Rhcsa day 10 operation

Homework today ：
1. Create the following users 、 Groups and group membership ：
    1. Create a sysmgrs Group
    2. Create user natasha At the same time specified sysmgrs As natasha Additional groups of
    3. Create user harry At the same time specified sysmgrs As natasha Additional groups of

[[email protected] ~]# groupadd -g 1004 sysmgrs
[[email protected] ~]# useradd -u 1004 -g 1004 natasha 
[[email protected] ~]# gpasswd -a natasha sysmgrs 
 Putting users “natasha” Add to “sysmgrs” In the group 
[[email protected] ~]# useradd -u 1005 -g 1004 harry
[[email protected] ~]# gpasswd -a harry sysmgrs 
 Putting users “harry” Add to “sysmgrs” In the group 

    4. Create user sarah Appoint shell The type is /sbin/false( You do not have access to interactive on the system shell)
         It's not sysmgrs Members of
    5. Set up natasha 、 harry and sarah All of your passwords are 123

    6. Create user lockuser, And specify home directory as /home/lock, Then lock the user

[[email protected] ~]# useradd -d /home/lock  lockuser;passwd -l locser
 Lock the user  lockuser  Password  .
passwd:  Successful operation 

    7. Create user limituser, gid by 1555,userid by 1666, Let its password in 10 Expires in days 8

[[email protected] ~]# useradd -g 1003 -u 1666 -e 10 limituser

    8. Unlock lockuser, And set that the password must be changed the next time you log in

    9. Give Way natasha With modification harry Password permissions (sudo)

   

10. Create user testuser And set the password , Change the user name to normaluser

[[email protected] ~]# useradd -p 123456 testuser
[[email protected] ~]# usermod -l noemaluser testuser

11. Delete lockuser

[[email protected] ~]# userdel lockuser 

2. 755-》 What permissions do you have ：

      755 Corresponding primary user 、 Group users 、 Other users have read, write, and execute permissions

600-》 What permissions do you have  

      The primary user of the file has read and write permissions on the file

644-》 What permissions do you have

        The primary user of the file has read and write permissions on the file , The readable permissions of the group user of the file , Readable permissions of all other users on the file .