/* Constants */
-#ifndef SHUT_RDWR
+#if defined(HAVE_DECL_SHUT_RD) && HAVE_DECL_SHUT_RD == 0
enum
{
SHUT_RD = 0, /* No more receptions. */
#endif
#endif
-#ifndef O_NONBLOCK /* Non Blocking Open */
-# define O_NONBLOCK 00004
+#if defined(HAVE_DECL_O_NONBLOCK) && HAVE_DECL_O_NONBLOCK == 0
+# define O_NONBLOCK 00004 /* Non Blocking Open */
#endif
#ifndef S_ISDIR