File permissions and directory settings for Linux

1.user/group/others

File Permissions Concepts :

ls meaning list, which focuses on displaying the file name and its associated properties.

First column: File type and Permissions

File type: D directory-file L link file

After nine characters: 1. File owner permissions 2. Same user group permissions 3. Other non-user group permissions

　　R Read W write x executable

Second column: How many file names are connected to this node

Column Three: Owner account

Fourth column: Owning user group

Fifth column: The size of the file, the default unit is B

Sixth column: creation date or last modified date

Column seventh: filename of the file

To change file properties and permissions:

1.CHGRP [-R]

Where-R indicates a recursive change

Change the owning user group

eg

2.chown

Change file Owner

3.chmod

Adapted permissions: R_4 w_2 x_1

Eg:chmod 777. BASHRC

U:user G:group O:other A:all

Eg:chmod U=rwx,go=rx. BASHRC

Eg:chmod a+w. BASHRC

Eg:chmod a-x. BASHRC

Ugoa can add and subtract permissions