commonly used
 115        commands. If the option '--all' or '-a' is given then all
 116        available commands are printed. If a git command is named this
 117        option will bring up the manual page for that command.
 118+
 119Other options are available to control how the manual page is
 120displayed. See linkgit:git-help[1] for more information,
 121because 'git --help ...' is converted internally into 'git
 122help ...'.
 123
 124--exec-path::
 125        Path to wherever your core git programs are installed.
 126        This can also be controlled by setting the GIT_EXEC_PATH
 127        environment variable. If no path is given 'git' will print
 128        the current setting and then exit.
 129
 130-p|--paginate::
 131        Pipe all output into 'less' (or if set, $PAGER).
 132
 133--no-pager::
 134        Do not pipe git output into a pager.
 135
 136--git-dir=<path>::
 137        Set the path to the repository. This can also be controlled by
 138        setting the GIT_DIR environment variable.
 139
 140--work-tree=<path>::
 141        Set the path to the working tree.  The value will not be
 142        used in combination with repositories found automatically in
 143        a .git directory (i.e. $GIT_DIR is not set).
 144        This can also be controlled by setting the GIT_WORK_TREE
 145        environment variable and the core.worktree configuration
 146        variable.
 147
 148--bare::
 149        Treat the repository as a bare repository.  If GIT_DIR
 150        environment is not set, it is set to the current working
 151        directory.
 152
 153
 154FURTHER DOCUMENTATION
 155---------------------
 156
 157See the references above to get started using git.  The following is
 158probably more detail than necessary for a first-time user.
 159
 160The link:user-manual.html#git-concepts[git concepts chapter of the
 161user-manual] and the link:core-tutorial.html[Core tutorial] both provide
 162introductions to the underlying git architecture.
 163
 164See also the link:howto-index.html[howto] documents for some useful
 165examples.
 166
 167The internals are documented link:technical/api-index.html[here].
 168
 169GIT COMMANDS
 170------------
 171
 172We divide git into high level ("porcelain") commands and low level
 173("plumbing") commands.
 174
 175High-level commands (porcelain)
 176-------------------------------
 177
 178We separate the porcelain commands into the main commands and some
 179ancillary user utilities.
 180
 181Main porcelain commands
 182~~~~~~~~~~~~~~~~~~~~~~~
 183
 184include::cmds-mainporcelain.txt[]
 185
 186Ancillary Commands
 187~~~~~~~~~~~~~~~~~~
 188Manipulators:
 189
 190include::cmds-ancillarymanipulators.txt[]
 191
 192Interrogators:
 193
 194include::cmds-ancillaryinterrogators.txt[]
 195
 196
 197Interacting with Others
 198~~~~~~~~~~~~~~~~~~~~~~~
 199
 200These commands are to interact with foreign SCM and with other
 201people via patch over e-mail.
 202
 203include::cmds-foreignscminterface.txt[]
 204
 205
 206Low-level commands (plumbing)
 207-----------------------------
 208
 209Although git includes its
 210own porcelain layer, its low-level commands are sufficient to support
 211development of alternative porcelains.  Developers of such porcelains
 212might start by reading about linkgit:git-update-index[1] and
 213linkgit:git-read-tree[1].
 214
 215The interface (input, output, set of options and the semantics)
 216to these low-level commands are meant to be a lot more stable
 217than Porcelain level commands, because these commands are
 218primarily for scripted use.  The interface to Porcelain commands
 219on the other hand are subject to change in order to improve the
 220end user experience.
 221
 222The following description divides
 223the low-level commands into commands that manipulate objects (in
 224the repository, index, and working tree), commands that interrogate and
 225compare objects, and commands that move objects and references between
 226repositories.
 227
 228
 229Manipulation commands
 230~~~~~~~~~~~~~~~~~~~~~
 231
 232include::cmds-plumbingmanipulators.txt[]
 233
 234
 235Interrogation commands
 236~~~~~~~~~~~~~~~~~~~~~~
 237
 238include::cmds-plumbinginterrogators.txt[]
 239
 240In general, the interrogate commands do not touch the files in
 241the working tree.
 242
 243
 244Synching repositories
 245~~~~~~~~~~~~~~~~~~~~~
 246
 247include::cmds-synchingrepositories.txt[]
 248
 249The following are helper programs used by the above; end users
 250typically do not use them directly.
 251
 252include::cmds-synchelpers.txt[]
 253
 254
 255Internal helper commands
 256~~~~~~~~~~~~~~~~~~~~~~~~
 257
 258These are internal helper commands used by other commands; end
 259users typically do not use them directly.
 260
 261include::cmds-purehelpers.txt[]
 262
 263
 264Configuration Mechanism
 265-----------------------
 266
 267Starting from 0.99.9 (actually mid 0.99.8.GIT), `.git/config` file
 268is used to hold per-repository configuration options.  It is a
 269simple text file modeled after `.ini` format familiar to some
 270people.  Here is an example:
 271
 272------------
 273#
 274# A '#' or ';' character indicates a comment.
 275#
 276
 277; core variables
 278[core]
 279        ; Don't trust file modes
 280        filemode = false
 281
 282; user identity
 283[user]
 284        name = "Junio C Hamano"
 285        email = "junkio@twinsun.com"
 286
 287------------
 288
 289Various commands read from the configuration file and adjust
 290their operation accordingly.
 291
 292
 293Identifier Terminology
 294----------------------
 295<object>::
 296        Indicates the object name for any type of object.
 297
 298<blob>::
 299        Indicates a blob object name.
 300
 301<tree>::
 302        Indicates a tree object name.
 303
 304<commit>::
 305        Indicates a commit object name.
 306
 307<tree-ish>::
 308        Indicates a tree, commit or tag object name.  A
 309        command that takes a <tree-ish> argument ultimately wants to
 310        operate on a <tree> object but automatically dereferences
 311        <commit> and <tag> objects that point at a <tree>.
 312
 313<commit-ish>::
 314        Indicates a commit or tag object name.  A
 315        command that takes a <commit-ish> argument ultimately wants to
 316        operate on a <commit> object but automatically dereferences
 317        <tag> objects that point at a <commit>.
 318
 319<type>::
 320        Indicates that an object type is required.
 321        Currently one of: `blob`, `tree`, `commit`, or `tag`.
 322
 323<file>::
 324        Indicates a filename - almost always relative to the
 325        root of the tree structure `GIT_INDEX_FILE` describes.
 326
 327Symbolic Identifiers
 328--------------------
 329Any git command accepting any <object> can also use the following
 330symbolic notation:
 331
 332HEAD::
 333        indicates the head of the current branch (i.e. the
 334        contents of `$GIT_DIR/HEAD`).
 335
 336<tag>::
 337        a valid tag 'name'
 338        (i.e. the contents of `$GIT_DIR/refs/tags/<tag>`).
 339
 340<head>::
 341        a valid head 'name'
 342        (i.e. the contents of `$GIT_DIR/refs/heads/<head>`).
 343
 344For a more complete list of ways to spell object names, see
 345"SPECIFYING REVISIONS" section in linkgit:git-rev-parse[1].
 346
 347
 348File/Directory Structure
 349------------------------
 350
 351Please see the link:repository-layout.html[repository layout] document.
 352
 353Read link:hooks.html[hooks] for more details about each hook.
 354
 355Higher level SCMs may provide and manage additional information in the
 356`$GIT_DIR`.
 357
 358
 359Terminology
 360-----------
 361Please see the link:glossary.html[glossary] document.
 362
 363
 364Environment Variables
 365---------------------
 366Various git commands use the following environment variables:
 367
 368The git Repository
 369~~~~~~~~~~~~~~~~~~
 370These environment variables apply to 'all' core git commands. Nb: it
 371is worth noting that they may be used/overridden by SCMS sitting above
 372git so take care if using Cogito etc.
 373
 374'GIT_INDEX_FILE'::
 375        This environment allows the specification of an alternate
 376        index file. If not specified, the default of `$GIT_DIR/index`
 377        is used.
 378
 379'GIT_OBJECT_DIRECTORY'::
 380        If the object storage directory is specified via this
 381        environment variable then the sha1 directories are created
 382        underneath - otherwise the default `$GIT_DIR/objects`
 383        directory is used.
 384
 385'GIT_ALTERNATE_OBJECT_DIRECTORIES'::
 386        Due to the immutable nature of git objects, old objects can be
 387        archived into shared, read-only directories. This variable
 388        specifies a ":" separated list of git object directories which
 389        can be used to search for git objects. New objects will not be
 390        written to these directories.
 391
 392'GIT_DIR'::
 393        If the 'GIT_DIR' environment variable is set then it
 394        specifies a path to use instead of the default `.git`
 395        for the base of the repository.
 396
 397'GIT_WORK_TREE'::
 398        Set the path to the working tree.  The value will not be
 399        used in combination with repositories found automatically in
 400        a .git directory (i.e. $GIT_DIR is not set).
 401        This can also be controlled by the '--work-tree' command line
 402        option and the core.worktree configuration variable.
 403
 404git Commits
 405~~~~~~~~~~~
 406'GIT_AUTHOR_NAME'::
 407'GIT_AUTHOR_EMAIL'::
 408'GIT_AUTHOR_DATE'::
 409'GIT_COMMITTER_NAME'::
 410'GIT_COMMITTER_EMAIL'::
 411'GIT_COMMITTER_DATE'::
 412'EMAIL'::
 413        see linkgit:git-commit-tree[1]
 414
 415git Diffs
 416~~~~~~~~~
 417'GIT_DIFF_OPTS'::
 418        Only valid setting is "--unified=??" or "-u??" to set the
 419        number of context lines shown when a unified diff is created.
 420        This takes precedence over any "-U" or "--unified" option
 421        value passed on the git diff command line.
 422
 423'GIT_EXTERNAL_DIFF'::
 424        When the environment variable 'GIT_EXTERNAL_DIFF' is set, the
 425        program named by it is called, instead of the diff invocation
 426        described above.  For a path that is added, removed, or modified,
 427        'GIT_EXTERNAL_DIFF' is called with 7 parameters:
 428
 429        path old-file old-hex old-mode new-file new-hex new-mode
 430+
 431where:
 432
 433        <old|new>-file:: are files GIT_EXTERNAL_DIFF can use to read the
 434                         contents of <old|new>,
 435        <old|new>-hex:: are the 40-hexdigit SHA1 hashes,
 436        <old|new>-mode:: are the octal representation of the file modes.
 437
 438+
 439The file parameters can point at the user's working file
 440(e.g. `new-file` in "git-diff-files"), `/dev/null` (e.g. `old-file`
 441when a new file is added), or a temporary file (e.g. `old-file` in the
 442index).  'GIT_EXTERNAL_DIFF' should not worry about unlinking the
 443temporary file --- it is removed when 'GIT_EXTERNAL_DIFF' exits.
 444+
 445For a path that is unmerged, 'GIT_EXTERNAL_DIFF' is called with 1
 446parameter, <path>.
 447
 448other
 449~~~~~
 450'GIT_MERGE_VERBOSITY'::
 451        A number controlling the amount of output shown by
 452        the recursive merge strategy.  Overrides merge.verbosity.
 453        See linkgit:git-merge[1]
 454
 455'GIT_PAGER'::
 456        This environment variable overrides `$PAGER`. If it is set
 457        to an empty string or to the value "cat", git will not launch
 458        a pager.
 459
 460'GIT_SSH'::
 461        If this environment variable is set then linkgit:git-fetch[1]
 462        and linkgit:git-push[1] will use this command instead
 463        of `ssh` when they need to connect to a remote system.
 464        The 'GIT_SSH' command will be given exactly two arguments:
 465        the 'username@host' (or just 'host') from the URL and the
 466        shell command to execute on that remote system.
 467+
 468To pass options to the program that you want to list in GIT_SSH
 469you will need to wrap the program and options into a shell script,
 470then set GIT_SSH to refer to the shell script.
 471+
 472Usually it is easier to configure any desired options through your
 473personal `.ssh/config` file.  Please consult your ssh documentation
 474for further details.
 475
 476'GIT_FLUSH'::
 477        If this environment variable is set to "1", then commands such
 478        as git-blame (in incremental mode), git-rev-list, git-log,
 479        git-whatchanged, etc., will force a flush of the output stream
 480        after each commit-oriented record have been flushed.   If this
 481        variable is set to "0", the output of these commands will be done
 482        using completely buffered I/O.   If this environment variable is
 483        not set, git will choose buffered or record-oriented flushing
 484        based on whether stdout appears to be redirected to a file or not.
 485
 486'GIT_TRACE'::
 487        If this variable is set to "1", "2" or "true" (comparison
 488        is case insensitive), git will print `trace:` messages on
 489        stderr telling about alias expansion, built-in command
 490        execution and external command execution.
 491        If this variable is set to an integer value greater than 1
 492        and lower than 10 (strictly) then git will interpret this
 493        value as an open file descriptor and will try to write the
 494        trace messages into this file descriptor.
 495        Alternatively, if this variable is set to an absolute path
 496        (starting with a '/' character), git will interpret this
 497        as a file path and will try to write the trace messages
 498        into it.
 499
 500Discussion[[Discussion]]
 501------------------------
 502
 503More detail on the following is available from the
 504link:user-manual.html#git-concepts[git concepts chapter of the
 505user-manual] and the link:core-tutorial.html[Core tutorial].
 506
 507A git project normally consists of a working directory with a ".git"
 508subdirectory at the top level.  The .git directory contains, among other
 509things, a compressed object database representing the complete history
 510of the project, an "index" file which links that history to the current
 511contents of the working tree, and named pointers into that history such
 512as tags and branch heads.
 513
 514The object database contains objects of three main types: blobs, which
 515hold file data; trees, which point to blobs and other trees to build up
 516directory hierarchies; and commits, which each reference a single tree
 517and some number of parent commits.
 518
 519The commit, equivalent to what other systems call a "changeset" or
 520"version", represents a step in the project's history, and each parent
 521represents an immediately preceding step.  Commits with more than one
 522parent represent merges of independent lines of development.
 523
 524All objects are named by the SHA1 hash of their contents, normally
 525written as a string of 40 hex digits.  Such names are globally unique.
 526The entire history leading up to a commit can be vouched for by signing
 527just that commit.  A fourth object type, the tag, is provided for this
 528purpose.
 529
 530When first created, objects are stored in individual files, but for
 531efficiency may later be compressed together into "pack files".
 532
 533Named pointers called refs mark interesting points in history.  A ref
 534may contain the SHA1 name of an object or the name of another ref.  Refs
 535with names beginning `ref/head/` contain the SHA1 name of the most
 536recent commit (or "head") of a branch under development.  SHA1 names of
 537tags of interest are stored under `ref/tags/`.  A special ref named
 538`HEAD` contains the name of the currently checked-out branch.
 539
 540The index file is initialized with a list of all paths and, for each
 541path, a blob object and a set of attributes.  The blob object represents
 542the contents of the file as of the head of the current branch.  The
 543attributes (last modified time, size, etc.) are taken from the
 544corresponding file in the working tree.  Subsequent changes to the
 545working tree can be found by comparing these attributes.  The index may
 546be updated with new content, and new commits may be created from the
 547content stored in the index.
 548
 549The index is also capable of storing multiple entries (called "stages")
 550for a given pathname.  These stages are used to hold the various
 551unmerged version of a file when a merge is in progress.
 552
 553Authors
 554-------
 555* git's founding father is Linus Torvalds <torvalds@osdl.org>.
 556* The current git nurse is Junio C Hamano <gitster@pobox.com>.
 557* The git potty was written by Andreas Ericsson <ae@op5.se>.
 558* General upbringing is handled by the git-list <git@vger.kernel.org>.
 559
 560Documentation
 561--------------
 562The documentation for git suite was started by David Greaves
 563<david@dgreaves.com>, and later enhanced greatly by the
 564contributors on the git-list <git@vger.kernel.org>.
 565
 566GIT
 567---
 568Part of the linkgit:git[7] suite