git fetch -p && for branch in `git branch -vv | grep '^[^\*].*: gone]' | awk '{print $1}'`; do echo $branch; done && read -p "Do you want to delete these local branches (y/n)?" choice
case "$choice" in
  y|Y ) git fetch -p && for branch in `git branch -vv | grep '^[^\*].*: gone]' | awk '{print $1}'`; do git branch -D $branch; done && read -p "Press enter to exit";;
  * ) echo "invalid";;
esac