Unix Shell scripting examples

 Some Unix Shell scripting examples

(Q1.) Write a script to calculate the factorial of a number entered by the user .

$vi factorial.sh

echo "Enter the number : "

read a

fact=1

while((a>0))

do

fact=$(($fact * a))

a=$(($a - 1))

done

echo "The factorial of the given number is " $fact

For Output : $sh factorial.sh

                    Enter the number : 5

                    The factorial of the given number is 120

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 (Q2.) Write a script to check whether the number entered by user is palindrome or not.

$vi palindrome.sh

echo "Enter the number :"

read num

n=$num

sum=0

while((num>0))

do

rem=$(($num%10))

num=$(($num/10))

sum=$(($sum*10+$rem))

done

if(($sum==$n))

then

echo "The given number is a palindrome"

else

echo "The given number is not a palindrome"

fi

For Output : $sh palindrome.sh

                    Enter the number : 221122

                    The given number is a palindrome

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 (Q3.) Write a script to check whether the number entered by the user is Armstrong or not.

$vi armstrong.sh

echo "Enter the number : "

read num

sum=0

n=$num

while((num>0))

do

rem=$(($num%10))

num=$(($num/10))

sum=$(($sum + $rem*$rem*$rem))

done

if(($sum==$n))

then

echo "The number is armstrong"

else

echo "The number is not armstrong"

fi

For Output : $sh armstrong.sh

                    Enter the number : 153

                    The number is armstrong

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 (Q4.) Write a script to generate a Fibonacci series where number of terms will be entered by the user .

$vi fibonacci.sh

echo "Enter the number of terms in fibonacci series : "

read a

fo=0

f1=1

echo "The series is shown below :"

echo -n $fo " " $f1 " "

for((i=1; i<$a-1; i++))

do

sum=$(($fo+$f1))

fo=$f1

f1=$sum

echo -n $sum " "

done

For Output : $sh fibonacci.sh

                    Enter the number of terms in fibonacci series : 8       

                    The series is shown below :

                    0  1  1  2  3  5  8  13

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 (Q5.) Write a script to check whether the number entered by the user is prime or not .

$vi prime.sh

echo "Enter the number : "

read n

c=0

for((i=2; i<=$n/2; i++))

do

if(($n%i==0))

then

c=1

fi

done

if(($c==o))

then

echo "The number is prime"

else

echo "The number is not prime"

fi

For Output : $sh prime.sh

                    Enter the number : 7

                    The number is prime

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 (Q6.) Write a script to generate the following pattern where maximum limit is entered by the user .

                          1

                          1 2

                          1 2 3

                          1 2 3 4 ...

$vi pattern.sh

echo "Enter the maximum limit : "

read n

for((i=1; i<$n+2; i++))

do

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

do

echo -n $j

done

echo " "

done

For Output : $sh pattern.sh

                    Enter the maximum limit : 4

                          1

               1 2

               1 2 3

               1 2 3 4

                  

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(Q7.) Write a script to generate the multiplication table of the number entered by the user.

$vi table.sh

echo "Enter the number : "

read n

for((i=1; i<11; i++))

do

echo $n " * " $i " = " $(($n*$i))

done

For Output : $sh table.sh

                    Enter the number : 7

                    7 * 1 = 7

                    7 * 2 = 14

                    7 * 3 = 21

                    7 * 4 = 28

                    7 * 5 = 35

                    7 * 6 = 42

                    7 * 7 = 49

                    7 * 8 = 56

                    7 * 9 = 63

                    7 * 10 = 70

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(Q8.) Write a script to check whether the filename entered by the user exists or not. If it exists then check whether it is empty or not.

$vi filecheck.sh

echo "Enter the file name : "

read a

if test -e $a

then

echo "File Exists"

if test -s $a

then

echo "File is not empty"

else

echo "File is empty"

fi

else

echo "File does not exist"

fi

For Output : $sh filecheck.sh

                    Enter the filename : frndz

                    File Exists

                    File is not empty

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 (Q9.) Write a script to check whether the string entered by the user exists in the filename entered by the user.

$vi strchk.sh

echo "Enter String :"

read a

echo "Enter filename :"

read b

if grep -c $a $b

then

echo "The given string is found ."

else

echo "The given string is not found ."

fi

For Output : $sh strchk.sh

                    Enter string : make

                    Enter filename : frndz

                    The given string is found .

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(Q10.) Write a script to run a C program .

$vi cprog.c

#include<stdio.h>

void main()

{int a;

printf("Enter a number : ");

scanf("%d",&a);

if(a%2==0)

printf("The number is even");

else

printf("The number is odd");

}

To compile the program :   $cc cprog.c

 To run the program :  ./a.out

Output :       Enter a number : 28

                    The number is even

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