第六周作业

编写脚本实现登陆远程主机。（使用expect和shell脚本两种形式）

expect

[root@ansible srete]# cat telnet
#!/usr/bin/expect
set user user
set passwd passwd
spawn telnet [lindex $argv 0]
expect {
  "Username"  { send "$user\n";exp_continue }
  "Password"  { send "$passwd\n" }
 }
 interact
alias telnet='/root/srete/telnet'
[root@ansible srete]# telnet 10.1.81.254
spawn telnet 10.1.81.254
Trying 10.1.81.254...
Connected to 10.1.81.254.
Escape character is '^]'.

Warning: Telnet is not a secure protocol, and it is recommended to use Stelnet.

Login authentication


Username:admin
admin
Password:
Info: The max number of VTY users is 10, and the number
      of current VTY users on line is 1.
      The current login time is 2022-04-12 09:08:43+00:00.
<OFFICE_8F>

　　shell

[root@ansible srete]# cat telnet.sh
#!/bin/bash
#
#********************************************************************
#Author:                陈濛
#Date:                  2022-04-12
#FileName：             telnet.sh
#Description：          Create from cm
#Copyright (C):        2022 All rights reserved
#********************************************************************
user=***
passwd=***
expect <<!
spawn telnet $1
expect {
  "Username"  { send "$user\n";exp_continue }
  "Password"  { send "$passwd\n" }
 }
expect eof
!
[root@ansible srete]# sh telnet.sh 10.1.81.254
spawn telnet 10.1.81.254
Trying 10.1.81.254...
Connected to 10.1.81.254.
Escape character is '^]'.

Warning: Telnet is not a secure protocol, and it is recommended to use Stelnet.

Login authentication


Username:admin
admin
Password:
Info: The max number of VTY users is 10, and the number
      of current VTY users on line is 1.
      The current login time is 2022-04-12 09:41:35+00:00.
<OFFICE_8F>

生成10个随机数保存于数组中，并找出其最大值和最小值（此题直接抄的）

 

#!/bin/bash
declare -i min max
declare -a nums
for ((i=0;i<10;i++));do
nums[$i]=$RANDOM
[ $i -eq 0 ] && min=${nums[0]} && max=${nums[0]}&& continue
[ ${nums[$i]} -gt $max ] && max=${nums[$i]} && continue
[ ${nums[$i]} -lt $min ] && min=${nums[$i]}
done
echo "All numbers are ${nums[*]}"
echo Max is $max
echo Min is $min

 

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（这题也是直接抄的）

 

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 "The initial array:"
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 "After sort:"
echo ${num[*]}
echo "the max integer is $num,the min integer is ${num[$((n-1))]}"

 

总结查看系统负载的几种命令，总结top命令的指标大概什么含义(不要求全部写出来)

uptime和w:负载查询

mpstat：显示CPU相关统计

top和htop: 查看进程实时状态

free：内存空间

vmstat：查看虚拟内存信息

iostat：统计cpu和设备IO信息

iotop：监视磁盘IO

iftop：显示网络带宽使用情况

nload：查看网络实时吞吐量

iptraf-ng：网络监视工具

dstat：系统资源统计

glances：综合监视工具

lsof：查看进程打开文件

top命令可以查看系统运行时间，平均负载，任务运行状态，如running，sleeping,stopped,zomblel;可以查看cpu利用率，内存利用率；可以查看进程PID，用户，运行时间，命令以及进程使用的cpu和内存占比

编写脚本，使用for和while分别实现192.168.0.0/24网段内，地址是否能够ping通，若ping通则输出"success!"，若ping不通则输出"fail!"

[root@ansible srete]# cat scanip.sh

#!/bin/bash
#
#********************************************************************
#Author: chenmeng
#QQ: 903575406
#Date: 2022-04-16
#FileName： scanip.sh
#Description： A test script
#Copyright (C): 2022 All rights reserved
#********************************************************************
net=$1
red="\e[1;31m"
end="\e[0;m"
scanip(){
for i in {1..254}; do
ip=$net.$i
{
ping -c2 -w2 $ip &> /dev/null && echo "$ip up" || echo "$ip down"
}&
shift
done
wait
}

scanip

up=`scanip |awk -F' ' '{print $2}' | uniq -c | head -1 |awk -F' +' '{print $2}'`
down=`scanip |awk -F' ' '{print $2}' | uniq -c | tail -1 |awk -F' +' '{print $2}'`
echo -e "$red 处于UP状态的IP数量为 $up$end"
echo -e "$red 处于DOWN状态的UP数量为$down$end"

 

[root@ansible ~]# cat scanip_w.sh
#!/bin/bash
#
#********************************************************************
#Author: chenmeng
#QQ: 903575406
#Date: 2022-04-18
#FileName： scanip_w.sh
#Description： A test script
#Copyright (C): 2022 All rights reserved
#********************************************************************
net=$1
i=1
while [ $i -le 254 ];do
ip=$net.$i
{
ping -c2 -w2 $ip &> /dev/null && echo "$ip up" || echo "$ip down"
}&
let i++
done
wait

 

 

 

 每周的工作日1:30，将/etc备份至/backup目录中，保存的文件名称格式 为“etcbak-yyyy-mm-dd-HH.tar.xz”，其中日期是前一天的时间

编写备份脚本

[root@ansible srete]# cat backupetc.sh
#!/bin/bash
#
#********************************************************************
#Author: chenmeng
#QQ: 903575406
#Date: 2022-04-18
#FileName： backupetc.sh
#Description： A test script
#Copyright (C): 2022 All rights reserved
#********************************************************************
dir=ectbak-`date -d "-1 day" +%F-%T`
tar -Jcvf /backup/$dir.tar.xz /etc/

创建计划任务

[root@ansible srete]# crontab -l
30 1 * * 1-5 /root/srete/backupetc.sh