Sample
Key
for
UNIX
Operating System
Level
I
C.
Ray Esparza
Glendale
Community College
Revised
June 2006
Only
For Open-Entry/Open-Exit UNIX Sections
Answers to REVIEW QUESTIONS UNIT I
1. Where, when, and by whom was the UNIX operating system developed?
The UNIX operating system was developed at Bell Laboratories in the late 1960s by Ken Thompson and Dennis Ritchie.
2. When we say that UNIX can be "ported," what do we mean?
We mean that it can be transferred
easily to different computer systems.
3. List and describe briefly 8 functions of an operating system:
a. Input/Output: it provides ways to store and retrieve data on disks or tapes, to interact with terminals, and produce paper output.
b. Command Interpreter: it reads commands typed at a terminal and translates them into instructions understood by the computer.
c. Data Management: provides a means of organizing data into logical groups called files.
d. Program Development Tools: provides assistance in writing and maintaining programs - compilers, debuggers, etc.
e. Time-Sharing: enables several people to use the computer at the same time (found only in larger operating systems, including UNIX).
f. Security: protects one user from another and the operating system from being damaged by all users; allows only authorized access to computer and data.
g. Communication: allows one computer to communicate with others and lets terminals transfer programs or data.
h. Accounting: keeps track of what each person has done on a computer in order to bill or account for resources used.
4. Briefly describe the function of the UNIX scheduler:
The UNIX scheduler enables more than one person to use the computer at a time (time-sharing). It shares computer resources among the users.
5. Briefly describe the process known as swapping.
Swapping is the process of copying programs/data which are needed/not needed from disk to memory or from memory to disk, as necessary.
6. What is the difference between paging and swapping?
Paging copies only parts of programs (and data) to and from memory as needed, while swapping technically copies the entire program or data file. Paging is a refinement of swapping.
7. What is the UNIX shell, and what is its function?
The UNIX shell is the command interpreter. It is a program which reads what the user types at a terminal, translates that into machine instructions, and performs those instructions.
8. What is primary storage, and what is it used for?
Primary storage is the computer's memory. The computer can only execute programs or manipulate data that are in primary storage.
9. What is secondary storage, and what is it used for?
Secondary storage consists of a computer's disks. (Note: tape units are also considered secondary storage.) Programs and data which are not needed immediately in primary storage are kept in secondary storage.
10. What is the purpose of creating file directories (often called, simply, directories)?
File directories help you to organize files in a structured fashion, so that all of your files are not jumbled up into one storage area. They are like dividers in a notebook or recipe file, enabling you to organize files by category.
11. What is your HOME directory?
Your HOME directory is the directory into which you are placed when you log in to your UNIX system; it was assigned by the system administrator when your user ID was created on the system.
12. What is a path name?
A path name is the list of
directories which must be traveled through in order to reach a particular
file. For example, the following path is the list of directories
which must be traversed in order to find a file located in the HOME directory
of student trwalla: /server/student/trwalla. Here is the way in which the student
directories on our UNIX system are arranged (their path):
root directory
represented by / when you do the pwd command
¯
/server directory
¯
¯
¯ ¯ ¯
/jjones /msmith ... /mtveriqu (student directories)
1. Student must fill in password
2. Listing I-A-1
The following lines should be in file
snow_white
Grumpy Gilliam
Bashful Baggins
Sneezy Snoqualmie
Dopey Dormer
Sleepy Slapdash
Doc Doberman
Happy Hooligan
Ima U. Student <-- student's name here
3. Listing I-A-2
The following lines should be in file
sort.out
Bashful Baggins
Doc Doberman
Dopey Dormer
Grumpy Gilliam
Happy Hooligan
Ima U. Student <--
student's name will be in
Sleepy Slapdash appropriate
sorted order
Sneezy Snoqualmie
4. Answers
to wc questions must be filled in:
a. Answers
to fill-in questions
b. will
not be given
c. in
this Example Book.
d.
Students must attempt these on their own!
e.
Try to use the format: wc ______ filename
5. Listing I-A-3
Only required file is shown; others may be present:
snow_white
6. Answer to pwd question must be filled
in:
Answer not given in this
Example Book.
Assignment I-B
1. Answer to copy question must be filled
in:
Answer not given in this
Example Book.
2. Listing I-B-1
Listing of file workers should have
following lines:
Grumpy Gilliam
Bashful Baggins
Sneezy Snoqualmie
Dopey Dormer
Sleepy Slapdash
Doc Doberman
Happy Hooligan
Ima U. Student <--
student's name
3. Answer to rename question must be
filled in:
Answer not given in this
Example Book.
4. Listing I-B-2
Only required files are shown; others may be present:
employee_file
practice
snow_white
5. Answer to mkdir question must be
filled in:
Answer not given in this
Example Book.
6. Answer to cd question must be
filled in:
Answer not given in this
Example Book.
7. Listing I-B-3
Only required files are shown; others may be present:
employee_file
snow_white
8. Answer to pwd question must be filled
in:
Answer not given in this
Example Book.
Assignment I-C
1. Listing I-C-1 - snow_white must
have these lines:
Winona Witch
Prince Pomeroy
Myra Mirror
Grumpy Gilliam
Sleepy Slapdash
Doc Doberman
Happy Hooligan
Ima U. Student <--
student's own name
2. Listing I-C-2 - employee_file must
have these lines:
Winona Witch
Prince Pomeroy
Myra Mirror
Grumpy Gilliam
Sleepy Slapdash
Doc Doberman
Happy Hooligan
Ima U. Student
3. Listing I-C-3
Only required files are shown; others may be present:
employee_file
snow_white
4. Listing I-C-4 - radio_days must have
these lines:
Student, Ima <-- student's own name here
Armstrong, Jack
Livingston, Mary
Trent, Helen
Gildersleeve, Throckmorton P.
5. Answer about copy must be filled in:
Answer not given in this
Example Book.
6. Answer about delete must be filled in:
Answer not given in this
Example Book.
7. Listing I-C-5 - old_timers must be
deleted; only required files are shown;
others may be present:
employee_file
radio_days
snow_whit`e
Assignment II-A
1. Answers about echo commands filled in:
Answers not given in this
Example Book.
2. Listing II-A-1
Only required files are shown; others may be present:
assignments
phone_book
practice
report1
report2
report3
snow_white
3. Answer about delete must be filled in:
Answer not given in this
Example Book.
4. Listing II-A-2 - must show only
ls.out2 ending in 0-9;
only required files are shown; others may be present:
assignments
phone_book
practice
snow_white
5. Answer about copy must be filled in:
Answer not given in this
Example Book.
6. Answer about copy must be filled in:
Answer not given in this
Example Book.
7. Listing II-A-3 (assignments directory)
Only required files are shown; others may be present:
employee_file
phone_book
phoney_book
radio_days
snow_white
Assignment II-A (continued)
8. Answer about grep must be filled in:
Answer not given in this
Example Book.
9. Answer about grep must be filled in:
Answer not given in this Example
Book.
10. Listing II-A-4 - snow_white should have
these lines:
Winona Witch
Prince Pomeroy
Myra Mirror
Doc Doberman
Grumpy Hooligan
Ima U. Student <--
student's name
11. Listing II-A-5 - employee_file should
have these lines:
Winona Witch
Prince Pomeroy
Myra Mirror
Grumpy Gilliam
Sleepy Slapdash
Doc Doberman
Happy Hooligan
Ima U. Student <-- student's name
12. Listing II-A-6 - employee_new should
have these lines:
Winona Witch
Grumpy Gilliam
Sleepy Slapdash
Doc Doberman
Happy Hooligan
Ima U. Student <-- student's name
13. Answer about tail must be filled in:
Answer not given in this
Example Book.
14. Answer about head must be filled in:
Answer not given in this
Example Book.
15. Answer about sdiff (or diff)
must be filled in:
Answer not given in this
Example Book.
Assignment II-B
1. Listing II-B-1 - radio_sorted should
have these lines:
Armstrong, Jack
Gildersleeve, Throckmorton P.
Livingston, Mary
Student, Ima <-- student's name will be in
Trent, Helen appropriate
sorted order
2. Listing II-B-2 - today should have a
line like this;
Fri Jan 21 14:09:00 MST 2006 <-- date/time
when
command
was done
will be
shown
3. Listing II-B-3 - employee_junk should
have these lines:
Winona Witch
Prince Pomeroy
Myra Mirror
Grumpy Gilliam
Sleepy Slapdash
Doc Doberman
Happy Hooligan
Ima U. Student <-- student's name
Winona Witch
Grumpy Gilliam
Sleepy Slapdash
Doc Doberman
Happy Hooligan
Ima U. Student <-- student's name
Winona Witch
Prince Pomeroy
Myra Mirror
Doc Doberman
Grumpy Hooligan
Ima U. Student <-- student's name
4. Answer to who-grep-sort command must
be filled in:
Answer not given in this
Example Book.
5. Answer to who-grep-sort-cut command
must be filled in:
Answer not given in this
Example Book.
Assignment II-B (continued)
6. Listing II-B-4: Student's output will vary according to who
was logged in when the command was done.
User IDs must be only those having tty, and they must be in
sorted order. The following is an
example only:
aefreun (Note: occasionally the
student will be
jtwilli the only person logged in; this is
pbmarsh acceptable.)
rmhowar
Assignment III-A
Listing III-A
Line printer listing of snow_white should
show the following lines:
Mrs. Winona Witch
Myra Mirror
Doc Doberman
Gumpy Hooligan
Ima U. Student VIP
Assignment III-B
Listing III-B
Note:
Paging of vi.doc will not be as shown. Student's name must appear in the first
line. Text which was to be changed or
added has been underlined for your convenience.
Ima U. Student's vi
Reference Document
Unless otherwise noted with <CR>, the
following commands
do not require the user to press <Enter> or
<Return>.
MODES:
Command mode: lets you use
commands noted below
Insert mode: lets you enter
text from the keyboard; use
<Esc> to exit
text mode and reenter Command mode
CURSOR MOVEMENT COMMANDS:
j moves cursor down
one line
k moves cursor up
one line
h moves cursor left
one space
l moves cursor right
one space
Ctrl-d moves screen down
1/2 page
Ctrl-u moves screen up
1/2 page
Ctrl-b moves screen up a
full page
Ctrl-f moves screen up a
full page
# moves cursor to #
number line of file
0 moves cursor to beginning
of current line
$ moves cursor to end of
current line
TEXT ENTERING COMMANDS:
a appends text AFTER
cursor position
i inserts text
BEFORE cursor position
o opens a new line below cursor
& enters insert
mode
O opens a new line
above cursor
& enters insert
mode
Listing III-B (continued)
TEXT DELETION COMMANDS:
x deletes character
under cursor
dw deletes from
cursor to beginning of next word
dd deletes line where
cursor is positioned
TEXT ALTERATION COMMANDS:
r replace character
at cursor with next character
typed
R writes over old
text (overstrike mode)
cw changes word to
new text
J joins next line
down to line with cursor
u undo last command
U undo all changes
to line with cursor
. repeat the last
command
SEARCH COMMANDS:
/pattern search for next occurrence
of pattern
?pattern search for previous
occurrence of pattern
n repeat last search
command given
TEXT MOVING COMMANDS:
yy yank a copy of a
line and put in a buffer
p put last item
yanked or deleted AFTER cursor
P put last item
yanked or deleted BEFORE cursor
SUBSTITUTION COMMAND:
:s/s1/s2/<CR> change
characters in string s1 to those in s2;
example: :s/teh/the/
changes the string "teh"
to "the" in the
current line"
SAVING TEXT and QUITTING EDITOR:
:w<CR> write the
current text into the file
:q<CR> quit if no
changes since last w
ZZ write and quit (same effect
as next command)
:wq<CR> write and
quit
:w
file2 write lines into a different
file
SCREEN OPTIONS:
:set showmode make vi display
INSERT or APPEND mode
:set noshowmode turn off display of mode
:set number cause vi to
precede each line with a number
:set nonumber turn off line
numbering
Assignment III-C
Listing III-C-1 (listing of curr_year)
Listing should show the entire calendar for the
current year (for example, 2006). If
your calendar is headed simply 06, then you have the calendar for 02 A.D. and
not 2006!
Listing III-C-2 (listing of calendar month and year of students birth month and year)
September 1987 EXAMPLE
ONLY-Answers Vary!!
Su Mo Tu We Th Fr Sa
1 2 3
4 5
6 7
8 9 10 11 12 NOTE: day of birth MUST be
13 14 15 16 17 18 19 circled!
20 21 22 23 24 25 26
27 28 29 30
Answers
to bc problems to be written on grading sheet:
Answers not given in this
Example Book.
Listing III-C-3
A listing of rm.doc should be attached; it
will have a little over a page of information about the rm command.
Assignment III-D
Listing III-D-1 (Listing of dec.spell)
The
following words will be listed in a single column:
Criator disolve
Goverment efffect
Hapiness institued
Natrue politicial
Safty pursuiing
aHappiness pusuit
coauses shewn
consemt theri
delcare willl
Listing III-D-2 (Listing of declaration with
spelling corrected [words in bold] and nroff commands)
.ll 5.5i
.pl 8.0i
When in the course of human events it becomes
necessary for one
people to dissolve the political
bands which have connected them with
another, and to assume among the powers of the
earth, the separate
and equal station to which the Laws of Nature
and of Nature's God
entitle them, a decent respect to the opinions of
mankind requires
that they should declare the causes which
impel them to the separation.
.sp
.ul
We hold these truths to be self-evident,
that all men are created equal,
that they are endowed by their Creator
with certain unalienable Rights,
that among these are Life, Liberty and the pursuit
of Happiness.
That to secure these rights, Governments are instituted
among Men,
deriving their just powers from the consent
of the governed.
.sp
That whenever any Form of Government
becomes destructive of these ends,
it is the Right of the People to alter or to
abolish it, and to
institute new Government, laying its foundation
on such principles
and organizing its powers in such form, as to
them shall seem most
likely to effect their Safety and Happiness.
.sp
.in .5i
Prudence, indeed, will dictate that
Governments long established should
not be changed for light and transient causes;
and accordingly all
experience hath shewn, that mankind are more
disposed to suffer,
while evils are sufferable, than to right
themselves by abolishing
the forms to which they are accustomed.
.sp
.in 0i
But when a long train of abuses and usurpations, pursuing
invariably the
same Object, evinces a design to reduce them
under absolute Despotism,
it is their right, it is their duty, to throw off
such Government,
and to provide new Guards for their future security.
Assignment III-D (continued)
Listing III-D-3 (listing of declaration.out
with correct nroff formatting)
NOTE:
occassionally you may have to enter one blank line at the beginning of the file
in order for it to print out correctly.
When in the course of human events it becomes
necessary
for
one people to dissolve the political bands which
have connected them with another, and to assume
among
the powers of the earth, the separate and equal
station
to which the Laws of Nature and of Nature's God
entitle
them,
a decent respect to the opinions
of mankind re-
quires that they should declare the causes
which impel
them to the separation.
We hold these truths to be self-evident,
that all
men
are created equal, that they are endowed by their
Crea-
tor with certain unalienable Rights, that among
these
are
Life, Liberty and the pursuit of
Happiness. That
to secure
these rights, Governments
are instituted
among Men,
deriving their just powers from the consent
of the governed.
That whenever any Form of Government becomes
destruc-
tive
of these ends, it is the Right of the People to
alter or to abolish it, and to institute
new Govern-
ment,
laying its foundation on such principles and or-
ganizing its powers in such form, as to them
shall seem
most likely to effect their Safety and Happiness.
Prudence, indeed, will
dictate that Governments
long established should not be changed for light
and
transient causes; and accordingly all
experi-
ence
hath shewn, that mankind are more disposed to
suffer, while evils are sufferable, than to right
themselves by abolishing the forms to which they
are
accustomed.
But when a long train of abuses and usurpations,
pursu-
ing
invariably the same
Object, evinces a design to
reduce them
under absolute Despotism,
it is their
right, it
is their duty, to throw off such Government,
and to provide new Guards for their future
security.