CSCI 243 UNIX/VMS
Operating Systems
Final Exam 2012
Instructions:
The usual…answer all questions completely and concisely. Show all work in order to receive any partial
credit. Write legibly, because if I
can’t read it I have to assume that it’s wrong.
This exam is closed book, closed notes, closed computer, closed cell
phone, etc, etc, and (hopefully) open brain.
Read through the entire exam first before starting to answer any
questions so that you do the easy questions first to maximize your score. There are a total of 140 points on the test,
not counting the Sudoku. Good luck, and
have fun!
1.
(2
points each—40 points) Write
the NUMBER of the matching action in the blank by the appropriate command or
library:
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_________ |
a. delete a file |
2.
alias |
|
_________ |
b. copy a file to another directory |
3.
at |
|
_________ |
c. type the contents of a file without pausing |
4.
bc |
|
_________ |
d. view the contents of a file one screen at a
time |
5.
cat |
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_________ |
e. find out who is currently logged in |
6.
cc |
|
_________ |
f. list all processes running on the machine |
7.
chgrp |
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_________ |
g. view a specific manual page |
8.
chmod |
|
_________ |
h. change the permissions on a file |
9.
chown |
|
_________ |
g. end a running job |
10.
cp |
|
_________ |
h. edit a text file |
11.
date |
|
_________ |
i. find a string in a file |
12.
echo |
|
_________ |
j. print the value of a shell variable |
13.
exit |
|
_________ |
k. build a parser from an input file |
14.
export |
|
_________ |
l. update one or more files as needed |
15.
for |
|
_________ |
m. compile a C program |
16.
grep |
|
_________ |
n. library for moving the cursor in a text
window |
17.
help |
|
_________ |
o. program to remove multiple occurrences of
an item |
18.
kill |
|
_________ |
p. arrange contents of a file in order |
19.
make |
|
_________ |
q. change the ownership of a file |
20.
man |
|
_________ |
r. wait a certain number of seconds |
21.
more |
|
_________ |
s. print or set the current date and time |
22.
ncurses |
|
_________ |
t. become another user without logging out |
23.
print |
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24.
ps |
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25.
rm |
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26.
sleep |
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27.
sort |
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28.
su |
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29.
time |
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30.
uniq |
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31.
vi |
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32.
who |
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33.
whoami |
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34.
whatis |
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35.
yacc |
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36.
none of the above |
a.
What
would you type to switch to your home directory?
b.
What
would you type to switch to the directory you were in just before the current
directory?
c.
How
would you switch to the parent directory of the current directory?
d.
Using
the mask 755 to set the permissions gives what permissions to all users?
e.
Describe
how to pass the output of one program to the input of a second program.
f.
How
do you capture the output of a program to a file?
g.
To
switch from insert mode to the command mode, what key do you press in vi?
h.
What
change do you need to make to your path in order to run programs in your
current working directory just by typing their names?
i.
What
options do you pass to the process status command to see all running processes
and not just the ones you own?
j.
What
types of files do not normally show up in a file listing?
k.
What
program do you run to find the load average, how much memory is being used,
etc?
l.
What
options do you pass to ls to see all files (including hidden ones) and also to
see the owners, permissions, sizes, time stamps, etc?
3. (4 points each…24 points total) Slightly longer answers…
a.
What
are three major services an operating system provides?
b.
Does
the average completion time depend on the order in which the jobs are run? Explain.
c.
What
is the best page replacement scheme? Why
can’t we use it in an operating system?
d.
What
is the difference between cooperative and preemptive multitasking?
e.
What
are the advantages and disadvantages of using NFS instead of local files?
f.
What
system is LaTeX built on top of?
Bonus: (5 points each)
Fill in the boxes below so that each
row, each column, and each highlighted 3x3 square contains each of the digits 1
through 9 exactly once. Obviously
when you are done, there should be 9
copies of each digit on the grid, and no row, column, or 3x3 square should
contain two of the same digit.
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7 |
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9 |
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8 |
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9 |
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2 |
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1 |
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7 |
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1 |
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7 |
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9 |
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Henry has been caught stealing cattle,
and is brought into town for justice. The judge is his ex-wife Gretchen, who
wants to show him some sympathy, but the law clearly calls for two shots to be
taken at Henry from close range. To make things a little better for Henry,
Gretchen tells him she will place two bullets into a six-chambered revolver in
successive order. She will spin the chamber, close it, and take one shot. If
Henry is still alive, she will then either take another shot, or spin the
chamber again before shooting.
Henry is a bit incredulous that his own
ex-wife would carry out the punishment, and a bit sad that she was always such
a rule follower. He steels himself as Gretchen loads the chambers, spins the
revolver, and pulls the trigger. Whew! It was blank. Then Gretchen asks, 'Do
you want me to pull the trigger again, or should I spin the chamber a second
time before pulling the trigger?'
What should Henry choose?
The Bay of Bengal is in which
state? (Careful…tricky question!!)