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c401b33c JS |
1 | git-filter-branch(1) |
2 | ==================== | |
3 | ||
4 | NAME | |
5 | ---- | |
6 | git-filter-branch - Rewrite branches | |
7 | ||
8 | SYNOPSIS | |
9 | -------- | |
10 | [verse] | |
b1889c36 | 11 | 'git filter-branch' [--env-filter <command>] [--tree-filter <command>] |
c401b33c JS |
12 | [--index-filter <command>] [--parent-filter <command>] |
13 | [--msg-filter <command>] [--commit-filter <command>] | |
14 | [--tag-name-filter <command>] [--subdirectory-filter <directory>] | |
5433235d | 15 | [--original <namespace>] [-d <directory>] [-f | --force] |
8afa4210 | 16 | [--] [<rev-list options>...] |
c401b33c JS |
17 | |
18 | DESCRIPTION | |
19 | ----------- | |
08203668 JS |
20 | Lets you rewrite git revision history by rewriting the branches mentioned |
21 | in the <rev-list options>, applying custom filters on each revision. | |
c401b33c JS |
22 | Those filters can modify each tree (e.g. removing a file or running |
23 | a perl rewrite on all files) or information about each commit. | |
24 | Otherwise, all information (including original commit times or merge | |
25 | information) will be preserved. | |
26 | ||
08203668 | 27 | The command will only rewrite the _positive_ refs mentioned in the |
bf7c9021 | 28 | command line (e.g. if you pass 'a..b', only 'b' will be rewritten). |
08203668 JS |
29 | If you specify no filters, the commits will be recommitted without any |
30 | changes, which would normally have no effect. Nevertheless, this may be | |
31 | useful in the future for compensating for some git bugs or such, | |
32 | therefore such a usage is permitted. | |
c401b33c | 33 | |
73616fd3 | 34 | *WARNING*! The rewritten history will have different object names for all |
c401b33c JS |
35 | the objects and will not converge with the original branch. You will not |
36 | be able to easily push and distribute the rewritten branch on top of the | |
37 | original branch. Please do not use this command if you do not know the | |
38 | full implications, and avoid using it anyway, if a simple single commit | |
39 | would suffice to fix your problem. | |
40 | ||
dfd05e38 JS |
41 | Always verify that the rewritten version is correct: The original refs, |
42 | if different from the rewritten ones, will be stored in the namespace | |
43 | 'refs/original/'. | |
c401b33c | 44 | |
bf7c9021 | 45 | Note that since this operation is very I/O expensive, it might |
08203668 JS |
46 | be a good idea to redirect the temporary directory off-disk with the |
47 | '-d' option, e.g. on tmpfs. Reportedly the speedup is very noticeable. | |
c401b33c JS |
48 | |
49 | ||
50 | Filters | |
51 | ~~~~~~~ | |
52 | ||
53 | The filters are applied in the order as listed below. The <command> | |
bf7c9021 RW |
54 | argument is always evaluated in the shell context using the 'eval' command |
55 | (with the notable exception of the commit filter, for technical reasons). | |
c401b33c JS |
56 | Prior to that, the $GIT_COMMIT environment variable will be set to contain |
57 | the id of the commit being rewritten. Also, GIT_AUTHOR_NAME, | |
58 | GIT_AUTHOR_EMAIL, GIT_AUTHOR_DATE, GIT_COMMITTER_NAME, GIT_COMMITTER_EMAIL, | |
bf7c9021 RW |
59 | and GIT_COMMITTER_DATE are set according to the current commit. The values |
60 | of these variables after the filters have run, are used for the new commit. | |
61 | If any evaluation of <command> returns a non-zero exit status, the whole | |
62 | operation will be aborted. | |
c401b33c JS |
63 | |
64 | A 'map' function is available that takes an "original sha1 id" argument | |
65 | and outputs a "rewritten sha1 id" if the commit has been already | |
32c37c12 JS |
66 | rewritten, and "original sha1 id" otherwise; the 'map' function can |
67 | return several ids on separate lines if your commit filter emitted | |
68 | multiple commits. | |
c401b33c JS |
69 | |
70 | ||
71 | OPTIONS | |
72 | ------- | |
73 | ||
74 | --env-filter <command>:: | |
bf7c9021 RW |
75 | This filter may be used if you only need to modify the environment |
76 | in which the commit will be performed. Specifically, you might | |
77 | want to rewrite the author/committer name/email/time environment | |
5162e697 | 78 | variables (see linkgit:git-commit[1] for details). Do not forget |
c401b33c JS |
79 | to re-export the variables. |
80 | ||
81 | --tree-filter <command>:: | |
82 | This is the filter for rewriting the tree and its contents. | |
83 | The argument is evaluated in shell with the working | |
84 | directory set to the root of the checked out tree. The new tree | |
85 | is then used as-is (new files are auto-added, disappeared files | |
86 | are auto-removed - neither .gitignore files nor any other ignore | |
73616fd3 | 87 | rules *HAVE ANY EFFECT*!). |
c401b33c JS |
88 | |
89 | --index-filter <command>:: | |
90 | This is the filter for rewriting the index. It is similar to the | |
91 | tree filter but does not check out the tree, which makes it much | |
5162e697 | 92 | faster. For hairy cases, see linkgit:git-update-index[1]. |
c401b33c JS |
93 | |
94 | --parent-filter <command>:: | |
95 | This is the filter for rewriting the commit's parent list. | |
96 | It will receive the parent string on stdin and shall output | |
97 | the new parent string on stdout. The parent string is in | |
483bc4f0 | 98 | the format described in linkgit:git-commit-tree[1]: empty for |
c401b33c JS |
99 | the initial commit, "-p parent" for a normal commit and |
100 | "-p parent1 -p parent2 -p parent3 ..." for a merge commit. | |
101 | ||
102 | --msg-filter <command>:: | |
103 | This is the filter for rewriting the commit messages. | |
104 | The argument is evaluated in the shell with the original | |
105 | commit message on standard input; its standard output is | |
106 | used as the new commit message. | |
107 | ||
108 | --commit-filter <command>:: | |
109 | This is the filter for performing the commit. | |
110 | If this filter is specified, it will be called instead of the | |
ba020ef5 | 111 | 'git-commit-tree' command, with arguments of the form |
c401b33c JS |
112 | "<TREE_ID> [-p <PARENT_COMMIT_ID>]..." and the log message on |
113 | stdin. The commit id is expected on stdout. | |
114 | + | |
115 | As a special extension, the commit filter may emit multiple | |
c5833f6e | 116 | commit ids; in that case, the rewritten children of the original commit will |
c401b33c | 117 | have all of them as parents. |
f95eef15 JS |
118 | + |
119 | You can use the 'map' convenience function in this filter, and other | |
120 | convenience functions, too. For example, calling 'skip_commit "$@"' | |
121 | will leave out the current commit (but not its changes! If you want | |
ba020ef5 | 122 | that, use 'git-rebase' instead). |
c401b33c JS |
123 | |
124 | --tag-name-filter <command>:: | |
125 | This is the filter for rewriting tag names. When passed, | |
126 | it will be called for every tag ref that points to a rewritten | |
127 | object (or to a tag object which points to a rewritten object). | |
128 | The original tag name is passed via standard input, and the new | |
129 | tag name is expected on standard output. | |
130 | + | |
131 | The original tags are not deleted, but can be overwritten; | |
5876b8ee | 132 | use "--tag-name-filter cat" to simply update the tags. In this |
c401b33c JS |
133 | case, be very careful and make sure you have the old tags |
134 | backed up in case the conversion has run afoul. | |
135 | + | |
1bf6551e BC |
136 | Nearly proper rewriting of tag objects is supported. If the tag has |
137 | a message attached, a new tag object will be created with the same message, | |
138 | author, and timestamp. If the tag has a signature attached, the | |
139 | signature will be stripped. It is by definition impossible to preserve | |
140 | signatures. The reason this is "nearly" proper, is because ideally if | |
141 | the tag did not change (points to the same object, has the same name, etc.) | |
142 | it should retain any signature. That is not the case, signatures will always | |
143 | be removed, buyer beware. There is also no support for changing the | |
144 | author or timestamp (or the tag message for that matter). Tags which point | |
145 | to other tags will be rewritten to point to the underlying commit. | |
c401b33c JS |
146 | |
147 | --subdirectory-filter <directory>:: | |
73616fd3 JS |
148 | Only look at the history which touches the given subdirectory. |
149 | The result will contain that directory (and only that) as its | |
150 | project root. | |
c401b33c | 151 | |
5433235d GB |
152 | --original <namespace>:: |
153 | Use this option to set the namespace where the original commits | |
154 | will be stored. The default value is 'refs/original'. | |
155 | ||
c401b33c JS |
156 | -d <directory>:: |
157 | Use this option to set the path to the temporary directory used for | |
158 | rewriting. When applying a tree filter, the command needs to | |
bf7c9021 | 159 | temporarily check out the tree to some directory, which may consume |
c401b33c JS |
160 | considerable space in case of large projects. By default it |
161 | does this in the '.git-rewrite/' directory but you can override | |
162 | that choice by this parameter. | |
163 | ||
3240240f SB |
164 | -f:: |
165 | --force:: | |
ba020ef5 | 166 | 'git-filter-branch' refuses to start with an existing temporary |
dfd05e38 JS |
167 | directory or when there are already refs starting with |
168 | 'refs/original/', unless forced. | |
169 | ||
f448e24e | 170 | <rev-list options>...:: |
8afa4210 TR |
171 | Arguments for 'git-rev-list'. All positive refs included by |
172 | these options are rewritten. You may also specify options | |
173 | such as '--all', but you must use '--' to separate them from | |
174 | the 'git-filter-branch' options. | |
c401b33c JS |
175 | |
176 | ||
177 | Examples | |
178 | -------- | |
179 | ||
180 | Suppose you want to remove a file (containing confidential information | |
181 | or copyright violation) from all commits: | |
182 | ||
183 | ------------------------------------------------------- | |
dfd05e38 | 184 | git filter-branch --tree-filter 'rm filename' HEAD |
c401b33c JS |
185 | ------------------------------------------------------- |
186 | ||
e4d594c6 JL |
187 | However, if the file is absent from the tree of some commit, |
188 | a simple `rm filename` will fail for that tree and commit. | |
189 | Thus you may instead want to use `rm -f filename` as the script. | |
190 | ||
c401b33c JS |
191 | A significantly faster version: |
192 | ||
dfd05e38 | 193 | -------------------------------------------------------------------------- |
eb72a514 | 194 | git filter-branch --index-filter 'git rm --cached filename' HEAD |
dfd05e38 | 195 | -------------------------------------------------------------------------- |
c401b33c | 196 | |
8ef44519 | 197 | Now, you will get the rewritten history saved in HEAD. |
c401b33c | 198 | |
8afa4210 TR |
199 | To rewrite the repository to look as if `foodir/` had been its project |
200 | root, and discard all other history: | |
201 | ||
202 | ------------------------------------------------------- | |
203 | git filter-branch --subdirectory-filter foodir -- --all | |
204 | ------------------------------------------------------- | |
205 | ||
206 | Thus you can, e.g., turn a library subdirectory into a repository of | |
207 | its own. Note the `\--` that separates 'filter-branch' options from | |
208 | revision options, and the `\--all` to rewrite all branches and tags. | |
209 | ||
32c37c12 JS |
210 | To set a commit (which typically is at the tip of another |
211 | history) to be the parent of the current initial commit, in | |
212 | order to paste the other history behind the current history: | |
c401b33c | 213 | |
dfd05e38 JS |
214 | ------------------------------------------------------------------- |
215 | git filter-branch --parent-filter 'sed "s/^\$/-p <graft-id>/"' HEAD | |
216 | ------------------------------------------------------------------- | |
c401b33c | 217 | |
08203668 JS |
218 | (if the parent string is empty - which happens when we are dealing with |
219 | the initial commit - add graftcommit as a parent). Note that this assumes | |
c401b33c JS |
220 | history with a single root (that is, no merge without common ancestors |
221 | happened). If this is not the case, use: | |
222 | ||
dfd05e38 | 223 | -------------------------------------------------------------------------- |
c401b33c | 224 | git filter-branch --parent-filter \ |
41e86a37 | 225 | 'test $GIT_COMMIT = <commit-id> && echo "-p <graft-id>" || cat' HEAD |
dfd05e38 | 226 | -------------------------------------------------------------------------- |
c401b33c | 227 | |
32c37c12 JS |
228 | or even simpler: |
229 | ||
230 | ----------------------------------------------- | |
231 | echo "$commit-id $graft-id" >> .git/info/grafts | |
dfd05e38 | 232 | git filter-branch $graft-id..HEAD |
32c37c12 JS |
233 | ----------------------------------------------- |
234 | ||
c401b33c JS |
235 | To remove commits authored by "Darl McBribe" from the history: |
236 | ||
237 | ------------------------------------------------------------------------------ | |
238 | git filter-branch --commit-filter ' | |
239 | if [ "$GIT_AUTHOR_NAME" = "Darl McBribe" ]; | |
240 | then | |
f95eef15 | 241 | skip_commit "$@"; |
c401b33c JS |
242 | else |
243 | git commit-tree "$@"; | |
dfd05e38 | 244 | fi' HEAD |
c401b33c JS |
245 | ------------------------------------------------------------------------------ |
246 | ||
8451c565 | 247 | The function 'skip_commit' is defined as follows: |
f95eef15 JS |
248 | |
249 | -------------------------- | |
250 | skip_commit() | |
251 | { | |
252 | shift; | |
253 | while [ -n "$1" ]; | |
254 | do | |
255 | shift; | |
256 | map "$1"; | |
257 | shift; | |
258 | done; | |
259 | } | |
260 | -------------------------- | |
261 | ||
c401b33c JS |
262 | The shift magic first throws away the tree id and then the -p |
263 | parameters. Note that this handles merges properly! In case Darl | |
264 | committed a merge between P1 and P2, it will be propagated properly | |
265 | and all children of the merge will become merge commits with P1,P2 | |
266 | as their parents instead of the merge commit. | |
267 | ||
a1748890 | 268 | You can rewrite the commit log messages using `--msg-filter`. For |
ba020ef5 | 269 | example, 'git-svn-id' strings in a repository created by 'git-svn' can |
ed10d9aa MV |
270 | be removed this way: |
271 | ||
272 | ------------------------------------------------------- | |
a1748890 | 273 | git filter-branch --msg-filter ' |
ed10d9aa MV |
274 | sed -e "/^git-svn-id:/d" |
275 | ' | |
276 | ------------------------------------------------------- | |
f95eef15 | 277 | |
c401b33c JS |
278 | To restrict rewriting to only part of the history, specify a revision |
279 | range in addition to the new branch name. The new branch name will | |
ba020ef5 | 280 | point to the top-most revision that a 'git-rev-list' of this range |
c401b33c JS |
281 | will print. |
282 | ||
08203668 JS |
283 | *NOTE* the changes introduced by the commits, and which are not reverted |
284 | by subsequent commits, will still be in the rewritten branch. If you want | |
c401b33c | 285 | to throw out _changes_ together with the commits, you should use the |
ba020ef5 | 286 | interactive mode of 'git-rebase'. |
c401b33c | 287 | |
08203668 | 288 | |
c401b33c JS |
289 | Consider this history: |
290 | ||
291 | ------------------ | |
292 | D--E--F--G--H | |
293 | / / | |
294 | A--B-----C | |
295 | ------------------ | |
296 | ||
297 | To rewrite only commits D,E,F,G,H, but leave A, B and C alone, use: | |
298 | ||
299 | -------------------------------- | |
dfd05e38 | 300 | git filter-branch ... C..H |
c401b33c JS |
301 | -------------------------------- |
302 | ||
303 | To rewrite commits E,F,G,H, use one of these: | |
304 | ||
305 | ---------------------------------------- | |
dfd05e38 JS |
306 | git filter-branch ... C..H --not D |
307 | git filter-branch ... D..H --not C | |
c401b33c JS |
308 | ---------------------------------------- |
309 | ||
310 | To move the whole tree into a subdirectory, or remove it from there: | |
311 | ||
312 | --------------------------------------------------------------- | |
313 | git filter-branch --index-filter \ | |
314 | 'git ls-files -s | sed "s-\t-&newsubdir/-" | | |
315 | GIT_INDEX_FILE=$GIT_INDEX_FILE.new \ | |
316 | git update-index --index-info && | |
dfd05e38 | 317 | mv $GIT_INDEX_FILE.new $GIT_INDEX_FILE' HEAD |
c401b33c JS |
318 | --------------------------------------------------------------- |
319 | ||
320 | ||
321 | Author | |
322 | ------ | |
323 | Written by Petr "Pasky" Baudis <pasky@suse.cz>, | |
324 | and the git list <git@vger.kernel.org> | |
325 | ||
326 | Documentation | |
327 | -------------- | |
328 | Documentation by Petr Baudis and the git list. | |
329 | ||
330 | GIT | |
331 | --- | |
9e1f0a85 | 332 | Part of the linkgit:git[1] suite |