GIT-FAST-EXPORT(1) Git Manual GIT-FAST-EXPORT(1)
NAME
git-fast-export - Git data exporter
SYNOPSIS
git fast-export [<options>] | git fast-import
DESCRIPTION
This program dumps the given revisions in a form suitable to be piped
into git fast-import.
You can use it as a human-readable bundle replacement (see git-
bundle(1)), or as a format that can be edited before being fed to git
fast-import in order to do history rewrites (an ability relied on by
tools like git filter-repo).
OPTIONS
--progress=<n>
Insert progress statements every <n> objects, to be shown by git
fast-import during import.
--signed-tags=(verbatim|warn|warn-strip|strip|abort)
Specify how to handle signed tags. Since any transformation after
the export can change the tag names (which can also happen when
excluding revisions) the signatures will not match.
When asking to abort (which is the default), this program will die
when encountering a signed tag. With strip, the tags will silently
be made unsigned, with warn-strip they will be made unsigned but a
warning will be displayed, with verbatim, they will be silently
exported and with warn, they will be exported, but you will see a
warning.
--tag-of-filtered-object=(abort|drop|rewrite)
Specify how to handle tags whose tagged object is filtered out.
Since revisions and files to export can be limited by path, tagged
objects may be filtered completely.
When asking to abort (which is the default), this program will die
when encountering such a tag. With drop it will omit such tags from
the output. With rewrite, if the tagged object is a commit, it will
rewrite the tag to tag an ancestor commit (via parent rewriting;
see git-rev-list(1))
-M, -C
Perform move and/or copy detection, as described in the git-diff(1)
manual page, and use it to generate rename and copy commands in the
output dump.
Note that earlier versions of this command did not complain and
produced incorrect results if you gave these options.
--export-marks=<file>
Dumps the internal marks table to <file> when complete. Marks are
written one per line as :markid SHA-1. Only marks for revisions are
dumped; marks for blobs are ignored. Backends can use this file to
validate imports after they have been completed, or to save the
marks table across incremental runs. As <file> is only opened and
truncated at completion, the same path can also be safely given to
--import-marks. The file will not be written if no new object has
been marked/exported.
--import-marks=<file>
Before processing any input, load the marks specified in <file>.
The input file must exist, must be readable, and must use the same
format as produced by --export-marks.
--mark-tags
In addition to labelling blobs and commits with mark ids, also
label tags. This is useful in conjunction with --export-marks and
--import-marks, and is also useful (and necessary) for exporting of
nested tags. It does not hurt other cases and would be the default,
but many fast-import frontends are not prepared to accept tags with
mark identifiers.
Any commits (or tags) that have already been marked will not be
exported again. If the backend uses a similar --import-marks file,
this allows for incremental bidirectional exporting of the
repository by keeping the marks the same across runs.
--fake-missing-tagger
Some old repositories have tags without a tagger. The fast-import
protocol was pretty strict about that, and did not allow that. So
fake a tagger to be able to fast-import the output.
--use-done-feature
Start the stream with a feature done stanza, and terminate it with
a done command.
--no-data
Skip output of blob objects and instead refer to blobs via their
original SHA-1 hash. This is useful when rewriting the directory
structure or history of a repository without touching the contents
of individual files. Note that the resulting stream can only be
used by a repository which already contains the necessary objects.
--full-tree
This option will cause fast-export to issue a "deleteall" directive
for each commit followed by a full list of all files in the commit
(as opposed to just listing the files which are different from the
commit's first parent).
--anonymize
Anonymize the contents of the repository while still retaining the
shape of the history and stored tree. See the section on
ANONYMIZING below.
--reference-excluded-parents
By default, running a command such as git fast-export
master~5..master will not include the commit master~5 and will make
master~4 no longer have master~5 as a parent (though both the old
master~4 and new master~4 will have all the same files). Use
--reference-excluded-parents to instead have the stream refer to
commits in the excluded range of history by their sha1sum. Note
that the resulting stream can only be used by a repository which
already contains the necessary parent commits.
--show-original-ids
Add an extra directive to the output for commits and blobs,
original-oid <SHA1SUM>. While such directives will likely be
ignored by importers such as git-fast-import, it may be useful for
intermediary filters (e.g. for rewriting commit messages which
refer to older commits, or for stripping blobs by id).
--reencode=(yes|no|abort)
Specify how to handle encoding header in commit objects. When
asking to abort (which is the default), this program will die when
encountering such a commit object. With yes, the commit message
will be re-encoded into UTF-8. With no, the original encoding will
be preserved.
--refspec
Apply the specified refspec to each ref exported. Multiple of them
can be specified.
[<git-rev-list-args>...]
A list of arguments, acceptable to git rev-parse and git rev-list,
that specifies the specific objects and references to export. For
example, master~10..master causes the current master reference to
be exported along with all objects added since its 10th ancestor
commit and (unless the --reference-excluded-parents option is
specified) all files common to master~9 and master~10.
EXAMPLES
$ git fast-export --all | (cd /empty/repository && git fast-import)
This will export the whole repository and import it into the existing
empty repository. Except for reencoding commits that are not in UTF-8,
it would be a one-to-one mirror.
$ git fast-export master~5..master |
sed "s|refs/heads/master|refs/heads/other|" |
git fast-import
This makes a new branch called other from master~5..master (i.e. if
master has linear history, it will take the last 5 commits).
Note that this assumes that none of the blobs and commit messages
referenced by that revision range contains the string
refs/heads/master.
ANONYMIZING
If the --anonymize option is given, git will attempt to remove all
identifying information from the repository while still retaining
enough of the original tree and history patterns to reproduce some
bugs. The goal is that a git bug which is found on a private repository
will persist in the anonymized repository, and the latter can be shared
with git developers to help solve the bug.
With this option, git will replace all refnames, paths, blob contents,
commit and tag messages, names, and email addresses in the output with
anonymized data. Two instances of the same string will be replaced
equivalently (e.g., two commits with the same author will have the same
anonymized author in the output, but bear no resemblance to the
original author string). The relationship between commits, branches,
and tags is retained, as well as the commit timestamps (but the commit
messages and refnames bear no resemblance to the originals). The
relative makeup of the tree is retained (e.g., if you have a root tree
with 10 files and 3 trees, so will the output), but their names and the
contents of the files will be replaced.
If you think you have found a git bug, you can start by exporting an
anonymized stream of the whole repository:
$ git fast-export --anonymize --all >anon-stream
Then confirm that the bug persists in a repository created from that
stream (many bugs will not, as they really do depend on the exact
repository contents):
$ git init anon-repo
$ cd anon-repo
$ git fast-import <../anon-stream
$ ... test your bug ...
If the anonymized repository shows the bug, it may be worth sharing
anon-stream along with a regular bug report. Note that the anonymized
stream compresses very well, so gzipping it is encouraged. If you want
to examine the stream to see that it does not contain any private data,
you can peruse it directly before sending. You may also want to try:
$ perl -pe 's/\d+/X/g' <anon-stream | sort -u | less
which shows all of the unique lines (with numbers converted to "X", to
collapse "User 0", "User 1", etc into "User X"). This produces a much
smaller output, and it is usually easy to quickly confirm that there is
no private data in the stream.
LIMITATIONS
Since git fast-import cannot tag trees, you will not be able to export
the linux.git repository completely, as it contains a tag referencing a
tree instead of a commit.
SEE ALSO
git-fast-import(1)
GIT
Part of the git(1) suite
Git 2.27.0 06/01/2020 GIT-FAST-EXPORT(1)