+void setlinebuf(FILE *);
+void setbuffer(FILE *, char *, size_t);
+int fgetc_unlocked(FILE *);
+int fputc_unlocked(int, FILE *);
+int fflush_unlocked(FILE *);
+size_t fread_unlocked(void *, size_t, size_t, FILE *);
+size_t fwrite_unlocked(const void *, size_t, size_t, FILE *);
+void clearerr_unlocked(FILE *);
+int feof_unlocked(FILE *);
+int ferror_unlocked(FILE *);
+int fileno_unlocked(FILE *);
+#endif
+
+#ifdef _GNU_SOURCE