Notes

#!/bin/bash

function area { #creating a function

((area=width*height)) #formula of area
echo "area of rectangle in sq cm is : $area"
sqmetre=$(echo "scale=4; $area/2.54" | bc -l) #convert sq cm into sq metre
echo "area of rectangle in sq m is : $sqmetre"
sqinch=$(echo "scale=4; $area /10000" | bc -l) #convert sq cm into sq inch
echo "area of rectangle in sq inch is : $sqinch"

continueAgain

}

function continueAgain {

echo "continue???"
read i

if [[ ($i != "Y") ]] #if i = Y the run the program again

then
exit


fi


}


i="Y"

while [ $i = "Y" ]
do

read -p "Enter the width of rectangle in cm: " width #enter the rectangle's width
read -p "Enter the height of rectangle in cm: " height #enter the rectangle's height

if [[ ($width =~ ^[0-9]+$ ) && ($height =~ ^[0-9]+$) ]] #checking thevalidity of the inputted numbers
then
area #calling a function
elif [[ ($width =~ ^[-+]?[0-9]*.?[0-9]+$) && ($height =~ ^[-+]?[0-9]*.?[0-9]+$) ]]
then
echo "Do not input floating point number"

continueAgain



else
echo "Invalid Input"
continueAgain
fi



done