Introduction to Linux file Rights Management

File permissions

2. File permissions

File permissions are defined primarily for three types of objects

Owner: Master, u

Group: Genus, G

Other: Others, O

Each file has three permissions defined for each type of visitor

R:readable

W:writable

X:excutable

File:

R: Use the File View class tool to get its contents

W: can modify its contents

X: This file can be brought to the kernel to start as a process

Directory:

R: You can use LS to view the list of files in this directory

W: You can create files in this directory or delete files in this directory

X: You can use Ls-l to view a list of files in this directory, and you can enter this directory by CD

Permission entries	File type	Read	Write	Perform	Read	Write	Perform	Read	Write	Perform
Character representation	( d|l|c|s|p )	(r)	(W)	(x)	(r)	(W)	(x)	(r)	(W)	(x)
Digital representation		4	2	1	4	2	1	4	2	1
Permission Assignment		File owner			File belongs to group user			Other users

Depending on the binary algorithm, set permissions on the file as follows:

3. Command

chmod (change model) + level + Flie

Eg:chmod 777 PMA

Of course each file has its own fixed permissions when it is initially created, not for each set, how is it implemented?

The answer is: when the system creates a file or folder, there will be a ' umask ' reverse mask reverse mask that is different for each user, and you can view the current user's value by entering ' umask '.

The initial setup file permissions are computed as: 777-022=755 is represented as W:7 RWX g:5 rw-o:5 rw-.

Introduction to Linux file Rights Management