Command Help for the Linux base command

Login
User name: User ID

Authentication mechanism: Authentication
Authorization: Authorization
Audit: Audition (logging)

Ctrl + Alt + F1 Toggle Command Line interface

Ctrl + Alt + F7 Toggle Graphical interface

STARTX & Toggle Graphical interface

Date: Displays time management time
Hardware time: Hwclock
System Time: Date
View Date: Cal
Hwclock-w write system time to hardware
Hwclock-s writes hardware time to the system

Shutdown-r now restart
Shutdown-h now shutdown,

Useradd Tom Create Tom User

passwd Tom returns two times set Tom password

SU Tom Switch to Tom

Su:switch User
SU-L User name full switch
SU user name half switch
Exit Tom User

USERDEL-RF Tom forced to delete Tom

Hostname View User Name
hostname + Name temporarily modified name restart invalidation

Clear = Shortcut key Ctrl + L Clear Screen

Command format: Command option parameter

Command definition: Shell is delivered to the kernel
Options: Modify how commands are executed (some options are available with parameters)
Short options:-Character multiple options can be combined-a-b =-ab
Long option:--word cannot be combined and must be written separately
Parameters: The Action object of the command

Command type:
Built-in command (shell built-in) internal, built-in
External command: There is an executable file corresponding to the command name in a path on the file system

To see whether a command is built-in or external by type, which

command to ask for help:

Internal command: Help command (help + command)
External command: COMMAND--HELP (Command--help)
Man command (Mans + command)

Find:

/string search string string down
? String: Search up string strings
Q Exit

CTRL + Z exit

Command Help for Linux basic commands