Script to delete branches without remote upstream

git-delete-without-upstream.sh

#!/bin/sh

while read branch; do
  upstream=$(git rev-parse --abbrev-ref $branch@{upstream} 2>/dev/null)
  if [[ $? == 0 ]]; then
    echo $branch tracks $upstream
  else
    echo $branch has no upstream configured
    git branch -D $branch
    if [ -z $? ]; then
      echo $branch was successfull deleted
    else
      echo "$branch was not fully merged. Force it change to -D in script"
    fi
  fi
done < <(git for-each-ref --format='%(refname:short)' refs/heads/*)