extern BOOL string_vformat(uschar *, int, const char *, va_list);
extern int strcmpic(const uschar *, const uschar *);
extern int strncmpic(const uschar *, const uschar *, int);
extern BOOL string_vformat(uschar *, int, const char *, va_list);
extern int strcmpic(const uschar *, const uschar *);
extern int strncmpic(const uschar *, const uschar *, int);