Double-quoted string backslash escape codes
\n = Newline or unix line feed. Same as \012 (oct)
\r = Return or \015
\t = tab
\f = formfeed
\b = backspace
\a = bell
\e = escape (ASCII escape character)
\0** = any octal ASCII value. the first 0 is for oct.
\x** = any hex ASCII value. the first x is for hex.
\c* = any control character. same as holding control key and pressing a key. c for control.
\\ = backslash
\" = double quote
\l = make next letter lowercase
\L = make letters lowercase until \E
\u = make next letter uppercase
\U = make letters uppercase until \E
\Q = quote non-word characters by adding a backslash until \E
\E = Terminate \L, \U, or \Q