[unix-history] / trek / dumpgame.c

# include	"trek.h"

/***  THIS CONSTANT MUST CHANGE AS THE DATA SPACES CHANGE ***/
# define	VERSION		1

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

struct dump	Dump_template[]
{
	&Ship,		sizeof Ship,
	&Now,		sizeof Now,
	&Param,		sizeof Param,
	&Etc,		sizeof Etc,
	&Game,		sizeof Game,
	&Sect,		sizeof Sect,
	&Quad,		sizeof Quad,
	&Move,		sizeof Move,
	&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 (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
520d5775 EA	1	# include "trek.h"
	2
	3	/* THIS CONSTANT MUST CHANGE AS THE DATA SPACES CHANGE */
	4	# define VERSION 1
	5
	6	struct dump
	7	{
	8	char *area;
	9	int count;
	10	};
	11
	12	struct dump Dump_template[]
	13	{
	14	&Ship, sizeof Ship,
	15	&Now, sizeof Now,
	16	&Param, sizeof Param,
	17	&Etc, sizeof Etc,
	18	&Game, sizeof Game,
	19	&Sect, sizeof Sect,
	20	&Quad, sizeof Quad,
	21	&Move, sizeof Move,
	22	&Event, sizeof Event,
	23	0
	24	};
	25
	26	/*
	27	** DUMP GAME
	28	**
	29	** This routine dumps the game onto the file "trek.dump". The
	30	** first two bytes of the file are a version number, which
	31	** reflects whether this image may be used. Obviously, it must
	32	** change as the size, content, or order of the data structures
	33	** output change.
	34	*/
	35
	36	dumpgame()
	37	{
	38	int version;
	39	register int fd;
	40	register struct dump *d;
	41	register int i;
	42
	43	if ((fd = creat("trek.dump", 0644)) < 0)
	44	return (printf("cannot dump\n"));
	45	version = VERSION;
	46	write(fd, &version, sizeof version);
	47
	48	/* output the main data areas */
	49	for (d = Dump_template; d->area; d++)
	50	{
	51	write(fd, &d->area, sizeof d->area);
	52	i = d->count;
	53	write(fd, d->area, i);
	54	}
	55
	56	close(fd);
	57	}
	58
	59
	60	/*
	61	** RESTORE GAME
	62	**
	63	** The game is restored from the file "trek.dump". In order for
	64	** this to succeed, the file must exist and be readable, must
65	** have the correct version number, and must have all the appro-
66	** priate data areas.
67	**
68	** Return value is zero for success, one for failure.
69	*/
70
71	restartgame()
72	{
73	register int fd;
74	int version;
75
76	if ((fd = open("trek.dump", 0)) < 0 \|\|
77	read(fd, &version, sizeof version) != sizeof version \|\|
78	version != VERSION \|\|
79	readdump(fd))
80	{
81	printf("cannot restart\n");
82	close(fd);
83	return (1);
84	}
85
86	close(fd);
87	return (0);
88	}
89
90
91	/*
92	** READ DUMP
93	**
94	** This is the business end of restartgame(). It reads in the
95	** areas.
96	**
97	** Returns zero for success, one for failure.
98	*/
99
100	readdump(fd1)
101	int fd1;
102	{
103	register int fd;
104	register struct dump *d;
105	register int i;
106	int junk;
107
108	fd = fd1;
109
110	for (d = Dump_template; d->area; d++)
111	{
112	if (read(fd, &junk, sizeof junk) != sizeof junk)
113	return (1);
114	if (junk != d->area)
115	return (1);
116	i = d->count;
117	if (read(fd, d->area, i) != i)
118	return (1);
119	}
120
121	/* make quite certain we are at EOF */
122	return (read(fd, &junk, 1));
123	}