The Emacs manual describes how you can customize certain variables on a per-file basis by including a file local variable block at the end of the file (see Local Variables in Files).
So far, you've only seen a functional interface for setting styles in CC Mode, and this can't be used here. CC Mode fills the gap by providing two variables for use in a file's local variable list. Don't use them anywhere else! These allow you to customize the style on a per-file basis:
Set this variable to a style name string in the Local Variables list. From now on, when you visit the file, CC Mode will automatically set the file's style to this one using
c-set-style.
Set this variable (in the Local Variables list) to an association list of the same format as
c-offsets-alist. From now on, when you visit the file, CC Mode will automatically institute these offsets usingc-set-offset.
Note that file style settings (i.e. c-file-style)
are applied before file offset settings (i.e.
c-file-offsets)1.
If you set any variable by the file local variables mechanism,
that setting takes priority over all other settings, even those
in your mode hooks (see CC
Hooks). Any individual setting of a variable will override
one made through c-file-style or
c-file-offsets.
[1] Also, if either of these are set in a
file's local variable section, all the style variable values
are made local to that buffer, even if
c-style-variables-are-local-p is nil.
Since this variable is virtually always non-nil
anyhow, you're unlikely to notice this effect.