Learning the ls command
-a can display all files under the target folder, including hidden files
-l can display all attributes of files in the target folder
-i displays the ID number of the file
-d displays the current directory
-h Display the size of the file (the unit is bytes by default) in the form of existing units
The concept of user groups
drwx------. 19 now now 4096 3月 4 16:38
d indicates that the current file is a directory
r (read) 4, w (write) 2, x (executable) 1
Each group of three in the red frame,
The first red box represents U, which means the user to which the current file or folder belongs, and the permissions it has
The second red box indicates G, which means the user group to which the current file or folder belongs, and the permissions it has
The third red box means O, which means other groups and permissions owned by the current file or folder
mkdir command
for creating directories
[-p] Create directories recursively
cd command
switch directory
pwd command
View the path of the current user
rmdir command
delete empty directory