grep  -v  ‘/sbin/nologin‘  /etc/passwd   | cut -d: -f 1
            grep  -v  ‘/sbin/nologin‘  /etc/passwd   | cut -d: -f 1 | wc -l

2、查出用户UID最大值的用户名、UID及shell类型

            cat /etc/passwd | cut -d: -f1,3,7 | sort  -t ":" -k 2   -rn | head -1

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

            ss -nt  | grep -v State |  tr -s " " : | cut -d: -f6   | sort  | uniq -c | sort -rn

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@centos8 scripts]# cat disk.sh 
        #!/bin/bash
        LIST_DISK_USERD=`df  | grep  ‘^/dev‘ | tr -s ‘ ‘  | cut -d " " -f 6,5 | sort  -t% -k1 -nr`

        echo   "$LIST_DISK_USERD"

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@centos8 scripts]# cat systeminfo.sh 
            #!/bin/bash

            RED="\033[1;31m"
            GREEN="\033[1;32m"
            END="\033[0m"

            echo -e "$GREEN---------------------------------- Host systeminfo------------------------------$END"
            echo -e "HOSTNAME:   $RED `hostname` $END"
            echo -e "IPADDR:     $RED `ifconfig ens33 | egrep -o ‘([0-9]{1,3}\.){3}[0-9]{1,3}‘ | head -n1` $END"
            echo -e "OSVERSION:  $RED `cat /etc/system-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 ‘^sda‘ | tr -s ‘ ‘ : | cut -d : -f 1,5` $END"
            echo -e "$GREEN--------------------------------------------------------------------------------$END"

Linux中shell练习