git-clean-merged-branches.sh

# Iterate through folders of git repos and show merged branches older than 3 months
for d in */; do
  cd "$d" && echo "*********** $d ***********" &&
  if [ -d .git ]; then
    git fetch --prune --quiet origin &&
    for k in $(git branch -r --merged | egrep -v 'HEAD|main|master'); do 
        if [ -z "$(git log -1 --since='3 months ago' -s $k)" ]; then
          echo -e `git show --format="%ci %cr %an" $k | head -n 1` \\t$k;
        fi
    done | sort -r
  else
    echo "Not a git repository, skipping.";
  fi
  cd .. && echo
done

# Iterate through folders of git repos and delete merged branches older than 3 months
for d in */; do
  cd "$d" && echo "*********** $d ***********" &&
  if [ -d .git ]; then
    git fetch --prune --quiet origin &&
    for k in $(git branch -r --merged | egrep -v 'HEAD|main|master'); do 
        if [ -z "$(git log -1 --since='3 months ago' -s $k)" ]; then
          git push --delete origin ${k//origin\/}
        fi
    done
    git fetch --prune --quiet origin
  else
    echo "Not a git repository, skipping.";
  fi
  cd .. && echo
done