+#elif defined __QNX__ /* QNX */
+ if (fp->_Mode & 0x400 /* _MLBF */)
+ return _IOLBF;
+ if (fp->_Mode & 0x800 /* _MNBF */)
+ return _IONBF;
+ return _IOFBF;
+#elif defined __MINT__ /* Atari FreeMiNT */
+ if (fp->__linebuf)
+ return _IOLBF;
+ return (fp->__bufsize > 0 ? _IOFBF : _IONBF);
+#elif HAVE___FLBF && HAVE___FBUFSIZE /* musl libc */
+ if (__flbf (fp))
+ return _IOLBF;
+ return (__fbufsize (fp) > 0 ? _IOFBF : _IONBF);
+#elif defined EPLAN9 /* Plan9 */
+ if (fp->flags & 2 /* LINEBUF */)
+ return _IOLBF;
+ if (fp->bufl)
+ return _IOFBF;
+ return _IONBF;