Linux/centos Basic Operation

File directory

1. USR: related to software Installation
2. VAR: system Run Process related
3. Bin: Executable file
4. Boot: System Boot related directory
5. Dev: Drive Directory
6. Home: Store user's individual user files
7. Lib:linux function Library
8. Media: can delete devices
9. MNT: Media-like
10. OPT: third-party software storage Directory
11. Root: Administrator Directory
12. Sbin: Administrator executable file
13. Temp: Temporary files that need to be deleted periodically
14. Proc: Virtual File system
15. SYS: Virtual file system, kernel module
16. ETC: Store the user group file "group", User information file ' passwd

Common commands

1. View Ip: ip Addr

2. View information ls

3. View more information ll or ls-l

4. View hidden files Ls-al

5. Create a folder (you can fill in the path, but the path must exist) mkdir <name>

6. Create file (path does not exist, create path automatically) Mkdir-p <name>

7. Safe deletion (only empty directories can be deleted or error) RmDir <name>

8. Delete Rm-rf <name>

9. Create File VI <name>

10. Save File Press ESC, enter: q / exit or wq / Save and exit

11. Edit press I--press ESC--q! / Force quit or wq / save and exit

12. The arrow keys in the file h / left, k /, j /, l / right

13. Fast Move cursor number key + arrow key

14. Page DOWN Ctrl + f

15. Page UP Ctrl + b

16. Turn up half a page ctrl + u

17. Turn down half a page ctrl + d

18. Move to end of line end or $

19. Move to the wardrobe home or 0

20. Move to the end of Wen Shift + g

21. Move to the beginning G + g

22. How many rows of numbers to move backwards + shift + g

23. Querying the command line / + query criteria

24. Query up the command line? + Query criteria

25. Delete Files Rm-f <name>

26. 10 lines after viewing the file tail <name>

27. 20 lines after viewing the file tail-20 <name>

28. Float, change the contents of the file, print out the changes tail-f <name>

29. Print file contents Cat <name>

30. filtering, finding grep <name>

31. ll | grep txt file in ‘txt’ folder

32. 
    

User actions

1. User must belong to a user group, you add a user, the system will automatically help you create a user group
2. Add user Information Useradd <name>
3. Print user Information cat/etc/passwd

Printed information cc:x: 1000:1000::/home/cc:/bin/bash

Directory for user name, password, user ID, user group ID, notes, user directory, Shell command, respectively

4. Add a password to the user passwd <name>

5. Remotely connect a computer SSH < user name >@ address

6. View user Groups Cat/etc/group

7. Create user group Groupadd < user group name >

8. Add user to User group Useradd-g < user group > < user name >

9. Delete user groups Groupdel < user groups >

However, the user primary group cannot be deleted, the user primary group is a user group with the same name as the user name, you can change

10. Delete User Userdel < user name >

11. See which user group the user belongs to, group < user name >

Direct write group, is to view the current user group

12. Modify user Primary group Usermod-g < user group > < user name >

13. View the user's details ID < user name >

14. Switch User Su < username >

15. Exit the user exit

Background operation

1. View Machine Type Lscpu
2. View disk full space DF
3. View disk space df-h
4. View index Space Df-i
5. View current running program PS aux
6. To see if the program is running PS aux |grep < user name >
7. View top of a computer's resource footprint
8. Exit Ctrl C
9. If you cannot connect to the server, you need to turn off the firewall

Systemctl Disable FIREWALLD

Reboot

All interfaces on Linux are in the form of files

Linux/centos Basic Operation