2022.07.04

Class hour 13

 

I made another mistake when creating new users , The panel must be adjusted to root Under the table of contents , But adjust to root Authentication password is required under the directory . When authenticating the password authentication  failure, So we need to reuse sudo passwd root This instruction is used to authenticate the password .

 

Now after the user is created , A user group will be created by default .

So where is this user group ？

  It can be used cat /etc/group Check it out. .

You can see that if you create a user , If you don't specify a group , By default, a group with the same user name will be created .

 

because root Permission is the highest , therefore id yes 0.

So how to put this test01 The user group of is modified ？

adopt usermod -g root test01 Just put test01 This user is moved to root This group .

  So sometimes , A user belongs to multiple user groups at the same time , And how to do it ？

This requires additional .

Just pay attention to when adding ,-g Must use capital -G.

  So how to create user groups directly ？

 

establish .

 

 

take test01 Append to test02 In the user group of .

 

 

  After deleting the Group , The information of the group to which the user belongs will also be updated .

Class hour 14

So how to modify the Group ？

 

The first change id It's simple , Direct use “groupmod -g Modified id Group name ” That's all right. .

 

Modify the group name directly “groupmod -n Modified group name The original group name ” That's all right. .

  Class hour 15 permissions

 

First switch back to your own user , then ll View details .

The first information you can see is the file type ,d The beginning is the directory , - It's a normal file .

rwx Represents the user's permissions ,-xr Is the permission of the user group , Later, there will be other permissions .

When I use vim There was an error when creating a new file .

It is displayed as asking me to enter detailed instructions （ I tried typing sudo It doesn't work ）

Then I tried vim.tiny solve .

Remember when editing files ,i Is to enter the input text mode ,esc After the introduction of text mode , Press ： key , Then input wq To save and launch .

 

 

So you can see , This newly added file , Only the current user has rw（ Reading and writing ） Authority , Other users only have read permission .

How to cancel or increase the permissions of other users ？ 

 

 

You can see the use of chmod That's all right. . Add or subtract with symbols .

So how to set permissions for user groups ？

 

Setting permissions for user groups is similar , But add one -R Use recursive settings .

 

Notice when adding the third item , Be sure to use small o.

Setting permissions on directories is the same . You can use —R Recursive settings .

 

  Class hour 16 Remote management

Input ipconfig You can go to cmd Check your own ip Address . 

And in the linux You need to enter ifconfig.

utilize ping+ The website can see the returned information .ctrl+c Cancel .

 

 

  For the experiment , Another computer is installed in the video .

He used clones to directly build a .