ref: 56278d4ed0aeb9e8896082e9aefdded9e9228a02
dir: /src/libc/stdio/fflush.c/
#include <stdio.h>
#include "../libc.h"
#undef fflush
int
fflush(FILE *fp)
{
	int err;
	if (fp)
		return _flsbuf(fp);
	err = 0;
	for (fp = __iob; fp < &__iob[FOPEN_MAX]; ++fp) {
		if ((fp->flags & _IOWRITE) == 0 && _flsbuf(fp))
			err = EOF;
	}
	return err;
}