Create a shell scripts that prints the menu and executes the following:

$1.$ Add email

$2.$ Get valid emails

$3.$ Exit

For $1,$ take an email as input from user and append it to the file emails.txt in a new line $($if

file doesn't exist, create it$)$

For $2,$ parses emails.txt and looks for valid email addresses and prints them in a separate

file. Criteria for valid email address: @$.$com

Create the file called valid$\_$emails.txt and output all the valid emails in it$.$