fflush

fflush - flush a stream

#include <stdio.h> I int fflush(FILE * stream );

The function R fflush () forces a write of all user-space buffered data for the given output or update stream via the stream's underlying write function. The open status of the stream is unaffected.

If the stream argument is NULL, R fflush () flushes all open output streams.

For a non-locking counterpart, see unlocked_stdio(3).

Upon successful completion 0 is returned. Otherwise, EOF is returned and the global variable errno is set to indicate the error.

EBADF

The function R fflush () may also fail and set errno for any of the errors specified for the routine write(2).

C89, C99.

Note that R fflush () only flushes the user space buffers provided by the C library. To ensure that the data is physically stored on disk the kernel buffers must be flushed too, for example, with sync(2) or fsync(2).

fsync(2), sync(2), write(2), fclose(3), fopen(3), setbuf(3), unlocked_stdio(3)