我有一个项目，其中包含一个utils开始在其他项目中有用的库，并且想将其历史拆分为子模块。没想到先看 SO，所以我自己写了，它在本地构建历史，所以速度要快一点，之后如果你愿意，你可以设置辅助命令的.gitmodules文件等，并将子模块历史自己推送到任何地方你要。
剥离的命令本身在这里，文档在评论中，在后面的未剥离的命令中。subdir使用set 将其作为自己的命令运行，就像subdir=utils git split-submodule您要拆分utils目录一样。这很 hacky，因为它是一次性的，但我在 Git 历史记录中的 Documentation 子目录中对其进行了测试。
#!/bin/bash
# put this or the commented version below in e.g. ~/bin/git-split-submodule
${GIT_COMMIT-exec git filter-branch --index-filter "subdir=$subdir; ${debug+debug=$debug;} $(sed 1,/SNIP/d "$0")" "$@"}
${debug+set -x}
fam=(`git rev-list --no-walk --parents $GIT_COMMIT`)
pathcheck=(`printf "%s:$subdir\\n" ${fam[@]} \
| git cat-file --batch-check='%(objectname)' | uniq`)
[[ $pathcheck = *:* ]] || {
subfam=($( set -- ${fam[@]}; shift;
for par; do tpar=`map $par`; [[ $tpar != $par ]] &&
git rev-parse -q --verify $tpar:"$subdir"
done
))
git rm -rq --cached --ignore-unmatch "$subdir"
if (( ${#pathcheck[@]} == 1 && ${#fam[@]} > 1 && ${#subfam[@]} > 0)); then
git update-index --add --cacheinfo 160000,$subfam,"$subdir"
else
subnew=`git cat-file -p $GIT_COMMIT | sed 1,/^$/d \
| git commit-tree $GIT_COMMIT:"$subdir" $(
${subfam:+printf ' -p %s' ${subfam[@]}}) 2>&-
` &&
git update-index --add --cacheinfo 160000,$subnew,"$subdir"
fi
}
${debug+set +x}
#!/bin/bash
# Git filter-branch to split a subdirectory into a submodule history.
# In each commit, the subdirectory tree is replaced in the index with an
# appropriate submodule commit.
# * If the subdirectory tree has changed from any parent, or there are
# no parents, a new submodule commit is made for the subdirectory (with
# the current commit's message, which should presumably say something
# about the change). The new submodule commit's parents are the
# submodule commits in any rewrites of the current commit's parents.
# * Otherwise, the submodule commit is copied from a parent.
# Since the new history includes references to the new submodule
# history, the new submodule history isn't dangling, it's incorporated.
# Branches for any part of it can be made casually and pushed into any
# other repo as desired, so hooking up the `git submodule` helper
# command's conveniences is easy, e.g.
# subdir=utils git split-submodule master
# git branch utils $(git rev-parse master:utils)
# git clone -sb utils . ../utilsrepo
# and you can then submodule add from there in other repos, but really,
# for small utility libraries and such, just fetching the submodule
# histories into your own repo is easiest. Setup on cloning a
# project using "incorporated" submodules like this is:
# setup: utils/.git
#
# utils/.git:
# @if _=`git rev-parse -q --verify utils`; then \
# git config submodule.utils.active true \
# && git config submodule.utils.url "`pwd -P`" \
# && git clone -s . utils -nb utils \
# && git submodule absorbgitdirs utils \
# && git -C utils checkout $$(git rev-parse :utils); \
# fi
# with `git config -f .gitmodules submodule.utils.path utils` and
# `git config -f .gitmodules submodule.utils.url ./`; cloners don't
# have to do anything but `make setup`, and `setup` should be a prereq
# on most things anyway.
# You can test that a commit and its rewrite put the same tree in the
# same place with this function:
# testit ()
# {
# tree=($(git rev-parse `git rev-parse $1`: refs/original/refs/heads/$1));
# echo $tree `test $tree != ${tree[1]} && echo ${tree[1]}`
# }
# so e.g. `testit make~95^2:t` will print the `t` tree there and if
# the `t` tree at ~95^2 from the original differs it'll print that too.
# To run it, say `subdir=path/to/it git split-submodule` with whatever
# filter-branch args you want.
# $GIT_COMMIT is set if we're already in filter-branch, if not, get there:
${GIT_COMMIT-exec git filter-branch --index-filter "subdir=$subdir; ${debug+debug=$debug;} $(sed 1,/SNIP/d "$0")" "$@"}
${debug+set -x}
fam=(`git rev-list --no-walk --parents $GIT_COMMIT`)
pathcheck=(`printf "%s:$subdir\\n" ${fam[@]} \
| git cat-file --batch-check='%(objectname)' | uniq`)
[[ $pathcheck = *:* ]] || {
subfam=($( set -- ${fam[@]}; shift;
for par; do tpar=`map $par`; [[ $tpar != $par ]] &&
git rev-parse -q --verify $tpar:"$subdir"
done
))
git rm -rq --cached --ignore-unmatch "$subdir"
if (( ${#pathcheck[@]} == 1 && ${#fam[@]} > 1 && ${#subfam[@]} > 0)); then
# one id same for all entries, copy mapped mom's submod commit
git update-index --add --cacheinfo 160000,$subfam,"$subdir"
else
# no mapped parents or something changed somewhere, make new
# submod commit for current subdir content. The new submod
# commit has all mapped parents' submodule commits as parents:
subnew=`git cat-file -p $GIT_COMMIT | sed 1,/^$/d \
| git commit-tree $GIT_COMMIT:"$subdir" $(
${subfam:+printf ' -p %s' ${subfam[@]}}) 2>&-
` &&
git update-index --add --cacheinfo 160000,$subnew,"$subdir"
fi
}
${debug+set +x}