"How does \e represent the escape key? Where do you find that?"

If you'd bothered to run the short piece of code ++haukex provided, and pressed the escape key, you would have seen:

Press a key
$VAR1 = "\e";
Escape pressed
[download]

Had you pressed the enter key:

Press a key
$VAR1 = "\n";
[download]

I suggest you also read ++haj's post for additional information and alternative methods to use.