Shell Scripting

All codes written by me, tested and working!!


Program 1: To write a program getting Armstrong number below 1000.

Algorithm:

1.      Start

2.      Initialize the variables.

3.      In while loop, break the numbers in to Units, Tens, Hundreds using reminder and division method.

4.      After dividing each number make the cube of each number and add them.

5.      If the number is equal to the sum, save that number as Armstrong number.

6.      Continue procedure in while loop until 1000 numbers.

7.      Print the Armstrong number.

8.      Stop.

Sample Input/Output

rushi@rushi-Inspiron-N5010:~/shellscript$ cat pg1arm2.sh

#!/bin/bash

    i=1

while((i<=1000))

do

    c=$i

    d=$i

    b=0

    a=0

        while((c>0))

        do

        a=$((c%10))

        b=$((b + a*a*a))

        c=$((c/10))

        done

    if((b==d)); then

        echo "$i"

    fi

    i=$((i+1))

done

rushi@rushi-Inspiron-N5010:~/shellscript$ bash pg1arm2.sh

1

153

370

371

407

Result: Shell scripting program can be used to find the Armstrong numbers using While and If structures.

Program 2: Write a program to find an occurrence of a particular character in a string using Shell scripting.

Algorithm:

1.      Start

2.      Take input from user, save input in a variable.

3.      Find the length of the character using wc –c command.

4.      Use cut command to cut each character using its index as input to the cut command.

5.      Compare each character with demanded character.

6.      Increment the count if successful.

7.      Print the count value.

8.      Stop.

Sample Input/Output:

rushi@rushi-Inspiron-N5010:~/shellscript$ cat pg2occ.sh

echo Enter the string

read userstr

echo enter the character to be found

read strch

l=`echo $userstr | wc -c`

echo "Length of the entered word is `expr $l - 1`"

echo "The occurrence of a character in a given text is"

grep -o "$strch" <<<"$userstr" | wc -l

rushi@rushi-Inspiron-N5010:~/shellscript$ ./pg2occ.sh

Enter the string

rushi

enter the character to be found

i

Length of the entered word is 5

The occurance of a character in a given text is

1

rushi@rushi-Inspiron-N5010:~/shellscript$ ./pg2occ.sh

Enter the string

rushi

enter the character to be found

x

Length of the entered word is 5

The occurrence of a character in a given text is

0

Result: Using length count we can count characters using wc –c and comparing each character with the desired character, we can find occurrence of the character.

Program 3: To replace a particular character into string using shell scripting.

Algorithm:

1.      Start

2.      Enter and store the string

3.      Get the character to be replaced.

4.      Enter the character with which it should be replaced.

5.      Using cut command, separate each character from string and compare each character with character to be replaced.

6.      If comparison command is successful, replace the character and print.

7.      Stop.

Sample Input/Output:

rushi@rushi-Inspiron-N5010:~/shellscript$ cat pg3replace.sh

echo "Enter the Text"

read userstr

echo "enter the character to be raplaced in given string"

read charq

echo "enter the character with which the $char to be replaced"

read newch

len=`echo $userstr | wc -c`

len=`expr $len - 1`

echo The length of the Entered string is `expr $len`

i=1

echo -e "New string is\n"

while [ $i -le $len ]

do

            cutch=`echo $userstr | cut -c $i`

            if [ "$cutch" = "$charq" ]

                        then

                        cutch=$newch

                        echo -n $cutch

            else

                        echo -n $cutch

            fi

i=`expr $i + 1`

done

echo -e "\n"

rushi@rushi-Inspiron-N5010:~/shellscript$ ./pg3replace.sh

Enter the Text

rushi

enter the character to be raplaced in given string

i

enter the character with which the  to be replaced

y

The length of the Entered string is 5

New string is

rushy

Result: Shell scripting program can be used to replace the particular character.

Program 4: To compare two strings using shell scripting.

Algorithm:

1.      Start

2.      Take input from user for string1 and string2.

3.      Find the length of both strings

4.      If length are equal then compare directly by using rational operator “=”

5.      If condition is true then print the result as both strings are same else not equal

6.      Stop

Sample Input/Output:

rushi@rushi-Inspiron-N5010:~/shellscript$ cat pg4comparestring.sh

echo "Enter string 1"

read string1

echo "Enter string 2"

read string2

len1=`echo $string1 | wc -c`

len2=`echo $string2 | wc -c`

echo The length of the string1 is `expr $len1 - 1`

echo The length of the string2 is `expr $len2 - 1`

if [ $len1 = $len2 ]

            then

            if [ $string1 = $string2 ]

                        then

                        echo "Yeah! Text are same!"

            else

                        echo "Oops, Not same!"

            fi

else

                        echo "Oops, Not same!"

fi

rushi@rushi-Inspiron-N5010:~/shellscript$ ./pg4comparestring.sh

Enter string 1

rushi

Enter string 2

rushi

The length of the string1 is 5

The length of the string2 is 5

Yeah! Text are same!

rushi@rushi-Inspiron-N5010:~/shellscript$ ./pg4comparestring.sh

Enter string 1

rushi

Enter string 2

gajjar

The length of the string1 is 5

The length of the string2 is 6

Oops, Not same!

Result:

We can compare the string directly using rational operator unlike pointer concept in C language.

Program 5: Write a program to find a sum and average for a given set of number using shell scripting.

Algorithm:

1.      Start

2.      Get the value of number of inputs from user.

3.      Get one by one number and add them successively

4.      Average the number by dividing the value get from user at step 2.

5.      Print the sum value and average value.

6.      Stop.

Sample Input/Output:

rushi@rushi-Inspiron-N5010:~/shellscript$ cat pg5sumavg.sh

echo "How many numbers you want to enter?"

read count

i=1

add=0

avg=0.0

echo "Start entering numbers"

while [ "$i" -le "$count" ]

do

            read number

            add=`expr $add + $number`

            i=`expr $i + 1`

done

avg=`expr $add / $count`

echo "Addition is $add"

echo "Average is $avg"

rushi@rushi-Inspiron-N5010:~/shellscript$ ./pg5sumavg.sh

How many numbers you want to enter?

5

Start entering numbers

1

2

3

4

5

Addition is 15

Average is 3

Result:We can get values from user using the while loop and we can find sum and average of given numbers.

Program 6: Write a program to find a number of vowels in a string using shell scripting.

Algorithm:

1.      Start

2.      Get the string from the user.

3.      Using wc –c command, find the length of the string.

4.      Using the cut command separate each character and compare with a,e,i,o,u using case structure.

5.      When the case is matched, increment the count.

6.      Print the count value.

7.      Stop

Sample Input/Output:

rushi@rushi-Inspiron-N5010:~/shellscript$ cat pg6vowel.sh

echo "Enter the string to count the vowels"

read string1

len=`echo $string1 | wc -c`

len=`expr $len - 1`

echo "The length of the word is $len"

echo -n "The vowels in the word are "

i=1

count=0

while [ $i -le $len ]

do

            res=`echo $string1 | cut -c $i`

            case "$res" in

                        a)

                        count=`expr $count + 1`;;

                        e)

                        count=`expr $count + 1`;;

                        i)

                        count=`expr $count + 1`;;

                        o)

                        count=`expr $count + 1`;;

                        u)

                        count=`expr $count + 1`;;

                        *)

                        count=`expr $count`;;

            esac

i=`expr $i + 1`

done

echo -n -e "$count \n"

rushi@rushi-Inspiron-N5010:~/shellscript$ ./pg6vowel.sh

Enter the string to count the vowels

rushigajjar

The length of the word is 11

The vowels in the word are 4

Result: Using case structure we can find the vowels in a string by sending each character.

Program 7: To copy strings using character by character copying using shell scripting.

Algorithm:

1.      Start.

2.      Get the string1 and string2

3.      Find length of both strings and consider the highest length.

4.      Using cut command put the character in the second string.

5.      Display the string.

6.      Stop.

Sample Input/Output:

rushi@rushi-Inspiron-N5010:~/shellscript$ cat pg7charbychar.sh

echo "Enter the string"

read string1

echo "Enter the string to be copied"

read string2

len1=`echo $string1 | wc -c`

len2=`echo $string2 | wc -c`

len1=`expr $len1 - 1`

len2=`expr $len2 - 1`

#finding the longest string length

if [ "$len1" -gt "$len2" ]

            then

            len="expr $len1"

else

            len="$len2"

fi

i=1

j=1

k=1

while [ $i -le $len ]

do

            while [ "$j" -le "$i" ]; do

            copycutchar=`echo $string1 | cut -c $i`

            echo -n $copycutchar

            j=`expr $j + 1`

            done

            j=1

                        k=`expr $i + 1`

                        while [ "$k" -le "$len2" ]; do

                                    string1cut=`echo $string2 | cut -c $k`

                                    echo -n "$string1cut"

                                    k=`expr $k + 1`

                        done

i=`expr $i + 1`

done

echo -e "\n"

rushi@rushi-Inspiron-N5010:~/shellscript$ ./pg7charbychar.sh

Enter the string

VIT

Enter the string to be copied

UNIVERSITY

VNIVERSITYIIIVERSITYTTTVERSITYERSITYRSITYSITYITYTYY

Result: We can find a interleave the words in a shell scripting.