/*
 * pANS stdio -- fflush
 */
#include "iolib.h"
int fflush(FILE *f){
	int error, cnt;
	if(f==NULL){
		error=0;
		for(f=_IO_stream;f!=&_IO_stream[FOPEN_MAX];f++)
			if(f->state==WR && fflush(f)==EOF)
				error=EOF;
		return error;
	}
	if(f->flags&STRING) return EOF;
	switch(f->state){
	default:	/* OPEN RDWR EOF RD */
		return 0;
	case CLOSED:
	case ERR:
		return EOF;
	case WR:
		cnt=(f->flags&LINEBUF?f->lp:f->wp)-f->buf;
		if(cnt && write(f->fd, f->buf, cnt)!=cnt){
			f->state=ERR;
			return EOF;
		}
		f->rp=f->wp=f->buf;
		f->state=RDWR;
		return 0;
	}
}