Ask the user to confirm an action.

confirm_action

#!/bin/bash
#
# This function asks the user to confirm an action with No used as a default
# answer.

confirm()
{
    while true; do
        read -p "$1" RES
        case "$RES" in
            Y|y) return 0 ;;
            N|n|"") return 1 ;;
        esac
    done
}

# Example usage.
if confirm "Do you want to do something? [y/N]: "; then
    # Yes, do that.
else
    # No, don't do that.
fi