Midterm 3 - Unix - with answers
DAT2330 - Ian Allen - Winter 20-1-		       45 minutes

Evaluation: 39 Questions	  Name: _________________________
		      Important Instructions

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


(Office use only: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19
20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39)

1.  If foo is a script containing the line TERM=linux ; export
    TERM, what is the output of the following sequence of bash
    commands: TERM=vt100 ; ./foo ; echo "$TERM"
    a. vt100
    b. linux
    c. foo
    d. TERM
    e. $TERM

2.  If file bar contains the line a=abc then what is the bash
    output of this sequence of three commands:
       a=123 ; source bar ; echo "I see '$a' here."
    a. I see 'abc' here.
    b. I see '123' here.
    c. I see '$a' here.
    d. I see $a here.
    e. "I see abc here."

3.  What is the output of the following sequence of bash
    commands:	cd /bin && echo "cd $(pwd)"
    a. cd /bin
    b. no output
    c. cd 0pwd)
    d. cd $(pwd)
    e. bash: cd: /bin: No such file or directory

4.  In an empty directory, how many files will be created using
    the following bash shell two-command sequence:
       yy='aa  b  cc  d' ; touch $yy
    a. 4 files
    b. 1 file
    c. 2 files
    d. 3 files
    e. 5 files

5.  In an empty directory, how many files will be created using
    the following bash shell two-command sequence:
       zzz='1111  2222	3333' ; touch "$zzz"
    a. 1 file
    b. 2 files
    c. 3 files
    d. 4 files
    e. 5 files






39 Questions   DAT2330 Test #3b - Unix Final - 15%     45 minutes



DAT2330 - Ian Allen - Winter 20-2-		       45 minutes

6.  In an empty directory, what is the shell output of these
    three commands:
       touch xx .x xy .y xz .z ; a='x* y*' ; echo "$a"
    a. x* y*
    b. xx xy
    c. xx xy xz y*
    d. $a
    e. *x *y

7.  In an empty directory, what is the shell output of these
    three commands:
       touch .1 .2 .3 11 12 ; b='.1* .2*' ; echo '$b'
    a. $b
    b. .1* .2*
    c. '.1* .2*'
    d. .1 .2
    e. 11 .1 12 .2

8.  In an empty directory, what is the length of the longest file
    name created by the following bash shell two-command
    sequence:	 ok='1 12 123 1234' ; touch '$ok'
    a. 3 characters
    b. 4 characters
    c. 2 characters
    d. 1 character
    e. 13 characters

9.  What is the output of the following sequence of bash
    commands:	false && echo "linux	 rocks $?"
    a. no output
    b. linux rocks 1
    c. linux	 rocks 0
    d. linux	 rocks 1
    e. linux rocks 0

10. What is the bash shell output of this command sequence:
       true && echo space     junk $?
    a. space junk 0
    b. space junk ?
    c. space	 junk ?
    d. space	 junk 1
    e. no output

11. How many arguments are passed to the command by the shell on
    this command line:	 <cow cow "-x" -y '-z' >cow cow
    a. 4
    b. 5
    c. 2
    d. 3
    e. 6










39 Questions   DAT2330 Test #3b - Unix Final - 15%     45 minutes



DAT2330 - Ian Allen - Winter 20-3-		       45 minutes

12. A shell script named foo is executed as follows:
       ./foo  aa  "bb  cc" '  dd'  ee
    Inside the script is the line:   argv.sh "$@"
    What is the count of arguments that the argv.sh command will
    display?
    a. 4
    b. 3
    c. 2
    d. 5
    e. 6

13. A shell script named foo is executed as follows:
       ./foo  11  '22  22  22'	"33  33"
    Inside the script is the line:   argv.sh $@
    What is the count of arguments that the argv.sh command will
    display?
    a. 6
    b. 5
    c. 4
    d. 3
    e. 2

14. A shell script named foo is executed as follows:
       ./foo  11  22  "33  44"	55
    Inside the script is the line:   argv.sh "$*"
    What is the count of arguments that the argv.sh command will
    display?
    a. 1
    b. 2
    c. 3
    d. 4
    e. 5

15. If dog=12 and cat=99 then which of the following bash command
    lines outputs only the word hi (and nothing else)?
    a. [ dog = dog ] && echo hi
    b. [ dog -ne cat ] && echo hi
    c. [!dog = cat] && echo hi
    d. [dog -ne cat] || echo hi
    e. [dog!=dog] || echo hi

16. What is the output of the following sequence of bash
    commands:	x=1 ; y=2 ; test $x -le $y ; echo $?
    a. 0
    b. 1
    c. the number 0 or 1 followed by another 0 or 1 on a new line
    d. test: $x: integer expression expected
    e. no output

17. What is the output of the following sequence of bash
    commands:	x=cow ; y=dog ; test -z $x ; echo $?
    a. 1
    b. 0
    c. the number 0 or 1 followed by another 0 or 1 on a new line
    d. test: $x: integer expression expected
    e. no output




39 Questions   DAT2330 Test #3b - Unix Final - 15%     45 minutes



DAT2330 - Ian Allen - Winter 20-4-		       45 minutes

18. If x=cow and y=dog then what is the output of the following
    sequence of bash commands:
       [ $x = dog -o $y = cow ] ; echo $?
    a. 1
    b. 0
    c. the number 0 or 1 followed by another 0 or 1 on a new line
    d. test: $x: integer expression expected
    e. no output

19. If x=cow and y=dog then what is the output of the following
    sequence of bash commands:
       [ $x = cow -a $y = cow ] ; echo $?
    a. 1
    b. 0
    c. the number 0 or 1 followed by another 0 or 1 on a new line
    d. test: $x: integer expression expected
    e. no output

20. If x=pig and y=dog then what is the output of the following
    sequence of bash commands:	 if $x = $y ; then echo $y ; fi
    a. bash: pig: command not found
    b. test: pig: integer expression expected
    c. test: $x: integer expression expected
    d. dog
    e. no output

21. If a bash shell script named foo contains the line:
       if [ "$1" = '$2' ] ; then echo SAME ; fi
    then which of the following command lines will produce SAME
    as output?
    a. ./foo '$2' bar
    b. ./foo bar bar
    c. ./foo "bar" 'bar'
    d. ./foo "$1" '$2'
    e. ./foo $2 $2

22. Which bash command sequence correctly compares the two
    numbers and prints OK?
    a. if [ 4 -gt 3 ] ; then echo OK ; fi
    b. if [ 4 -gr 3 ] ; then echo OK ; fi
    c. if [ 4 > 3 ] ; then echo OK ; fi
    d. if [ ! 4 <= 3 ] ; then echo OK ; fi
    e. if ( ! 4 < 3 ) ; then echo OK ; fi

23. If cow=5 and dog=5, which bash command sequence correctly
    compares the two numbers as equal and prints OK?
    a. if test $cow -eq $dog ; then echo OK ; fi
    b. if test cow -eq dog ; then echo OK ; fi
    c. if [ cow = dog ] ; then echo OK ; fi
    d. if ( cow == dog ) ; then echo OK ; fi
    e. if [ $cow==$dog ] ; then echo OK ; fi









39 Questions   DAT2330 Test #3b - Unix Final - 15%     45 minutes



DAT2330 - Ian Allen - Winter 20-5-		       45 minutes

24. Which bash command sequence correctly searches for the string
    and then prints OK if it is found inside the password file?
    a. if grep string /etc/passwd ; then echo OK ; fi
    b. if [ grep string /etc/passwd ] ; then echo OK ; fi
    c. if test string /etc/passwd ; then echo OK ; fi
    d. if test string = /etc/passwd ; then echo OK ; fi
    e. if [ test string /etc/passwd ] ; then echo OK ; fi

25. If variable cow might contain nothing (a null value - defined
    but empty), which bash command sequence correctly tests for
    this and prints OK?
    a. if [ "" = "$cow" ] ; then echo OK ; fi
    b. if [ $cow -eq : ] ; then echo OK ; fi
    c. if [ $cow -eq "" ] ; then echo OK ; fi
    d. if [ ''$cow'' = '''' ] ; then echo OK ; fi
    e. if [ "$cow" = * ] ; then echo OK ; fi

26. Which bash command sequence below always outputs just the
    word OK only if the first argument is either readable or
    executable?
    a. if [ -r "$1" -o -x "$1" ]; then echo OK;fi
    b. if [ "-r $1" || "-x $1" ]; then echo OK;fi
    c. if [ "$1" -eq -r -o "$1" -eq -x ]; then echo OK;fi
    d. if [ -r -o -x "$1" ]; then echo OK;fi
    e. if [ -r || -x "$1" ]; then echo OK;fi

27. Which line below is most likely to be the beginning of an
    error message?
    a. echo 1>&2 "... "
    b. echo 1<&2 "... "
    c. echo 2>&1 "... "
    d. echo 2<$1 "... "
    e. echo 2>$1 "... "

28. Which line below puts the count of the number of lines in the
    password file into the variable foo?
    a. foo=$( wc -l </etc/passwd )
    b. foo=$( cat -c /etc/passwd )
    c. foo=[ wc /etc/passwd | echo $1 ]
    d. foo=[ cat -l /etc/passwd ]
    e. foo=[ grep -c /etc/passwd ]

29. What is the output of the following sequence of bash
    commands:	echo wc >wc ; wc wc >wc ; sort wc
    a. 0 0 0 wc
    b. 1 1 3 wc
    c. 1 1 2 wc
    d. no output
    e. wc











39 Questions   DAT2330 Test #3b - Unix Final - 15%     45 minutes



DAT2330 - Ian Allen - Winter 20-6-		       45 minutes

30. Which line below passes three separate arguments to the sort
    command when placed inside a shell script named foo invoked
    by the command line:  ./foo	 111  222  333
    a. sort "$@"
    b. sort "$*"
    c. sort "$#"
    d. sort "$1 $2 $3"
    e. sort "$? $? $?"

31. Given the following bash shell command line:
       read  xx	 yy  zz
    which user keyboard input line below will assign the text 22
    to the shell variable named yy?
    a. 11  22  33
    b. xx=11  yy=22  zz=33
    c. 11,22,33
    d. 11:22:33
    e. 11;22;33

32. What is the bash shell output of this two-command sequence if
    run in a directory containing 888 files with names that are
    all the numbers from 1 to 888 inclusive:
	 cow="*" ; echo '$cow'
    a. $cow
    b. *
    c. '$cow'
    d. the file names 1 through 888
    e. the file names 1 through 888, surrounded by quotes

33. What is the bash shell output of this two-command sequence if
    run in a directory containing 123 files with names that are
    all the numbers from 1 to 123 inclusive:
	 bat="*" ; echo "$bat"
    a. *
    b. $bat
    c. "$bat"
    d. the file names 1 through 123
    e. the file names 1 through 123, surrounded by quotes

34. What is the bash shell output of this two-command sequence if
    run in a directory containing 765 files with names that are
    all the numbers from 1 to 765 inclusive:
	 foo="*" ; echo $foo
    a. the file names 1 through 765
    b. all the file names that start with an asterisk ('*')
    c. an asterisk ('*') and the file names 1 through 765
    d. *
    e. $foo

35. Which bash command line below allows programs in the current
    directory to execute without preceding the names with ./?
    a. PATH=/usr/bin:$HOME:.
    b. PATH=/usr/bin/.:$HOME
    c. PATH=./$HOME:/usr/bin
    d. $PATH=/usr/bin:./$HOME
    e. $PATH=.:$HOME:/usr/bin




39 Questions   DAT2330 Test #3b - Unix Final - 15%     45 minutes



DAT2330 - Ian Allen - Winter 20-7-		       45 minutes

36. A shell script named foo is executed as follows:
       ./foo  1	 "2 3 4"  5
    Inside the script is the line:   echo "$2"
    What is the output from this line?
    a. 2 3 4
    b. 2
    c. "2
    d. $2
    e. a bash error message: unbound (undefined) variable

37. Select the correct bash shell order of command line
    processing:
    a. aliases, redirection, variables, globs
    b. aliases, variables, redirection, globs
    c. aliases, variables, globs, redirection
    d. aliases, globs, variables, redirection
    e. redirection, aliases, globs, variables

38. If these two lines are put in an executable script named foo:
      #!/bin/mv dog
      echo cow
    What is the result of the command line:   ./foo
    a. The file dog is renamed to be ./foo
    b. The file dog is copied to the file ./foo
    c. The word "cow" appears on the screen
    d. The mv command displays an error message about a missing
       argument
    e. The file dog appears on the screen followed by the word
       "hi"

39. What is the output of the following sequence of bash
    commands:	wc='one two' ; test wc = wc
    a. no output
    b. 1   2   8 wc
    c. 1
    d. 0
    e. test: too many arguments























39 Questions   DAT2330 Test #3b - Unix Final - 15%     45 minutes



DAT2330 - Ian Allen - Winter 20-8-		       45 minutes

Answer Key - DAT2330 - Ian Allen - Winter 2003 - DAT2330 Test #3b
		       - Unix Final - 15%

Office use only: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19
20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39
   1. a
   2. a
   3. a
   4. a
    5. a
    6. a
    7. a
    8. a
   9. a
  10. a
  11. a
  12. a
   13. a
   14. a
   15. a
   16. a
  17. a
  18. a
  19. a
  20. a
   21. a
   22. a
   23. a
   24. a
  25. a
  26. a
  27. a
  28. a
   29. a
   30. a
   31. a
   32. a
  33. a
  34. a
  35. a
  36. a
   37. a
   38. a
   39. a

Count of a:  39	 100%

With 5 choices: 39
 1 2 3 4 5 6 7 8 9 10 11 12 13
 14 15 16 17 18 19 20 21 22 23
 24 25 26 27 28 29 30 31 32 33
 34 35 36 37 38 39

Macro .cmd splits: 17
Macro .ans splits: 0





39 Questions   DAT2330 Test #3b - Unix Final - 15%     45 minutes