Question

Linux

2)   Write a bash script which when executed, expects two integers, say n1 and n2. If the first argument, n1, is greater than the second argument, n2, the script calls a function (written within the script) and passes to the function n1 and n2 to compute the sum from n1 to n2. This function returns the sum which the script prints. If n1 is not greater than n2, the script calls the same function and passes the n1 and n2 to compute the sum from n2 to n1, and the script prints the sum returned by the function. Below is the expected dialog or interface

    $ ./script9
    ERROR: The script expects two arguments.

    $ ./script9 3 6
    The sum from 3 to 6 is 18.

    $ ./script9 3 3
    The sum from 3 to 3 is 3.

    $ ./script9 6 3
    The sum from 3 to 6 is 18.

Answer 1

Program:

#!/bin/bash

airth_sum(){
n1=$1
n2=$2
if [ "$n1" -gt "$n2" ];then
sum=$((n1*(n1+1)/2-(n2-1)*n2/2))
elif [ "$n1" -lt "$n2" ];then
sum=$((n2*(n2+1)/2-(n1-1)*n1/2))
else
sum=$n1
fi
echo "$sum" #Whatever is printed is stored in sum_calc variable, by default shell return will return the status of execution
}

#Condition to evaluate the no of arguments
if [ "$#" -ne 2 ];
then
echo "ERROR: The script expects two arguments."
exit 1;
fi
n1=$1
n2=$2
sum_calc=$(airth_sum $n1 $n2)
if [ "$n1" -lt "$n2" ];then
large_no=$n2
small_no=$n1
else
large_no=$n1
small_no=$n2
fi
echo "The sum from $small_no to $large_no is $sum_calc"

Output: