-char* strnlwr (char* start_l ,int n);
-char* strnupr (char* start_l, int n);
+char *strnlwr (char *start, int n);
+char *strnupr (char *start, int n);
+
+#if ! HAVE_MEMMEM /* GNU extension. */
+void *memmem (void const *haystack, int haystack_len,
+ void const *needle, int needle_len);
+#endif /* HAVE_MEMMEM */
+
+#if ! HAVE_MEMRCHR
+unsigned char *memrchr (unsigned char const *p, int n, char c);
+#endif
+
+#if ! HAVE_MEMREV
+unsigned char *memrev (unsigned char *byte, int length_i);
+#endif