the file while preserving the current ownership?

The group named support is unable to make changes to the config file.

An administrator is reviewing the permissions and sees the following:

S Is -1 config

-rw-rw—-. 1 root app 4682 02-15 11:25 config

Which of the following should the administrator execute in order to give the support group access to modify

the file while preserving the current ownership?
A . chown :support config
B . setfacl -m g:support:rw- config
C . chmod 664 config
D . chmod g+s config

View Answer

Answer: C

Explanation:

To give the support group access to modify the config file while preserving the current ownership, the administrator can execute the command chmod 664 config ©. This will change the permissions of the config file to read and write for the owner and group, and read only for others. The owner and group of the file will remain as root and app respectively. The other commands will not achieve this task, but either change the group ownership, set an access control list, or set a setgid bit.

References:

[CompTIA Linux+ Study Guide], Chapter 3: Working with Files, Section: Changing File Permissions

[How to Use chmod Command in Linux]