git-author-rewrite.sh

#!/bin/sh

# orig: https://help.github.com/articles/changing-author-info

#WD=~/tmp/wd
#DST_DIR="$WD/my_project"
#cd "$DST_DIR"

REPO=repo.git

git clone --bare https://github.com/user/"$REPO"
cd "$REPO"

rewrite_author() {
  export OLD_EMAIL="$1"
  export CORRECT_NAME="$2"
  export CORRECT_EMAIL="$3"

  git filter-branch --env-filter '
    if [ "$GIT_COMMITTER_EMAIL" = "$OLD_EMAIL" ]
    then
      export GIT_COMMITTER_NAME="$CORRECT_NAME"
      export GIT_COMMITTER_EMAIL="$CORRECT_EMAIL"
    fi
    if [ "$GIT_AUTHOR_EMAIL" = "$OLD_EMAIL" ]
    then
      export GIT_AUTHOR_NAME="$CORRECT_NAME"
      export GIT_AUTHOR_EMAIL="$CORRECT_EMAIL"
    fi
  ' --tag-name-filter cat -- --branches --tags
}

rewrite_author old@email.addr "new name" new@email.addr

## to make more changes:
#rm -rf .git/refs/original/refs
#rewrite_author old2@email.addr "new2 name" new2@email.addr
#...

## push back:

##git push --force --tags origin 'refs/heads/*'
##cd ..
##rm -rf "$REPO"

git-repo-combine.sh

#/bin/bash -x

# combines only MASTER branches

# look at https://gofore.com/ohjelmistokehitys/merge-multiple-git-repositories-one-retaining-history/

## Absolute Directories:
#

ORIG=~/tmp/_original_repos_git
WD=~/tmp/wd
DST_DIR=$WD/combined_project

#
########################

rm -rf "$WD"

mkdir -p $WD
git init $DST_DIR


git_deep_clone_repository() {
  REPO_URL=$1
  LOCAL_DIR=$2

  cd $WD
  git clone $REPO_URL $LOCAL_DIR
  cd $LOCAL_DIR

  for branch in `git branch -a | grep remotes | grep -v HEAD | grep -v master`; do
    git branch --track ${branch##*/} $branch
  done
  git remote rm origin
}

git_cleanup_repository() {
  LOCAL_DIR=$1
  BIGFOLDER=$2
  BIGFILE=$3

  cd $WD/$LOCAL_DIR

  git filter-branch --tag-name-filter cat --index-filter "git rm -r --cached --ignore-unmatch $BIGFOLDER" --prune-empty -f -- --all
  git filter-branch --tag-name-filter cat --index-filter "git rm --cached --ignore-unmatch $BIGFILE" --prune-empty -f -- --all
}

git_rewrite_history() {
  LOCAL_DIR=$1

  cd $WD/$LOCAL_DIR

  filter='git ls-files -s | sed "s-\t\"*-&'$LOCAL_DIR'/-" |
    GIT_INDEX_FILE=$GIT_INDEX_FILE.new \
    git update-index --index-info &&
    mv "$GIT_INDEX_FILE.new" "$GIT_INDEX_FILE"
'

  git filter-branch --index-filter \
    "$filter" --tag-name-filter cat -f -- --all
}

git_merge_master() {
  LOCAL_DIR=$1

  cd "$WD/$LOCAL_DIR"

  cd "$DST_DIR"
  git remote add -f "$LOCAL_DIR" "$WD/$LOCAL_DIR"
  git merge -m "Merge to the combined repository." "$LOCAL_DIR/master"
  git remote rm "$LOCAL_DIR"
}

git_deep_clone_repository $ORIG/proj_A.git A
git_cleanup_repository nm_Branding bigfolder somefolder/bigfile.zip
git_rewrite_history A
git_merge_master A

git_deep_clone_repository $ORIG/proj_B.git B
git_cleanup_repository nm_Navigation bigfolder somefolder/bigfile.zip
git_rewrite_history B
git_merge_master B