Second article: The first knowledge of Linux

Linux basic Commands

shutdown System: Init 0
Exit Current User: Exit
switch Terminal: ctr+alt+f[1-6]
view directories and files in the current directory: LS
view directories and files under current directory (Details): ls-l (=LL)
View all directories and files (including hidden files) in the current directory: Ls-a or Ls-all
view directories and files under the specified path: LS path
view current logged in User: WhoAmI
to view all Terminal logins: Who
viewing time: Date
Modified: Date ' month of the year '
View calendar: Cal Month Year
Clear Screen: Clear
Append user name: Useradd user name
Change Password: passwd user name
Switch User: Su-user name
Change Password: passwd user name
View command Help information: Man command, Command--help
View current path: pwd

Linux operating system directory and file operations

1. Important Catalogue:

A.bin directory: Used to store common executable files

B.sbin Directory: The executable file used to store the system

C. Home directory: Used to store the user's own files or directories, where Superuser root home directory is/root, while the normal user's home directory is stored in the/home directory, and use the user name as the last level directory (family directory) name, such as User01 user's home directory is/home/ User01

D.dev directory: Device Files directory

E.ETC Directory: Configuration file directory

F. Mount point (Directory): Typically removable hardware is mounted in the/media or/mnt directory

2. File operation

A. Switch to the current user's home directory: cd ~ or CD

B. Return to the previous level directory: CD-

C. copy files and rename files: CP original path new path/file name

D. Alias the command: for example, alias xx= ' Ls-l ', execute XX command equivalent to execute ls-l

E. Moving files, directories: MV Original path New path

F. Change of name: MV formerly known as New

G. Creating a directory: mkdir path

Create a tree-shaped directory: Mkdir-p/dir1/dir2/dir3

H. Creating a File: Touch path/File name

I. Delete Files: RM path/file name
J. Deleting a directory: Rm-r path/directory name
K. Display file All contents: Cat file
L. displaying the first 5 lines of a file: Head-5 file
M. displaying files last 5 lines: tail-5 file
Dynamic View file contents: Tail-f file

3. Create user-related files

A. User information exists in file:/etc/passwd, less/etc/passwd can view user information
Each line in the file represents a user's information, with each piece of information separated into seven paragraphs
1th paragraph: User
2nd paragraph: Password placeholder (x indicates password)
3rd: User ID (root id=0, normal self-created user ID starting from 500, the normal user ID changed to 0, that is, the root authority)
4th: Group ID (Root id=0, normal self-created user ID starting from 500)
5th paragraph: Description information
6th paragraph: Home directory
7th: Whether you can log in to the operating system executable file (/bin/bash means you can log in,/sbin/nologin means no login)
B. User password file exists:/etc/shadow
C. group file exists:/etc/group
Group name: Group Password: Group ID: Team member
D. The group password file exists:/etc/gshadow
E. User mailbox file:/var/spool/mail/user name
F. Check user Id,group ID, group: ID user name

Second article: The first knowledge of Linux