shell脚本练习（5）

一、需求：判断192.168.121.0/24网络中，当前在线的ip有哪些，并编写脚本打印出来。

[root@openEuler-1 script]# cat exist_IP.sh
#!/bin/bash
#########################
#File name:exist_IP.sh
#Email:obboda@163.com
#Created time:2025-01-13 03:20:57
#Description:查看192.168.121.0/24网络中在线的ip有哪些
#########################

# 为了方便，这里只测试前20台主机
for i in 192.168.121.{1..20}
do
        if ping -c 1 $i &> /dev/null
        then
                echo "$i主机在线中..."
        else
                echo "$i主机离线中..."
        fi
done


# 测试脚本
[root@openEuler-1 script]# bash exist_IP.sh
192.168.121.1主机离线中...
192.168.121.2主机在线中...
192.168.121.3主机离线中...
192.168.121.4主机离线中...
192.168.121.5主机离线中...
192.168.121.6主机离线中...
192.168.121.7主机离线中...
192.168.121.8主机离线中...
192.168.121.9主机离线中...
192.168.121.10主机离线中...
192.168.121.11主机在线中...
192.168.121.12主机在线中...
192.168.121.13主机在线中...
192.168.121.14主机离线中...
192.168.121.15主机离线中...
192.168.121.16主机离线中...
192.168.121.17主机离线中...
192.168.121.18主机离线中...
192.168.121.19主机离线中...
192.168.121.20主机离线中...

二、设计一个 Shell 程序，在/userdata 目录下建立50个目录，即 user1~user50，并设置每个目录的权限，其中其他用户的权限为:读;文件所有者的权限为:读、写、执行;文件所有者所在组的权限为:读、执行。

[root@openEuler-1 script]# cat create_dirs.sh
#!/bin/bash
#########################
#File name:create_dirs.sh
#Email:obboda@163.com
#Created time:2025-01-13 04:18:45
#Description:批量创建用户
#########################

for i in user{1..50}
do
        # rwx-rx-r
        mkdir -pm 754 /userdata/$i
done


# 测试脚本
[root@openEuler-1 script]# bash create_dirs.sh
[root@openEuler-1 script]# echo $?
0
[root@openEuler-1 script]# ll /userdata/
total 200
drwxr-xr-- 2 root root 4096 Jan 13 04:31 user1
drwxr-xr-- 2 root root 4096 Jan 13 04:31 user10
drwxr-xr-- 2 root root 4096 Jan 13 04:31 user11
drwxr-xr-- 2 root root 4096 Jan 13 04:31 user12
drwxr-xr-- 2 root root 4096 Jan 13 04:31 user13
drwxr-xr-- 2 root root 4096 Jan 13 04:31 user14
drwxr-xr-- 2 root root 4096 Jan 13 04:31 user15
drwxr-xr-- 2 root root 4096 Jan 13 04:31 user16
drwxr-xr-- 2 root root 4096 Jan 13 04:31 user17
drwxr-xr-- 2 root root 4096 Jan 13 04:31 user18
drwxr-xr-- 2 root root 4096 Jan 13 04:31 user19
drwxr-xr-- 2 root root 4096 Jan 13 04:31 user2
drwxr-xr-- 2 root root 4096 Jan 13 04:31 user20
drwxr-xr-- 2 root root 4096 Jan 13 04:31 user21
drwxr-xr-- 2 root root 4096 Jan 13 04:31 user22
drwxr-xr-- 2 root root 4096 Jan 13 04:31 user23
drwxr-xr-- 2 root root 4096 Jan 13 04:31 user24
drwxr-xr-- 2 root root 4096 Jan 13 04:31 user25
drwxr-xr-- 2 root root 4096 Jan 13 04:31 user26
drwxr-xr-- 2 root root 4096 Jan 13 04:31 user27
drwxr-xr-- 2 root root 4096 Jan 13 04:31 user28
drwxr-xr-- 2 root root 4096 Jan 13 04:31 user29
drwxr-xr-- 2 root root 4096 Jan 13 04:31 user3
drwxr-xr-- 2 root root 4096 Jan 13 04:31 user30
drwxr-xr-- 2 root root 4096 Jan 13 04:31 user31
drwxr-xr-- 2 root root 4096 Jan 13 04:31 user32
drwxr-xr-- 2 root root 4096 Jan 13 04:31 user33
drwxr-xr-- 2 root root 4096 Jan 13 04:31 user34
drwxr-xr-- 2 root root 4096 Jan 13 04:31 user35
drwxr-xr-- 2 root root 4096 Jan 13 04:31 user36
drwxr-xr-- 2 root root 4096 Jan 13 04:31 user37
drwxr-xr-- 2 root root 4096 Jan 13 04:31 user38
drwxr-xr-- 2 root root 4096 Jan 13 04:31 user39
drwxr-xr-- 2 root root 4096 Jan 13 04:31 user4
drwxr-xr-- 2 root root 4096 Jan 13 04:31 user40
drwxr-xr-- 2 root root 4096 Jan 13 04:31 user41
drwxr-xr-- 2 root root 4096 Jan 13 04:31 user42
drwxr-xr-- 2 root root 4096 Jan 13 04:31 user43
drwxr-xr-- 2 root root 4096 Jan 13 04:31 user44
drwxr-xr-- 2 root root 4096 Jan 13 04:31 user45
drwxr-xr-- 2 root root 4096 Jan 13 04:31 user46
drwxr-xr-- 2 root root 4096 Jan 13 04:31 user47
drwxr-xr-- 2 root root 4096 Jan 13 04:31 user48
drwxr-xr-- 2 root root 4096 Jan 13 04:31 user49
drwxr-xr-- 2 root root 4096 Jan 13 04:31 user5
drwxr-xr-- 2 root root 4096 Jan 13 04:31 user50
drwxr-xr-- 2 root root 4096 Jan 13 04:31 user6
drwxr-xr-- 2 root root 4096 Jan 13 04:31 user7
drwxr-xr-- 2 root root 4096 Jan 13 04:31 user8
drwxr-xr-- 2 root root 4096 Jan 13 04:31 user9

三、编写一个模拟双色球摇号过程的脚本。要求如下：