Accept newline in bash script

Question

I have the following script that continuously accepts input from the user until he/she enters some form of y* or Y* .

while true; do
read -p "Are you ready? " yn
case $yn in
    [Yy]* ) break;;
    [Nn]* ) ;;
    * ) echo "Please answer yes or no.";;
esac
done

However, I would like to break out of the while loop when the user simply presses enter . I tried using \\n , \\r , and \\r\\n but these don't seem to be the right patterns.

I am using Cygwin if that makes a difference (though I would also like to know the answer for a Linux distribution like Ubuntu).

Answer 1

Because read strips the newline, you'll have to match an empty string, "" :

#!/bin/bash
while true; do
    read -p "Are you ready? " yn
    case "$yn" in
        [Yy]*|"") break;;
        [Nn]*) ;;
        *) echo "Please answer yes or no.";;
    esac
done

Depending on your application logic, you can (obviously) make that a separate case branch, like: "") break;; .