fflush(3) Library Functions Manual fflush(3) fflush - (libc -lc) #include int fflush(FILE *_Nullable stream); fflush() stream . ( ) fflush() . . stream (NULL) fflush() . unlocked_stdio(3). 0. EOF errno . EBADF stream . fflush() errno write(2). attributes(7). +------------+------------------------------------+--------------------+ || | | +------------+------------------------------------+--------------------+ |fflush() | | MT-Safe | +------------+------------------------------------+--------------------+ C11, POSIX.1-2008. C89 POSIX.1-2001 POSIX.1-2008. POSIX.1-2001 POSIX.1-2008. fflush() C. sync(2) fsync(2). fsync(2) sync(2) write(2) fclose(3) fileno(3) fopen(3) fpurge(3) setbuf(3) unlocked_stdio(3) 3 . . : . 6.18 17 2025 fflush(3)