/* * pANS stdio -- setvbuf */#include "iolib.h"int setvbuf(FILE *f, char *buf, int mode, long size){	if(f->state!=OPEN){		f->state=ERR;		return -1;	}	f->state=RDWR;	switch(mode){	case _IOLBF:		f->flags|=LINEBUF;	case _IOFBF:		if(buf==0){			buf=malloc(size);			if(buf==0){				f->state=ERR;				return -1;			}			f->flags|=BALLOC;		}		f->bufl=size;		break;	case _IONBF:		buf=f->unbuf;		f->bufl=0;		break;	}	f->rp=f->wp=f->lp=f->buf=buf;	f->state=RDWR;	return 0;}int _IO_setvbuf(FILE *f){	static int isatty(int);	if(f==stderr || (f==stdout && isatty(1)))		setvbuf(f, (char *)0, _IOLBF, BUFSIZ);	else setvbuf(f, (char *)0, _IOFBF, BUFSIZ);}static intisatty(int fd){	Dir d1, d2; 	if(dirfstat(fd, &d1) >= 0 && dirstat("/dev/cons", &d2) >= 0)		return (d1.qid.path == d2.qid.path) &&			(d1.type == d2.type) &&			(d1.dev == d2.dev);	return 0;}