老李分享：《Linux Shell脚本攻略》 要点（六）

1、打印网络接口列表

[[email protected] 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

[[email protected] touch_more]# cat /etc/resolv.conf 
# Generated by NetworkManager
domain localdomain
search localdomain
nameserver 192.168.119.2

3、DNS查找

[[email protected] 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

[[email protected] program_test]# cat list_active_hosts.sh 
#!/bin/bash

for ip in 192.168.119.{1..255} ;
do
ping $ip -c 2 &> /dev/null;

if [ $? -eq 0 ];
then
echo $ip is active!
fi
done
[[email protected] program_test]# ./list_active_hosts.sh 
192.168.119.1 is active!
192.168.119.2 is active!

5、系统运行时间监视

<pre name="code" class="plain" style="font-size: 14px;">[[email protected] program_test]# cat ssh_test.sh
#!/bin/bash

IP_LIST="192.168.119.1 192.168.119.2 192.168.119.128"
USER="yxy"

for ip in $IP_LIST;
do
utime=$(ssh [email protected]$ip uptime | awk ‘{ print $3 }‘ )
echo $ip uptime: $utime
done