Create user/set password/delete user

serial number	Order	effect	illustrate
01	useradd -m -g group new user name	add new user	-m Automatically create the user's home directory -g specifies the group the user is in, otherwise a group with the same name will be created.
02	passwd username	set user password	If it is an ordinary user, use passwd directly You can change your account password
03	userdel -r username	delete users	-r will automatically delete the user's home directory
04	cat /etc/passwd | grep username	Confirm user information	After creating a new user, the user information will be saved in the /etc/passwd file

hint:

When creating a user, if you forget to add the -m option to specify the home directory of the new user, the easiest way is to delete the user and recreate it .

When creating a user, a group name with the same name as the user name is created by default.

User information is stored in the /etc/passwd file.

passwd file:

The /etc/passwd file stores user information, 7 pieces of information composed of 6 semicolons, which are

1. username

2. password (x indicates encrypted password)

3. UID (User ID)

4. GID (group identifier)

5. User full name or local account

6. home directory

7. The shell used for login is after login, the terminal command used by Ubuntu is dash by default

view user information

serial number	Order	effect
01	id[username]	View user UID and GID information
02	who	View a list of all currently logged in users
03	whoami	View the account name of the currently logged in user