100 Shell Programs in Unix

echo Enter Salary of  an Employee

read sal

if [ $sal -ge 5000 ]

then

bonus=‘echo $sal \* .05 | bc’

else

bonus=250

fi

echo bonus is: $bonus

Sample Run

$sh prg25

Enter Salary of an Employee

6500

bonus is: 325.00

$sh prg25

Enter Salary of an Employee

7000

bonus is: 350.00

$sh prg25

Enter Salary of an Employee

3500

bonus is: 250

26. Write a shell script to find out greatest among n input integers where n is to be input by the user.

$vi prg26

clear

echo “Enter number of integers”

read n

echo “enter value of  integer number 1”

read j

i=2

while test $i -le $n

do

echo enter value of integer number $i

read k

if [ $j -lt $k ]

then

j=$k

fi

i=‘expr $i + 1’

done

echo Greatest input is $j

Sample Run

$sh prg26

Enter number of integers

5

enter value of integer number 1

8

enter value of integer number 2

3

enter value of integer number 3

22

enter value of integer number 4

44

enter value of integer number 5

11

Greatest input is 44

27. Write a shell script to read an integer and print its digits in reverse order.

$vi prg27

clear

echo “enter any integer”

read num

b=0

while test $num -gt 0

do

a=‘expr $num % 10’

b=‘expr \( $b + $a \) \* 10’

num=‘expr $num / 10’

done

b=‘expr $b / 10’ echo reverse=$b

Sample Run

$sh prg27

enter any integer

123

reverse=321

28.  Sort the given numbers in the given order, i.e., either in ascending or descending order.

$vi prg28

clear

ans=y

while test $ans = y

do

echo Enter no. of elements to be sorted

read no

echo Enter $no elements

i=1

rm sort1

while test $i –le $no

do

read n

‘echo $n >> sort1’

i=‘expr $i + 1’

done

clear

echo input order of sorting

echo 1.Ascending

echo 2.Descending

echo enter choice

read ch

clear

case $ch in

1)    sort –n sort1>file1

echo Inputted elements in Ascending order:

cat file1 ;;

1)    sort –r sort1>file1

echo Inputted elements in Descending order:

cat file1 ;;

1)    echo “Invalid Input” ;;

esac

echo continue…….y/n

read ans

done

Sample Run

$sh prg28

Enter no. of elements to be sorted

4

Enter 4 elements

3

5

2

1

input order of sorting

1.Ascending Press 1

2.Descending Press 2

enter choice

1

Inputted elements in Ascending order:

1

2

3

5

continue…….y/n

y

Enter no. of elements to be sorted

5

Enter 5 elements

4

6

1

3

3

input order of sorting

1.Ascending Press 1

2.Descending Press 2

enter choice

2

Inputted elements in Descending order:

6

4

3

3

1

continue…….y/n

n

29.  Write a shell script to compare two strings input by the user for equality.

$vi prg29

clear

echo enter string1

read str1

echo enter string2

read str2

if test $str1 = $str2

then

echo strings are equal

else

echo strings are not equal

fi

Sample Run

$sh prg29

enter string1

abc

enter string2

abc

strings are equal

$sh prg29

enter string1

xyz

enter string2

abc

strings are not equal

30. Write a shell script to print the characters of an input string into reverse order.

$vi prg30

clear

echo enter any string

read str

len=‘echo $str | wc -c’

len=‘expr $len - 1’

while test $len -ne 0

do

i=‘echo $str | cut -c $len’

a=$a$i

len=‘expr $len - 1’

done

echo reverse is $a

Sample Run

$sh prg30

enter any string

programming

reverse is gnimmargorp

31. Write a shell script to tell whether input string is palindrome or not.

$vi prg31

clear

echo enter any string

read str

len=‘echo $str | wc –c’

len=‘expr $len -1’

while test $len –ne 0

do

i=‘echo $str | cut –c $len’

a=$a$i

len=‘expr $len -1’

done

if test $str = $a

then

echo String is Palindrome

else

echo String is not Palindrome

fi

Sample Run

$sh prg31

enter any string

cmc

String is Palindrome

$sh prg31

enter any string

abc

String is not Palindrome

32. Write a shell script to find out the location of an input character into an input string.

$vi prg32

clear

echo enter any string

read str

echo enter character

read c

len=‘echo $str | wc –c’

len=‘expr $len – 1’

i=1

while test $i –le $len

do

a=‘echo $str | cut –c $i’

if test $a = $c

then

echo Position=$i

fi

i=‘expr $i + 1’

done

Sample Run

$sh prg32

enter any string

Programming

enter character

g

Position=4

Position=11

33. Write a shell script to count the number of characters, words, spaces in a given text.

$vi prg33

clear

echo “enter text”

read t

w=‘expr $t | wc –w’

c=‘expr $t | wc –c’

c=‘expr $c - 1’

s=‘expr $w – 1’

echo characters = $c

echo words = $w

echo spaces = $s

Sample Run

$sh prg33

enter text

that is a table

characters = 15

words = 4

spaces = 3