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 kind of an interactive
  21 'git filter-branch'.
  22
  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 Any commits that have already been marked will not be exported again.
  80 If the backend uses a similar --import-marks file, this allows for
  81 incremental bidirectional exporting of the repository by keeping the
  82 marks 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 --reference-excluded-parents::
 114         By default, running a command such as `git fast-export
 115         master~5..master` will not include the commit master{tilde}5
 116         and will make master{tilde}4 no longer have master{tilde}5 as
 117         a parent (though both the old master{tilde}4 and new
 118         master{tilde}4 will have all the same files).  Use
 119         --reference-excluded-parents to instead have the stream
 120         refer to commits in the excluded range of history by their
 121         sha1sum.  Note that the resulting stream can only be used by a
 122         repository which already contains the necessary parent
 123         commits.
 124
 125 --show-original-ids::
 126         Add an extra directive to the output for commits and blobs,
 127         `original-oid <SHA1SUM>`.  While such directives will likely be
 128         ignored by importers such as git-fast-import, it may be useful
 129         for intermediary filters (e.g. for rewriting commit messages
 130         which refer to older commits, or for stripping blobs by id).
 131
 132 --reencode=(yes|no|abort)::
 133         Specify how to handle `encoding` header in commit objects.  When
 134         asking to 'abort' (which is the default), this program will die
 135         when encountering such a commit object.  With 'yes', the commit
 136         message will be reencoded into UTF-8.  With 'no', the original
 137         encoding will be preserved.
 138
 139 --refspec::
 140         Apply the specified refspec to each ref exported. Multiple of them can
 141         be specified.
 142
 143 [<git-rev-list-args>...]::
 144         A list of arguments, acceptable to 'git rev-parse' and
 145         'git rev-list', that specifies the specific objects and references
 146         to export.  For example, `master~10..master` causes the
 147         current master reference to be exported along with all objects
 148         added since its 10th ancestor commit and (unless the
 149         --reference-excluded-parents option is specified) all files
 150         common to master{tilde}9 and master{tilde}10.
 151
 152 EXAMPLES
 153 --------
 154
 155 -------------------------------------------------------------------
 156 $ git fast-export --all | (cd /empty/repository && git fast-import)
 157 -------------------------------------------------------------------
 158
 159 This will export the whole repository and import it into the existing
 160 empty repository.  Except for reencoding commits that are not in
 161 UTF-8, it would be a one-to-one mirror.
 162
 163 -----------------------------------------------------
 164 $ git fast-export master~5..master |
 165         sed "s|refs/heads/master|refs/heads/other|" |
 166         git fast-import
 167 -----------------------------------------------------
 168
 169 This makes a new branch called 'other' from 'master~5..master'
 170 (i.e. if 'master' has linear history, it will take the last 5 commits).
 171
 172 Note that this assumes that none of the blobs and commit messages
 173 referenced by that revision range contains the string
 174 'refs/heads/master'.
 175
 176
 177 ANONYMIZING
 178 -----------
 179
 180 If the `--anonymize` option is given, git will attempt to remove all
 181 identifying information from the repository while still retaining enough
 182 of the original tree and history patterns to reproduce some bugs. The
 183 goal is that a git bug which is found on a private repository will
 184 persist in the anonymized repository, and the latter can be shared with
 185 git developers to help solve the bug.
 186
 187 With this option, git will replace all refnames, paths, blob contents,
 188 commit and tag messages, names, and email addresses in the output with
 189 anonymized data.  Two instances of the same string will be replaced
 190 equivalently (e.g., two commits with the same author will have the same
 191 anonymized author in the output, but bear no resemblance to the original
 192 author string). The relationship between commits, branches, and tags is
 193 retained, as well as the commit timestamps (but the commit messages and
 194 refnames bear no resemblance to the originals). The relative makeup of
 195 the tree is retained (e.g., if you have a root tree with 10 files and 3
 196 trees, so will the output), but their names and the contents of the
 197 files will be replaced.
 198
 199 If you think you have found a git bug, you can start by exporting an
 200 anonymized stream of the whole repository:
 201
 202 ---------------------------------------------------
 203 $ git fast-export --anonymize --all >anon-stream
 204 ---------------------------------------------------
 205
 206 Then confirm that the bug persists in a repository created from that
 207 stream (many bugs will not, as they really do depend on the exact
 208 repository contents):
 209
 210 ---------------------------------------------------
 211 $ git init anon-repo
 212 $ cd anon-repo
 213 $ git fast-import <../anon-stream
 214 $ ... test your bug ...
 215 ---------------------------------------------------
 216
 217 If the anonymized repository shows the bug, it may be worth sharing
 218 `anon-stream` along with a regular bug report. Note that the anonymized
 219 stream compresses very well, so gzipping it is encouraged. If you want
 220 to examine the stream to see that it does not contain any private data,
 221 you can peruse it directly before sending. You may also want to try:
 222
 223 ---------------------------------------------------
 224 $ perl -pe 's/\d+/X/g' <anon-stream | sort -u | less
 225 ---------------------------------------------------
 226
 227 which shows all of the unique lines (with numbers converted to "X", to
 228 collapse "User 0", "User 1", etc into "User X"). This produces a much
 229 smaller output, and it is usually easy to quickly confirm that there is
 230 no private data in the stream.
 231
 232
 233 LIMITATIONS
 234 -----------
 235
 236 Since 'git fast-import' cannot tag trees, you will not be
 237 able to export the linux.git repository completely, as it contains
 238 a tag referencing a tree instead of a commit.
 239
 240 SEE ALSO
 241 --------
 242 linkgit:git-fast-import[1]
 243
 244 GIT
 245 ---
 246 Part of the linkgit:git[1] suite