+static int
+_nc_vdisable(void)
+{
+ int value = -1;
+#if defined(_POSIX_VDISABLE) && HAVE_UNISTD_H
+ value = _POSIX_VDISABLE;
+#endif
+#if defined(_PC_VDISABLE)
+ if (value == -1) {
+ value = fpathconf(0, _PC_VDISABLE);
+ if (value == -1) {
+ value = 0377;
+ }
+ }
+#elif defined(VDISABLE)
+ if (value == -1)
+ value = VDISABLE;
+#endif
+ return value;
+}