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HTML rendering created 2024-06-26 by Michael Kerrisk, author of The Linux Programming Interface. For details of in-depth Linux/UNIX system programming training courses that I teach, look here. Hosting by jambit GmbH. |
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NAME | SYNOPSIS | DESCRIPTION | OPTIONS | EXAMPLES | ANONYMIZING | LIMITATIONS | SEE ALSO | GIT | COLOPHON |
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GIT-FAST-EXPORT(1) Git Manual GIT-FAST-EXPORT(1)
git-fast-export - Git data exporter
git fast-export [<options>] | git fast-import
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).
--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.
--anonymize-map=<from>[:<to>]
Convert token <from> to <to> in the anonymized output. If
<to> is omitted, map <from> to itself (i.e., do not anonymize
it). 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.
$ 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.
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.
Reproducing some bugs may require referencing particular commits
or paths, which becomes challenging after refnames and paths have
been anonymized. You can ask for a particular token to be left
as-is or mapped to a new value. For example, if you have a bug
which reproduces with git rev-list sensitive -- secret.c, you can
run:
$ git fast-export --anonymize --all \
--anonymize-map=sensitive:foo \
--anonymize-map=secret.c:bar.c \
>stream
After importing the stream, you can then run git rev-list foo --
bar.c in the anonymized repository.
Note that paths and refnames are split into tokens at slash
boundaries. The command above would anonymize subdir/secret.c as
something like path123/bar.c; you could then search for bar.c in
the anonymized repository to determine the final pathname.
To make referencing the final pathname simpler, you can map each
path component; so if you also anonymize subdir to publicdir,
then the final pathname would be publicdir/bar.c.
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.
git-fast-import(1)
Part of the git(1) suite
This page is part of the git (Git distributed version control
system) project. Information about the project can be found at
⟨http://git-scm.com/⟩. If you have a bug report for this manual
page, see ⟨http://git-scm.com/community⟩. This page was obtained
from the project's upstream Git repository
⟨https://github.com/git/git.git⟩ on 2024-06-14. (At that time,
the date of the most recent commit that was found in the
repository was 2024-06-12.) If you discover any rendering
problems in this HTML version of the page, or you believe there
is a better or more up-to-date source for the page, or you have
corrections or improvements to the information in this COLOPHON
(which is not part of the original manual page), send a mail to
[email protected]
Git 2.45.2.492.gd63586 2024-06-12 GIT-FAST-EXPORT(1)
Pages that refer to this page: git(1), git-fast-import(1), gitremote-helpers(7)
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HTML rendering created 2024-06-26 by Michael Kerrisk, author of The Linux Programming Interface. For details of in-depth Linux/UNIX system programming training courses that I teach, look here. Hosting by jambit GmbH. |
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