Commands/sequence useful for git repository refactoring

Git repo refactoring.sh

#!/bin/bash

# Delete everything except some files:
find . -not \( -path "./.git" -o -path "./.git/*" -o -path "./pom.xml" \) -delete

# checkout all branches you want to have:
for i in develop br1 br2 br3; do git branch -t $i origin/$i; done
# automatically find all remote branches:
for i in `git show-ref | awk '/ refs\/remotes\/origin\// { sub(/refs\/remotes\/origin\//,""); print $2 }' | grep -v '^HEAD$'`; do git branch -t $i origin/$i; done


# remove origin just in case not to push accidentally:
git remote rm origin

# filter-branch - remove files except some 
git filter-branch --tag-name-filter cat --prune-empty --tree-filter 'find . -not \( -path "./.git" -o -path "./.git/*" -o -path "./pom.xml" \) -delete' -- --all

# or filters-branch - only leave one subdir
git filter-branch --tag-name-filter cat --prune-empty --subdirectory-filter ABC -- --all

# cleanup
git reset --hard
git for-each-ref --format="%(refname)" refs/original/ | xargs -n 1 git update-ref -d
git reflog expire --expire=now --all
git gc --aggressive --prune=now