Documentation / git-p4.txton commit Documentation: update "howto maintain git" (cc1b258)
   1git-p4(1)
   2=========
   3
   4NAME
   5----
   6git-p4 - Import from and submit to Perforce repositories
   7
   8
   9SYNOPSIS
  10--------
  11[verse]
  12'git p4 clone' [<sync options>] [<clone options>] <p4 depot path>...
  13'git p4 sync' [<sync options>] [<p4 depot path>...]
  14'git p4 rebase'
  15'git p4 submit' [<submit options>] [<master branch name>]
  16
  17
  18DESCRIPTION
  19-----------
  20This command provides a way to interact with p4 repositories
  21using git.
  22
  23Create a new git repository from an existing p4 repository using
  24'git p4 clone', giving it one or more p4 depot paths.  Incorporate
  25new commits from p4 changes with 'git p4 sync'.  The 'sync' command
  26is also used to include new branches from other p4 depot paths.
  27Submit git changes back to p4 using 'git p4 submit'.  The command
  28'git p4 rebase' does a sync plus rebases the current branch onto
  29the updated p4 remote branch.
  30
  31
  32EXAMPLE
  33-------
  34* Clone a repository:
  35+
  36------------
  37$ git p4 clone //depot/path/project
  38------------
  39
  40* Do some work in the newly created git repository:
  41+
  42------------
  43$ cd project
  44$ vi foo.h
  45$ git commit -a -m "edited foo.h"
  46------------
  47
  48* Update the git repository with recent changes from p4, rebasing your
  49  work on top:
  50+
  51------------
  52$ git p4 rebase
  53------------
  54
  55* Submit your commits back to p4:
  56+
  57------------
  58$ git p4 submit
  59------------
  60
  61
  62COMMANDS
  63--------
  64
  65Clone
  66~~~~~
  67Generally, 'git p4 clone' is used to create a new git directory
  68from an existing p4 repository:
  69------------
  70$ git p4 clone //depot/path/project
  71------------
  72This:
  73
  741.   Creates an empty git repository in a subdirectory called 'project'.
  75+
  762.   Imports the full contents of the head revision from the given p4
  77depot path into a single commit in the git branch 'refs/remotes/p4/master'.
  78+
  793.   Creates a local branch, 'master' from this remote and checks it out.
  80
  81To reproduce the entire p4 history in git, use the '@all' modifier on
  82the depot path:
  83------------
  84$ git p4 clone //depot/path/project@all
  85------------
  86
  87
  88Sync
  89~~~~
  90As development continues in the p4 repository, those changes can
  91be included in the git repository using:
  92------------
  93$ git p4 sync
  94------------
  95This command finds new changes in p4 and imports them as git commits.
  96
  97P4 repositories can be added to an existing git repository using
  98'git p4 sync' too:
  99------------
 100$ mkdir repo-git
 101$ cd repo-git
 102$ git init
 103$ git p4 sync //path/in/your/perforce/depot
 104------------
 105This imports the specified depot into
 106'refs/remotes/p4/master' in an existing git repository.  The
 107'--branch' option can be used to specify a different branch to
 108be used for the p4 content.
 109
 110If a git repository includes branches 'refs/remotes/origin/p4', these
 111will be fetched and consulted first during a 'git p4 sync'.  Since
 112importing directly from p4 is considerably slower than pulling changes
 113from a git remote, this can be useful in a multi-developer environment.
 114
 115
 116Rebase
 117~~~~~~
 118A common working pattern is to fetch the latest changes from the p4 depot
 119and merge them with local uncommitted changes.  Often, the p4 repository
 120is the ultimate location for all code, thus a rebase workflow makes
 121sense.  This command does 'git p4 sync' followed by 'git rebase' to move
 122local commits on top of updated p4 changes.
 123------------
 124$ git p4 rebase
 125------------
 126
 127
 128Submit
 129~~~~~~
 130Submitting changes from a git repository back to the p4 repository
 131requires a separate p4 client workspace.  This should be specified
 132using the 'P4CLIENT' environment variable or the git configuration
 133variable 'git-p4.client'.  The p4 client must exist, but the client root
 134will be created and populated if it does not already exist.
 135
 136To submit all changes that are in the current git branch but not in
 137the 'p4/master' branch, use:
 138------------
 139$ git p4 submit
 140------------
 141
 142To specify a branch other than the current one, use:
 143------------
 144$ git p4 submit topicbranch
 145------------
 146
 147The upstream reference is generally 'refs/remotes/p4/master', but can
 148be overridden using the '--origin=' command-line option.
 149
 150The p4 changes will be created as the user invoking 'git p4 submit'. The
 151'--preserve-user' option will cause ownership to be modified
 152according to the author of the git commit.  This option requires admin
 153privileges in p4, which can be granted using 'p4 protect'.
 154
 155
 156OPTIONS
 157-------
 158
 159General options
 160~~~~~~~~~~~~~~~
 161All commands except clone accept these options.
 162
 163--git-dir <dir>::
 164        Set the 'GIT_DIR' environment variable.  See linkgit:git[1].
 165
 166--verbose, -v::
 167        Provide more progress information.
 168
 169Sync options
 170~~~~~~~~~~~~
 171These options can be used in the initial 'clone' as well as in
 172subsequent 'sync' operations.
 173
 174--branch <branch>::
 175        Import changes into given branch.  If the branch starts with
 176        'refs/', it will be used as is, otherwise the path 'refs/heads/'
 177        will be prepended.  The default branch is 'master'.  If used
 178        with an initial clone, no HEAD will be checked out.
 179+
 180This example imports a new remote "p4/proj2" into an existing
 181git repository:
 182+
 183----
 184    $ git init
 185    $ git p4 sync --branch=refs/remotes/p4/proj2 //depot/proj2
 186----
 187
 188--detect-branches::
 189        Use the branch detection algorithm to find new paths in p4.  It is
 190        documented below in "BRANCH DETECTION".
 191
 192--changesfile <file>::
 193        Import exactly the p4 change numbers listed in 'file', one per
 194        line.  Normally, 'git p4' inspects the current p4 repository
 195        state and detects the changes it should import.
 196
 197--silent::
 198        Do not print any progress information.
 199
 200--detect-labels::
 201        Query p4 for labels associated with the depot paths, and add
 202        them as tags in git. Limited usefulness as only imports labels
 203        associated with new changelists. Deprecated.
 204
 205--import-labels::
 206        Import labels from p4 into git.
 207
 208--import-local::
 209        By default, p4 branches are stored in 'refs/remotes/p4/',
 210        where they will be treated as remote-tracking branches by
 211        linkgit:git-branch[1] and other commands.  This option instead
 212        puts p4 branches in 'refs/heads/p4/'.  Note that future
 213        sync operations must specify '--import-local' as well so that
 214        they can find the p4 branches in refs/heads.
 215
 216--max-changes <n>::
 217        Limit the number of imported changes to 'n'.  Useful to
 218        limit the amount of history when using the '@all' p4 revision
 219        specifier.
 220
 221--keep-path::
 222        The mapping of file names from the p4 depot path to git, by
 223        default, involves removing the entire depot path.  With this
 224        option, the full p4 depot path is retained in git.  For example,
 225        path '//depot/main/foo/bar.c', when imported from
 226        '//depot/main/', becomes 'foo/bar.c'.  With '--keep-path', the
 227        git path is instead 'depot/main/foo/bar.c'.
 228
 229--use-client-spec::
 230        Use a client spec to find the list of interesting files in p4.
 231        See the "CLIENT SPEC" section below.
 232
 233Clone options
 234~~~~~~~~~~~~~
 235These options can be used in an initial 'clone', along with the 'sync'
 236options described above.
 237
 238--destination <directory>::
 239        Where to create the git repository.  If not provided, the last
 240        component in the p4 depot path is used to create a new
 241        directory.
 242
 243--bare::
 244        Perform a bare clone.  See linkgit:git-clone[1].
 245
 246-/ <path>::
 247        Exclude selected depot paths when cloning.
 248
 249Submit options
 250~~~~~~~~~~~~~~
 251These options can be used to modify 'git p4 submit' behavior.
 252
 253--origin <commit>::
 254        Upstream location from which commits are identified to submit to
 255        p4.  By default, this is the most recent p4 commit reachable
 256        from 'HEAD'.
 257
 258-M::
 259        Detect renames.  See linkgit:git-diff[1].  Renames will be
 260        represented in p4 using explicit 'move' operations.  There
 261        is no corresponding option to detect copies, but there are
 262        variables for both moves and copies.
 263
 264--preserve-user::
 265        Re-author p4 changes before submitting to p4.  This option
 266        requires p4 admin privileges.
 267
 268--export-labels::
 269        Export tags from git as p4 labels. Tags found in git are applied
 270        to the perforce working directory.
 271
 272--dry-run, -n::
 273        Show just what commits would be submitted to p4; do not change
 274        state in git or p4.
 275
 276--prepare-p4-only::
 277        Apply a commit to the p4 workspace, opening, adding and deleting
 278        files in p4 as for a normal submit operation.  Do not issue the
 279        final "p4 submit", but instead print a message about how to
 280        submit manually or revert.  This option always stops after the
 281        first (oldest) commit.  Git tags are not exported to p4.
 282
 283--conflict=(ask|skip|quit)::
 284        Conflicts can occur when applying a commit to p4.  When this
 285        happens, the default behavior ("ask") is to prompt whether to
 286        skip this commit and continue, or quit.  This option can be used
 287        to bypass the prompt, causing conflicting commits to be automatically
 288        skipped, or to quit trying to apply commits, without prompting.
 289
 290Rebase options
 291~~~~~~~~~~~~~~
 292These options can be used to modify 'git p4 rebase' behavior.
 293
 294--import-labels::
 295        Import p4 labels.
 296
 297DEPOT PATH SYNTAX
 298-----------------
 299The p4 depot path argument to 'git p4 sync' and 'git p4 clone' can
 300be one or more space-separated p4 depot paths, with an optional
 301p4 revision specifier on the end:
 302
 303"//depot/my/project"::
 304    Import one commit with all files in the '#head' change under that tree.
 305
 306"//depot/my/project@all"::
 307    Import one commit for each change in the history of that depot path.
 308
 309"//depot/my/project@1,6"::
 310    Import only changes 1 through 6.
 311
 312"//depot/proj1@all //depot/proj2@all"::
 313    Import all changes from both named depot paths into a single
 314    repository.  Only files below these directories are included.
 315    There is not a subdirectory in git for each "proj1" and "proj2".
 316    You must use the '--destination' option when specifying more
 317    than one depot path.  The revision specifier must be specified
 318    identically on each depot path.  If there are files in the
 319    depot paths with the same name, the path with the most recently
 320    updated version of the file is the one that appears in git.
 321
 322See 'p4 help revisions' for the full syntax of p4 revision specifiers.
 323
 324
 325CLIENT SPEC
 326-----------
 327The p4 client specification is maintained with the 'p4 client' command
 328and contains among other fields, a View that specifies how the depot
 329is mapped into the client repository.  The 'clone' and 'sync' commands
 330can consult the client spec when given the '--use-client-spec' option or
 331when the useClientSpec variable is true.  After 'git p4 clone', the
 332useClientSpec variable is automatically set in the repository
 333configuration file.  This allows future 'git p4 submit' commands to
 334work properly; the submit command looks only at the variable and does
 335not have a command-line option.
 336
 337The full syntax for a p4 view is documented in 'p4 help views'.  'Git p4'
 338knows only a subset of the view syntax.  It understands multi-line
 339mappings, overlays with '+', exclusions with '-' and double-quotes
 340around whitespace.  Of the possible wildcards, 'git p4' only handles
 341'...', and only when it is at the end of the path.  'Git p4' will complain
 342if it encounters an unhandled wildcard.
 343
 344Bugs in the implementation of overlap mappings exist.  If multiple depot
 345paths map through overlays to the same location in the repository,
 346'git p4' can choose the wrong one.  This is hard to solve without
 347dedicating a client spec just for 'git p4'.
 348
 349The name of the client can be given to 'git p4' in multiple ways.  The
 350variable 'git-p4.client' takes precedence if it exists.  Otherwise,
 351normal p4 mechanisms of determining the client are used:  environment
 352variable P4CLIENT, a file referenced by P4CONFIG, or the local host name.
 353
 354
 355BRANCH DETECTION
 356----------------
 357P4 does not have the same concept of a branch as git.  Instead,
 358p4 organizes its content as a directory tree, where by convention
 359different logical branches are in different locations in the tree.
 360The 'p4 branch' command is used to maintain mappings between
 361different areas in the tree, and indicate related content.  'git p4'
 362can use these mappings to determine branch relationships.
 363
 364If you have a repository where all the branches of interest exist as
 365subdirectories of a single depot path, you can use '--detect-branches'
 366when cloning or syncing to have 'git p4' automatically find
 367subdirectories in p4, and to generate these as branches in git.
 368
 369For example, if the P4 repository structure is:
 370----
 371//depot/main/...
 372//depot/branch1/...
 373----
 374
 375And "p4 branch -o branch1" shows a View line that looks like:
 376----
 377//depot/main/... //depot/branch1/...
 378----
 379
 380Then this 'git p4 clone' command:
 381----
 382git p4 clone --detect-branches //depot@all
 383----
 384produces a separate branch in 'refs/remotes/p4/' for //depot/main,
 385called 'master', and one for //depot/branch1 called 'depot/branch1'.
 386
 387However, it is not necessary to create branches in p4 to be able to use
 388them like branches.  Because it is difficult to infer branch
 389relationships automatically, a git configuration setting
 390'git-p4.branchList' can be used to explicitly identify branch
 391relationships.  It is a list of "source:destination" pairs, like a
 392simple p4 branch specification, where the "source" and "destination" are
 393the path elements in the p4 repository.  The example above relied on the
 394presence of the p4 branch.  Without p4 branches, the same result will
 395occur with:
 396----
 397git config git-p4.branchList main:branch1
 398git p4 clone --detect-branches //depot@all
 399----
 400
 401
 402PERFORMANCE
 403-----------
 404The fast-import mechanism used by 'git p4' creates one pack file for
 405each invocation of 'git p4 sync'.  Normally, git garbage compression
 406(linkgit:git-gc[1]) automatically compresses these to fewer pack files,
 407but explicit invocation of 'git repack -adf' may improve performance.
 408
 409
 410CONFIGURATION VARIABLES
 411-----------------------
 412The following config settings can be used to modify 'git p4' behavior.
 413They all are in the 'git-p4' section.
 414
 415General variables
 416~~~~~~~~~~~~~~~~~
 417git-p4.user::
 418        User specified as an option to all p4 commands, with '-u <user>'.
 419        The environment variable 'P4USER' can be used instead.
 420
 421git-p4.password::
 422        Password specified as an option to all p4 commands, with
 423        '-P <password>'.
 424        The environment variable 'P4PASS' can be used instead.
 425
 426git-p4.port::
 427        Port specified as an option to all p4 commands, with
 428        '-p <port>'.
 429        The environment variable 'P4PORT' can be used instead.
 430
 431git-p4.host::
 432        Host specified as an option to all p4 commands, with
 433        '-h <host>'.
 434        The environment variable 'P4HOST' can be used instead.
 435
 436git-p4.client::
 437        Client specified as an option to all p4 commands, with
 438        '-c <client>', including the client spec.
 439
 440Clone and sync variables
 441~~~~~~~~~~~~~~~~~~~~~~~~
 442git-p4.syncFromOrigin::
 443        Because importing commits from other git repositories is much faster
 444        than importing them from p4, a mechanism exists to find p4 changes
 445        first in git remotes.  If branches exist under 'refs/remote/origin/p4',
 446        those will be fetched and used when syncing from p4.  This
 447        variable can be set to 'false' to disable this behavior.
 448
 449git-p4.branchUser::
 450        One phase in branch detection involves looking at p4 branches
 451        to find new ones to import.  By default, all branches are
 452        inspected.  This option limits the search to just those owned
 453        by the single user named in the variable.
 454
 455git-p4.branchList::
 456        List of branches to be imported when branch detection is
 457        enabled.  Each entry should be a pair of branch names separated
 458        by a colon (:).  This example declares that both branchA and
 459        branchB were created from main:
 460+
 461-------------
 462git config       git-p4.branchList main:branchA
 463git config --add git-p4.branchList main:branchB
 464-------------
 465
 466git-p4.ignoredP4Labels::
 467        List of p4 labels to ignore. This is built automatically as
 468        unimportable labels are discovered.
 469
 470git-p4.importLabels::
 471        Import p4 labels into git, as per --import-labels.
 472
 473git-p4.labelImportRegexp::
 474        Only p4 labels matching this regular expression will be imported. The
 475        default value is '[a-zA-Z0-9_\-.]+$'.
 476
 477git-p4.useClientSpec::
 478        Specify that the p4 client spec should be used to identify p4
 479        depot paths of interest.  This is equivalent to specifying the
 480        option '--use-client-spec'.  See the "CLIENT SPEC" section above.
 481        This variable is a boolean, not the name of a p4 client.
 482
 483Submit variables
 484~~~~~~~~~~~~~~~~
 485git-p4.detectRenames::
 486        Detect renames.  See linkgit:git-diff[1].  This can be true,
 487        false, or a score as expected by 'git diff -M'.
 488
 489git-p4.detectCopies::
 490        Detect copies.  See linkgit:git-diff[1].  This can be true,
 491        false, or a score as expected by 'git diff -C'.
 492
 493git-p4.detectCopiesHarder::
 494        Detect copies harder.  See linkgit:git-diff[1].  A boolean.
 495
 496git-p4.preserveUser::
 497        On submit, re-author changes to reflect the git author,
 498        regardless of who invokes 'git p4 submit'.
 499
 500git-p4.allowMissingP4Users::
 501        When 'preserveUser' is true, 'git p4' normally dies if it
 502        cannot find an author in the p4 user map.  This setting
 503        submits the change regardless.
 504
 505git-p4.skipSubmitEdit::
 506        The submit process invokes the editor before each p4 change
 507        is submitted.  If this setting is true, though, the editing
 508        step is skipped.
 509
 510git-p4.skipSubmitEditCheck::
 511        After editing the p4 change message, 'git p4' makes sure that
 512        the description really was changed by looking at the file
 513        modification time.  This option disables that test.
 514
 515git-p4.allowSubmit::
 516        By default, any branch can be used as the source for a 'git p4
 517        submit' operation.  This configuration variable, if set, permits only
 518        the named branches to be used as submit sources.  Branch names
 519        must be the short names (no "refs/heads/"), and should be
 520        separated by commas (","), with no spaces.
 521
 522git-p4.skipUserNameCheck::
 523        If the user running 'git p4 submit' does not exist in the p4
 524        user map, 'git p4' exits.  This option can be used to force
 525        submission regardless.
 526
 527git-p4.attemptRCSCleanup::
 528        If enabled, 'git p4 submit' will attempt to cleanup RCS keywords
 529        ($Header$, etc). These would otherwise cause merge conflicts and prevent
 530        the submit going ahead. This option should be considered experimental at
 531        present.
 532
 533git-p4.exportLabels::
 534        Export git tags to p4 labels, as per --export-labels.
 535
 536git-p4.labelExportRegexp::
 537        Only p4 labels matching this regular expression will be exported. The
 538        default value is '[a-zA-Z0-9_\-.]+$'.
 539
 540git-p4.conflict::
 541        Specify submit behavior when a conflict with p4 is found, as per
 542        --conflict.  The default behavior is 'ask'.
 543
 544IMPLEMENTATION DETAILS
 545----------------------
 546* Changesets from p4 are imported using git fast-import.
 547* Cloning or syncing does not require a p4 client; file contents are
 548  collected using 'p4 print'.
 549* Submitting requires a p4 client, which is not in the same location
 550  as the git repository.  Patches are applied, one at a time, to
 551  this p4 client and submitted from there.
 552* Each commit imported by 'git p4' has a line at the end of the log
 553  message indicating the p4 depot location and change number.  This
 554  line is used by later 'git p4 sync' operations to know which p4
 555  changes are new.