Documentation/git-fast-export.txt

   1 git-fast-export(1)
   2 ==================
   3
   4 NAME
   5 ----
   6 git-fast-export - Git data exporter
   7
   8
   9 SYNOPSIS
  10 --------
  11 [verse]
  12 'git fast-export [<options>]' | 'git fast-import'
  13
  14 DESCRIPTION
  15 -----------
  16 This program dumps the given revisions in a form suitable to be piped
  17 into 'git fast-import'.
  18
  19 You can use it as a human-readable bundle replacement (see
  20 linkgit:git-bundle[1]), or as a format that can be edited before being
  21 fed to 'git fast-import' in order to do history rewrites (an ability
  22 relied on by tools like 'git filter-repo').
  23
  24 OPTIONS
  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 +
  35 When asking to 'abort' (which is the default), this program will die
  36 when encountering a signed tag.  With 'strip', the tags will silently
  37 be made unsigned, with 'warn-strip' they will be made unsigned but a
  38 warning will be displayed, with 'verbatim', they will be silently
  39 exported and with 'warn', they will be exported, but you will see a
  40 warning.
  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 +
  47 When asking to 'abort' (which is the default), this program will die
  48 when encountering such a tag.  With 'drop' it will omit such tags from
  49 the output.  With 'rewrite', if the tagged object is a commit, it will
  50 rewrite the tag to tag an ancestor commit (via parent rewriting; see
  51 linkgit: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 +
  59 Note that earlier versions of this command did not complain and
  60 produced 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
  79 --mark-tags::
  80         In addition to labelling blobs and commits with mark ids, also
  81         label tags.  This is useful in conjunction with
  82         `--export-marks` and `--import-marks`, and is also useful (and
  83         necessary) for exporting of nested tags.  It does not hurt
  84         other cases and would be the default, but many fast-import
  85         frontends are not prepared to accept tags with mark
  86         identifiers.
  87 +
  88 Any commits (or tags) that have already been marked will not be
  89 exported again.  If the backend uses a similar --import-marks file,
  90 this allows for incremental bidirectional exporting of the repository
  91 by keeping the marks the same across runs.
  92
  93 --fake-missing-tagger::
  94         Some old repositories have tags without a tagger.  The
  95         fast-import protocol was pretty strict about that, and did not
  96         allow that.  So fake a tagger to be able to fast-import the
  97         output.
  98
  99 --use-done-feature::
 100         Start the stream with a 'feature done' stanza, and terminate
 101         it with a 'done' command.
 102
 103 --no-data::
 104         Skip output of blob objects and instead refer to blobs via
 105         their original SHA-1 hash.  This is useful when rewriting the
 106         directory structure or history of a repository without
 107         touching the contents of individual files.  Note that the
 108         resulting stream can only be used by a repository which
 109         already contains the necessary objects.
 110
 111 --full-tree::
 112         This option will cause fast-export to issue a "deleteall"
 113         directive for each commit followed by a full list of all files
 114         in the commit (as opposed to just listing the files which are
 115         different from the commit's first parent).
 116
 117 --anonymize::
 118         Anonymize the contents of the repository while still retaining
 119         the shape of the history and stored tree.  See the section on
 120         `ANONYMIZING` below.
 121
 122 --reference-excluded-parents::
 123         By default, running a command such as `git fast-export
 124         master~5..master` will not include the commit master{tilde}5
 125         and will make master{tilde}4 no longer have master{tilde}5 as
 126         a parent (though both the old master{tilde}4 and new
 127         master{tilde}4 will have all the same files).  Use
 128         --reference-excluded-parents to instead have the stream
 129         refer to commits in the excluded range of history by their
 130         sha1sum.  Note that the resulting stream can only be used by a
 131         repository which already contains the necessary parent
 132         commits.
 133
 134 --show-original-ids::
 135         Add an extra directive to the output for commits and blobs,
 136         `original-oid <SHA1SUM>`.  While such directives will likely be
 137         ignored by importers such as git-fast-import, it may be useful
 138         for intermediary filters (e.g. for rewriting commit messages
 139         which refer to older commits, or for stripping blobs by id).
 140
 141 --reencode=(yes|no|abort)::
 142         Specify how to handle `encoding` header in commit objects.  When
 143         asking to 'abort' (which is the default), this program will die
 144         when encountering such a commit object.  With 'yes', the commit
 145         message will be reencoded into UTF-8.  With 'no', the original
 146         encoding will be preserved.
 147
 148 --refspec::
 149         Apply the specified refspec to each ref exported. Multiple of them can
 150         be specified.
 151
 152 [<git-rev-list-args>...]::
 153         A list of arguments, acceptable to 'git rev-parse' and
 154         'git rev-list', that specifies the specific objects and references
 155         to export.  For example, `master~10..master` causes the
 156         current master reference to be exported along with all objects
 157         added since its 10th ancestor commit and (unless the
 158         --reference-excluded-parents option is specified) all files
 159         common to master{tilde}9 and master{tilde}10.
 160
 161 EXAMPLES
 162 --------
 163
 164 -------------------------------------------------------------------
 165 $ git fast-export --all | (cd /empty/repository && git fast-import)
 166 -------------------------------------------------------------------
 167
 168 This will export the whole repository and import it into the existing
 169 empty repository.  Except for reencoding commits that are not in
 170 UTF-8, it would be a one-to-one mirror.
 171
 172 -----------------------------------------------------
 173 $ git fast-export master~5..master |
 174         sed "s|refs/heads/master|refs/heads/other|" |
 175         git fast-import
 176 -----------------------------------------------------
 177
 178 This makes a new branch called 'other' from 'master~5..master'
 179 (i.e. if 'master' has linear history, it will take the last 5 commits).
 180
 181 Note that this assumes that none of the blobs and commit messages
 182 referenced by that revision range contains the string
 183 'refs/heads/master'.
 184
 185
 186 ANONYMIZING
 187 -----------
 188
 189 If the `--anonymize` option is given, git will attempt to remove all
 190 identifying information from the repository while still retaining enough
 191 of the original tree and history patterns to reproduce some bugs. The
 192 goal is that a git bug which is found on a private repository will
 193 persist in the anonymized repository, and the latter can be shared with
 194 git developers to help solve the bug.
 195
 196 With this option, git will replace all refnames, paths, blob contents,
 197 commit and tag messages, names, and email addresses in the output with
 198 anonymized data.  Two instances of the same string will be replaced
 199 equivalently (e.g., two commits with the same author will have the same
 200 anonymized author in the output, but bear no resemblance to the original
 201 author string). The relationship between commits, branches, and tags is
 202 retained, as well as the commit timestamps (but the commit messages and
 203 refnames bear no resemblance to the originals). The relative makeup of
 204 the tree is retained (e.g., if you have a root tree with 10 files and 3
 205 trees, so will the output), but their names and the contents of the
 206 files will be replaced.
 207
 208 If you think you have found a git bug, you can start by exporting an
 209 anonymized stream of the whole repository:
 210
 211 ---------------------------------------------------
 212 $ git fast-export --anonymize --all >anon-stream
 213 ---------------------------------------------------
 214
 215 Then confirm that the bug persists in a repository created from that
 216 stream (many bugs will not, as they really do depend on the exact
 217 repository contents):
 218
 219 ---------------------------------------------------
 220 $ git init anon-repo
 221 $ cd anon-repo
 222 $ git fast-import <../anon-stream
 223 $ ... test your bug ...
 224 ---------------------------------------------------
 225
 226 If the anonymized repository shows the bug, it may be worth sharing
 227 `anon-stream` along with a regular bug report. Note that the anonymized
 228 stream compresses very well, so gzipping it is encouraged. If you want
 229 to examine the stream to see that it does not contain any private data,
 230 you can peruse it directly before sending. You may also want to try:
 231
 232 ---------------------------------------------------
 233 $ perl -pe 's/\d+/X/g' <anon-stream | sort -u | less
 234 ---------------------------------------------------
 235
 236 which shows all of the unique lines (with numbers converted to "X", to
 237 collapse "User 0", "User 1", etc into "User X"). This produces a much
 238 smaller output, and it is usually easy to quickly confirm that there is
 239 no private data in the stream.
 240
 241
 242 LIMITATIONS
 243 -----------
 244
 245 Since 'git fast-import' cannot tag trees, you will not be
 246 able to export the linux.git repository completely, as it contains
 247 a tag referencing a tree instead of a commit.
 248
 249 SEE ALSO
 250 --------
 251 linkgit:git-fast-import[1]
 252
 253 GIT
 254 ---
 255 Part of the linkgit:git[1] suite