else
    echo curl is not installed, will try wget for downloading files.
  fi

  # Try wget.
  if command -v wget > /dev/null; then
    DOWNLOAD_COMMAND="wget -qO -"
    return
  fi
  echo wget is not installed.

  echo Error: curl is not installed or does not support https, wget is not installed. \
       Cannot download envoy. Please install wget or add support of https to curl.

  else
    echo curl is not installed, will try wget for downloading files.
  fi

  # Try wget.
  if command -v wget > /dev/null; then
    DOWNLOAD_COMMAND="wget -qO -"
    return
  fi
  echo wget is not installed.

  echo Error: curl is not installed or does not support https, wget is not installed. \
       Cannot download envoy. Please install wget or add support of https to curl.