#include	<u.h>#include	<libc.h>#include	<bio.h> intBputc(Biobufhdr *bp, int c){	int i; 	assert(bp->state != Bractive && bp->state != Bracteof);	for(;;) {		i = bp->ocount;		if(i) {			bp->ebuf[i++] = c;			bp->ocount = i;			return 0;		}		if(Bflush(bp) == Beof)			break;	}	return Beof;}