01 basic concepts (Linux Shell programming and Server Management)

1. login and logout

Tty1 ~ is enabled by default in Linux ~ Seven tty7 terminal interfaces, 1-6 text terminals and 7 graphics Terminals

Use CTRL + ALT + F1 to switch

Remote login: Method 1: SSH-l account host name or IP address

Method 2: SSH account @ host name or IP address

Logout: Exit

 

Ii. Files And Directories

File Path: view the file type

File permissions include U, G, O, and R, W, X, and S (special permissions)

 

3. Wildcards and escape characters

Wildcard character: * represents any character, can be a Null String

? Represents a non-null character

\ And ''can be used for escape of special characters, \ can be used for continuation of line symbols

 

Iv. Character Set combination

Character Set combination is a character in the range of characters listed in []. Its length is 1

 

V. bracket Extension

The expanded symbol of parentheses is {}, used to combine strings, that is, strings listed in {}, respectively, and external characters.

 

6. files enabled by default

When each shell script is executed, three standard files (stdin) are enabled by default.Code0), stdout (File Code 1), stderr (File Code 2)

 

VII. Standard Input/Output

Turn to output:>

Additional steering:>

Steering input: <

You can use both input and output to change the content of a text and save it to another text.

 

8. Pipelines

MakeProgramCan be changed to the input of another program.

Usage: command 1 | command 2

 

9. frontend and backend work