The init file contains one or more Lisp function call
expressions. Each consists of a function name followed by
arguments, all surrounded by parentheses. For example,
fill-column 60) represents a call to the function
setq which is
used to set the variable
fill-column (see Filling) to 60.
The second argument to
setq is an expression for the new value
of the variable. This can be a constant, a variable, or a function call
expression. In the init file, constants are used most of the time.
They can be:
Integers are written in decimal, with an optional initial minus sign.
If a sequence of digits is followed by a period and another sequence of digits, it is interpreted as a floating point number.
The number prefixes ‘#b’, ‘#o’, and ‘#x’ are supported to represent numbers in binary, octal, and hexadecimal notation (or radix).
Lisp string syntax is the same as C string syntax with a few extra features. Use a double-quote character to begin and end a string constant.
Newlines and special characters may be present literally in strings. They can also be represented as backslash sequences: ‘\n’ for newline, ‘\b’ for backspace, ‘\r’ for return, ‘\t’ for tab, ‘\f’ for formfeed (control-l), ‘\e’ for escape, ‘\\’ for a backslash, ‘\"’ for a double-quote, or ‘\ooo’ for the character whose octal code is ooo. Backslash and double-quote are the only characters for which backslash sequences are mandatory.
You can use ‘\C-’ as a prefix for a control character, as in ‘\C-s’ for ASCII Control-S, and ‘\M-’ as a prefix for a Meta character, as in ‘\M-a’ for Meta-A or ‘\M-\C-a’ for Control-Meta-A.
Lisp character constant syntax consists of a ‘?’ followed by
either a character or an escape sequence starting with ‘\’.
?\). Note that
strings and characters are not interchangeable in Lisp; some contexts
require one and some contexts require the other.
t stands for ‘true’.
nil stands for ‘false’.
Write a single-quote (’) followed by the Lisp object you want.