Questions:

1. What is the purpose of the 'setuid' and 'setgid' permissions on executable files, and how do they work?

'setuid' and 'setgid' are user authentication protocols used in Linux.
'setuid' and 'setgid' permissions allow users to execute files with the permissions of the file owner or group owner, respectively.
'setuid' and 'setgid' permissions allow users to modify system files without authentication.
'setuid' and 'setgid' permissions are used for changing the system hostname and group name.

2. In Linux, which directory contains user home directories?

/usr
/home
/var
/root

3. What is the purpose of the "chown" command in Linux?

Change the user's password
Change file ownership
Change the system hostname
Change the shell prompt

4. Which of the following statements about SELinux is true?

SELinux only provides optional access controls
SELinux uses discretionary access control (DAC) as its primary model
SELinux implements mandatory access controls (MAC) to enhance security
SELinux is only available on Ubuntu systems

5. What is the purpose of the "journalctl" command in Linux, and how is it used?

It is used to view the system journal logs, including kernel messages and application logs.
It is used to manage journaling filesystems like ext4.
It is used to create journal entries for user activity.
It is used to display CPU utilization statistics.