Representing Unprintable Characters
Problem
You need to make reference to a control character, a strange UTF-8 character, or some other character that's not on your keyboard.
Solution
Ruby gives you a number of escaping mechanisms to refer to unprintable characters. By using one of these mechanisms within a double-quoted string, you can put any binary character into the string.
You can reference any any binary character by encoding its octal representation into the format "