setsid - run a program in a new session

syntax
$ setsid [options] program [arguments]

$ cat add.sh

#!/bin/bash
# Take input from user and calculate sum.
read -p "Enter first number: " num1
read -p "Enter second number: " num2
sum=$(( $num1 + $num2 ))
echo "Sum is: $sum"  

:x

To execute shell script in a new session.
$ sudo setsid ./add.sh

To set the controlling terminal to the current one.

$ sudo setsid -c ./add.sh

To wait for the execution of the program to  end,  and  return  the
exit value of this program as the return value of setsid

$ setsid -w ./add.sh

regards,

T.Dhanasekar