To prevent a specific user from scheduling tasks with at, what should the administrator do?

To prevent a specific user from scheduling tasks with at, what should the administrator do?
A . Add the specific user to /etc/at.allow file.
B . Add the specific user to [deny] section in the /etc/atd.conf file.
C . Add the specific user to /etc/at.deny file.
D . Add the specific user to nojobs group.
E . Run the following: atd –deny [user].

View Answer

Answer: C

Explanation:

The /etc/at.deny file is a file that contains a list of users who are not allowed to use the at command to schedule jobs. If the file exists, any user who is not in the /etc/at.allow file and is in the /etc/at.deny file will be denied access to the at command. To prevent a specific user from scheduling tasks with at, the administrator can simply add the user’s name to the /etc/at.deny file. For example, to prevent the user bob from using the at command, the administrator can use the following command:

echo “bob” | sudo tee -a /etc/at.deny

The other options are not correct. The /etc/at.allow file is a file that contains a list of users who are allowed to use the at command. Adding a user to this file will not prevent them from scheduling tasks with at. The /etc/atd.conf file is a configuration file for the at daemon, which does not have a [deny] section. Adding a user to this file will not affect their access to the at command. The nojobs group is not a predefined group in Linux, and adding a user to this group will not prevent them from scheduling tasks with at. The atd command does not have a –deny option, and running this command will not prevent a user from scheduling tasks with at.

Reference: at Command in Linux with Examples – GeeksforGeeks

How to Use the Linux at Command {9 Examples} – phoenixNAP at(1) – Linux man page