Linux how to do file and directory permissions

The chmod command can change permissions for all subdirectories:

To change the permissions of a file:

The code is as follows	Copy Code
chmod mode File|dir

To change permissions for all subdirectories:

The code is as follows	Copy Code
chmod mode Dir-r

Note that the-R parameter is appended

For example, change all files under File directory to 777:

The code is as follows	Copy Code
chmod 777 File-r

Digital Setting method

We must first understand the meaning of a number-represented attribute: 0 means no permission, 1 for executable, 2 for writable, 4 for readable, and then adds. Therefore, the format of the numeric attribute should be 3 octal from 0 to 7, in the Order of (U) (g) (O).

For example, if you want the owner of a file to have read/write two permissions, you need to have 4 (readable) +2 (writable) =6 (read/write).