+#if defined(_GNU_SOURCE) || defined(_BSD_SOURCE) || defined(_XOPEN_SOURCE)
+
+#ifdef PAGESIZE
+#define PAGE_SIZE PAGESIZE
+#endif
+#define NZERO 20
+#define NL_LANGMAX 32
+
+#endif
+
+#if defined(_GNU_SOURCE) || defined(_BSD_SOURCE) \
+ || (defined(_XOPEN_SOURCE) && _XOPEN_SOURCE+0 < 700)
+
+#define NL_NMAX 16
+
+#endif
+