#include	"lib9.h"#include	<bio.h> enum{	MAXBUFS	= 20}; static	Biobuf*	wbufs[MAXBUFS];static	int		atexitflag; staticvoidbatexit(void){	Biobuf *bp;	int i; 	for(i=0; i<nelem(wbufs); i++) {		bp = wbufs[i];		if(bp != 0) {			wbufs[i] = 0;			Bflush(bp);		}	}} staticvoiddeinstall(Biobuf *bp){	int i; 	for(i=0; i<nelem(wbufs); i++)		if(wbufs[i] == bp)			wbufs[i] = 0;} staticvoidinstall(Biobuf *bp){	int i; 	deinstall(bp);	for(i=0; i<nelem(wbufs); i++)		if(wbufs[i] == 0) {			wbufs[i] = bp;			break;		}	if(atexitflag == 0) {		atexitflag = 1;		atexit(batexit);	}} intBinits(Biobuf *bp, int f, int mode, uchar *p, int size){ 	p += Bungetsize;	/* make room for Bungets */	size -= Bungetsize; 	switch(mode) {	default:		fprint(2, "Bopen: unknown mode %d\n", mode);		return Beof; 	case OREAD:		bp->state = Bractive;		bp->ocount = 0;		break; 	case OWRITE:		install(bp);		bp->state = Bwactive;		bp->ocount = -size;		break;	}	bp->bbuf = p;	bp->ebuf = p+size;	bp->bsize = size;	bp->icount = 0;	bp->gbuf = bp->ebuf;	bp->fid = f;	bp->flag = 0;	bp->rdline = 0;	bp->offset = 0;	bp->runesize = 0;	return 0;}  intBinit(Biobuf *bp, int f, int mode){	return Binits(bp, f, mode, bp->b, sizeof(bp->b));} Biobuf*Bopen(char *name, int mode){	Biobuf *bp;	int f; 	switch(mode) {	default:		fprint(2, "Bopen: unknown mode %d\n", mode);		return 0; 	case OREAD:		f = open(name, OREAD);		if(f < 0)			return 0;		break; 	case OWRITE:		f = create(name, OWRITE, 0666);		if(f < 0)			return 0;	}	bp = malloc(sizeof(Biobuf));	if(bp == nil)		return 0;	Binits(bp, f, mode, bp->b, sizeof(bp->b));	bp->flag = Bmagic;	return bp;} intBterm(Biobuf *bp){ 	deinstall(bp);	Bflush(bp);	if(bp->flag == Bmagic) {		bp->flag = 0;		close(bp->fid);		free(bp);	}	return 0;}