Bash:- 通过while和shift判断脚本位置参数格式是否合法

if [[ $# -lt 2 ]];then
  echo "请输入2个位置参数..."
  exit 1
else
  num=$#
  while(($#>=1));do
   
    case ${num} in
      2)
        if ! echo "${1}" | grep -qP "\d+\.\d+\.\d+\.\d+";then
          echo "中心机IP输入格式不对..."
          exit 1 
        fi
   
        SALT_MASTER_IP=${1}
        ;;
      1)
         
        if ! echo "${1}" | grep -qP "AAAA_\w+_(ENGINE|COMMON|WEB)_\d+\.\d+\.\d+\.\d+";then
          echo "salt-minion主机名不对..."
          exit 1
        fi
   
        SALT_MINION_LOCAL=${1}
        ;;
      *)
        echo "输入超过2个位置参数无效..."
        echo "salt-minion.sh 中心机IP 本地主机名"
        exit 1
        ;;
    esac
   
    num=`expr ${num} - 1`
    shift
  done
fi