Removes already pushed branches from your local repository.

git-purge-branches

currentBranch=$(git rev-parse --abbrev-ref HEAD)
ignore=(dev master)

function red {
  echo -e "\e[1;31m$1\e[0m"
}

function green {
  echo -e "\e[1;32m$1\e[0m"
}

function yellow {
echo -e "\e[1;33m$1\e[0m"
}

function ignored {
  for branch in ${ignore[@]}; do
    if [ $1 = $branch ]; then return 0; fi
  done
  return 1
}

for branch in $(git for-each-ref --format='%(refname:short)' refs/heads); do
  if $(ignored $branch); then continue; fi

  if [ $branch = $currentBranch ]; then
    echo Ignoring current branch $(green $branch)
    continue
  fi

  upstream=$(git rev-parse --symbolic-full-name $branch@{u} 2>/dev/null)
  if [ $upstream ]; then
    pendingCommits=$(git rev-list --count $upstream..$branch)

    if [ $pendingCommits -eq 0 ]; then
      git branch -d $branch &> /dev/null && echo Deleted branch $branch
    else
      echo Ignoring branch $(yellow $branch) as it has $pendingCommits not-pushed commits
    fi
  else
    echo Ignoring branch $(red $branch) because it has no upstream defined
  fi
done

Please note that this anayses "pushed" instead of "merged" branches. This difference is useful when using a "squash and merge" strategy for your PRs, because your branches never get really "merged".