1、统计出/etc/passwd文件中其默认shell为非/sbin/nologin的用户个数,并将用户都显示出来

[root@client ~]#{ grep -v "/sbin/nologin" /etc/passwd |cut -d: -f1;grep -v "/sbin/nologin" /etc/passwd|wc -l;}

2、查出用户UID最大值的用户名、UID及shell类型

[root@client ~]#cut -d: -f1,3,7 /etc/passwd|sort -t: -k2 -nr|head -n1

3、统计当前连接本机的每个远程主机IP的连接数,并按从大到小排序

#方法一
[root@client ~]#ss -ant|grep  "ESTAB"|tr -s ' '|cut -d ' ' -f5|cut -d: -f1|uniq -c|sort -nr
      2 10.0.0.1
#方法二
[root@client ~]#ss -ant|grep "ESTAB"|awk '{print $5}'|awk -F: '{print $1}'|sort |uniq -c|sort -nr
      2 10.0.0.1

4、编写脚本disk.sh,显示当前硬盘分区中空间利用率最大的值

[root@client ~]#cat disk.sh 
#!/bin/bash
#
#********************************************************************
#Author:		jiangfeng
#QQ: 			1461918614
#Date: 			2021-07-21
#FileName:		disk.sh
#Description:		The test script
#Copyright (C): 	2021 All rights reserved
#********************************************************************
DISK=$(df|grep "^/dev/sd*"|tr -s " " "%" |cut -d% -f5|sort -nr|head -n1)
echo "$DISK"
[root@client ~]#bash disk.sh 
15

5、编写脚本 systeminfo.sh,显示当前主机系统信息,包括:主机名,IPv4地址,操作系统版本,内核版本,CPU型号,内存大小,硬盘大小

[root@client ~]#cat systeminfo.sh 
#!/bin/bash
#
#********************************************************************
#Author:		jiangfeng
#QQ: 			1461918614
#Date: 			2021-07-21
#FileName:		systeminfo.sh
#Description:		The test script
#Copyright (C): 	2021 All rights reserved
#********************************************************************
RED="\E[1;31m"
GREEN="\E[1;32m"
END="\E[0m"
echo -e "$GREEN----------------Host systeminfo---------------------$END"
echo -e "HOSTNAME:      $RED`hostname`$END"
echo -e "IPADDR:        $RED`ifconfig eth0|grep -Eo '([0-9]{1,3}\.){3}[0-9]{1,3}' |head -n1`$END" 
echo -e "OSVERSION:     $RED`cat /etc/redhat-release`$END"
echo -e "KERNEL:        $RED`uname -r`$END"
echo -e "CPU:           $RED`lscpu|grep 'Model name'|tr -s ' '|cut -d: -f2`$END"
echo -e "MEMORY:        $RED`free -h|grep Mem|tr -s ' ' :|cut -d: -f2`$END"
echo -e "DISK:          $RED`lsblk |grep '^sd' |tr -s ' '|cut -d " " -f4`$END"
echo -e "$GREEN----------------------------------------------------$END"

[root@client ~]#bash systeminfo.sh 
----------------Host systeminfo---------------------
HOSTNAME:      client
IPADDR:        10.0.0.133
OSVERSION:     CentOS Linux release 8.3.2011
KERNEL:        4.18.0-240.el8.x86_64
CPU:            Intel(R) Core(TM) i5-8300H CPU @ 2.30GHz
MEMORY:        1.9Gi
DISK:          200G
----------------------------------------------------

6、通关vimtutor(可参考https://yyqing.me/post/2017/2017-02-22-vimtutor-chinese-summary)