第四周作业

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

cat /etc/passwd | grep -Ev "/sbin/nologin" | wc -l

2、查出用户UID最大值的用户名、UID及shell类型

grep `cat /etc/passwd | cut -d: -f3 |sort -nr|head -1` /etc/passwd | cut -d: -f1,3,7

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

netstat -t | grep ':ssh' | grep -Eo '([0-9]{1,3}\.){3}[0-9]{1,3}' | uniq -c |sort -nr

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

#!/bin/bash
df -h | grep -Eo [0-9]+% | sort -n |tail -n1

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

#!/bin/bash
#
#*********************************************************#
#Author:		*****
#Blog:			https://www.cnblogs.com/handsomezhy/
#Date:			2020-11-13 16:26:17
#FileName:		systeminfo.sh
#Version:		V1.0
#QQ:			******
#Description:		This is a production script.
#Copyright(C):       	2020 All rights reserved
#*********************************************************#
RED="\e[1;31m"
GREEN="echo -e \e[1;32m"
END="\e[0m"
$GREEN-----------------------Host Systeminfo----------------------------$END
echo -e  "HOSTNAME:		$RED `hostname` $END"
echo -e  "IPADDR:		$RED `ifconfig|grep -Eo '([0-9]{1,3}\.){3}[0-9]{1,3}'|head -n1` $END"
echo -e  "OVERSION:		$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: -f5 | tr "\n" " "` $END"
$GREEN------------------------------------------------------------------$END