判断三次URL可用性脚本

#!/bin/bash
check_url() {
        HTTP_CODE=$(curl -o /dev/null --connect-timeout  -s -w "%{http_code}" $)
        if [ $HTTP_CODE -eq  ];then
                continue
        fi
}
URL_LIST="www.baidu.com www.cnblogs.com www.xzwcmp.cn"
for URL in $URL_LIST; do
        check_url $URL
        check_url $URL
        check_url $URL
        echo "Warning: $URL Access failure!"
done