老李分享：《Linux Shell脚本攻略》 要点（六）上

老李分享：《Linux Shell脚本攻略》 要点（六）

1、打印网络接口列表
[root@localhost touch_more]# ifconfig | cut -c-10 | tr -d ' ' | tr -s '\n'
eth0
lo
//cut -c-10 ; 输出前10个字符;
//tr -d ' ' ; 删除所有空格;
//tr -s '\n'; 压缩重复的换行符

2、查看名字服务器
[root@localhost touch_more]# cat /etc/resolv.conf
# Generated by NetworkManager
domain localdomain
search localdomain
nameserver 192.168.119.2

3、DNS查找
[root@localhost touch_more]# nslookup www.csdn.net
Server: 192.168.119.2
Address: 192.168.119.2#53

Non-authoritative answer:
www.csdn.net canonical name = www.csdn.net.aqb.so.
Name: www.csdn.net.aqb.so
Address: 14.17.69.22

4、列举出局域网中同一网段的所有的活动主机
[root@localhost program_test]# cat list_active_hosts.sh
#!/bin/bashfor ip in 192.168.119.{1..255} ;
do
ping $ip -c 2 &> /dev/null;if [ $? -eq 0 ];
then
echo $ip is active!
fi
done
[root@localhost program_test]# ./list_active_hosts.sh
192.168.119.1 is active!
192.168.119.2 is active!