linux-user groups, permissions

The Linux user group is divided into: owner, group, other group

• Owner: Who created, who is the owner. Command: Ls-al
• Group: When creating a file or folder, this file or folder is assigned to the user group, which effectively isolates the file.
• Other groups: In contrast to the group, it is the other group

Linux file permissions: File properties, modify file properties, and permissions

• File properties: The file attributes are 10 bits in total. In addition to the first, the remaining three-bit one-component three groups

First bit: attributes (-for files, D for directories, L for linked files, B-Interface devices, C-port devices)

First group: Permissions for the file owner.

Second group: Permissions for the same user group

Group Three: Permissions for other groups

Rights r =4 Readable, W =2 writable, x = 1 executable

• Modify file properties

CHGRP: Change the user group that the file belongs to chgrp [user group name] File

Chown: Change the file owner Chown [account name] file or directory

chmod: Change the permissions of a file r=4,w=2,x=1

Or

A=all; U=user, G=group; O=other; + Add permissions;-turn off permissions; = Set permissions

For example: Modify the permissions to-rwx rw-r

Mode one: the first group rwx = 4+2+1=7; the second group rw-= 4+2+0=6; The third group r--: 4+0+0=4;

Command: chmod 764 FileName

Mode two; chmod u=rwx,g=rw,o=r FileName

For example, if you do not need to know the file permissions, you need to increase the file execution permissions or remove the execution permissions

chmod a+x FileName; chmod a-x FileName

Permission meanings for directories and files:

• For file:
  • • R = Read: reads the actual contents of the file.
    • w = write: Edits the actual contents of the file. The file cannot be deleted.
    • X =execute: Executes the file. The file cannot be deleted.
• For directory:
  • • R: The LS command can be used to read files in the directory.
    • W: You can change the list of directory structures.
      • Create a new file or directory
      • Delete files, directories
      • Renaming files or directories
      • Transferring files, directories
    
    
    • X: Whether the user has permission to enter the current directory for Work commands: CD to switch directories.

File, r= can access the file directory linked list of this file, can allow access to this file requires X permission.

x= switch, whether access to this directory is allowed. Whether the directory can be accessed via the CD command.

　　　

linux-user groups, permissions