课堂作业1

1.（1）[root@localhost ~]# mkdir test_dir

[root@localhost ~]# cd test_dir
[root@localhost test_dir]# touch test_file.txt
（2）[root@localhost ~]# cp test_dir/test_file.txt  /tmp/copy_of_test.txt

（3）[root@localhost ~]# rm -rf  test_dir

（4）[root@localhost ~]# mkdir test_dir

[root@localhost test_dir]# touch ~/test_dir/test_file.txt

[root@localhost test_dir]# ln -s test_file.txt  soft_link.txt

[root@localhost test_dir]# ln test_file.txt  hard_link.txt

（5）[root@localhost test_dir]# test_file.txt

[root@localhost test_dir]# cat soft_link.txt

软 ：提示"没有那个文件或目录"   它存储的是指向原文件的路径。当原文件被删除后，软链接就会失效，无法访问。

硬 ：可以正常访问   硬链接指向原来的数据块，故可以访问

2.（1）[root@localhost ~]#  head -n 10 /etc/passwd

（2）[root@localhost ~]#  echo "这是追加的测试内容" >>  copy_of_test.txt 

[root@localhost ~]# cat copy_of_test.txt

(3)[root@localhost ~]# vim copy_of_test.txt

 :%s/测试/练习/g 
 :wq

3.(1)[root@localhost ~]# cd /home 

[root@localhost home]# mkdir /backup

[root@localhost home]# cp /etc/*.conf  /home/backup

(2)[root@localhost ~]# ls /home/backup | wc -l

(3)[root@localhost ~]# tar -zcvf etc_backup.tar.gz /home/backup

[root@localhost ~]#  rm -rf /home/backup

4.(1)[root@localhost ~]# chown user1 : group1 /copy_of_test.txt

(2)[root@localhost ~]# chmod 754 /copy_of_test.txt

(3)[root@localhost ~]# ls -l /copy_of_test.txt

5.(1)[root@localhost ~]# sudo useradd -s /bin/bash newuser1

(2)[root@localhost ~]# sudo groupadd newgroup1

[root@localhost ~]# sudo usermod -aG newgroup1 newuser1

(3)[root@localhost ~]# sudo userdel newuser1

6.（1）[root@localhost ~]# mkdir /perm_test_dir

[root@localhost ~]# touch /perm_test_file.txt

[root@localhost ~]# chmod 750 /perm_test_dir

[root@localhost ~]# chmod 644 /perm_test_file.txt

（2）[root@localhost ~]# chgrp -R newgroup1 /perm_test_dir

(3)[root@localhost ~]# chmod -R 774 /perm_test_dir

7.[root@localhost ~]# mount  /dev/sr0   /mnt

[root@localhost ~]# vim /etc/yum.repos.d/base.repo

[BaseOS]
name=BaseOS  
baseurl=file:///mnt/BaseOS
gpgcheck=0
[AppStream]
name=AppStream
baseurl=file:///mnt/AppStream
gpgcheck=0

[root@localhost ~]# dnf   install   cockpit    -y
[root@localhost ~]# systemctl restart cockpit  
[root@localhost ~]# systemctl stop   firewalld