extern int enlist (struct list *the_list, const char *str);
extern int enlist_unique (struct list *the_list, const char *str, int num_significant_chars);
extern int enlist_unique_header (struct list *the_list, const char *name, const char *value);
extern int enlist (struct list *the_list, const char *str);
extern int enlist_unique (struct list *the_list, const char *str, int num_significant_chars);
extern int enlist_unique_header (struct list *the_list, const char *name, const char *value);