Operating System – Unix Shell Scripts Examples

Here in this section of Operating System Long Questions and Answers,We have listed out some of the important Long Questions with Answers on Unix Shell Scripts Examples which will help students to answer it correctly in their University Written Exam.

Lists of Unix Shell Scripts Examples that may be asked in Written Exams.

• 1) Write a shell script to scans the name of the command and executes it.
• 2) Write a shell script Which works like calculator and performs below operations Addition , Subtract ,Division ,Multiplication
  
• 3) Write a shell script to print the pyramid structure for the given number.
  
• 4) Write a shell script to find the largest among the 3 given numbers.
  
• 5) Write a shell script to find factorial of given number n.
  
• 6) Write a shell script to print all prime numbers from 1 to n.
  
• 7) Write a shell script to reverse a number supplied by a user.
  
• 8) Write a shell script to find first n Fibonacci numbers like: 0 1, 1, 2, 3, 5, 13,…
  9) Write a shell script to check whether the given number is Perfect or not.
  
• 10) Write a shell script which displays a list of all files in the current directory to which you have read, write and execute permissions
  
• 11) Write a shell script that deletes all the files in the current directory which are 0 bytes in length.
  
• 12) Write a shell script to check whether the given string is Palindrome or not.
  
• 13) Write a shell script to display the digits which are in odd position in a given 5 digit number
  
• 14) Write a shell script to check given year is leap year or not.
  
• 15) Write a shell script to find the value of one number raised to the power of another.
  

read cmd

$cmd

cal

February 2019

Su Mo Tu We Th Fr Sa

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

echo ” Enter one no.”

read n1

echo “Enter second no.”

read n2

echo “1.Addition”

echo “2.Subtraction”

echo “3.Multiplication”

echo “4.Division”

echo “Enter your choice”

read ch

if [ $ch = “1” ]

then

sum=`expr $n1 + $n2`

echo “Sum =”$sum

elif [ $ch = “2” ]

then

sum=`expr $n1 – $n2`

echo “Sub = “$sum

elif [ $ch = “3” ]

then

echo “Mul = “$sum

elif [ $ch = “4” ]

then

sum=`expr $n1 / $n2`

echo “Div = “$sum

fi

32

Enter second no.

12

1.Addition

2.Subtraction

3.Multiplication

4.Division

Enter your choice

2

Sub = 20

i=”y”

while [ $i = “y” ]

do

echo ” Enter one no.”

read n1

echo “Enter second no.”

read n2

echo “1.Addition”

echo “2.Subtraction”

echo “3.Multiplication”

echo “4.Division”

echo “Enter your choice”

read ch

case $ch in

1)sum=`expr $n1 + $n2`

echo “Sum =”$sum;;

2)sum=`expr $n1 – $n2`

echo “Sub = “$sum;;

3)sum=`expr $n1 \* $n2

echo “Mul = “$sum;;

4)sum=`expr $n1 / $n2`

echo “Div = “$sum;;

*)echo “Invalid choice”;;

esac

echo “Do u want to continue ? y/n”

read i

if [ $i != “y” ]

then

exit

fi

done

Enter one no.

32

Enter second no.

22

1.Addition

2.Subtraction

3.Multiplication

4.Division

Enter your choice

2

Sub = 10

Do u want to continue ? y/n

N

read n

printf “\n”

for((i=1;i<=$n;i++))

do

for((j=1;j<=$i;j++))

do

printf “$j”

done

printf “\n”

done

4

1

12

123

1234

echo “Enter first number: ”

read a

echo “Enter second number: ”

read b

echo “Enter third number: ”

read c

if [ $a -ge $b -a $a -ge $c ]

then

echo “$a is largest integer”

elif [ $b -ge $a -a $b -ge $c ]

then

echo “$b is largest integer”

elif [ $c -ge $a -a $c -ge $b ]

then

echo “$c is largest integer”

fi

22

Enter second number:

33

Enter third number:

42

44 is largest integer

fact=1

echo “Enter number to find factorial : ”

read n

a=$n

#if enter value less than 0

if [ $n -le 0 ]

then

echo “invalid number”

exit

fi

#factorial logic

while [ $n -ge 1 ]

do

fact=`expr $fact \* $n`

n=`expr $n – 1`

done

echo “Factorial for $a is $fact”

5

Factorial for 5 is 120

echo “enter the range”

read n

echo “the prime no are:”

m=2

while [ $m -le $n ]

do

i=2

flag=0

while [ $i -le `expr $m / 2` ]

do

if [ `expr $m % $i` -eq 0 ]

then

flag=1

break

fi

i=`expr $i + 1`

done

if [ $flag -eq 0 ]

then

echo $m

fi

m=`expr $m + 1`

done

10

the prime no are

2

3

5

7

then

if [ $1 -gt 0 ]

then

num=$1

sumi=0

while [ $num -ne 0 ]

do

lnum=`expr $num % 10`

sumi=`expr $sumi \* 10 + $lnum`

num=`expr $num / 10`

done

echo “Reverse of digits is $sumi of $1″

else

echo ” Number is less than 0″

fi

else

echo “Insert only one parameter ”

fi

Reverse of digits is 321 of 123

echo “How many number of terms to be generated ?”

read n

x=0

y=1

i=2

echo “Fibonacci Series up to $n terms :”

echo “$x”

echo “$y”

while [ $i -lt $n ]

do

i=`expr $i + 1 `

z=`expr $x + $y `

echo “$z”

x=$y

y=$z

done

5

Fibonacci Series up to 5 terms :

0

1

1

2

3

read no

i=1

ans=0

while [ $i -le `expr $no / 2` ]

do

if [ `expr $no % $i` -eq 0 ]

then

ans=`expr $ans + $i`

fi

i=`expr $i + 1`

done

if [ $no -eq $ans ]

then

echo $no is perfect

else

echo $no is NOT perfect

fi

6

6 is perfect

Enter a number

10

10 is NOT perfect

do

if [ -r $File -a -w $File -a -x $File ]

then

echo $File

fi

done

Documents

Downloads

lab

Music

Pictures

Public

shellscript

Templates

Videos

find . -name “*” -size -1k –delete

echo “files deleted”

echo “Enter the string:”

read str

echo

len=`echo $str | wc -c`

len=`expr $len – 1`

i=1

j=`expr $len / 2`

while test $i -le $j

do

k=`echo $str | cut -c $i`

l=`echo $str | cut -c $len`

if test $k != $l

then

echo “String is not palindrome”

exit

fi

i=`expr $i + 1`

len=`expr $len – 1`

done

echo “String is palindrome”

abba

String is palindrome

Enter the string:

abc

String is not palindrome

read num

n=1

while [ $n -le 5 ]

do

a=`echo $num | cut -c $n`

echo $a

n=`expr $n + 2`

done

12345

1

3

5

echo “enter any year”

read num

if [ `expr $num % 4` -eq 0 ]

then

if [ `expr $num % 100` -eq 0 -a `expr $num % 400` -ne 0 ]

then

echo “Not a leap year”

else

echo “Leap year ”

fi

else

echo “Not a leap year”

fi

2016

Leap year

enter any year

2100

Not a leap year

read no

echo “Input power”

read power

counter=0

ans=1

while [ $power -ne $counter ]

do

ans=`echo $ans \* $no | bc`

counter=`echo $counter + 1 | bc`

done

echo “$no power of $power is $ans”

5

Input power

3

5 power of 3 is 125