-extern int lf_check_file(int, uschar *, int, int, uid_t *, gid_t *, char *,
- uschar **);
-extern uschar *lf_quote(uschar *, uschar *, int, uschar *, int *, int *);
+extern int lf_check_file(int, const uschar *, int, int, uid_t *, gid_t *,
+ const char *, uschar **);
+extern gstring *lf_quote(uschar *, uschar *, int, gstring *);
+extern int lf_sqlperform(const uschar *, const uschar *, const uschar *,
+ const uschar *, uschar **,
+ uschar **, uint *, const uschar *,
+ int(*)(const uschar *, uschar *, uschar **,
+ uschar **, BOOL *, uint *, const uschar *));