1CG-ADMIN-REWRITEHIST(1) CG-ADMIN-REWRITEHIST(1)
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6 cg-admin-rewritehist - rewrite revision history
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9 cg-admin-rewritehist [-d TEMPDIR] [-r STARTREV]... [-k KEEPREV]...
10 [FILTERS] DESTBRANCH
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14 Lets you rewrite GIT revision history by creating a new branch from
15 your current branch by applying custom filters on each revision. Those
16 filters can modify each tree (e.g. removing a file or running a perl
17 rewrite on all files) or information about each commit. Otherwise, all
18 information (including original commit times or merge information) will
19 be preserved.
20 The command takes the new branch name as a mandatory argument and the
22 filters as optional arguments. If you specify no filters, the commits
23 will be recommitted without any changes, which would normally have no
24 effect and result with the new branch pointing to the same branch as
25 your current branch. (Nevertheless, this may be useful in the future
26 for compensating for some Git bugs or such, therefore such a usage is
27 permitted.)
28 WARNING! The rewritten history will have different ids for all the
30 objects and will not converge with the original branch. You will not be
31 able to easily push and distribute the rewritten branch. Please do not
32 use this command if you do not know the full implications, and avoid
33 using it anyway - do not do what a simple single commit on top of the
34 current version would fix.
35 Always verify that the rewritten version is correct before disposing
37 the original branch.
38
41 -d TEMPDIR
42 When applying a tree filter, the command needs to temporary
43 checkout the tree to some directory, which may consume
44 considerable space in case of large projects. By default it does
45 this in the .git-rewrite/ directory but you can override that
46 choice by this parameter.
47 -r STARTREV
49 Normally, the command will rewrite the entire history. If you
50 pass this argument, though, this will be the first commit it
51 will rewrite and keep the previous commits intact.
52 -k KEEPREV
54 If you pass this argument, this commit and all of its
55 predecessors are kept intact.
56 -h, --help
58 Print usage summary.
59 --long-help
61 Print user manual. The same as found in cg-admin-rewritehist(1).
62 Filters
64 The filters are applied in the order as listed below. The COMMAND
65 argument is always evaluated in shell using the eval command. The
66 $GIT_COMMIT environment variable is permanently set to contain the id
67 of the commit being rewritten. The author/committer environment
68 variables are set before the first filter is run.
69 A map function is available that takes an "original sha1 id" argument
71 and outputs a "rewritten sha1 id" if the commit has been already
72 rewritten, fails otherwise; the map function can return several ids on
73 separate lines if your commit filter emitted multiple commits (see
74 below).
75 --env-filter COMMAND
78 This is the filter for modifying the environment in which the
79 commit will be performed. Specifically, you might want to
80 rewrite the author/committer name/email/time environment
81 variables (see cg-commit(1) for details). Do not forget to
82 re-export the variables.
83 --tree-filter COMMAND
85 This is the filter for rewriting the tree and its contents. The
86 COMMAND argument is evaluated in shell with the working
87 directory set to the root of the checked out tree. The new tree
88 is then used as-is (new files are auto-added, disappeared files
89 are auto-removed - .gitignore files nor any other ignore rules
90 HAVE NO EFFECT!).
91 --index-filter COMMAND
93 This is the filter for rewriting the Git's directory index. It
94 is similar to the tree filter but does not check out the tree,
95 which makes it much faster. However, you must use the lowlevel
96 Git index manipulation commands to do your work.
97 --parent-filter COMMAND
99 This is the filter for rewriting the commit's parent list. It
100 will receive the parent string on stdin and shall output the new
101 parent string on stdout. The parent string is in format accepted
102 by git-commit-tree: empty for initial commit, "-p parent" for a
103 normal commit and "-p parent1 -p parent2 -p parent3 ..." for a
104 merge commit.
105 --msg-filter COMMAND
107 This is the filter for rewriting the commit messages. The
108 COMMAND argument is evaluated in shell with the original commit
109 message on standard input; its standard output is is used as the
110 new commit message.
111 --commit-filter COMMAND
113 If this filter is passed, it will be called instead of the
114 git-commit-tree command, with those arguments:
115 TREE_ID [-p PARENT_COMMIT_ID]...
117 and the log message on stdin. The commit id is expected on
119 stdout. As a special extension, the commit filter may emit
120 multiple commit ids; in that case, all of them will be used
121 as parents instead of the original commit in further commits.
122
124 Suppose you want to remove a file (containing confidential information
125 or copyright violation) from all commits:
126 cg-admin-rewritehist --tree-filter 'rm filename' newbranch
129 A significantly faster version:
130 cg-admin-rewritehist --index-filter 'git-update-index --remove filename' newbranch
133 Now, you will get the rewritten history saved in the branch newbranch
134 (your current branch is left untouched).
135 To "etch-graft" a commit to the revision history (set a commit to be
137 the parent of the current initial commit and propagate that):
138 cg-admin-rewritehist --parent-filter sed\ 's/^$/-p graftcommitid/' newbranch
141 (if the parent string is empty - therefore we are dealing with the
142 initial commit - add graftcommit as a parent). Note that this assumes
143 history with a single root (that is, no cg-merge -j happened). If this
144 is not the case, use:
145 cg-admin-rewritehist --parent-filter 'cat; [ "$GIT_COMMIT" = "COMMIT" ] && echo "-p GRAFTCOMMIT"' newbranch
148 To remove commits authored by "Darl McBribe" from the history:
149 cg-admin-rewritehist --commit-filter 'if [ "$GIT_AUTHOR_NAME" = "Darl McBribe" ]; then shift; while [ -n "$1" ]; do shift; echo "$1"; shift; done; else git-commit-tree "$@"; fi' newbranch
152 (the shift magic first throws away the tree id and then the -p
153 parameters). Note that this handles merges properly! In case Darl
154 committed a merge between P1 and P2, it will be propagated properly and
155 all children of the merge will become merge commits with P1,P2 as their
156 parents instead of the merge commit.
157 To restrict rewriting to only part of the history, use -r or -k or
159 both. Consider this history:
160 D--E--F--G--H
163 / /
164 A--B-----C
165 To rewrite only commits F,G,H, use:
166 cg-admin-rewritehist -r F ...
169 To rewrite commits E,F,G,H, use one of these:
170 cg-admin-rewritehist -r E -k C ...
173 cg-admin-rewritehist -k D -k C ...
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176 Copyright © Petr Baudis, 2006
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180 cg-admin-rewritehist is part of cogito(7), a toolkit for managing
181 git(7) trees.
182 12/11/2006 CG-ADMIN-REWRITEHIST(1)