Check wheather a branch has differences with master or not

detect_merged_remote_branches.sh

#!/usr/bin/env bash
for branch in $(git branch -a | grep "remotes/origin/" | grep -v "master" | sed 's|remotes/||')
do
  echo "checking $branch for unmerged changes"
  if git diff --exit-code master...$branch > /dev/null
    then
      echo "no commits found which were not already merged into master"
      echo "should i delete the branch $branch?(y/n): "
      read answer
      if [ $answer = "y" ]
        then
          echo "deleting $branch"
          git branch -d -r $branch
          git push origin :`echo $branch | sed 's|origin/||'`
        else
          echo "not deleting $branch"
      fi
    else
      echo "--> DIFFERENCES found, should not be deleted"
  fi
done