Faculty of Computing and Informatics, Department of Computer Science
SAD622S: pt Opportunity Examination Paper
10. Your class has ended in an FCI lab at NUST. You were using a lab computer running MS
(6)
Windows. Before you leave your desk, you make sure nobody can access data from
your session by:
i. Pressing Start ⇒ Power off
ii. Removing the power cord from the computer
iii. Pressing <CRTL>-<ALT>-<DEL> and selecting "Lock screen"
For each of the possibilities above, state how the same action can be emulated on a
MS Windows guest in a hypervisor (Virtual Box/ VMWare) [2 marks each]
11. For each of the Linux commands (first line) and their respective output (subsequent
lines) below, briefly explain why its execution results in an error [1 mark each] . Also
state what the correct command would be [1 mark each].
(a) peter©lenovo:-$ sudu ls -1 /dev/sdb1
(2)
Command 'sudu' not found, did you mean:
command 'tudu' from deb tudu (0.10.4-1)
command 'sudo' from deb sudo (1 . 9.9-1ubuntu2 . 5)
command 'sudo' from deb sudo-ldap (1.9.9-1ubuntu2.5)
Try : sudo apt install <deb name>
(b) peter©lenovo:-$ tail -11 /etc/shadow
(2)
tail: cannot open '/etc/shadow' for reading: Permission denied
12. Consider the following interaction between user and Linux command line:
peter©lenovo:-$ find /usr/bin - name peter
peter©lenovo:-$
Note that, while the command does not give any output, a new command prompt ap-
pears .
(a) Is this an error? How can you tell?
(2)
(b) Why is there no output?
(3)
13. Consider the following interaction between user and Linux command line:
peter©lenovo:-$ ping 169.9.0 . 1
PING 169.9.0.1 (169.9.0.1) 56(84) bytes of data.
Note that no new command line prompt appears after the initial feedback in the sec-
ond line.
(a) Is this an error? How can you tell?
(2)
(b) Why is there no output?
(2)
(c) How V1,1ill the user get their normal command prompt back?
(1)
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