Gets a list of available security updates on Red Hat with different display summaries

yum-check-security-updates.sh

yum-check-security-updates () {
  local OPTERR OPTIND OPT OPTARG v_usage v_help v_mode v_type v_update_list

  v_usage="yum-check-security-updates [-s|-l|-c] -t [m[moderate]|i[important]|c[critical]]"
  v_help="$v_usage

OPTIONS:
  -s,[no arg]
      Shows a summary (default option)

  -l
      Long listing

  -c
      List CVEs

  -t [m|i|c]
      Select update type as moderate, important or critical

  -h,
      This help menu

EXAMPLES:
  Shows a summary (count) of all security updates available
      $ yum-check-security-updates

  Lists all security updates available
      $ yum-check-security-updates -l

  Lists all critical security updates available
      $ yum-check-security-updates -l -t c
"

  # OPTERR=0
  while getopts ":slct:h" OPT ; do
    case $OPT in
      s) v_mode="summary" ;;
      l) v_mode="long" ;;
      c) v_mode="cve" ;;
      t) v_type="$OPTARG" ;;
      h) echo -e "$v_help" && return 0 ;;
      *) echo "Unknown option" ; return 1 ;;
    esac
  done

  v_mode="${v_mode:-summary}"

  if [ "$v_type" ] ; then
    case "$v_type" in
      m|M|Moderate|moderate|mod*) v_type="Moderate" ;;
      i|I|Important|important|imp*) v_type="Important" ;;
      c|C|Critical|critical|cri*) v_type="Critical" ;;
      *) echo 'Duhh!! Wrong option' ; return 1 ;;
    esac
  fi

  echo -e "\n ** Getting the update list... Please wait a few secs\n"

  if [[ "${v_mode^^}" == "CVE" ]] ; then
    v_update_list="$(sudo yum updateinfo list cves)"
  else
    v_update_list="$(sudo yum updateinfo list sec)"
  fi

  case "$v_mode" in
    "summary")
      if [ "$v_type" ] ; then
        echo "=> Here's a summary of all the security updates available to be installed:"
        echo "${v_type}: $(echo "$v_update_list" | grep -c ${v_type})"
        return 0
      else
        echo "=> Here's a summary of all the security updates available to be installed:"
        for i in Critical Important Moderate Low None ; do
          echo "${i}: $(echo "$v_update_list" | grep -c ${i})"
        done
        return 0
      fi
      ;;
    "long")
      if [ "$v_type" ] ; then
        echo "=> Here are all the available $v_type security updates:"
        echo "$v_update_list" | grep --color=never "$v_type"
        return 0
      else
        echo "=> Here are all the security updates available to be installed:"
        echo "$v_update_list" | grep --color=never '/Sec'
        return 0
      fi
      ;;
    "cve")
      echo "=> Here are all the available CVE updates:"
      echo "$v_update_list" | grep --color=never '/Sec'
      return 0
      ;;
  esac
}