some operations (removing an effect, controlling the playback).
This if field must be set to -1 by the user in order to tell the driver to
allocate a new effect.
-See <linux/input.h> for a description of the ff_effect stuct. You should also
+See <linux/input.h> for a description of the ff_effect struct. You should also
find help in a few sketches, contained in files shape.fig and interactive.fig.
You need xfig to visualize these files.