***/
int copy_file(const char *from, const char *to, int flags, mode_t mode);
-int copy_tree(const char *from, const char *to);
-int copy_bytes(int fdf, int fdt);
+int copy_tree(const char *from, const char *to, bool merge);
+int copy_bytes(int fdf, int fdt, off_t max_bytes);