Practice Test #3 Questions - answers at end

                             Important Instructions

     1. Read all the instructions and both sides of all pages.
     2. Manage your time when answering questions on this test.
        Answer the questions you know, first.

________________________________________________________________________________

                         Multiple Choice - 44 Questions
This is a practice test containing many practice questions.  The real test will
contain some questions similar to these.  There are probably many more questions
in this practice test than there will be time for in the real test.  The real
test will have approximately one question per minute.

The real test may have some questions unlike anything given here.  Knowing the
concepts behind the questions is necessary; memorizing these specific answers
won't help.

The answers to this test are in the Answer Key on the last page(s).

1.  Which command line deletes all the blank lines from the input file?
    a. awk -F' ' '{ delete; }' file
    b. awk '/^$/ == "" { delete; }' file
    c. sed -e ' d' file
    d. tr -d '[^$]' <file
    e. sed -e '/^$/d' file

2.  Which awk command outputs all lines where the second field contains only the
    string xyzzy and where the third field exactly matches the first field:
    a. $2 == /^xyzzy$/ && $3 == $1 { print }
    b. $1 == $3 && "xyzzy" == $2 { print }
    c. $2 ~ /^xyzzy/ && $3 == $1 { print }
    d. $2 ~ /^xyzzy/ && $3 ~ /$1/ { print }
    e. $3 == $1 || "^xyzzy$" ~ $2 { print }

3.  Which command displays only the top 5 lines of file?
    a. sed -n -e '1,5 p' file
    b. sed -e '5 d' file
    c. sed -n -e '5 p' file
    d. sed -e '5 $' file
    e. sed -n -e '/5/ p' file

4.  What is the output (if any) of this bash shell program fragment?  (There are
    blanks between all the letters in the word list sections of the for loops.)

         str=''
         for x in   s l i c k  r u n  o x   ; do
             for y in   l i n u x  r o c k s   ; do
                 if [ $x = $y ] ; then
                     str=$str$y
                 fi
             done
         done
         echo $str | sed -e 's/^\(.....\)/\1 /'

    a. x
    b. s
    c. slick runox
    d. linux rocks
    e. no output

5.  Which sed command deletes only lines that do not contain any lower-case
    vowels (including blank lines):
    a. /![aeiou]/d
    b. s/![aeiou]\+//g
    c. /[aeiou]/!d
    d. s/^[!aeiou]*$//
    e. /[^aeiou]/d

6.  Which command displays only the top 5 lines of file?
    a. sed -e '5 q' file
    b. sed -e '5 d' file
    c. sed -e '5 $' file
    d. sed -e '5 p' file
    e. sed -e '/5/ p' file

7.  When you place several sed instructions in a file called instruction-file,
    you may issue the following command to tell sed to apply these instructions
    to file file:
    a. sed -f instruction-file file
    b. sed -v instruction-file file
    c. sed -r instruction-file file
    d. sed -n instruction-file file
    e. sed -w instruction-file file

8.  Which awk command outputs the sum of the first two fields on every line:
    a. $FN >= 2 { print $(1+$2) }
    b. { print $(1+2) }
    c. RN >= 2 { print $(1+$2) }
    d. { print $1+$2 }
    e. $1 > 0 && $2 > 0 { print $(1+$2) }

9.  A shell script named bar is executed as follows:  ./bar a  "b c"  'a  '
    Inside the script is the line:   head $@
    How many arguments are passed to the head command inside the script?
    a. 6
    b. 5
    c. 4
    d. 3
    e. 2

10. Which awk command outputs all lines where the second field is larger than
    the line number:
    a. $2 > LN { print }
    b. $2 > $LN { print $0 }
    c. NR < $2 { print }
    d. $NF < $2 { print }
    e. $2 > $NR { print }

11. What is the sed command to delete all empty lines (lines with no characters)
    from file file?
    a. sed -e '/^,$/ d' file
    b. sed -e '/^*$/ d' file
    c. sed -e '/^ $/ d' file
    d. sed -e '/^[^ ]$/ d' file
    e. sed -n -e '/./ p' file

12. Which sed command behaves identically to this:   grep '.' file
    a. sed -e '/^[^ ]$/ d' file
    b. sed -e 's/.//g' file
    c. sed -e '/./ s/.*//' file
    d. sed -n -e '/./ p' file
    e. sed -n -e '/^$/ d' file

13. If guru=linus then which one of the following case patterns will match this
    statement:   case "$guru" in
    a. [linus] | [LINUS] ) echo yes ;;
    b. "linu?" ) echo yes ;;
    c. * ) echo yes ;;
    d. lin? ) echo yes ;;
    e. (*nus  echo yes ;;

14. Which sed command finds every occurrence of three adjacent letters and
    reverses them: (e.g.  dogcatcow would become godtacwoc; but, do3ca;c.o would
    not change).
    a. s/\(![0-9]\)\{3\}/\3\2\1/g
    b. s/\([a-z]\)\([a-z]\)\([a-z]\)/\3\2\1/g
    c. s/\(![0-9]\)\(![0-9]\)\(![0-9]\)/\3\2\1/g
    d. s/\(^[0-9]\)\{3,3\}/\3\2\1/g
    e. s/\([^0-9]\)\([^0-9]\)\([^0-9]\)/\3\2\1/g

15. A shell script named bar is executed as follows:  ./bar a  "b c"  'a  '
    Inside the script is the line:   head "$@"
    How many arguments are passed to the head command inside the script?
    a. 5
    b. 4
    c. 2
    d. 3
    e. 6

16. What is the output of the following sequence of bash commands:
       echo 'Good-day World' | tr -d -c 'W'
    a. GoodWay World
    b. GoodWay orld
    c. GoodW ay World
    d. W
    e. Good-day orld

17. What is the output of this bash shell program fragment?  (There are blanks
    between all the letters in the word list section of the for loop.)

         in='' out=''
         for char in   l i n u x   ; do
             case "$char" in
             L|l)  in=$in$char ; out=${out}L ;;
             [Xx]) in=$in$char ; out=${out}X ;;
             esac
         done
         echo "linux rox" | tr $in $out

    a. linux rox
    b. louux rox
    c. lINUx ROx
    d. LINUX ROX
    e. LinuX roX

18. Which sed command finds every line that ends in the digits 123 and removes
    the first occurrence of the string xyzzy from those lines:
    a. /[0-9][0-9][0-9]$/s/xyzzy//
    b. s/xyzzy.*123$/123/
    c. /123$/s/xyzzy//
    d. s/^.*xyzzy\(.*123\)$/\1/
    e. /xyzzy/s/[0-9][0-9][0-9]\$//

19. Which command line deletes all the blank lines from the input file?
    a. awk -F' ' '{ delete; }' file
    b. awk '/^$/ == "" { delete; }' file
    c. tr -d '[^$]' <file
    d. sed -e ' d' file
    e. sed -n -e '/./p' file

20. Which awk command outputs lines where the last field is numeric?
    a. $FN == "^[0-9]\+$" { print }
    b. NF == /^[0-9][0-9]*$/ { print $0 }
    c. $FN ~ /^[0-9]*$/ { print $0 }
    d. FN ~ /[0-9]\+/ { print $0-FN }
    e. $NF ~ /^[0-9]+$/ { print }

21. If a script named bar contains a loop that starts:   for i do
    and the script is executed using this command line:
       ./bar a ' b d ' e f " g h " a
    how many times will the loop iterate?
    a. 1 iteration
    b. 7 iterations
    c. 6 iterations
    d. 9 iterations
    e. 8 iterations

22. Which sed command turns the string Good-Day; World-Traveller into Day-Good;
    World-Traveller:
    a. s/\([a-z]*\)-\([a-z]*\)/$2-$1/
    b. s/\(.*\)-\(.*\)/$2-$1/
    c. s/\([^-]\+\)-\([^-;]\+\)/\2-\1/
    d. s/\(![-]\+\)-\(![-;]\+\)/\2-\1/
    e. s!/\([-]\+\)-\([-;]\+\)/\2-\1/

23. Which command line deletes all the blank lines from the input file?
    a. sed -n -e '/^$/p' file
    b. awk '/^$/ == "" { delete }' file
    c. awk -F' ' '{ delete; }' file
    d. tr -d '[^$]' <file
    e. awk '! /^$/ { print }' file

24. What is the value of variable foobar at the end of the loop that starts:
       for foobar in 5 5 $# $? 6 1 ; do
    a. 0
    b. the value is undefined
    c. 6
    d. 1
    e. 5

25. What is the sed command to delete all empty lines (lines with no characters)
    from file file?
    a. sed -e '/^*$/ d' file
    b. sed -e '/^$/ d' file
    c. sed -e '/^ $/ d' file
    d. sed -e '/^[^ ]$/ d' file
    e. sed -e '/^,$/ d' file

26. If a script named bar contains a loop that starts:   for i in "$@" ; do
    and the script is executed using this command line:
       ./bar a ' b d ' e f " g h " a
    how many times will the loop iterate?
    a. 6 iterations
    b. 9 iterations
    c. 7 iterations
    d. 8 iterations
    e. 1 iteration

27. In a shell case structure, the case segment that will GLOB match the text x,
    y, or z, is coded as
    a. x\y\z )
    b. x,y,z )
    c. x/y/z )
    d. x|y|z )
    e. x:y:z )

28. Which awk command outputs non-blank lines where the line number is an exact
    multiple of the number of fields:
    a. /FN >= 1 && (RN % FN == 0)/ { print }
    b. NR > 0 && (NF % NR) == 0 { print $0 }
    c. /FN >= 1/ { if (RN % FN == 0) print $0 }
    d. 1 <= NF && 0 == (NR % NF) { print }
    e. 1 <= RN && 0 == (FN % RN) { print }

29. If a script named bar contains a loop that starts:   for i in "$*" ; do
    and the script is executed using this command line:
       ./bar a ' b d ' e f " g h " a
    how many times will the loop iterate?
    a. 6 iterations
    b. 9 iterations
    c. 8 iterations
    d. 7 iterations
    e. 1 iteration

30. A shell script named bar is executed as follows:  ./bar a  "b c"  'a  '
    Inside the script is the line:   head "$*"
    How many arguments are passed to the head command inside the script?
    a. 1
    b. 4
    c. 5
    d. 2
    e. 3

31. Which awk command outputs all lines where the first field begins with the
    letters abc and the last field ends with the letters xyz:
    a. $1 ~ /abc$/ && $NR ~ /^xyz/ { print }
    b. $NF ~ /xyz$/ && $1 ~ /^abc/ { print }
    c. NR = /^xyz$/ && $1 = /^abc$/ { print }
    d. $1 == "abc" && $FN == "xyz" { print }
    e. $1 = /abc/ && $FN = /xyz/ { print }

32. If guru=linus then which one of the following case patterns will match this
    statement:   case "$guru" in
    a. [linus] | [LINUS] ) echo yes ;;
    b. "linu?" ) echo yes ;;
    c. l?nus ) echo yes ;;
    d. lin? ) echo yes ;;
    e. guru ) echo yes ;;

33. If a script named bar contains a loop that starts:   for i in $* ; do
    and the script is executed using this command line:
       ./bar a ' b d ' e f " g h " a
    how many times will the loop iterate?
    a. 8 iterations
    b. 7 iterations
    c. 12 iterations
    d. 9 iterations
    e. 6 iterations

34. Which sed command takes every occurrence of an asterisk (*) followed by a
    period (.) and reverses all of them:
    a. s/[*][.]/\2\1/g
    b. s/\(\*\)\(\.\)/\2\1/
    c. s/(\*)(\.)/\2\1/g
    d. s/\(*\)\(.\)/\2\1/g
    e. s/\*\./.*/g

35. The sed command has the syntax format:
       sed 'Address1, Address2 Instruction Flag' Filename(s)
    If both Address1 and Address2 are omitted from the sed command,
    a. only the last line of the file will be examined for editing.
    b. only the first line of the file will be examined for editing.
    c. only the first 10 lines of the file will be examined for editing.
    d. all lines of the file will be examined for editing.
    e. only the last 10 lines of the file will be examined for editing.

36. Why is the instruction used in a sed command usually enclosed in a pair of
    single quotes (')?
    a. because single quotes are easier to type than double quotes.
    b. to forbid the shell from interpreting some of the special characters used
       in the sed instruction.
    c. to distinguish the sed instruction from the optional grep expression on
       the sed command.
    d. to prevent sed from interpreting the instruction as a file name.
    e. to permit the shell to expand the $USER variable in the sed expression.

37. Which sed command deletes only lines that contain at least one non-digit?
    a. s/^[!0-9]*$//
    b. /[0-9]/!d
    c. /[^0-9]/d
    d. /![0-9]/d
    e. s/![0-9]\+//g

38. What is the output on your screen of this command line:
       echo hi | sed -n -e 's/HI/HO/p'
    a. no output on screen
    b. HI
    c. ho
    d. hi
    e. HO

39. What is the output on your screen of this command line:
       echo hi | sed -e 's/HI/HO/'
    a. ho
    b. hi
    c. HO
    d. no output on screen
    e. HI

40. Which sed command finds every line that contains the four digits 1, 2, 3,
    and 4 in ascending order (but with any number of any characters in between)
    and deletes the first letter on these lines:
    a. /1.*2.*3.*4/s/[a-zA-Z]//
    b. /[1-1]*[1-2]*[1-3]*[1-4]/s/a-zA-Z/d
    c. /\1.*\2.*\3.*\4/[a-zA-Z]/d
    d. /[0-9].*[0-9].*[0-9].*[0-9]/s//[a-zA-Z]/
    e. /(1)*(2)*(3)*(4)/[a-zA-Z]\1\2\3\4/d

41. Which awk command outputs the third field of lines that have at least three
    fields:
    a. 3 <= NF { print $(1+3-1) }
    b. FN >= 3 { print $3 }
    c. /$3/ { print $2+1 }
    d. /$3 != ""/ { print $1+1+1 }
    e. 2 < $FN { print $3 }

42. What is the output of the following sequence of bash commands:
       echo 'Good-day World' | tr -d 'W'
    a. Good-day orld
    b. GoodWay orld
    c. Good-day World
    d. GoodW ay World
    e. GoodWay World

43. Which sed command behaves identically to this:   grep -v '.' file
    a. sed -e '/./ d' file
    b. sed -e '/./ s/.*//' file
    c. sed -e '/^$/ d' file
    d. sed -e 's/.//g' file
    e. sed -e '/-v ./ p' file

44. What is the output of the following sequence of bash commands:
       echo 'Good-day World' | sed -e 's/^/99/g'
    a. 99Good-day World
    b. 99ood-day World
    c. Good-day World
    d. 99Good-day 99World
    e. 99ood-day 99orld

      Answer Key - CST8129 - Ian Allen - Fall 2005 - CST8129 Practice Test

   1. e
   2. b
   3. a
   4. c
    5. c
    6. a
    7. a
    8. d
   9. c
  10. c
  11. e
  12. d
   13. c
   14. b
   15. d
   16. d
  17. e
  18. c
  19. e
  20. e
   21. c
   22. c
   23. e
   24. d
  25. b
  26. a
  27. d
  28. d
   29. e
   30. a
   31. b
   32. c
  33. a
  34. e
  35. d
  36. b
   37. c
   38. a
   39. b
   40. a
  41. a
  42. a
  43. a
  44. a

Count of a:  12  27%
Count of b:  6  14%
Count of c:  10  23%
Count of d:  8  18%
Count of e:  8  18%

With 5 choices: 44

Macro .cmd split with indent: 11