Documentation / git-fast-export.txton commit Merge branch 'ds/reachable' (0f7ac90)
   1git-fast-export(1)
   2==================
   3
   4NAME
   5----
   6git-fast-export - Git data exporter
   7
   8
   9SYNOPSIS
  10--------
  11[verse]
  12'git fast-export [<options>]' | 'git fast-import'
  13
  14DESCRIPTION
  15-----------
  16This program dumps the given revisions in a form suitable to be piped
  17into 'git fast-import'.
  18
  19You can use it as a human-readable bundle replacement (see
  20linkgit:git-bundle[1]), or as a kind of an interactive
  21'git filter-branch'.
  22
  23
  24OPTIONS
  25-------
  26--progress=<n>::
  27        Insert 'progress' statements every <n> objects, to be shown by
  28        'git fast-import' during import.
  29
  30--signed-tags=(verbatim|warn|warn-strip|strip|abort)::
  31        Specify how to handle signed tags.  Since any transformation
  32        after the export can change the tag names (which can also happen
  33        when excluding revisions) the signatures will not match.
  34+
  35When asking to 'abort' (which is the default), this program will die
  36when encountering a signed tag.  With 'strip', the tags will silently
  37be made unsigned, with 'warn-strip' they will be made unsigned but a
  38warning will be displayed, with 'verbatim', they will be silently
  39exported and with 'warn', they will be exported, but you will see a
  40warning.
  41
  42--tag-of-filtered-object=(abort|drop|rewrite)::
  43        Specify how to handle tags whose tagged object is filtered out.
  44        Since revisions and files to export can be limited by path,
  45        tagged objects may be filtered completely.
  46+
  47When asking to 'abort' (which is the default), this program will die
  48when encountering such a tag.  With 'drop' it will omit such tags from
  49the output.  With 'rewrite', if the tagged object is a commit, it will
  50rewrite the tag to tag an ancestor commit (via parent rewriting; see
  51linkgit:git-rev-list[1])
  52
  53-M::
  54-C::
  55        Perform move and/or copy detection, as described in the
  56        linkgit:git-diff[1] manual page, and use it to generate
  57        rename and copy commands in the output dump.
  58+
  59Note that earlier versions of this command did not complain and
  60produced incorrect results if you gave these options.
  61
  62--export-marks=<file>::
  63        Dumps the internal marks table to <file> when complete.
  64        Marks are written one per line as `:markid SHA-1`. Only marks
  65        for revisions are dumped; marks for blobs are ignored.
  66        Backends can use this file to validate imports after they
  67        have been completed, or to save the marks table across
  68        incremental runs.  As <file> is only opened and truncated
  69        at completion, the same path can also be safely given to
  70        --import-marks.
  71        The file will not be written if no new object has been
  72        marked/exported.
  73
  74--import-marks=<file>::
  75        Before processing any input, load the marks specified in
  76        <file>.  The input file must exist, must be readable, and
  77        must use the same format as produced by --export-marks.
  78+
  79Any commits that have already been marked will not be exported again.
  80If the backend uses a similar --import-marks file, this allows for
  81incremental bidirectional exporting of the repository by keeping the
  82marks the same across runs.
  83
  84--fake-missing-tagger::
  85        Some old repositories have tags without a tagger.  The
  86        fast-import protocol was pretty strict about that, and did not
  87        allow that.  So fake a tagger to be able to fast-import the
  88        output.
  89
  90--use-done-feature::
  91        Start the stream with a 'feature done' stanza, and terminate
  92        it with a 'done' command.
  93
  94--no-data::
  95        Skip output of blob objects and instead refer to blobs via
  96        their original SHA-1 hash.  This is useful when rewriting the
  97        directory structure or history of a repository without
  98        touching the contents of individual files.  Note that the
  99        resulting stream can only be used by a repository which
 100        already contains the necessary objects.
 101
 102--full-tree::
 103        This option will cause fast-export to issue a "deleteall"
 104        directive for each commit followed by a full list of all files
 105        in the commit (as opposed to just listing the files which are
 106        different from the commit's first parent).
 107
 108--anonymize::
 109        Anonymize the contents of the repository while still retaining
 110        the shape of the history and stored tree.  See the section on
 111        `ANONYMIZING` below.
 112
 113--refspec::
 114        Apply the specified refspec to each ref exported. Multiple of them can
 115        be specified.
 116
 117[<git-rev-list-args>...]::
 118        A list of arguments, acceptable to 'git rev-parse' and
 119        'git rev-list', that specifies the specific objects and references
 120        to export.  For example, `master~10..master` causes the
 121        current master reference to be exported along with all objects
 122        added since its 10th ancestor commit.
 123
 124EXAMPLES
 125--------
 126
 127-------------------------------------------------------------------
 128$ git fast-export --all | (cd /empty/repository && git fast-import)
 129-------------------------------------------------------------------
 130
 131This will export the whole repository and import it into the existing
 132empty repository.  Except for reencoding commits that are not in
 133UTF-8, it would be a one-to-one mirror.
 134
 135-----------------------------------------------------
 136$ git fast-export master~5..master |
 137        sed "s|refs/heads/master|refs/heads/other|" |
 138        git fast-import
 139-----------------------------------------------------
 140
 141This makes a new branch called 'other' from 'master~5..master'
 142(i.e. if 'master' has linear history, it will take the last 5 commits).
 143
 144Note that this assumes that none of the blobs and commit messages
 145referenced by that revision range contains the string
 146'refs/heads/master'.
 147
 148
 149ANONYMIZING
 150-----------
 151
 152If the `--anonymize` option is given, git will attempt to remove all
 153identifying information from the repository while still retaining enough
 154of the original tree and history patterns to reproduce some bugs. The
 155goal is that a git bug which is found on a private repository will
 156persist in the anonymized repository, and the latter can be shared with
 157git developers to help solve the bug.
 158
 159With this option, git will replace all refnames, paths, blob contents,
 160commit and tag messages, names, and email addresses in the output with
 161anonymized data.  Two instances of the same string will be replaced
 162equivalently (e.g., two commits with the same author will have the same
 163anonymized author in the output, but bear no resemblance to the original
 164author string). The relationship between commits, branches, and tags is
 165retained, as well as the commit timestamps (but the commit messages and
 166refnames bear no resemblance to the originals). The relative makeup of
 167the tree is retained (e.g., if you have a root tree with 10 files and 3
 168trees, so will the output), but their names and the contents of the
 169files will be replaced.
 170
 171If you think you have found a git bug, you can start by exporting an
 172anonymized stream of the whole repository:
 173
 174---------------------------------------------------
 175$ git fast-export --anonymize --all >anon-stream
 176---------------------------------------------------
 177
 178Then confirm that the bug persists in a repository created from that
 179stream (many bugs will not, as they really do depend on the exact
 180repository contents):
 181
 182---------------------------------------------------
 183$ git init anon-repo
 184$ cd anon-repo
 185$ git fast-import <../anon-stream
 186$ ... test your bug ...
 187---------------------------------------------------
 188
 189If the anonymized repository shows the bug, it may be worth sharing
 190`anon-stream` along with a regular bug report. Note that the anonymized
 191stream compresses very well, so gzipping it is encouraged. If you want
 192to examine the stream to see that it does not contain any private data,
 193you can peruse it directly before sending. You may also want to try:
 194
 195---------------------------------------------------
 196$ perl -pe 's/\d+/X/g' <anon-stream | sort -u | less
 197---------------------------------------------------
 198
 199which shows all of the unique lines (with numbers converted to "X", to
 200collapse "User 0", "User 1", etc into "User X"). This produces a much
 201smaller output, and it is usually easy to quickly confirm that there is
 202no private data in the stream.
 203
 204
 205LIMITATIONS
 206-----------
 207
 208Since 'git fast-import' cannot tag trees, you will not be
 209able to export the linux.git repository completely, as it contains
 210a tag referencing a tree instead of a commit.
 211
 212SEE ALSO
 213--------
 214linkgit:git-fast-import[1]
 215
 216GIT
 217---
 218Part of the linkgit:git[1] suite