Empty a stream's buffer to its host environment.

This function is compatible with the following targets:

ANSI

BeOS

EMB/RTOS

Mac OS

Palm OS

Win32

#include <stdio.h>

int fflush(FILE *stream);

Parameters for this facility are:

stream

FILE *

A pointer to a FILE stream

The fflush() function empties stream's buffer to the file associated with stream. If the stream points to an output stream or an update stream in which the most recent operation was not input, the fflush function causes any unwritten data for that stream to be delivered to the host environment to be written to the file; otherwise the behavior is undefined.

The function fflush() returns EOF if a write error occurs, otherwise it returns zero.

"setvbuf"

#include <stdio.h>
#include <stdlib.h>

int main(void)
{
	FILE *f;
	int count;

	// create a new file for output
	if (( f = fopen("foofoo", "w")) == NULL) {
		printf("Can't open file.\n");
		exit(1);
	}
	for (count = 0; count < 100; count++) {
		fprintf(f, "%5d\n", count);
		if (count % 10) 
			fflush(f);		// flush buffer every 10 numbers
	}
	fclose(f);

	return 0;
}