-#if defined(DIRENT) || defined(_POSIX_VERSION)
-#include <dirent.h>
-#define NLENGTH(direct) (strlen((direct)->d_name))
-#else /* not (DIRENT or _POSIX_VERSION) */
-#define dirent direct
-#define NLENGTH(direct) ((direct)->d_namlen)
-#ifdef SYSNDIR
-#include <sys/ndir.h>
-#endif /* SYSNDIR */
-#ifdef SYSDIR
-#include <sys/dir.h>
-#endif /* SYSDIR */
-#ifdef NDIR
-#include <ndir.h>
-#endif /* NDIR */
-#endif /* DIRENT or _POSIX_VERSION */
-
-#ifdef VOID_CLOSEDIR
+#ifdef HAVE_DIRENT_H
+# include <dirent.h>
+# define NLENGTH(direct) (strlen((direct)->d_name))
+#else /* not HAVE_DIRENT_H */
+# define dirent direct
+# define NLENGTH(direct) ((direct)->d_namlen)
+# ifdef HAVE_SYS_NDIR_H
+# include <sys/ndir.h>
+# endif /* HAVE_SYS_NDIR_H */
+# ifdef HAVE_SYS_DIR_H
+# include <sys/dir.h>
+# endif /* HAVE_SYS_DIR_H */
+# ifdef HAVE_NDIR_H
+# include <ndir.h>
+# endif /* HAVE_NDIR_H */
+#endif /* HAVE_DIRENT_H */
+
+#ifdef CLOSEDIR_VOID