1、统计出/etc/passwd文件中其默认shel为非/s bin/nologin的用户个数，并将用户都显示出来
[root@localhost data]# grep -v /sbin/nologin /etc/passwd|cut -d: -f1
rootsyncshutdown
halt
dingchao
mageia
user1
user2
user3
[root@localhost data]# grep -v /sbin/nologin /etc/passwd|cut -d: -f1|wc -l9
2、查出用户UID最大值的用户名、UID及shell类型
[root@localhost data]# cut -d: -f3 /etc/passwd|sort -nr
2005
2004
2003
2002
1100
1000
999
192
99
89
81
74
48
38
14
12
11
8
7
6
5
4
3
2
1
0
[root@localhost data]# grep 2005 /etc/passwd |cut -d: -f1,3,7
user3:2005:/bin/bash
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
[root@localhost data]# ss -nt|tail -n+2|tr -s " " : |cut -d: -f6|uniq -c|sort -rn
2 192.168.1.44
1 192.168.1.4
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@localhost ~]# sh disk.sh
\#!/bin/bash
\#Description:
\#Author:root
\#Version:1.0
\#CreateTime:2021-04-02 08:51:10
df -h |tr -s " " :|sort -rn -k 5 -t :|grep -Eo -m 1 [0-9]*%
[root@localhost ~]# chmod +x disk.sh
[root@localhost ~]# ./disk.sh
18%
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
#Description:
#Author:root
#Version:1.0
#CreateTime:2021-04-02 09:50:42
hostname=" `hostname` " #hostname
address=`ifconfig eth0 | sed -n '2p' | grep -Eo '([0-9]{1,3}.){3}[0-9]{1,3}'|head -1` #network address
systemversion=" `cat /etc/redhat-release` " #system version
kernelversion=`uname -r` #kernel version
cputype=`grep -E "model name" /proc/cpuinfo |cut -d: -f2` #cpu version
mermory=`free -mh|tail -2|tr -s " " :|cut -d: -f2|head -1` #mermory
harddisk=`fdisk -l | grep Disk|head -1` #hard disk
echo "hostname is $hostname"
echo "network address is $address"
echo "system version is $systemversion"
echo "kernel version is $kernelversion"
echo "cpu type is $cputype"
echo "mermory is $mermory"
echo "hard disk is $harddisk"
[root@dingchao ~]# ./systeminfo1.sh
hostname is dingchao
network address is 192.168.1.48
system version is CentOS Linux release 7.7.1908 (Core)
kernel version is 5.4.106-1.el7.elrepo.x86_64
cpu type is Intel(R) Xeon(R) Silver 4210R CPU @ 2.40GHz
mermory is 1.9G
hard disk is Disk /dev/sda: 107.4 GB, 107374182400 bytes, 209715200 sectors
