#define	BLKSIZ	512
#define	MAXLINE	128

char	*bfilnm 0;		/* Buffered input file name */
int	bfile 0;		/* Buffered input file */
char	*bufloc;		/* Current read loc within buffer */
int	bufnum;			/* Number of chars left in buffer */
char	ibuf[BLKSIZ];
char	lbuf[MAXLINE];


bufopen(fnm, dflg)
char	*fnm;

{	if (dflg)
		printf("Bufopen: '%s'\n", fnm);

	if (bfile != 0)
		cerror("Buffer file already open");

	bfilnm = fnm;

	bfile = open(fnm, 0);
	if (bfile < 0)
		serror("Can't open buffer file");

	bufnum = 0;
}


bufstart(dflg)

{	if (dflg)
		printf("Bufstart: '%s'\n", bfilnm);

	if (bfile == 0)
		cerror("Buffer file not open");

	if (seek(bfile, 0, 0) < 0)
		serror("Can't seek buffer file");

	bufnum = 0;
}


bufclose(dflg)

{	if (dflg)
		printf("Bufclose: '%s'\n", bfilnm);

	if (bfile == 0)
		cerror("Buffer file already closed");

	if (close(bfile) < 0)
		serror("Can't close buffer file");

	bfile = 0;
	bufnum = 0;
}


rdline()

{	register char	*bp, *lp;
			int	i;
			char	c;

	bp = bufloc;
	lp = &lbuf[0];

	i = 0;
	while (i++ < MAXLINE) {
		if (bufnum == 0) {
			bufnum = read(bfile, &ibuf[0], BLKSIZ);
			if (bufnum < 0)
				serror("Buffer file read error");

			if (bufnum == 0)
				return(i);

			bp = &ibuf[0];
			}

		*lp++ = (c = *bp++);
		bufnum--;

		if (c == '\n') {
			*--lp = '\0';
			bufloc = bp;
			return(i);
			}
		}

	cerror("Line too long");
}