foo

startup_check() 
{
  # Need to do a git fecth first to download remote changes for us to compare against
  git fetch
  # Most of this code was taken from the __git_ps1_changes method of https://github.com/markgandolfo/git-bash-completion
  local branch_ref
  branch_ref="$(git symbolic-ref -q HEAD 2>/dev/null)";
  if [ -n "$branch_ref" ]; then
    local branch_origin
    branch_origin="$(git for-each-ref --format='%(upstream:short)' $branch_ref)";
    if [ -n "$branch_origin" ]; then
      local branch
      branch=${branch_ref##refs/heads/};

      if [ "$branch" != "master" ]; then
        echo "Not working on the master - cannot proceed"
        exit 1
      fi

      local unpush
      unpush=$(git rev-list $branch_origin..$branch --count);
      local unpull
      unpull=$(git rev-list $branch..$branch_origin --count);
      local staged
      staged=$(git diff --staged --name-status | wc -l);
      local uncommits
      uncommits=$(git status -s -uall --porcelain);

      if [[ $unpush -gt 0 ]]; then
        echo "There are changes which have not been pushed - cannot proceed. The following commits need to be pushed:"
        local unpushed
        unpushed=$(git rev-list $branch_origin..$branch);
        for commit in $unpushed; do
          git --no-pager log --pretty=format:"%H - %an, %ar : %s" -n 1 $commit
        done
        exit 1
      fi

      if [[ $unpull -gt 0 ]]; then
        echo "There are changes which have not been pulled - cannot proceed. The following commits have been added to master since your last pull:"
        local unpulled
        unpulled=$(git rev-list $branch..$branch_origin);
        for commit in $unpulled; do
          git --no-pager log --pretty=format:"%H - %an, %ar : %s" -n 1 $commit
        done
        exit 1
      fi

      if [[ $staged -gt 0 ]]; then
        local staging
        staging=$(git diff --staged --name-status);
        echo "There are changes which are staged but have been commited - cannot proceed"
        echo $staging
        exit 1
      fi

      local unstaged
      unstaged=$(echo "$uncommits" | grep -c "^ [A-Z]");
      if [[ $unstaged -gt 0 ]]; then
        echo "There are unstaged changes - cannot proceed"
        echo $(echo "$uncommits" | grep "^ [A-Z]")
        exit 1
      fi

      local untracked
      untracked=$(echo "$uncommits" | grep -c "^??");
      if [[ $untracked -gt 0 ]]; then
        echo "There are untracked changes - cannot proceed"
        echo $(echo "$uncommits" | grep "^??")
        exit 1
      fi
    fi
  else
    echo "Working folder isn't a git folder"
    exit 1
  fi
}

startup_check