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SHELL PROGRAMS

EXPERIMENT 1

AIM : To swap two numbers with out using temporary variable

REQUIREMENTS :

HARDWARE : PIII Processor , 128 MB RAM, 10GBSOFTWARE : OS: LINUX

THEORY :

Shell is a user interface to the operating system built on the programming interface.The shell executes commands of the form:

CommandName [ argument1]

The shell executes the program CommandName and passes argument on the command line toit. Then the shell waits for the command to exit.

This program is for swapping two numbers using only two variables

ALGORITHM :

STEP 1. Read two numbers a and b

STEP 2. a=èxpr $a + $b`

STEP 3.b=èxpr $a -$b`

STEP 4. c=èxpr $a-$b`

STEP 5. Echo the swapped values as $a and $b

DEPARTMENT OF COMPUTER SCIENCE

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PROGRAM:

echo -n "enter two numbers"read a

read becho "Before swapping"echo " A = $a B = $b"a=èxpr $a + $b`

b=èxpr $a - $bà=èxpr $a - $bècho "After swapping "echo "A = $a B = $b"

OUTPUT :

[balu@krishna-edu shell]$ sh swap.shenter two numbers45Before swappingA = 4 B = 5After swappingA = 5 B = 4


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EXPERIMENT 2

AIM: To Swap two numbers using temporary variable

REQUIREMENTS :


THEORY :


CommandName [ argument1]

The shell executes the program CommandName and passes argument on the command lineto it. Then the shell waits fro the command to exit.

This program is for swapping two numbers using three variables

ALGORITHM:

STEP 1. Read two numbers a and b

STEP 2. Echo the numbers a and b

STEP 3. c=$aSTEP 4. a=$b

STEP 5. b=$c

STEP 6. Echo a and b after swapping


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PROGRAM:

echo -n "enter a number"

read numsqr=èxpr $num \* $num`cube=èxpr $sqr \* $numècho "the squre of $num is $sqr"echo "the cube of $num is $cube"

OUTPUT:

[balu@krishna-edu shell]$ sh sqcu.sh

enter a number 4

the squre of 4 is 16

the cube of 4 is 64

[balu@krishna-edu shell]$


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EXPERIMENT 4

AIM : To check whether a given number is even or odd .

REQUIREMENTS :


THEORY:


CommandName [ argument]

The shell executes the program CommandName and passes argument on the command line toit. Then the shell waits fro the command to exit.

This program is to check whether a given number is even or odd .

ALGORITHM :

STEP 1. Read the number n

STEP 2. Perform modulo division on n and store it in r

STEP 3. If r is equal to zero then

Echo the given number is even

STEP 4. If the condition is not satisfied then

Echo the output is an odd number


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PROGRAM:

clearecho enter the numberread n

r=1r=`expr $n % 2`if [ $r -eq 0 ]then

echo evenelse

echo oddfi

OUTPUT:

[krishna-edu-balu]$ sh eorodd

enter the number

5

odd

[krishna-edu balu]$


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EXPERIMENT 5

AIM : To find whether the given input name is a file or a directory.

REQUIREMENTS:


THEORY:

Shell is a user interface to the operating system built on the programming interface. The shellexecutes commands of the form:

CommandName [argument1,..]

The shell executes the program CommandName and passes argument on thecommand line to it. Then the shell waits for the command to exit. Files are the passivecontainers of data on disk. Many operating systems name hardware devices in the same wayas files and allow access to devices using the same interface as to files: open, read, write,close.

This program checks whether the given name is file or directory

ALGORITHM:

STEP 1. Read a file name.

STEP 2. Check for the type of file using f option.

STEP 3. If condition is satisfied then

Echo file as an ordinary file

Else

Echo file as a directory

.


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PROGRAM

clear

echo enter a filenameread $fnameif test f $fnamethen

echo file is a ordinary fileelse

echo directoryfi

OUTPUT:

[krishna-edu balu]$ sh fd

enter a filename

string

file is a ordinary file

[krishna-edu balu]$


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EXPERIMENT 6

AIM: To check the type of character entered.

REQUIREMENTS:


THEORY:



The shell executes the program CommandName and passes argument on thecommand line to it. Then the shell waits for the command to exit.

This program is to check the type of input character using case statement.

ALGORITHM:

STEP 1. Read a character from the keyboard.

STEP 2. Use case statement to checkfor the type of character

STEP 3. Echo the character as alphabet or number or special character

STEP 4. End case


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PROGRAM:

clearecho enter a character from the keyboardread chcase $ch in

[a-z]) echo its a alphabet;;[0-9]) echo its a number;;

?) echo it is a special character;;

*) echo u entered more;;

esac

OUTPUT:

[krishna-edu balu]$ sh case1

enter a character from the keyboard

a

its a character

[krishna-edu balu]$


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EXPERIMENT 7

AIM: To illustrate the usage of case statement.

REQUIREMENTS:


THEORY:




This program is an example for using case statement.

ALGORITHM:

STEP 1: Read the choice

STEP 2: If choice is 1 then display the fileSTEP 3: If choice is 2 then copy one file to another.

STEP 4: If choice is 3 then create a directory.

STEP 5: End case


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PROGRAM

clearecho 1.display a fileecho 2.copy a file

echo 3.create a directoryecho enter ur choiceread chcase $ch in

1) echo enter filenameread fnamecat $fname;;

2) echo enter two filesread file1 file2cp $file1 $file2;;

3) echo enter the directoryread dnamemkdir $dname

;;*) echo invalid option

esac

OUTPUT:

[krishna-edu balu] sh case

1.print a file

2.copy a file

3.create a directory

enter ur choice

2

enter two files

c2 ch

[krishna-edu balu]$ vi ch

This is unix environment.


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EXPERIMENT 8

AIM: To compare two strings.

REQUIREMENTS:


THEORY:



The shell executes the program CommandName and passes argument on thecommand line to it(via the argv array of strings). Then the shell waits for the command toexit.

This program is to compare two strings

ALGORITHM:

STEP 1:Read string1.STEP 2:Read string2.

STEP 3:compare the two strings.

STEP 4:If string is equal to string2 then

Echo strings are equal

Echo strings are not equal


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PROGRAM

clearecho "enter a string1"read first

echo "enter a string2"read secondif [ $first = $second ]

thenecho equal

elseecho unequal

fi

OUTPUT:

[krishna-edu balu]$ sh string

enter a string1

hello

enter a string2

krishna

unequal

[krishna-edu balu]$


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EXPERIMENT 9

AIM: To compare two strings by reading strings from the command line .

REQUIREMENTS :


THEORY:



The shell executes the program CommandName and passes argument on the command lineto it. Then the shell waits fro the command to exit

This program is for comparing two strings by reading strings from the commandline

ALGORITHM:

STEP 1. Read the value of first string

STEP 2. Read the value of second string

STEP 3. If string1 is equal to string2

Echo strings are equal

STEP 4. Else echo strings as unequal


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PROGRAM:

if [ $1 = $2 ]then

echo "Strings are equal ...."elseecho "Strings are not equal....."

fi

[balu@krishna-edu shell]$ sh comparecmd.sh krishna krishnaStrings are equal ....[balu@krishna-edu shell]$


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EXPERIMENT 10

AIM: To find the length of a string

REQUIREMENTS :


THEORY:




This program is for finding the length of the string .

ALGORITHM:

STEP 1. Read the value of the string

STEP 2. Count the number of characters in the string using the wc c command and store

the result in the variable length

STEP 3. Subtract the new line character

STEP 4. Echo the value of the length of the string


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PROGRAM

echo -n "Enter the string "read strlen=ècho $str | wc -c`

len=èxpr $len - 1ècho " the length of the string is $len"

OUTPUT

[balu@krishna-edu shell]$ sh length.sh

Enter the string krishna

the length of the string is 6



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EXPERIMENT 11

AIM: To calculate the value of X n

REQUIREMENTS :


THEORY:




This program is for finding the value of Xn

ALGORITHM:

STEP 1. Read the values of x and n

STEP 2. Initialize sum and I to 1

STEP 3. Check for the condition [ $I -le $n ]

STEP 4.Repeat the following steps until the above condition becomes false

Sum=`expr $sum \* $x`

i=`expr $i + 1

STEP 5. Echo the value of sum as the value of x power n


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PROGRAM:

echo -n "enter ther value of x "

read xecho -n "enter the value of n:"read nsum=1i=1while [ $i -le $n ]do

sum=èxpr $sum \* $xì=èxpr $i + 1`doneecho "the value of $x power $n is $sum"

OUTPUT:

[balu@krishna-edu shell]$ sh power.sh

enter ther value of x 5

enter the value of n:2

the value of 5 power 2 is 25[balu@krishna-edu shell]$


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EXPERIMENT 12

AIM: To read 10 numbers from the user and to find the sum andaverage of the numbers .

REQUIREMENTS :


THEORY:



The shell executes the program CommandName and passes argument on the command line toit.

This is the program for reading 10 numbers from the user and finding the sum and average of

the numbers

ALGORITHM:

STEP 1. Initialize the values n to 1 and sum to 0

STEP 2. Repeat the following steps until the condition [ $n -le 10 ] becomes false

Read the number

Sum=èxpr $sum + $num`

Num=0N=èxpr $n + 1`

STEP 3. Calculate the average

avg=èxpr $sum / 10`

STEP 4. Echo the average of 10 numbers


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PROGRAM:

n=1sum=0while [ $n -le 10 ]do

echo -n "enter number $n"read numsum=èxpr $sum + $num`num=0;n=èxpr $n + 1`

doneavg=èxpr $sum / 10ècho "ther sum of 10 numbers is $sum"echo "the average of 10 numbers is $avg"

OUTPUT :

[balu@krishna-edu shell]$ sh sumarg.sh

enter number 1 is : 1










ther sum of 10 numbers is 55the average of 10 numbers is 5



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EXPERIMENT 13

AIM: To accept a number from the user and display the list of even numbersbelow that number

REQUIREMENTS :


THEORY:




This is the program for accepting numbers from the user and display the list of even numbersbelow that number

ALGORITHM:

STEP 1. Read the limit value

STEP 2. Initialize x to 2

STEP 3. Read the number

STEP 4. Repeat the following steps until the condition x

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PROGRAM:

echo -n "enter the limit:"x=2read numwhile [ $x -lt $num ]do

echo -n "$x \t"x=`expr $x + 2`

done

OUTPUT :

[balu@krishna-edu shell]$ sh evenbelow.sh

enter the limit:10

2 4 6 8



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EXPERIMENT 14

AIM: To find the count and sum of even and odd numbers separately

REQUIREMENTS :


THEORY:




This is the program for finding the count and sum of even and odd numbers separately

ALGORITHM

STEP 1. Read the limit n

STEP 2. Initialize the values of i ,j ,sumodd and sumeven as 0

STEP 3. calculate modulo division for each number

STEP 4. If the answer is 0 then add the number to sumeven

else add it to sumodd

STEP 5.Echo the values of i, j ,sumeven and sumodd


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PROGRAM:

echo -n "enter the limit"read necho -n "enter the number"

i=0j=0k=0sumodd=0sumeven=0while [ $i -lt $n ]do

read numif [ èxpr $num % 2` -eq 0 ]then

sumodd=èxpr $sumodd + $num`

k=èxpr $k + 1èlse

sumeven=èxpr $sumeven + $num`j=èxpr $j + 1`

fi

i=èxpr $i + 1`

OUTPUT :

[balu@krishna-edu shell]$ sh oddeven.sh

enter the limit5

enter the number1

2

3

4

5

total even number is 2

total odd numbers is 3

the sum of even numbers is 9

the sumof odd number is 6



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EXPERIMENT 15

AIM: To count the number of digits in an integer

REQUIREMENTS :


THEORY:

Shell is a user interface to the operating system built on the programming interface.

The shell executes commands of the form:CommandName [ argument]


This is the program for counting the number of digits in an integer

ALGORITHM:

STEP 1.Read the numberSTEP 2.Initialize digit to 0

STEP 3.Repeat the following steps until the condition num > 0 becomes false

a=èxpr $num % 10`

digit=èxpr $digit + 1`

num=èxpr $num / 10`

STEP 4.Echo the number of digits in the integer


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PROGRAM:

echo -n "Enter an interge:"read num

digit=0while [ $num -gt 0 ]do

a=èxpr $num % 10`digit=èxpr $digit + 1`num=èxpr $num / 10`

doneecho "the number of digits in the integer is $digit"

OUTPUT:

[balu@krishna-edu shell]$ sh count.sh

Enter an interge:12345

the number of digits in the integer is 5



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EXPERIMENT 16

AIM : To find the sum of digits in an integer

REQUIREMENTS :


THEORY:




This is the program for finding the sum of digits in an integer.

ALGORITHM:

STEP 1.Read the number

STEP 2.Initialize sum to 0

STEP 3.Repeat the following steps until the condition num > 0 becomes false

a=`expr $num % 10`

sum=`expr $sum + a`


STEP 4.Echo the sum of digits in the integer


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PROGRAM:

echo -n "enter an integer"read numsum=0

while [ $num -gt 0 ]do

a=èxpr $num % 10`sum=èxpr $sum + $a`num=èxpr $num / 10`

doneecho "the sum of digits in the integer is $sum"

OUTPUT :

[balu@krishna-edu shell]$ sh sumdigit.shenter an integer12345the sum of digits in the integer is 15[balu@krishna-edu shell]$


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EXPERIMENT 17

AIM: To print the multiplication table of a given number .

REQUIREMENTS :


THEORY:




This is the program for printing the multiplication table of the given number

ALOGRITHM :

STEP 1.Read the values of table number and limit as x and n

STEP 2.Initialize the value of I to 1

STEP 3.Repeat the following statements until the condition [ $I le $n ] becomes false

Sum=`expr $x \* $I`

Echo $x x $I = $sum

Increment the value of I


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PROGRAM:

echo -n "Enter the table number"read xecho -n "Enter the limit"read nechoecho "The multiplication table for $x is "echoi=1while [ $i -le $n ]do

sum=èxpr $x \* $iècho "$x x $i = $sum "

i=èxpr $i + 1`done

OUTPUT :

[balu@krishna-edu shell]$ sh multiply.sh

Enter the table number5

Enter the limit10

The multiplication table for 5 is

5 x 1 = 5

5 x 2 = 10

5 x 3 = 15

5 x 4 = 20

5 x 5 = 25

5 x 6 = 30

5 x 7 = 35

5 x 8 = 40

5 x 9 = 45

5 x 10 = 50



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EXPERIMENT 18

AIM: To print all the divisors of a given integer.

REQUIREMENTS :


THEORY:




This program for printing all the divisors of a given integer.

ALGORITHM:

STEP 1. Read the number

STEP 2. Initialize the value of I to 1

STEP 3.Repeat the following statements until the condition I

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PROGRAM :

echo -n "Enter the number"read numecho "The divisors are"

i=1while [ $i -le $num ]do

temp=èxpr $num % $iìf [ $temp -eq 0 ]then

echo -n " $i "fii=èxpr $i + 1`

done

OUTPUT :

[balu@krishna-edu shell]$ sh divisor.sh

Enter the number5

The divisors are

1 5 [balu@krishna-edu shell]$


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EXPERIMENT 19

AIM : To find the factorial of a give number.

REQUIREMENTS:

HARDWARE: P-IV Processor, 128 MB RAM, 40 GBSOFTWARE: OS: LINUX

THEORY:




This program is to find the factorial of a given number.

ALGORITHM:

STEP 1:Read the numberSTEP 2:Initialize res to 1 and i to 1

STEP 3:Repeat the following steps until the condition i

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PROGRAM

clearecho enter the numberread n

res=1i=1while [ $i -le $n ]dores=èxpr $res \* $iì=èxpr $i + 1`

doneecho factorial=$res

OUTPUT:

[krishna-edu balu]$ sh fact

enter the number

6

factorial=720

[krishna-edu balu]$


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EXPERIMENT 20

AIM: To generate fibonacci series.

REQUIREMENTS :


THEORY :



The shell executes the program CommandName and passes argument on the command line toit. Then the shell waits for the command to exit.

This program is to generate fibonacci series upto a given limit.

ALGORITHM:

STEP 1:Enter a number upto which the series has to be generated.

STEP 2:Initialize a=0,b=1,d=2.

STEP 3:Repeat the following steps until the condition d

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PROGRAM:

clearecho enter the no. of numbers in the seriesread n

a=0b=1d=2echo $aecho $bwhile [ $d -lt $n ]do

c=èxpr $a + $bècho $ca=$bb=$c

d=èxpr $d + 1`done

OUTPUT:

[krishna-edu balu]$ sh fibo

enter the no. of numbers in the series

50

1

1

2

3


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EXPERIMENT 21

AIM: To find the reverse of number.

REQUIREMENTS:


THEORY:




This program is to find the reverse of a number.

ALGORITHM:

STEP 1:Read the number.STEP 2:Initialize the value of reverse to 0.

STEP 3:Repeat the following steps until the condition n>0 becomes false

dig=èxpr $n % 10`

rev=èxpr $rev \* 10 + $dig`

n=èxpr $n / 10`

STEP 4:Echo Reverse


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EXPERIMENT 22

AIM: To find whether a given number is Armstrong number or not .

REQUIREMENTS:


THEORY:



The shell executes the program CommandName and passes argument on thecommand line to it. Then the shell waits for the command to exit. This program is to find thereverse of a number.

This program is to find whether a given number is Armstrong number or not .

ALGORITHM:

STEP 1.Read a numberSTEP 2.Initialize x to num and sum to 0

STEP 3.Repeat the following statements until the condition [ $num -gt 0 ]

becomes false

y=èxpr $num %10`

z=èxpr $y \* $y \* $y`

sum=èxpr $sum + $z`


STEP 4. If x is equal to sum then echo x as armstrong

Else echo x as not Armstrong


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PROGRAM

echo -n "Enter a number :"read numx=$numsum=0while [ $num -gt 0 ]do

y=èxpr $num % 10`z=èxpr $y \* $y \* $y`sum=èxpr $num + $z`num=èxpr $num / 10`

doneif [ $x -eq $sum ]then

echo "$x is an armstrong number"elseecho " $x is not an armstrong number"

fi

OUTPUT:

[balu@krishna-edu balu]$ sh amstrong.sh

enter a number :153153 is armstrong number

[balu@krishna-edu balu]$


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EXPERIMENT 23

AIM: To check whether a give number is prime or not.

REQUIREMENTS:


THEORY:




This program is to check whether a given number is prime or not.

ALGORITHM:

STEP 1:Read the value of n.

STEP 2:If the flag is equal to 0

then the echo $n is not a prime.

STEP 3:If the flag is equal to 1

Then the echo $n is prime.

STEP 4:End program.


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PROGRAM:

clearecho enter a numberread n

i=2flag=1m=1

j=èxpr $n / 2`while [ $i -le $j ]do

m=èxpr $n % $iìf [ $m -eq 0 ]then

flag=0break

fii=èxpr $i +1`

doneif [ $flag -eq 1 ]then

echo $n is primeelse

echo $n is not a primefi

OUTPUT:

[krishna-edu balu]$ sh prime

enter the number

79

79 is prime

[krishna-edu balu]$


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EXPERIMENT 24

AIM: To read numbers from the user from command line and to displayits sum using until statement.

REQUIREMENTS:


THEORY:



The shell executes the program CommandName and passes argument on thecommand line to it. Then the shell waits for the command to exit

This program is for reading a number from the command line and to display its sum usinguntil statement.

ALGORITHM:

STEP 1. If the count of number of command line arguments is 0

Then echo as invalid numbers

STEP 2. Initialize the values of sum to 0 and I to 1 and n to $#

STEP 3. Repeat the following statements until the condition becomes true

sum=`expr $sum + $1`

Increment the count of command line arguments

STEP 4. .If n!=0 then echo the value of sum.


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PROGRAM :

if [ $# -eq 0 ]then

echo " Invalid numbers"

fisum=0i=1n=$#until [ $# -eq 0 ]do

sum=`expr $sum + $i`shift

done

if [ $n -ne 0 ]

thenecho " The sum of $n numbers is $sum"

fi

OUTPUT :

[balu@krishna-edu shell]$ sh until_cmd_sum.sh 3 4

The sum of 2 numbers is 7



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EXPERIMENT 25

AIM:To read n numbers from the user from the command line and to display itssum using while statement

REQUIREMENTS:


THEORY:

Shell is a user interface to the operating system built on the programming interface. The shell

executes commands of the form:



This program is for reading numbers from the user from the command lineand to display its sum using while statement.

ALGORITHM:

STEP 1. If the count of the number of command line arguments is 0 then Echo as Invalid

Numbers

STEP 2. Initialize the values of sum to 0 and n to $#

STEP 3. While $# is not equal to zero repeat the following steps

sum=`expr $sum + $i`

Increment the value of $#

STEP 4. If n is not equal to 0 then echo the value of sum


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PROGRAM:

if [ $# -eq 0 ]then

echo "Invalid numbers"fisum=0i=1n=$#while [ $# -ne 0 ]do

sum=`expr $sum + $1`shift

doneif [ $n -ne 0 ]then

echo "The sum of $n numbers is $sum"fi

OUTPUT :

[balu@krishna-edu shell]$ sh while_cmd_sum.sh 4 5


balu@krishna-edu shell]$


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EXPERIMENT 26

AIM :-To read a numbers from the user from the command line and to display itssum using for statement

REQUIREMENTS:


THEORY:




This program is for reading a number from the user from the command line and to display itssum using for statement

ALGORITHM :

STEP 1. If the count of the number of command line arguments is 0 thenEcho as Invalid numbers

STEP 2. Initialize the values of sum to 0 and n to $#

STEP 3. for I in $*

sum=`expr $sum + $I`

Increment the value of $#

STEP 4. If n is not equal to 0 then echo the value ofsum


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PROGRAM:

if [ $# -eq 0 ]then

echo " Invalid numbers"fi

sum=0n=$#for i in $*do

sum=`expr $sum + $i`shift

done

if [ $n -ne 0 ]thenecho "The sum of $n numbers is $sum"

fi

OUTPUT :

[balu@krishna-edu shell]$ sh for_cmd_sum.sh 4 5




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EXPERIMENT 27

AIM: To copy a string into another string, character by character.

REQUIREMENTS :


THEORY:

Shell is a user interface to the operating system built on the programming interface.

The shell executes commands of the form:



This program is to copy one string to another

ALGORITHM:

STEP 1.Read the value of the string

STEP 2. Find the length of the string

STEP 3. Initialize the value of a to 1

STEP 4.Repeat the following statements until the condition a

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PROGRAM:

echo -n "Enter the string :"read str

len=ècho $str | wc -c à=1while [ $a -lt $len ]do

rev=ècho $str | cut -c$a ècho $reva=èxpr $a + 1`temp=ècho $temp$rev`

doneecho " The copied string is $temp"

[balu@krishna-edu balu]$ sh strcpy.shEnter the string :krishnavasaviThe copied string is krishna[balu@krishna-edu balu]$


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EXPERIMENT 28

AIM: To reverse the given string

REQUIREMENTS :


THEORY:




This program is for reversing the given string

ALGORITHM:

STEP 1.Read the value of string

STEP 2. Find the length of the stringSTEP 3.Initialize the value of a

STEP 4. Repeat the following steps until the condition length > 0 becomes false

rev=ècho $str | cut -c $len`

len=èxpr $len - 1`

temp=ècho $temp$rev`

STEP 5.Echo the reversed string


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PROGRAM :

echo -n "Enter the string "read strlen=ècho $str | wc -c`

while [ $len -gt 0 ]dorev=ècho $str | cut -c $len`len=èxpr $len - 1`temp=ècho $temp$rev`

done

echo "The reversed string is $temp"

[balu@krishna-edu shell]$ sh revers.shEnter the string abc

The reversed string is cba[balu@krishna-edu shell]$


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EXPERIMENT 29

AIM: To convert lowercase letters to uppercase .

REQUIREMENTS :


THEORY:




This program converts lowercase letters to uppercase

ALGORITHM:

STEP 1.Read the value of the string

STEP 2.Use tr command to translate from lower letters to upper letters

STEP 3.Echo the changed string


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PROGRAM:

echo -n "Enter a string "read strtemp=`echo $str | tr a-z A-Z`

echo " The case changed string is $temp"

OUTPUT:

[balu@krishna-edu shell]$ sh lower_upper.sh

Enter a string krishna

The case changed string is KRISHNA



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EXPERIMENT 30

AIM: To count the number of vowels in the string

REQUIREMENTS :


THEORY:




This program is for counting the number of vowels in the string

ALGORITHM:

STEP 1. Read the value of the string

STEP 2. count the characters of the string using wc command

STEP 3. caculate the length of the string by subtracting the new line character

STEP 4. Initialize the value of vowel as 0

STEP 5. Repeat the following steps until the condition len>0 becomes false

Cut each character of the string and store in temp

Check if the value of temp is any of the letters a,e,i,o,u

And increment the value of vowel

Decrement the value of length

STEP 6. Echo the number of vowels in the string


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PROGRAM:

echo -n "Enter th string "read strlen=1echo $str | wc -c`

len=èxpr $len - 1`vowel=0while [ $len -gt 0 ]do

temp=ècho $str | cut -c $lenìf [ $temp = athen

vowel=èxpr $vowel + 1èlif [ $temp = e ]then

vowel=èxpr $vowel + 1`

elif [ $temp = i ]then

vowel=èxpr $vowel + 1èlif [ $temp = o ]then

vowel=èxpr $vowel + 1èlif

[ $temp = u ]then

vowel=èxpr $vowel + 1`filen=èxpr $len - 1`

doneecho " the number of vowels in the string $str is $vowel"

OUTPUT:

[balu@krishna-edu shell]$ sh vowel.sh

Enter th string aeiou

the number of vowels in the string aeiou is 5



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EXPERIMENT 31

AIM: To replace a particular character in the string

REQUIREMENTS :


THEORY:




This program for replacing a particular character in the string

ALGORITHM:

STEP 1.Read the value of string

STEP 2.Read the character to be changed

STEP 3.Read the character to be replaced

STEP 4.find the length of the string

STEP 5.Initialize the value of count to 0 and I to 1

STEP 6.Repeat the following statements until the condition I

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PROGRAM:

echo -n "Enter the string :"read strecho -n "Enter the character to be counted:"

read clen=ècho $str | wc -c`len=èxpr $len - 1`count=0while [ $len -gt 0 ]do

temp=ècho $str | cut -c $lenìf [ $temp = $c ]then

count=èxpr $count + 1`fi

len=èxpr $len - 1`doneecho "The number of occurrence of the character $c in the string $str is $count"

OUTPUT:

[balu@krishna-edu last]$ sh count_char.sh

Enter the string :krishna

Enter the character to be counted:v

The number of occurrence of the character v in the string krishna is 2

[balu@krishna-edu last]$

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OS Lab Manual 06 07