File Access Permissions - Who may access?

• Access Permissions are split into 3: for the User-owner, the Group-owner and for "others".
• If the User accessing the file is the User-owner of the file, only the "User-owner" permissions are checked.
• Thus, a file with permissions for 'others' but no permissions for 'User-owner' - won't allow the User-owner to access it...
• ...But as we said, the User-owner may always change the permissions of the file, so she can give herself access to the file, and then access the file.
• A similar check is performed if the User accessing the file, belongs to the Group-owner of the file (but is not the User-owner of the file).

Originally written by guy keren