第八周技术作业

1、显示统计占用系统内存最多的进程，并排序。

使用top命令显示系统资源使用情况，按M依照内存使用情况排序。

image.png

2、编写脚本，使用for和while分别实现192.168.0.0/24网段内，地址是否能够ping通，若ping通则输出"success!"，若ping不通则输出"fail!"

for循环

[root@localhost scripts]# vim for_ping.sh
for i in {1..254};do
     {
      if  ping -W1 -c1 $NETID$i &> /dev/null;then
       echo ping:$NETID$i successs!
      else
       echo ping:$NETID$i fail
      fi
      }
done
wait
[root@localhost scripts]# bash -n for_ping.sh 
[root@localhost scripts]# chmod +x for_ping.sh 
[root@localhost scripts]# ./for_ping.sh 
ping:192.168.0.1 fail
ping:192.168.0.2 fail
ping:192.168.0.3 fail
ping:192.168.0.4 fail
ping:192.168.0.5 fail
ping:192.168.0.6 fail
ping:192.168.0.7 fail
ping:192.168.0.8 fail
ping:192.168.0.9 fail
ping:192.168.0.10 fail
ping:192.168.0.11 fail
ping:192.168.0.12 fail
ping:192.168.0.13 fail
ping:192.168.0.14 fail
ping:192.168.0.15 fail
ping:192.168.0.16 fail
ping:192.168.0.17 fail
ping:192.168.0.18 fail
ping:192.168.0.19 fail
ping:192.168.0.20 fail
······  //以下输出省略

while循环

[root@localhost scripts]# vim while_ping.sh
NETID=192.168.0
i=1
while [ $i -lt  255 ];do
     {
      if ping  -W1 -c1 $NETID.$i &> /dev/null;then
         echo ping:$NETID.$i success!
      else
         echo ping:$NETID.$i fail
      fi
     }
done
wait
[root@localhost scripts]# bash -n while_ping.sh 
[root@localhost scripts]# chmod +x while_ping.sh
[root@localhost scripts]# ./while_ping.sh 
ping:192.168.0.1 fail
ping:192.168.0.2 fail
ping:192.168.0.3 fail
ping:192.168.0.4 fail
ping:192.168.0.5 fail
ping:192.168.0.6 fail
ping:192.168.0.7 fail
ping:192.168.0.8 fail
ping:192.168.0.9 fail
ping:192.168.0.10 fail
ping:192.168.0.11 fail
ping:192.168.0.12 fail
ping:192.168.0.13 fail
ping:192.168.0.14 fail
ping:192.168.0.15 fail
ping:192.168.0.16 fail
ping:192.168.0.17 fail
ping:192.168.0.18 fail
······  //以下输出省略

3、每周的工作日1:30，将/etc备份至/backup目录中，保存的文件名称格式 为“etcbak-yyyy-mm-dd-HH.tar.xz”，其中日期是前一天的时间

[root@localhost scripts]# vim bakup.sh
BACKNAME=etcbak-`date -d -1day +%F-%H`
tar -Jcvf /backup/${BACKNAME}.tar.xz /etc &> /dev/null
[root@localhost scripts]# bash -n bakup.sh 
[root@localhost scripts]# chmod +x bakup.sh 
[root@localhost scripts]# crontab -e
30 13 * * 1-5 /usr/bin/bash /data/scripts/bakup.sh
[root@localhost scripts]# ./bakup.sh 

[root@localhost scripts]# 
[root@localhost scripts]# echo $?
0
[root@localhost scripts]# ll /backup/
total 7640
-rw-r--r--. 1 root root 7822328 Aug 10 21:28 etcbak-2020-08-09-21.tar.xz

4、工作日时间，每10分钟执行一次磁盘空间检查，一旦发现任何分区利用率高 于80%，就发送邮件报警

[root@localhost scripts]# vim checkdisk.sh
USED=`df -h|awk -F " +|%" '/^\/dev\/sd.*/{print $5}'|sort -nr|head -1`
if [ $USED -gt 80 ];then
mail root << eof
someone disk used more than 80%,please check!
eof
fi
[root@localhost scripts]# bash -n checkdisk.sh 
[root@localhost scripts]# chmod +x checkdisk.sh 
[root@localhost scripts]# crontab -e 
30 13 * * 1-5 /usr/bin/bash /data/scripts/bakup.sh
*/10 * * * 1-5  /usr/bin/bash /data/scripts/diskcheck.sh