1、Ubuntu系统网络配置总结（包括主机名、网卡名称、网卡配置）
#修改主机名：
#设置主机名
root@ubuntu1804:~# hostnamectl set-hostname test
#查看主机名配置文件
root@ubuntu1804:~# cat /etc/hostname
test
#重新加载生效
root@ubuntu1804:~# logout
yang@ubuntu1804:~$ su -
Password:
root@test:~#
#修改网卡名称：
root@test:~# sed -i.bak '/^GRUB_CMDLINE_LINUX=/s#"$#net.ifnames=0"#' /etc/default/grub
#生成新grub文件
root@test:~# grub-mkconfig -o /boot/grub/grub.cfg
#网卡配置：
#修改网卡配置文件
root@test:~# vim /etc/netplan/01-netcfg.yaml
network:
version: 2
renderer: networkd
ethernets:
eth0:
dhcp4: no
addresses: [10.0.0.12/24]
gateway4: 10.0.0.251
optional: true
nameservers:
addresses: [223.6.6.6,223.5.5.5]
#设置完后应用生效
root@test:~# netplan apply
2、编写脚本实现登陆远程主机。（使用expect和shell脚本两种形式）。
#expect方式
yum -y install expect
vim remote_ssh.sh
#!/usr/bin/expect
set ip [lindex $argv 0]
set password [lindex $argv 1]
set user [lindex $argv 2]
spawn ssh $user@$ip
expect {
"yes/no" { send "yes\n";exp_continue }
"password" { send "$password\n" }
}
interact
[root@centos8 ~]#chmod +x ssh-remote.sh
[root@centos8 ~]# ./ssh-remote.sh 10.0.0.18 root 123
spawn ssh root@10.0.0.18
The authenticity of host '10.0.0.18 (10.0.0.18)' can't be established.
ECDSA key fingerprint is SHA256:02uItPDAzOBaE2gpjGYc58RxdG9PSTv0nOKdGxyc5n8.
Are you sure you want to continue connecting (yes/no/[fingerprint])? yes
Warning: Permanently added '10.0.0.18' (ECDSA) to the list of known hosts.
root@10.0.0.18's password:
Last login: Sun Jan 31 23:49:09 2021 from 10.0.0.8
[root@centos8 ~]# ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
inet 127.0.0.1/8 scope host lo
valid_lft forever preferred_lft forever
inet6 ::1/128 scope host
valid_lft forever preferred_lft forever
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000
link/ether 00:0c:29:91:ba:50 brd ff:ff:ff:ff:ff:ff
inet 10.0.0.18/24 brd 10.0.0.255 scope global noprefixroute eth0
valid_lft forever preferred_lft forever
inet6 fe80::64ed:295f:cba6:8479/64 scope link dadfailed tentative noprefixroute
valid_lft forever preferred_lft forever
[root@centos8 ~]# exit
logout
Connection to 10.0.0.18 closed.
#shell方式
[root@centos8 ~]#yum -y install sshpass
[root@centos8 ~]# vim ssh-remote.sh
#!/bin/bash
IP=$1
USER=$2
PASSWORD=$3
sshpass -p $PASSWORD ssh -o StrictHostKeyChecking=no $user@$ip
[root@centos8 ~]#chmod +x ssh-remote.sh
[root@centos8 ~]#./ssh-remote.sh 10.0.0.18 root 123
3、生成10个随机数保存于数组中，并找出其最大值和最小值
vim max_min.sh
#!/bin/bash
declare -i min max
declare -a nums
for ((i=0;i<10;i++));do
nums[$i]=$RANDOM
[ $i -eq 0 ] && min=${nums[$i]} && max=${nums[$i]}&& continue
[ ${nums[$i]} -gt $max ] && max=${nums[$i]}
[ ${nums[$i]} -lt $min ] && min=${nums[$i]}
done
echo “Numbers are ${nums[*]}”
echo Max is $max
echo Min is $min
4、输入若干个数值存入数组中，采用冒泡算法进行升序或降序排序
vim argssum.sh
read -p "请输入数值个数：" COUNT
declare -a nums
for ((i=0;i<$COUNT;i++));do
num[$i]=$RANDOM
done
echo "${num[@]}"
declare -i n=$COUNT
for (( i=0; i<n-1; i++ ));do
for (( j=0; j<n-1-i; j++ ));do
let x=$j+1
if (( ${num[$j]} < ${num[$x]} ));then
#从大到小排列
tmp=${num[$x]}
num[$x]=${num[$j]}
num[$j]=$tmp
fi
done
done
echo ${num[*]}
echo "the max integer is $num,the min integer is ${num[$((n-1))]}"
