[unix-history] / usr / src / games / trek / dumpgame.c

#ifndef lint
static char sccsid[] = "@(#)dumpgame.c	4.2	(Berkeley)	5/27/83";
#endif not lint

# include	"trek.h"

/***  THIS CONSTANT MUST CHANGE AS THE DATA SPACES CHANGE ***/
# define	VERSION		2

struct dump
{
	char	*area;
	int	count;
};


struct dump	Dump_template[] =
{
	(char *)&Ship,		sizeof (Ship),
	(char *)&Now,		sizeof (Now),
	(char *)&Param,		sizeof (Param),
	(char *)&Etc,		sizeof (Etc),
	(char *)&Game,		sizeof (Game),
	(char *)Sect,		sizeof (Sect),
	(char *)Quad,		sizeof (Quad),
	(char *)&Move,		sizeof (Move),
	(char *)Event,		sizeof (Event),
	0
};

/*
**  DUMP GAME
**
**	This routine dumps the game onto the file "trek.dump".  The
**	first two bytes of the file are a version number, which
**	reflects whether this image may be used.  Obviously, it must
**	change as the size, content, or order of the data structures
**	output change.
*/

dumpgame()
{
	int			version;
	register int		fd;
	register struct dump	*d;
	register int		i;

	if ((fd = creat("trek.dump", 0644)) < 0)
		return (printf("cannot dump\n"));
	version = VERSION;
	write(fd, &version, sizeof version);

	/* output the main data areas */
	for (d = Dump_template; d->area; d++)
	{
		write(fd, &d->area, sizeof d->area);
		i = d->count;
		write(fd, d->area, i);
	}

	close(fd);
}


/*
**  RESTORE GAME
**
**	The game is restored from the file "trek.dump".  In order for
**	this to succeed, the file must exist and be readable, must
**	have the correct version number, and must have all the appro-
**	priate data areas.
**
**	Return value is zero for success, one for failure.
*/

restartgame()
{
	register int	fd;
	int		version;

	if ((fd = open("trek.dump", 0)) < 0 ||
	    read(fd, &version, sizeof version) != sizeof version ||
	    version != VERSION ||
	    readdump(fd))
	{
		printf("cannot restart\n");
		close(fd);
		return (1);
	}

	close(fd);
	return (0);
}


/*
**  READ DUMP
**
**	This is the business end of restartgame().  It reads in the
**	areas.
**
**	Returns zero for success, one for failure.
*/

readdump(fd1)
int	fd1;
{
	register int		fd;
	register struct dump	*d;
	register int		i;
	int			junk;

	fd = fd1;

	for (d = Dump_template; d->area; d++)
	{
		if (read(fd, &junk, sizeof junk) != (sizeof junk))
			return (1);
		if ((char *)junk != d->area)
			return (1);
		i = d->count;
		if (read(fd, d->area, i) != i)
			return (1);
	}

	/* make quite certain we are at EOF */
	return (read(fd, &junk, 1));
}
Commit	Line	Data
1184f029	1	#ifndef lint
0f4556f1	2	static char sccsid[] = "@(#)dumpgame.c 4.2 (Berkeley) 5/27/83";
1184f029 KM	3	#endif not lint
	4
	5	# include "trek.h"
	6
	7	/* THIS CONSTANT MUST CHANGE AS THE DATA SPACES CHANGE */
401a08c7	8	# define VERSION 2
1184f029 KM	9
	10	struct dump
	11	{
	12	char *area;
	13	int count;
	14	};
	15
401a08c7 KL	16
401a08c7 KL	17	struct dump Dump_template[] =
1184f029	18	{
401a08c7 KL	19	(char *)&Ship, sizeof (Ship),
	20	(char *)&Now, sizeof (Now),
	21	(char *)&Param, sizeof (Param),
	22	(char *)&Etc, sizeof (Etc),
	23	(char *)&Game, sizeof (Game),
	24	(char *)Sect, sizeof (Sect),
	25	(char *)Quad, sizeof (Quad),
	26	(char *)&Move, sizeof (Move),
	27	(char *)Event, sizeof (Event),
1184f029 KM	28	0
	29	};
	30
	31	/*
	32	** DUMP GAME
	33	**
	34	** This routine dumps the game onto the file "trek.dump". The
	35	** first two bytes of the file are a version number, which
	36	** reflects whether this image may be used. Obviously, it must
	37	** change as the size, content, or order of the data structures
	38	** output change.
	39	*/
	40
	41	dumpgame()
	42	{
	43	int version;
	44	register int fd;
	45	register struct dump *d;
	46	register int i;
	47
	48	if ((fd = creat("trek.dump", 0644)) < 0)
	49	return (printf("cannot dump\n"));
	50	version = VERSION;
	51	write(fd, &version, sizeof version);
	52
	53	/* output the main data areas */
	54	for (d = Dump_template; d->area; d++)
	55	{
	56	write(fd, &d->area, sizeof d->area);
	57	i = d->count;
	58	write(fd, d->area, i);
	59	}
	60
	61	close(fd);
	62	}
	63
	64
	65	/*
	66	** RESTORE GAME
	67	**
	68	** The game is restored from the file "trek.dump". In order for
	69	** this to succeed, the file must exist and be readable, must
	70	** have the correct version number, and must have all the appro-
	71	** priate data areas.
	72	**
	73	** Return value is zero for success, one for failure.
	74	*/
	75
	76	restartgame()
	77	{
	78	register int fd;
	79	int version;
	80
	81	if ((fd = open("trek.dump", 0)) < 0 \|\|
	82	read(fd, &version, sizeof version) != sizeof version \|\|
	83	version != VERSION \|\|
	84	readdump(fd))
	85	{
	86	printf("cannot restart\n");
	87	close(fd);
	88	return (1);
	89	}
	90
	91	close(fd);
92	return (0);
93	}
94
95
96	/*
97	** READ DUMP
98	**
99	** This is the business end of restartgame(). It reads in the
100	** areas.
101	**
102	** Returns zero for success, one for failure.
103	*/
104
105	readdump(fd1)
106	int fd1;
107	{
108	register int fd;
109	register struct dump *d;
110	register int i;
111	int junk;
112
113	fd = fd1;
114
115	for (d = Dump_template; d->area; d++)
116	{
401a08c7	117	if (read(fd, &junk, sizeof junk) != (sizeof junk))
1184f029	118	return (1);
401a08c7	119	if ((char *)junk != d->area)
1184f029 KM	120	return (1);
	121	i = d->count;
	122	if (read(fd, d->area, i) != i)
	123	return (1);
	124	}
	125
	126	/* make quite certain we are at EOF */
	127	return (read(fd, &junk, 1));
	128	}