set-auto-coding

set-auto-coding is a compiled Lisp function in `mule.el'.

(set-auto-coding FILENAME SIZE)

Return coding system for a file FILENAME of which SIZE bytes follow point.
See `find-auto-coding' for how the coding system is found.
Return nil if an invalid coding system is found.

The variable `set-auto-coding-function' (which see) is set to this
function by default.