#include <fontconfig/fontconfig.h>
FcFontSet * FcFontSetList (FcConfig *config, FcFontSet **sets, intnsets, FcPattern *pattern, FcObjectSet *object_set);
Selects fonts matching pattern from sets, creates patterns from those fonts containing only the objects in object_set and returns the set of unique such patterns. If config is NULL, the default configuration is checked to be up to date, and used.