Remove closed mercurial branches from git

my.bashrc

# pass --simulate to avoid actual deletion
# pass --donotprompt to delete without prompting
function rmbHgClosed() {
  option=$1
  current_branch=$(git branch --no-color 2> /dev/null | sed -e '/^[^*]/d' -e 's/* \(.*\)/\1/')
  if [ "$current_branch" != "master" ]; then
    echo "WARNING: You are on branch $current_branch, NOT master."
  fi
  echo "Fetching remote branches..."
  remote_branches=$(git branch -r | grep -v '/master$' | grep -v "/$current_branch$")
  prefix="origin/"
  branches_ahead=""
  closed_branches_more_than_one_ahead=""
  count_removed=0
  echo "Closed branches with just 1 close commit ahead:"
  while read -r branch; do
    b=${branch#$prefix}
    git rev-list --left-right ${origin/current_branch}...${branch} -- 2>/dev/null >/tmp/git_upstream_status_delta || continue
    # https://stackoverflow.com/a/7774433
    left_ahead=$(grep -c '^<' /tmp/git_upstream_status_delta)
    right_ahead=$(grep -c '^>' /tmp/git_upstream_status_delta)
    last_commit=`git log -1 --oneline ${branch}`
    info="$current_branch (ahead $left_ahead) | (behind $right_ahead) $branch -- $last_commit"
    if [[ "$last_commit" =~ [Cc]lose(.*)branch$ ]]; then
      if [[ $right_ahead == 1 ]]; then
        echo $info
        if [[ $option == "--simulate" ]]; then
          let "count_removed += 1"
          continue
        fi
        if [[ $option == "--donotprompt" ]]; then
          git push origin ":$b"
          let "count_removed += 1"
        else
          read -p "Remove $branch? (y/n): " -n 1 choice </dev/tty
          echo
          if [ "$choice" == "y" ] || [ "$choice" == "Y" ]; then
            git push origin ":$b"
            let "count_removed += 1"
          fi
        fi
      else
        closed_branches_more_than_one_ahead+="$info\n"
      fi
    else
      branches_ahead+="$info\n"
    fi
  done <<< "$remote_branches"
  echo "Removed $count_removed branches"
  echo ""
  echo "Closed branches with more than one commit ahead: "
  echo -e $closed_branches_more_than_one_ahead
  echo "Branches ahead: "
  echo -e $branches_ahead
}