44098595dd6a2e7d303a2ee78f348207813186b8
[git/git.git] / 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 --refspec::
114 Apply the specified refspec to each ref exported. Multiple of them can
115 be specified.
116
117 [<git-rev-list-args>...]::
118 A list of arguments, acceptable to 'git rev-parse' and
119 'git rev-list', that specifies the specific objects and references
120 to export. For example, `master~10..master` causes the
121 current master reference to be exported along with all objects
122 added since its 10th ancestor commit.
123
124 EXAMPLES
125 --------
126
127 -------------------------------------------------------------------
128 $ git fast-export --all | (cd /empty/repository && git fast-import)
129 -------------------------------------------------------------------
130
131 This will export the whole repository and import it into the existing
132 empty repository. Except for reencoding commits that are not in
133 UTF-8, it would be a one-to-one mirror.
134
135 -----------------------------------------------------
136 $ git fast-export master~5..master |
137 sed "s|refs/heads/master|refs/heads/other|" |
138 git fast-import
139 -----------------------------------------------------
140
141 This makes a new branch called 'other' from 'master~5..master'
142 (i.e. if 'master' has linear history, it will take the last 5 commits).
143
144 Note that this assumes that none of the blobs and commit messages
145 referenced by that revision range contains the string
146 'refs/heads/master'.
147
148
149 ANONYMIZING
150 -----------
151
152 If the `--anonymize` option is given, git will attempt to remove all
153 identifying information from the repository while still retaining enough
154 of the original tree and history patterns to reproduce some bugs. The
155 goal is that a git bug which is found on a private repository will
156 persist in the anonymized repository, and the latter can be shared with
157 git developers to help solve the bug.
158
159 With this option, git will replace all refnames, paths, blob contents,
160 commit and tag messages, names, and email addresses in the output with
161 anonymized data. Two instances of the same string will be replaced
162 equivalently (e.g., two commits with the same author will have the same
163 anonymized author in the output, but bear no resemblance to the original
164 author string). The relationship between commits, branches, and tags is
165 retained, as well as the commit timestamps (but the commit messages and
166 refnames bear no resemblance to the originals). The relative makeup of
167 the tree is retained (e.g., if you have a root tree with 10 files and 3
168 trees, so will the output), but their names and the contents of the
169 files will be replaced.
170
171 If you think you have found a git bug, you can start by exporting an
172 anonymized stream of the whole repository:
173
174 ---------------------------------------------------
175 $ git fast-export --anonymize --all >anon-stream
176 ---------------------------------------------------
177
178 Then confirm that the bug persists in a repository created from that
179 stream (many bugs will not, as they really do depend on the exact
180 repository contents):
181
182 ---------------------------------------------------
183 $ git init anon-repo
184 $ cd anon-repo
185 $ git fast-import <../anon-stream
186 $ ... test your bug ...
187 ---------------------------------------------------
188
189 If the anonymized repository shows the bug, it may be worth sharing
190 `anon-stream` along with a regular bug report. Note that the anonymized
191 stream compresses very well, so gzipping it is encouraged. If you want
192 to examine the stream to see that it does not contain any private data,
193 you can peruse it directly before sending. You may also want to try:
194
195 ---------------------------------------------------
196 $ perl -pe 's/\d+/X/g' <anon-stream | sort -u | less
197 ---------------------------------------------------
198
199 which shows all of the unique lines (with numbers converted to "X", to
200 collapse "User 0", "User 1", etc into "User X"). This produces a much
201 smaller output, and it is usually easy to quickly confirm that there is
202 no private data in the stream.
203
204
205 LIMITATIONS
206 -----------
207
208 Since 'git fast-import' cannot tag trees, you will not be
209 able to export the linux.git repository completely, as it contains
210 a tag referencing a tree instead of a commit.
211
212 SEE ALSO
213 --------
214 linkgit:git-fast-import[1]
215
216 GIT
217 ---
218 Part of the linkgit:git[1] suite