学步园

In this post I will be discussing the Scripts from
the Mathematical and Number point
of view. Although I have posted a more complex script (Simple Calculator)
in the previous post, but on a user part it was difficult to understand and hence I thought to make you people learn the other useful side of learning in small packets.

Prior to this article, three article of Shell Scripting Series are published and they are:

1. Understand
   Linux Shell and Basic Shell Scripting – Part I
2. 5
   Shell Scripts to Learn Shell Programming – Part II
3. Sailing
   Through The World of Linux BASH Scripting – Part III

Let’s start the further learning process with some new exciting scripts, start withMathematics scripts:

Script 1: Additions

Create a file “Addition.sh” and chmod
755 to the script as described in previous post and run it.

#!/bin/bash
echo “Enter the First Number: ” 
read a 
ter the Second Number: ” 
read b 
echo “E
n
x=$(expr "$a" + "$b") 
echo $a + $b = $x

Sample Output

[root@tecmint ~]# vi Additions.sh
[root@tecmint ~]# chmod 755 Additions.sh
[root@tecmint ~]# ./Additions.sh

nter the Second Number: ” 
“Enter the First Number: ” 
12 
“
E13 
13 = 25
12 +
 

Download
Additions.sh

Script 2: Substraction

#!/bin/bash
echo “Enter the First Number: ” 
read a 
ter the Second Number: ” 
read b 
echo “E
n
x=$(($a - $b)) 
echo $a - $b = $x

Note: Here we replaced the expr and
let the mathematical calculation be performed in shell.

Sample Output

[root@tecmint ~]# vi Substraction.sh
[root@tecmint ~]# chmod 755 Substraction.sh
[root@tecmint ~]# ./Substraction.sh

r the Second Number: ” 
20 
“Enter the First Number: ” 
13 
“Ent
e
 - 20 = -7
1
3

Download
Substraction.sh

Script 3: Multiplication

So far you would be enjoying a lot, learning scripts in such an easy way, so the next in chronological order is Multiplication.

#!/bin/bash
echo “Enter the First Number: ” 
read a 
ter the Second Number: ” 
read b 
echo “E
n
ho "$a * $b = $(expr $a \* $b)"
e
c

Note: Yup! Here we didn’t put the value of multiplication in a variable but performed it directly in output statement.

Sample Output

[root@tecmint ~]# vi Multiplication.sh
[root@tecmint ~]# chmod 755 Multiplication.sh
[root@tecmint ~]# ./Multiplication.sh

the Second Number: ” 
11 
1
“Enter the First Number: ” 
11 
“Enter
 1 * 11 = 121

Download
Multiplication.sh

Script 4: Division

Right! Next is Division, and again it is a very simple script. Check it Yourself.

#!/bin/bash
echo “Enter the First Number: ” 
read a 
ter the Second Number: ” 
read b 
echo “E
n
ho "$a / $b = $(expr $a / $b)"
e
c

Sample Output

[root@tecmint ~]# vi Division.sh
[root@tecmint ~]# chmod 755 Division.sh
[root@tecmint ~]# ./Division.sh

Enter the Second Number: ” 
“Enter the First Number: ” 
12 

“
3 
3 = 4
12 /
 

Download
Division.sh

Script 5: Table

Fine! What after these basic mathematical operation. Lets write a script that prints table of any number.

#!/bin/bash
echo “Enter The Number upto which you want to Print Table: ” 
read n 
i=1 
while [ $i -ne 10 ] 
do 
i=$(expr $i + 1) 
table=$(expr $i \* $n) 
echo $table 
done

Sample Output

[root@tecmint ~]# vi Table.sh
[root@tecmint ~]# chmod 755 Table.sh
[root@tecmint ~]# ./Table.sh

ou want to Print Table: ” 
29 
58 
87 
116 
145 
174 
20
“Enter The Number upto which 
y3 
232 
261 
290

Download
Table.sh

Script 6: EvenOdd

We as a child always have carried out calculation to find if the number is odd or even. Won’t it be a good idea to implement it in script.

#!/bin/bash
echo "Enter The Number" 
read n 
pr $n % 2) 
if [ $n
num=$(e
xum -eq 0 ] 
then 
ber" 
else 
echo "is a O
echo "is a Even Nu
mdd Number" 
fi

Sample Output

[root@tecmint ~]# vi EvenOdd.sh
[root@tecmint ~]# chmod 755 EvenOdd.sh
[root@tecmint ~]# ./EvenOdd.sh

Number
Enter The Number 
12 
is a Even
 

[root@tecmint ~]# ./EvenOdd.sh

Enter The Number 
11 
is a Odd Number

Download
EvenOdd.sh

Script 7: Factorial

Next is to find the Factorial.

#!/bin/bash 
echo "Enter The Number" 
read a 
fact=1 
 ] 
do 
fact=$(expr
while [ $a -ne 
0 $fact \* $a) 
a=$(expr $a - 1) 
done 
fact
echo 
$

Sample Output

[root@tecmint ~]# vi Factorial.sh
[root@tecmint ~]# chmod 755 Factorial.sh
[root@tecmint ~]# ./Factorial.sh

Enter The Number 
12 
479001600

You may now relax with a feeling that calculating 12*11*10*9*7*7*6*5*4*3*2*1 would be more difficult than a simple script as produced
above. Think of the situation where you require to find 99! or something like that. Sure! This script will be very much handy in that
situation.

Download
Factorial.sh

Script 8: Armstrong

Armstrong Number! Ohhh You forget what an Armstrong
Number is. Well an Armstrong number of three digits is an integer such that the sum of the cubes of its digits is equal to the number itself. For example, 371 is
an Armstrong number since 3**3 + 7**3 + 1**3 = 371.

#!/bin/bash 
echo "Enter A Number" 
read n 
arm=0 
[ $n -ne
temp=$n 
while
  0 ] 
do 
 % 10) 
arm=$(expr
r=$(expr $
n $arm + $r \* $r \* $r) 
cho $arm 
if [ $ar
n=$(expr $n / 10) 
done 

em -eq $temp ] 
then 
echo "Armstrong" 
else 
echo "Not Armstrong" 
fi

Sample Output

[root@tecmint ~]# vi Armstrong.sh
[root@tecmint ~]# chmod 755 Armstrong.sh
[root@tecmint ~]# ./Armstrong.sh

g
Enter A Number 
371 
371 
Armstro
n

[root@tecmint ~]# ./Armstrong.sh

Enter A Number 
123 
36 
Not Armstrong

Download
Armstrong.sh

Script 9: Prime

The last script is to distinguish whether a number is prime or not.

#!/bin/bash 
echo “Enter Any Number”
read n
i=1
c=1
$n ]
do
i=$(expr $i
while [ $i -le
  + 1)
r=$(expr $n % $i)
expr $c + 1)
fi
if [ $r -eq 0 ]
then
c=$
(
done
if [ $c -eq 2 ]
then
echo “Prime”
else
echo “Not Prime”
fi

Sample Output

[root@tecmint ~]# vi Prime.sh
[root@tecmint ~]# chmod 755 Prime.sh
[root@tecmint ~]# ./Prime.sh

Prime”
“Enter Any Number” 
12 

“Not
 

Download
Prime.sh

That’s all for now. In our very next article we will be covering other mathematical programs in the shell Scripting programming language. Don’t forget to mention your views regarding article in the Comment section. Like and share
us and help us spread. Come Visitingtecmint.com for News and
articles relating to FOSS. Till then Stay tuned.