#if defined(_POSIX_SOURCE) || defined(_POSIX_C_SOURCE) \
|| defined(_XOPEN_SOURCE) || defined(_GNU_SOURCE)
+FILE *fmemopen(void *, size_t, const char *);
FILE *open_memstream(char **, size_t *);
FILE *fdopen(int, const char *);
FILE *popen(const char *, const char *);
void setlinebuf(FILE *);
void setbuffer(FILE *, char *, size_t);
int fpurge(FILE *);
+int fgetc_unlocked(FILE *);
+int fputc_unlocked(int, FILE *);
+char *fgets_unlocked(char *, int, FILE *);
+int fputs_unlocked(const char *, FILE *);
#endif
#ifdef __cplusplus