Detailed explanation of ACL usage

ACL: access control list, mainly used to set permissions for files or directories

How to use:

Getfacl [FILE]: view this file acl permissions

Setfacl [- bkndRLPvh] [{- m |-x} acl_spec] [{- M |-X} acl_file] file.

Special permissions:

Mask permission: this permission is the maximum valid permission. When the permission set for the user or group has the same permission as the mask permission, it is the final permission.

Common options:

-m: create a new acl permission

-x: removes the specified acl permission

-b: remove all acl permissions

-d: set default acl permissions

-k: delete the default acl permission

-R: set acl permissions recursively

View the acl permissions of the current file or directory:

# getfacl test

Set acl permissions on the user:

# setfacl-m u:liu:rwx test

Set acl permissions on the group:

# setfacl-m g:tgroup:rx test

Set the maximum valid permission mask:

# setfacl-m m:rx test previously set the permission for the user liu to rwx. After setting the mask permission, the final valid permission is rx.

Remove user permissions:

# setfacl-x u:liu test can see that the permissions previously set for user liu are gone

Delete group permissions:

# setfacl-x g:tgroup test can see that the permissions previously set for the group tgroup are gone

Set recursive permissions:

# setfacl-R-m u:liu:rx test all files or directories in this directory, user liu has only rx permission

Remove all permissions:

# setfacl-b test

Set the default permissions:

# setfacl-m d:u:liu:rx test

Delete default permissions:

# setfacl-k test