#ifdef HAS_SETLINEBUF
#define PerlIO_setlinebuf(f) PerlSIO_setlinebuf(f);
#else
-#define PerlIO_setlinebuf(f) PerlSIO_setvbuf(f, Nullch, _IOLBF, 0);
+#define PerlIO_setlinebuf(f) PerlSIO_setvbuf(f, NULL, _IOLBF, 0);
#endif
/* Now our interface to Configure's FILE_xxx macros */