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Basic Unix Shell Script MCQ

1. Which of the following shows the correct precedence order of operators used in a shell? Operators on left side of comma have higher precedence than those on the right side of comma.

( ) , ** , * or / , + or -

( ) , * or / , ** , + or -

( ) , ** , + or - , * or /

** , ( ) , + or - ,* or /

Answer

Correct Answer: ( ) , ** , * or / , + or -

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2.
Suppose there are three files test0.sh, test1.sh, and test2.sh in your current directory. Which of the following options would occur during the execution of read statement?

exec < test0.sh
exec < test2.sh
exec < test3.sh
read line
echo $line

It would not read any file

It would read all the files in reverse order

It would read only the test0.sh

It would read only test3.sh

Answer

Correct Answer:

It would read only test3.sh

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3. Which of the following expressions is valid?

t = 256 (space on both sides of '=' operator)

3.14 * $r * $r = area

k=`expr a*b`

tput cup $row $col

Answer

Correct Answer: tput cup $row $col

Note: This Question is unanswered, help us to find answer for this one

4.
What is the output of the following program?
k=35
echo `[ $k -eq 35 ]``[ $k -eq 50 ]`

1 1

0 0

An error will occur

A blank line will result

Answer

Correct Answer:

A blank line will result

Note: This Question is unanswered, help us to find answer for this one

5.
What is the output of the following program when directory name "home" is given as input?
echo Enter a directory Name
read dirname
case $dirname in
) echo any directory name ;;
c) echo cobol directory name ;;
f) echo fortran directory name ;;
p) echo pascal directory name ;;
esac

any directory name

cobol directory name

fortran directory name

pascal directory name

An error will occur

Answer

Correct Answer:

any directory name

Note: This Question is unanswered, help us to find answer for this one

6.
What is the output of the following program?
1. x=3 y=5 z=10
2. if [ $$x -eq 3$ -a $ $y -eq 5 -o $z -eq 10 $ ]
3. then
4. echo $x
5. else
6. echo $y
7. fi

1 and a warning about line 2 will occur

3 and a warning about line 2 will occur

5 and a warning about line 2 will occur

10 and a warning about line 2 will occur

An error will occur

Answer

Correct Answer:

5 and a warning about line 2 will occur

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7.
Suppose you are writing a shell script that accepts five positional parameters from the terminal. What will be the effect of using statement "shift 1" in your shell script and then executing the shell script?

The positional parameters would be shifted by one position towards left i.e. parameter 1 will have value of parameter 2, parameter 2 will have value of parameter 3 and so on.

Only the first positional parameter would be shifted to left position.

All of the positional parameters would be shifted by one position towards right i.e. parameter 2 will have value of parameter 3, parameter 3 will have value of parameter 4 and so on.

It would result in an error.

Answer

Correct Answer:

The positional parameters would be shifted by one position towards left i.e. parameter 1 will have value of parameter 2, parameter 2 will have value of parameter 3 and so on.

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8. Which of the following loops is invalid?

while [ $? -eq 0 ]

while [ $count -le 0.1]

while [ $1 -gt 10]

while [ 0 ]

while $

Answer

Correct Answer: while $

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9.
What is the error in the following program?
1. j=10 k=12
2. if test [ $k -ge $j ]
3. then
4. k=$j
5. j=$k
6. fi
7. echo $j $k

There is no error.

Variable declaration on line 1 is incorrect.

The variables to be outputted on line 7 should be enclosed within quotes.

Output will be 10 12 with a warning message in line 2

fi should be replaced by endif on line 6

Answer

Correct Answer:

Output will be 10 12 with a warning message in line 2

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10.
What will be the output of the following program assuming that the command line arguments are Unix shell scripting?
for argument in *
do
echo $argument
done

An error will occur

Unix shell scripting

shell

The names of all files in the current directory would be displayed

Answer

Correct Answer:

The names of all files in the current directory would be displayed

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11.
What is the output of the following program?
for i in a b c d e
do
echo $i
done

1 2 3 4 5

a b c d e

e d c b a

An error will occur

a b c d e

Answer

Correct Answer:

a b c d e

Note: This question has more than 1 correct answers

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12.
What is the error in the following program?
1. j=1
2. while [ $j -le 10 ]
3. do
4. echo $j
5. j = j + 1
6. done

There is no error

Line 1 should be j=$1

Statements on lines 3 and 4 should be between curly brackets

Line 4 should be echo {$j}

Line 5 should be j=`expr $j + 1`

Answer

Correct Answer:

Line 5 should be j=`expr $j + 1`

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13. Which of the following is/are correct declaration(s) of a null variable "a" in shell script?

a= ''

All of the above.

Answer

Correct Answer: All of the above.

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14. A shell script is executed by:

a code generator.

an assembler.

an interpreter.

a compiler.

Answer

Correct Answer: an interpreter.

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15.
On executing the statement:
set -3 + 1

$1 would be -3

$1 would be 1

$1 would be -

$1 would be set

An error would occur

Answer

Correct Answer:

An error would occur

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16. Which of the following assignments is illegal?

a=`ls`

b=`ls -l`

c=`1972`

d=`who`

e=`who | grep aa1`

Answer

Correct Answer: c=`1972`

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17. Which of the following variable names is invalid?

_newvar

variable

#regpay

expr

Answer

Correct Answer: #regpay

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18. The expression expr -2 % 7 evaluates to:

-2

0.285

Answer

Correct Answer: -2

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19. The statement z=`expr 5 / 2` would store which of the following values in z?

2.5

Answer

Correct Answer: 2

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20.
What is the error in the following loop statement?
while [ $1 -gt 10 -a $$2 -o -w $3 $ ]

There is no error

( ) brackets are to be used instead of []

{} brackets are to be used instead of []

One cannot use -gt and -o in the same expression

One cannot use -o and -w in the same expression

Answer

Correct Answer:

There is no error

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21. Which of the following is not a shell keyword?

shift

readonly

unset

echo

Answer

Correct Answer: ls

Note: This Question is unanswered, help us to find answer for this one

22.
What is the output of the following program?
terminal=vt100
case $terminal in
vt100) echo Dec terminal;;
vt200) echo Old terminal;;
ansi) echo Commonly used terminal;;
v) echo vt series terminal;;
) echo Any terminal;;
esac

Dec terminal

Old terminal

commonly used terminal

vt series terminal

Any terminal

Answer

Correct Answer:

Dec terminal

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23.
What is the output of the following program?
i=4 z=12
[ $i = 5 -a $z -gt 5 ]

Answer

Correct Answer:

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24.
What is the error in the following shell script code?
#!/bin/sh
1. a=12.25 b=12.52
2. if [a=b]
3. then
4. echo "\na and b are equal"
5. fi

There is no error

Variable declaration on line 1 is incorrect

The statement to be printed with echo on line 4 should be within curly brackets

fi should be replaced by endif on line 5

On line 2, [a=b] should be replaced with [ $a -eq $b ]

Answer

Correct Answer:

On line 2, [a=b] should be replaced with [ $a -eq $b ]

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25. The exit statement is used in a loop to:

exit from the

terminate the execution of a script.

exit from an

Answer

Correct Answer: terminate the execution of a script.

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26.
What is the output of the following program?
i=1 j=1 k=1 while [ $i -lt 10 ] do while [ $j -lt 10 ] do while [ $k -lt 10 ] do echo $i $j $k k='expr $k + 1' break 3 done j='expr $j + 1' done i='expr $i + 1'

An error will occur

3 4 5

2 2 2

2 3 4

1 1 1

Answer

Correct Answer: 1 1 1

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27. Precedence hierarchy decides which operator:

is used last.

is used first.

is unary type i.e. the operators that operate on single operand.

is binary type i.e. the operators that operate on two operands.

Answer

Correct Answer: is used first.

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28.
What is the error in the following program?
1. j=10 k=12
2. if [ $k>=$j ]
3. then
4. k=$j
5. j=$k
6. fi
7. echo $j $k

One cannot declare two variables on line 1

Statements on lines 4 and 5 must appear with curly braces {}

On line 2, test should be used instead of []

There is no error

On line 2 -ge should be used instead of >=

Answer

Correct Answer:

There is no error

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29.
The break statement is used to exit from:

the script.

the shell.

the

Answer

Correct Answer:

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30.
What is the output of the following program?
i=1
for [ i -le 10 ]
do
echo $i
i=

An error will occur

Answer

Correct Answer:

An error will occur

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31. Which of the following assignments is illegal?

a='cat file'

b=100

c=50

d = 25

e='ls'

Answer

Correct Answer: d = 25

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32.
What is the error in the following program?
1. while who | grep aa12 | wc -l
2. do
3. echo false
4. done

There is no error

Condition on line 1 is invalid

Line 3 should be echo

Line 3 should be enclosed with {}

Line 3 should be echo {false}

Answer

Correct Answer:

There is no error

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33.
Which of the following lines have an error?
1. echo enter your name
2. read filename
3. read name < $filename
4. echo $name

There is no error.

Answer

Correct Answer:

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34. Which of the following is true about the "continue" statement?

It cannot be used inside a loop.

It continues the control to the beginning of the loop, bypassing the statements below it, inside the loop.

It can only be used in a while loop.

It has to be associated with an if statement.

It is used with the case construct.

Answer

Correct Answer: It continues the control to the beginning of the loop, bypassing the statements below it, inside the loop.

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35. What will be the output of the following program assuming that the command line arguments are dog parrot cuckoo? for argument in $* do echo $argument done

An error will occur

dog

cuckoo

cuckoo parrot dog

dog parrot cuckoo

Answer

Correct Answer: dog parrot cuckoo

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36. Which of the following expressions is correct?

a=expr $b + $c

a=`expr $b * $c

a=`expr $b * ( $c + $d )`

a=expr $c * $d

a=`expr $b \* \( $c + $d \ )

Answer

Correct Answer: a=`expr $b \* \( $c + $d \ )

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37.
If x=11 and y=6, then what is the exit status of the following expression?
[ $x -eq 11 -a $y -ne 89 ]

Answer

Correct Answer:

Note: This Question is unanswered, help us to find answer for this one

38. Which of the following statements is incorrect regarding if-then-fi?

It is a decision making construct.

The group of commands between the then and else forms the if block.

The else block is optional.

The indentation is done in the if-then-fi to improve readability.

The indentation is mandatory otherwise an error will occur on execution.

Answer

Correct Answer: The indentation is mandatory otherwise an error will occur on execution.

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39. What would be the condition to check whether file with name "xyz" is a regular file?

if [ -f xyz ]

if [ -d xyz ]

if [ -v xyz ]

if [ -r xyz ]

if [ -e xyz ]

Answer

Correct Answer: if [ -f xyz ]

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40.
What is the output of the following shell script code?
suite=3
case $suite in
1) echo Diamond ;;
2) echo Spade ;;
3) echo Heart ;;
4) echo Club ;;

Diamond

Spade

Heart

Club

An error will occur

Answer

Correct Answer:

Heart

Note: This Question is unanswered, help us to find answer for this one

41. Which of the following statements is false?

Output of echo statement can be redirected to a file.

Shell variables are case sensitive.

Programs written for Bourne shell are compatible with Korn shell.

expr can handle only integers.

Comments can be split over multiple lines if each line is preceded by #.

Answer

Correct Answer: Output of echo statement can be redirected to a file.

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42.
What is the output of the following program?
z='[$x -lt 10 ]'
echo x=$x y=$y z=$z
x=3
y=

x=3 y=1 z=1

x=3 y=0 z=0

x=3 y=3 z=5

x=3 y=2 z=1

None of the above

Answer

Correct Answer:

None of the above

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43.
If x=11 and y=6, then what is the exit status of the following expression?
[ ! $x -gt 9 -a ! $y -ne 23 ]

Answer

Correct Answer:

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44. Which of the following is true about "until" loop?

The condition is tested at the end.

It is executed as long as the given condition or list of items evaluate to true.

It cannot test for conditions.

We cannot use exit statement under until loop.

Answer

Correct Answer: It cannot test for conditions.

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45.
What is the error in the following program?
1. x=10
2. if [ x -ge 2 ]
3. then
4. echo $x
5. fi

There is no error

Line 4 should be echo x

Test should be used on line 2 instead of []

Line 1 should be x={10}

Line 2 should be if [ $x -ge 2 ]

Answer

Correct Answer:

Line 2 should be if [ $x -ge 2 ]

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46.
What is the output of the following program?
a=300
[ -n $a ]
echo $?
[ -z $a ]
echo $?

1 2

0 2

2 3

0 0

0 1

Answer

Correct Answer:

0 1

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47.
What is the output of the following program?
b= [ -n $b ]
echo $?
[ -z $b ]
echo $?

1 1

2 2

0 0

0 1

An error will occur

Answer

Correct Answer:

An error will occur

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48.
What is the error in the following shell script code?
1. until=1
2. while [ $until -eq 5 ]
3. do
4. echo until cannot be used as a variable name
5. until=`expr $until + 1`
6. done

Line 1 should be until=$1

Until cannot be used as a variable name

There is no error

Line 4 should be echo

Line 4 should be enclosed within { }

Answer

Correct Answer:

Line 1 should be until=$1

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49. A shell variable cannot start with:

An alphabet

An underscore

A number and an underscore

An alphabet and an underscore

A number and a special symbol other than the underscore

Answer

Correct Answer: A number and a special symbol other than the underscore

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50. Which of the following is/are allowed in an arithmetic statement involving expr command?

{}

( )

3-5

Answer

Correct Answer: ( )
%
3-5

Note: This question has more than 1 correct answers

Note: This Question is unanswered, help us to find answer for this one

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Basic Unix Shell Script MCQ

1. Which of the following shows the correct precedence order of operators used in a shell? Operators on left side of comma have higher precedence than those on the right side of comma.

2. Suppose there are three files test0.sh, test1.sh, and test2.sh in your current directory. Which of the following options would occur during the execution of read statement?exec < test0.shexec < test2.shexec < test3.shread lineecho $line

3. Which of the following expressions is valid?

4. What is the output of the following program?k=35echo `[ $k -eq 35 ]``[ $k -eq 50 ]`

5. What is the output of the following program when directory name "home" is given as input?echo Enter a directory Nameread dirnamecase $dirname in *) echo any directory name ;; c*) echo cobol directory name ;; f*) echo fortran directory name ;; p*) echo pascal directory name ;;esac

6. What is the output of the following program?1. x=3 y=5 z=10 2. if [ \($x -eq 3\) -a \( $y -eq 5 -o $z -eq 10 \) ]3. then4. echo $x5. else6. echo $y7. fi

7. Suppose you are writing a shell script that accepts five positional parameters from the terminal. What will be the effect of using statement "shift 1" in your shell script and then executing the shell script?

8. Which of the following loops is invalid?

9. What is the error in the following program?1. j=10 k=12 2. if test [ $k -ge $j ]3. then4. k=$j5. j=$k6. fi7. echo $j $k

10. What will be the output of the following program assuming that the command line arguments are Unix shell scripting?for argument in *do echo $argumentdone

11. What is the output of the following program? for i in a b c d edo echo $idone

12. What is the error in the following program? 1. j=12. while [ $j -le 10 ]3. do4. echo $j5. j = j + 16. done

13. Which of the following is/are correct declaration(s) of a null variable "a" in shell script?

14. A shell script is executed by:

15. On executing the statement: set -3 + 1

16. Which of the following assignments is illegal?

17. Which of the following variable names is invalid?

18. The expression expr -2 % 7 evaluates to:

19. The statement z=`expr 5 / 2` would store which of the following values in z?

20. What is the error in the following loop statement?while [ $1 -gt 10 -a \($2 -o -w $3 \) ]

21. Which of the following is not a shell keyword?

22. What is the output of the following program? terminal=vt100case $terminal in vt100) echo Dec terminal;; vt200) echo Old terminal;; ansi) echo Commonly used terminal;; v*) echo vt series terminal;; *) echo Any terminal;;esac

23. What is the output of the following program? i=4 z=12 [ $i = 5 -a $z -gt 5 ]

24. What is the error in the following shell script code?#!/bin/sh1. a=12.25 b=12.522. if [a=b]3. then4. echo "\na and b are equal"5. fi

25. The exit statement is used in a loop to:

26. What is the output of the following program? i=1 j=1 k=1 while [ $i -lt 10 ] do while [ $j -lt 10 ] do while [ $k -lt 10 ] do echo $i $j $k k='expr $k + 1' break 3 done j='expr $j + 1' done i='expr $i + 1'

27. Precedence hierarchy decides which operator:

28. What is the error in the following program? 1. j=10 k=122. if [ $k>=$j ]3. then4. k=$j5. j=$k6. fi7. echo $j $k

29. The break statement is used to exit from:

30. What is the output of the following program?i=1for [ i -le 10 ]doecho $ii=

31. Which of the following assignments is illegal?

32. What is the error in the following program?1. while who | grep aa12 | wc -l2. do3. echo false4. done

33. Which of the following lines have an error? 1. echo enter your name2. read filename3. read name < $filename4. echo $name

34. Which of the following is true about the "continue" statement?

35. What will be the output of the following program assuming that the command line arguments are dog parrot cuckoo? for argument in $* do echo $argument done

36. Which of the following expressions is correct?

37. If x=11 and y=6, then what is the exit status of the following expression?[ $x -eq 11 -a $y -ne 89 ]

38. Which of the following statements is incorrect regarding if-then-fi?

39. What would be the condition to check whether file with name "xyz" is a regular file?

40. What is the output of the following shell script code?suite=3case $suite in 1) echo Diamond ;; 2) echo Spade ;; 3) echo Heart ;; 4) echo Club ;;

41. Which of the following statements is false?

42. What is the output of the following program?z='[$x -lt 10 ]'echo x=$x y=$y z=$zx=3 y=

43. If x=11 and y=6, then what is the exit status of the following expression? [ ! $x -gt 9 -a ! $y -ne 23 ]

44. Which of the following is true about "until" loop?

45. What is the error in the following program?1. x=10 2. if [ x -ge 2 ]3. then4. echo $x5. fi

46. What is the output of the following program? a=300 [ -n $a ] echo $? [ -z $a ] echo $?

47. What is the output of the following program?b= [ -n $b ]echo $?[ -z $b ]echo $?

48. What is the error in the following shell script code?1. until=12. while [ $until -eq 5 ]3. do4. echo until cannot be used as a variable name5. until=`expr $until + 1`6. done

49. A shell variable cannot start with:

50. Which of the following is/are allowed in an arithmetic statement involving expr command?

2.
Suppose there are three files test0.sh, test1.sh, and test2.sh in your current directory. Which of the following options would occur during the execution of read statement?

exec < test0.sh
exec < test2.sh
exec < test3.sh
read line
echo $line

4.
What is the output of the following program?
k=35
echo `[ $k -eq 35 ]``[ $k -eq 50 ]`

5.
What is the output of the following program when directory name "home" is given as input?
echo Enter a directory Name
read dirname
case $dirname in
) echo any directory name ;;
c) echo cobol directory name ;;
f) echo fortran directory name ;;
p) echo pascal directory name ;;
esac

6.
What is the output of the following program?
1. x=3 y=5 z=10
2. if [ \($x -eq 3\) -a \( $y -eq 5 -o $z -eq 10 \) ]
3. then
4. echo $x
5. else
6. echo $y
7. fi

7.
Suppose you are writing a shell script that accepts five positional parameters from the terminal. What will be the effect of using statement "shift 1" in your shell script and then executing the shell script?

9.
What is the error in the following program?
1. j=10 k=12
2. if test [ $k -ge $j ]
3. then
4. k=$j
5. j=$k
6. fi
7. echo $j $k

10.
What will be the output of the following program assuming that the command line arguments are Unix shell scripting?
for argument in *
do
echo $argument
done

11.
What is the output of the following program?
for i in a b c d e
do
echo $i
done

12.
What is the error in the following program?
1. j=1
2. while [ $j -le 10 ]
3. do
4. echo $j
5. j = j + 1
6. done

15.
On executing the statement:
set -3 + 1

20.
What is the error in the following loop statement?
while [ $1 -gt 10 -a \($2 -o -w $3 \) ]

22.
What is the output of the following program?
terminal=vt100
case $terminal in
vt100) echo Dec terminal;;
vt200) echo Old terminal;;
ansi) echo Commonly used terminal;;
v) echo vt series terminal;;
) echo Any terminal;;
esac

23.
What is the output of the following program?
i=4 z=12
[ $i = 5 -a $z -gt 5 ]

24.
What is the error in the following shell script code?
#!/bin/sh
1. a=12.25 b=12.52
2. if [a=b]
3. then
4. echo "\na and b are equal"
5. fi

26.
What is the output of the following program?
i=1 j=1 k=1 while [ $i -lt 10 ] do while [ $j -lt 10 ] do while [ $k -lt 10 ] do echo $i $j $k k='expr $k + 1' break 3 done j='expr $j + 1' done i='expr $i + 1'

28.
What is the error in the following program?
1. j=10 k=12
2. if [ $k>=$j ]
3. then
4. k=$j
5. j=$k
6. fi
7. echo $j $k

29.
The break statement is used to exit from:

30.
What is the output of the following program?
i=1
for [ i -le 10 ]
do
echo $i
i=

32.
What is the error in the following program?
1. while who | grep aa12 | wc -l
2. do
3. echo false
4. done

33.
Which of the following lines have an error?
1. echo enter your name
2. read filename
3. read name < $filename
4. echo $name

37.
If x=11 and y=6, then what is the exit status of the following expression?
[ $x -eq 11 -a $y -ne 89 ]

40.
What is the output of the following shell script code?
suite=3
case $suite in
1) echo Diamond ;;
2) echo Spade ;;
3) echo Heart ;;
4) echo Club ;;

42.
What is the output of the following program?
z='[$x -lt 10 ]'
echo x=$x y=$y z=$z
x=3
y=

43.
If x=11 and y=6, then what is the exit status of the following expression?
[ ! $x -gt 9 -a ! $y -ne 23 ]

45.
What is the error in the following program?
1. x=10
2. if [ x -ge 2 ]
3. then
4. echo $x
5. fi

46.
What is the output of the following program?
a=300
[ -n $a ]
echo $?
[ -z $a ]
echo $?

47.
What is the output of the following program?
b= [ -n $b ]
echo $?
[ -z $b ]
echo $?

48.
What is the error in the following shell script code?
1. until=1
2. while [ $until -eq 5 ]
3. do
4. echo until cannot be used as a variable name
5. until=`expr $until + 1`
6. done