1. Why should a regular user edit his personal crontab by using the command crontab instead of just editing his crontab file manually?

A) A. Because user specific crontab entries are stored in a common database and must be extracted before editing.
B) B. Because crontab starts the cron daemon in case it is not running due to no other crontab entries existing.
C) C. Because user specific crontab entries are stored in a special directory which is maintained by the cron daemon and not writable for regular users.
D) D. Because crontab collects information about all users crontabs and recommends similar commands used by other users of the system.



2. What is true about groups in a Linux system? (Choose TWO correct answers.)(Select 2answers)

A) A. Each user may be a member of several groups. However, only one group is the user's primary group.
B) B. Groups may have a password that allows users to join that group temporarily.
C) C. Each user can only be a member of one group at a time.
D) D. Group memberships are optional such that there may be users that do not belong to any group.
E) E. Groups can be nested meaning that one group can be a member of another group.


3. What is true about UIDs and GIDs?

A) A. UIDs and GIDs share a common number space. Each time a new user or group is created, the next free ID is assigned.
B) B. The first four digits of each UID are the GID of the primary group of that user.
C) C. The GID of a group is always the sum of the UIDs of its members.
D) D. The number space is split up. UIDs usually reside in the range from 0 to 32767 while GIDs reside in the range from 32768 to 65535.
E) E. There are distinct number spaces for UIDs and GIDs, i.e. the same number may be used as both a UID and a GID.


4. What happens if the password of a user in the /etc/shadow file is prepended with the ! character?

A) A. When logging in, the user automatically gets root privileges in addition to his regular privileges.
B) B. The password is inverted which allows the user to log in with any password other than the current password.
C) C. The user is disabled and all login methods, including but not limited to password based logins, are disabled.
D) D. Upon the next log in, the user is forced to change his password.
E) E. The password becomes invalid which disables password based logins although other login methods remain usable.


5. Which of the following details can be found in an entry of a user specific crontab? (Choose TWO correct answers.)(Select 2answers)

A) A. The verbal description of the job.
B) B. The syslog facility to where the output of the job should be sent.
C) C. The time when the cron job should run.
D) D. The command that should be started by the cron job.
E) E. The name of the user which should run the job.