1 typedef int (*cmp_t)(void*,void*); /* for function pointer casts */ 2 3 extern void register_sort_function (int dir, cmp_t func); 4 extern void reset_sort_options(void); 5 extern int mult_lvl_cmp(void* a, void* b); 6 extern const char *parse_sort_opt(const char* opt); 7 extern const char *parse_long_sort(const char* opt); 8 9