Commit c401b33c authored by Johannes Schindelin's avatar Johannes Schindelin Committed by Junio C Hamano

Document git-filter-branch

This moves the documentation in git-filter-branch.sh to its own
man page, with a few touch ups (incorporating comments by Frank
Lichtenheld).
Signed-off-by: Johannes Schindelin's avatarJohannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: default avatarJunio C Hamano <gitster@pobox.com>
parent 843103d6
......@@ -105,6 +105,7 @@ sub format_one {
git-fast-import ancillarymanipulators
git-fetch mainporcelain
git-fetch-pack synchingrepositories
git-filter-branch ancillarymanipulators
git-fmt-merge-msg purehelpers
git-for-each-ref plumbinginterrogators
git-format-patch mainporcelain
......
This diff is collapsed.
......@@ -4,190 +4,9 @@
# Copyright (c) Petr Baudis, 2006
# Minimal changes to "port" it to core-git (c) Johannes Schindelin, 2007
#
# Lets you rewrite GIT revision history by creating a new branch from
# your current branch by applying custom filters on each revision.
# Those filters can modify each tree (e.g. removing a file or running
# a perl rewrite on all files) or information about each commit.
# Otherwise, all information (including original commit times or merge
# information) will be preserved.
#
# The command takes the new branch name as a mandatory argument and
# the filters as optional arguments. If you specify no filters, the
# commits will be recommitted without any changes, which would normally
# have no effect and result with the new branch pointing to the same
# branch as your current branch. (Nevertheless, this may be useful in
# the future for compensating for some Git bugs or such, therefore
# such a usage is permitted.)
#
# WARNING! The rewritten history will have different ids for all the
# objects and will not converge with the original branch. You will not
# be able to easily push and distribute the rewritten branch. Please do
# not use this command if you do not know the full implications, and
# avoid using it anyway - do not do what a simple single commit on top
# of the current version would fix.
#
# Always verify that the rewritten version is correct before disposing
# the original branch.
#
# Note that since this operation is extensively I/O expensive, it might
# be a good idea to do it off-disk, e.g. on tmpfs. Reportedly the speedup
# is very noticeable.
#
# OPTIONS
# -------
# -d TEMPDIR:: The path to the temporary tree used for rewriting
# When applying a tree filter, the command needs to temporary
# checkout the tree to some directory, which may consume
# considerable space in case of large projects. By default it
# does this in the '.git-rewrite/' directory but you can override
# that choice by this parameter.
#
# Filters
# ~~~~~~~
# The filters are applied in the order as listed below. The COMMAND
# argument is always evaluated in shell using the 'eval' command.
# The $GIT_COMMIT environment variable is permanently set to contain
# the id of the commit being rewritten. The author/committer environment
# variables are set before the first filter is run.
#
# A 'map' function is available that takes an "original sha1 id" argument
# and outputs a "rewritten sha1 id" if the commit has been already
# rewritten, fails otherwise; the 'map' function can return several
# ids on separate lines if your commit filter emitted multiple commits
# (see below).
#
# --env-filter COMMAND:: The filter for modifying environment
# This is the filter for modifying the environment in which
# the commit will be performed. Specifically, you might want
# to rewrite the author/committer name/email/time environment
# variables (see `git-commit` for details). Do not forget to
# re-export the variables.
#
# --tree-filter COMMAND:: The filter for rewriting tree (and its contents)
# This is the filter for rewriting the tree and its contents.
# The COMMAND argument is evaluated in shell with the working
# directory set to the root of the checked out tree. The new tree
# is then used as-is (new files are auto-added, disappeared files
# are auto-removed - .gitignore files nor any other ignore rules
# HAVE NO EFFECT!).
#
# --index-filter COMMAND:: The filter for rewriting index
# This is the filter for rewriting the Git's directory index.
# It is similar to the tree filter but does not check out the
# tree, which makes it much faster. However, you must use the
# lowlevel Git index manipulation commands to do your work.
#
# --parent-filter COMMAND:: The filter for rewriting parents
# This is the filter for rewriting the commit's parent list.
# It will receive the parent string on stdin and shall output
# the new parent string on stdout. The parent string is in
# format accepted by `git commit-tree`: empty for initial
# commit, "-p parent" for a normal commit and "-p parent1
# -p parent2 -p parent3 ..." for a merge commit.
#
# --msg-filter COMMAND:: The filter for rewriting commit message
# This is the filter for rewriting the commit messages.
# The COMMAND argument is evaluated in shell with the original
# commit message on standard input; its standard output is
# is used as the new commit message.
#
# --commit-filter COMMAND:: The filter for performing the commit
# If this filter is passed, it will be called instead of the
# `git commit-tree` command, with those arguments:
#
# TREE_ID [-p PARENT_COMMIT_ID]...
#
# and the log message on stdin. The commit id is expected on
# stdout. As a special extension, the commit filter may emit
# multiple commit ids; in that case, all of them will be used
# as parents instead of the original commit in further commits.
#
# --tag-name-filter COMMAND:: The filter for rewriting tag names.
# If this filter is passed, it will be called for every tag ref
# that points to a rewritten object (or to a tag object which
# points to a rewritten object). The original tag name is passed
# via standard input, and the new tag name is expected on standard
# output.
#
# The original tags are not deleted, but can be overwritten;
# use "--tag-name-filter=cat" to simply update the tags. In this
# case, be very careful and make sure you have the old tags
# backed up in case the conversion has run afoul.
#
# Note that there is currently no support for proper rewriting of
# tag objects; in layman terms, if the tag has a message or signature
# attached, the rewritten tag won't have it. Sorry. (It is by
# definition impossible to preserve signatures at any rate, though.)
#
# --subdirectory-filter DIRECTORY:: Only regard the history, as seen by
# the given subdirectory. The result will contain that directory as
# its project root.
#
# EXAMPLE USAGE
# -------------
# Suppose you want to remove a file (containing confidential information
# or copyright violation) from all commits:
#
# git-filter-branch --tree-filter 'rm filename' newbranch
#
# A significantly faster version:
#
# git-filter-branch --index-filter 'git update-index --remove filename' newbranch
#
# Now, you will get the rewritten history saved in the branch 'newbranch'
# (your current branch is left untouched).
#
# To "etch-graft" a commit to the revision history (set a commit to be
# the parent of the current initial commit and propagate that):
#
# git-filter-branch --parent-filter sed\ 's/^$/-p graftcommitid/' newbranch
#
# (if the parent string is empty - therefore we are dealing with the
# initial commit - add graftcommit as a parent). Note that this assumes
# history with a single root (that is, no git-merge without common ancestors
# happened). If this is not the case, use:
#
# git-filter-branch --parent-filter 'cat; [ "$GIT_COMMIT" = "COMMIT" ] && echo "-p GRAFTCOMMIT"' newbranch
#
# To remove commits authored by "Darl McBribe" from the history:
#
# git-filter-branch --commit-filter 'if [ "$GIT_AUTHOR_NAME" = "Darl McBribe" ]; then shift; while [ -n "$1" ]; do shift; echo "$1"; shift; done; else git commit-tree "$@"; fi' newbranch
#
# (the shift magic first throws away the tree id and then the -p
# parameters). Note that this handles merges properly! In case Darl
# committed a merge between P1 and P2, it will be propagated properly
# and all children of the merge will become merge commits with P1,P2
# as their parents instead of the merge commit.
#
# To restrict rewriting to only part of the history, specify a revision
# range in addition to the new branch name. The new branch name will
# point to the top-most revision that a 'git rev-list' of this range
# will print.
#
# Consider this history:
#
# D--E--F--G--H
# / /
# A--B-----C
#
# To rewrite commits D,E,F,G,H, use:
#
# git-filter-branch ... new-H C..H
#
# To rewrite commits E,F,G,H, use one of these:
#
# git-filter-branch ... new-H C..H --not D
# git-filter-branch ... new-H D..H --not C
#
# To move the whole tree into a subdirectory, or remove it from there:
#
# git-filter-branch --index-filter \
# 'git ls-files -s | sed "s-\t-&newsubdir/-" |
# GIT_INDEX_FILE=$GIT_INDEX_FILE.new \
# git update-index --index-info &&
# mv $GIT_INDEX_FILE.new $GIT_INDEX_FILE' directorymoved
# Testsuite: TODO
# Lets you rewrite the revision history of the current branch, creating
# a new branch. You can specify a number of filters to modify the commits,
# files and trees.
set -e
......
Markdown is supported
0% or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment