git-fast-export.1 (12905B)
- '\" t
- .\" Title: git-fast-export
- .\" Author: [FIXME: author] [see http://www.docbook.org/tdg5/en/html/author]
- .\" Generator: DocBook XSL Stylesheets v1.79.2 <http://docbook.sf.net/>
- .\" Date: 2025-03-14
- .\" Manual: Git Manual
- .\" Source: Git 2.49.0
- .\" Language: English
- .\"
- .TH "GIT\-FAST\-EXPORT" "1" "2025-03-14" "Git 2\&.49\&.0" "Git Manual"
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- .\" * Define some portability stuff
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- .\" http://bugs.debian.org/507673
- .\" http://lists.gnu.org/archive/html/groff/2009-02/msg00013.html
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- .\" * MAIN CONTENT STARTS HERE *
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- .SH "NAME"
- git-fast-export \- Git data exporter
- .SH "SYNOPSIS"
- .sp
- .nf
- \fIgit fast\-export\fR [<options>] | \fIgit fast\-import\fR
- .fi
- .SH "DESCRIPTION"
- .sp
- This program dumps the given revisions in a form suitable to be piped into \fIgit fast\-import\fR\&.
- .sp
- You can use it as a human\-readable bundle replacement (see \fBgit-bundle\fR(1)), or as a format that can be edited before being fed to \fIgit fast\-import\fR in order to do history rewrites (an ability relied on by tools like \fIgit filter\-repo\fR)\&.
- .SH "OPTIONS"
- .PP
- \-\-progress=<n>
- .RS 4
- Insert
- \fIprogress\fR
- statements every <n> objects, to be shown by
- \fIgit fast\-import\fR
- during import\&.
- .RE
- .PP
- \-\-signed\-tags=(verbatim|warn|warn\-strip|strip|abort)
- .RS 4
- 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\&.
- .sp
- When asking to
- \fIabort\fR
- (which is the default), this program will die when encountering a signed tag\&. With
- \fIstrip\fR, the tags will silently be made unsigned, with
- \fIwarn\-strip\fR
- they will be made unsigned but a warning will be displayed, with
- \fIverbatim\fR, they will be silently exported and with
- \fIwarn\fR, they will be exported, but you will see a warning\&.
- .RE
- .PP
- \-\-tag\-of\-filtered\-object=(abort|drop|rewrite)
- .RS 4
- 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\&.
- .sp
- When asking to
- \fIabort\fR
- (which is the default), this program will die when encountering such a tag\&. With
- \fIdrop\fR
- it will omit such tags from the output\&. With
- \fIrewrite\fR, if the tagged object is a commit, it will rewrite the tag to tag an ancestor commit (via parent rewriting; see
- \fBgit-rev-list\fR(1))\&.
- .RE
- .PP
- \-M, \-C
- .RS 4
- Perform move and/or copy detection, as described in the
- \fBgit-diff\fR(1)
- manual page, and use it to generate rename and copy commands in the output dump\&.
- .sp
- Note that earlier versions of this command did not complain and produced incorrect results if you gave these options\&.
- .RE
- .PP
- \-\-export\-marks=<file>
- .RS 4
- Dumps the internal marks table to <file> when complete\&. Marks are written one per line as
- \fB:markid\fR
- \fBSHA\-1\fR\&. 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\&.
- .RE
- .PP
- \-\-import\-marks=<file>
- .RS 4
- 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\&.
- .RE
- .PP
- \-\-mark\-tags
- .RS 4
- In addition to labelling blobs and commits with mark ids, also label tags\&. This is useful in conjunction with
- \fB\-\-export\-marks\fR
- and
- \fB\-\-import\-marks\fR, 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\&.
- .sp
- 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\&.
- .RE
- .PP
- \-\-fake\-missing\-tagger
- .RS 4
- 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\&.
- .RE
- .PP
- \-\-use\-done\-feature
- .RS 4
- Start the stream with a
- \fIfeature done\fR
- stanza, and terminate it with a
- \fIdone\fR
- command\&.
- .RE
- .PP
- \-\-no\-data
- .RS 4
- 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\&.
- .RE
- .PP
- \-\-full\-tree
- .RS 4
- 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\(cqs first parent)\&.
- .RE
- .PP
- \-\-anonymize
- .RS 4
- Anonymize the contents of the repository while still retaining the shape of the history and stored tree\&. See the section on
- \fBANONYMIZING\fR
- below\&.
- .RE
- .PP
- \-\-anonymize\-map=<from>[:<to>]
- .RS 4
- Convert token
- \fI<from>\fR
- to
- \fI<to>\fR
- in the anonymized output\&. If
- \fI<to>\fR
- is omitted, map
- \fI<from>\fR
- to itself (i\&.e\&., do not anonymize it)\&. See the section on
- \fBANONYMIZING\fR
- below\&.
- .RE
- .PP
- \-\-reference\-excluded\-parents
- .RS 4
- By default, running a command such as
- \fBgit\fR
- \fBfast\-export\fR
- \fBmaster~5\fR\fB\&.\&.\fR\fBmaster\fR
- 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\&.
- .RE
- .PP
- \-\-show\-original\-ids
- .RS 4
- Add an extra directive to the output for commits and blobs,
- \fBoriginal\-oid\fR
- \fI<SHA1SUM>\fR\&. 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)\&.
- .RE
- .PP
- \-\-reencode=(yes|no|abort)
- .RS 4
- Specify how to handle
- \fBencoding\fR
- header in commit objects\&. When asking to
- \fIabort\fR
- (which is the default), this program will die when encountering such a commit object\&. With
- \fIyes\fR, the commit message will be re\-encoded into UTF\-8\&. With
- \fIno\fR, the original encoding will be preserved\&.
- .RE
- .PP
- \-\-refspec
- .RS 4
- Apply the specified refspec to each ref exported\&. Multiple of them can be specified\&.
- .RE
- .PP
- [<git\-rev\-list\-args>\&...\:]
- .RS 4
- A list of arguments, acceptable to
- \fIgit rev\-parse\fR
- and
- \fIgit rev\-list\fR, that specifies the specific objects and references to export\&. For example,
- \fBmaster~10\fR\fB\&.\&.\fR\fBmaster\fR
- 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\&.
- .RE
- .SH "EXAMPLES"
- .sp
- .if n \{\
- .RS 4
- .\}
- .nf
- $ git fast\-export \-\-all | (cd /empty/repository && git fast\-import)
- .fi
- .if n \{\
- .RE
- .\}
- .sp
- 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\&.
- .sp
- .if n \{\
- .RS 4
- .\}
- .nf
- $ git fast\-export master~5\&.\&.master |
- sed "s|refs/heads/master|refs/heads/other|" |
- git fast\-import
- .fi
- .if n \{\
- .RE
- .\}
- .sp
- This makes a new branch called \fIother\fR from \fImaster~5\&.\&.master\fR (i\&.e\&. if \fImaster\fR has linear history, it will take the last 5 commits)\&.
- .sp
- Note that this assumes that none of the blobs and commit messages referenced by that revision range contains the string \fIrefs/heads/master\fR\&.
- .SH "ANONYMIZING"
- .sp
- If the \fB\-\-anonymize\fR 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\&.
- .sp
- 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\&.
- .sp
- If you think you have found a git bug, you can start by exporting an anonymized stream of the whole repository:
- .sp
- .if n \{\
- .RS 4
- .\}
- .nf
- $ git fast\-export \-\-anonymize \-\-all >anon\-stream
- .fi
- .if n \{\
- .RE
- .\}
- .sp
- 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):
- .sp
- .if n \{\
- .RS 4
- .\}
- .nf
- $ git init anon\-repo
- $ cd anon\-repo
- $ git fast\-import <\&.\&./anon\-stream
- $ \&.\&.\&. test your bug \&.\&.\&.
- .fi
- .if n \{\
- .RE
- .\}
- .sp
- If the anonymized repository shows the bug, it may be worth sharing \fBanon\-stream\fR 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:
- .sp
- .if n \{\
- .RS 4
- .\}
- .nf
- $ perl \-pe \*(Aqs/\ed+/X/g\*(Aq <anon\-stream | sort \-u | less
- .fi
- .if n \{\
- .RE
- .\}
- .sp
- 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\&.
- .sp
- 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 \fBgit\fR \fBrev\-list\fR \fBsensitive\fR \fB\-\-\fR \fBsecret\&.c\fR, you can run:
- .sp
- .if n \{\
- .RS 4
- .\}
- .nf
- $ git fast\-export \-\-anonymize \-\-all \e
- \-\-anonymize\-map=sensitive:foo \e
- \-\-anonymize\-map=secret\&.c:bar\&.c \e
- >stream
- .fi
- .if n \{\
- .RE
- .\}
- .sp
- After importing the stream, you can then run \fBgit\fR \fBrev\-list\fR \fBfoo\fR \fB\-\-\fR \fBbar\&.c\fR in the anonymized repository\&.
- .sp
- Note that paths and refnames are split into tokens at slash boundaries\&. The command above would anonymize \fBsubdir/secret\&.c\fR as something like \fBpath123/bar\&.c\fR; you could then search for \fBbar\&.c\fR in the anonymized repository to determine the final pathname\&.
- .sp
- To make referencing the final pathname simpler, you can map each path component; so if you also anonymize \fBsubdir\fR to \fBpublicdir\fR, then the final pathname would be \fBpublicdir/bar\&.c\fR\&.
- .SH "LIMITATIONS"
- .sp
- Since \fIgit fast\-import\fR 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\&.
- .SH "SEE ALSO"
- .sp
- \fBgit-fast-import\fR(1)
- .SH "GIT"
- .sp
- Part of the \fBgit\fR(1) suite