Ruby Version updating script

ruby_version.sh

function rv() {
  new_version=${1};
  sed_command_base="^ruby.*\([[:digit:]]\.\)*[[:digit:]]*";

  if [[ -z "$new_version" ]]; then
    if [[ -e Gemfile ]]; then
      echo "Gemfile: $(sed -ne /${sed_command_base}/p Gemfile)";
    fi

    if [[ -e .ruby-version ]]; then
      echo ".ruby-version: $(sed -ne /${sed_command_base}/p .ruby-version)";
    fi
  else
    if [[ -e Gemfile ]]; then
      sed -i '' -e "s/${sed_command_base}/ruby '${new_version}'/" Gemfile;
      echo 'Gemfile updated';
      bundle;
    fi

    if [[ -e .ruby-version ]]; then
      sed -i '' -e s/${sed_command_base}/ruby-${new_version}/ .ruby-version;
      echo '.ruby-version updated';
    fi
  fi
}