extern uschar *spool_fname(const uschar *, uschar *, uschar *, uschar *);
extern uschar *spool_sname(const uschar *, uschar *);
extern int spool_open_datafile(uschar *);
extern uschar *spool_fname(const uschar *, uschar *, uschar *, uschar *);
extern uschar *spool_sname(const uschar *, uschar *);
extern int spool_open_datafile(uschar *);