#define SET_CLOSE_ON_EXEC(fd) (fcntl ((fd), F_SETFD, FD_CLOEXEC))
#define SET_OPEN_ON_EXEC(fd) (fcntl ((fd), F_SETFD, FD_NCLOEXEC))
+/* How to open a file in non-blocking mode, the Posix.1 way. */
+#if !defined (O_NONBLOCK)
+# if defined (O_NDELAY)
+# define O_NONBLOCK O_NDELAY
+# else
+# define O_NONBLOCK 0
+# endif
+#endif
+
#endif /* ! _FILECNTL_H_ */