Pathname identifying location of buffer .
An external format spec.
A buffer whose contents are examined.
Length (an integer) up to which buffer should be examined.
The result of reading the value returned from the encoding or external-format option as a Lisp expression in the keyword package.
Looks in the file options (EMACS-style -*- line) for an option called encoding or external-format , with value value . If found, read value as a Lisp expression in the keyword package and return the result.