xref: /dragonfly/games/trek/dumpgame.c (revision f746689a)
1 /*
2  * Copyright (c) 1980, 1993
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. All advertising materials mentioning features or use of this software
14  *    must display the following acknowledgement:
15  *	This product includes software developed by the University of
16  *	California, Berkeley and its contributors.
17  * 4. Neither the name of the University nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  *
33  * @(#)dumpgame.c	8.1 (Berkeley) 5/31/93
34  * $FreeBSD: src/games/trek/dumpgame.c,v 1.6 1999/11/30 03:49:46 billf Exp $
35  * $DragonFly: src/games/trek/dumpgame.c,v 1.3 2006/09/07 21:19:44 pavalos Exp $
36  */
37 
38 #include <fcntl.h>
39 
40 # include	"trek.h"
41 
42 /***  THIS CONSTANT MUST CHANGE AS THE DATA SPACES CHANGE ***/
43 # define	VERSION		2
44 
45 struct dump
46 {
47 	char	*area;
48 	int	count;
49 };
50 
51 
52 struct dump	Dump_template[] =
53 {
54 	{ (char *)&Ship,	sizeof (Ship)	},
55 	{ (char *)&Now,		sizeof (Now)	},
56 	{ (char *)&Param,	sizeof (Param)	},
57 	{ (char *)&Etc,		sizeof (Etc)	},
58 	{ (char *)&Game,	sizeof (Game)	},
59 	{ (char *)Sect,		sizeof (Sect)	},
60 	{ (char *)Quad,		sizeof (Quad)	},
61 	{ (char *)&Move,	sizeof (Move)	},
62 	{ (char *)Event,	sizeof (Event)	},
63 	{ NULL,			0		}
64 };
65 
66 static bool	readdump(int);
67 
68 /*
69 **  DUMP GAME
70 **
71 **	This routine dumps the game onto the file "trek.dump".  The
72 **	first two bytes of the file are a version number, which
73 **	reflects whether this image may be used.  Obviously, it must
74 **	change as the size, content, or order of the data structures
75 **	output change.
76 */
77 
78 void
79 dumpgame(__unused int unused)
80 {
81 	int			version;
82 	int		fd;
83 	struct dump	*d;
84 	int		i;
85 
86 	if ((fd = creat("trek.dump", 0644)) < 0) {
87 		printf("cannot dump\n");
88 		return;
89 	}
90 	version = VERSION;
91 	write(fd, &version, sizeof version);
92 
93 	/* output the main data areas */
94 	for (d = Dump_template; d->area; d++)
95 	{
96 		write(fd, &d->area, sizeof d->area);
97 		i = d->count;
98 		write(fd, d->area, i);
99 	}
100 
101 	close(fd);
102 }
103 
104 
105 /*
106 **  RESTORE GAME
107 **
108 **	The game is restored from the file "trek.dump".  In order for
109 **	this to succeed, the file must exist and be readable, must
110 **	have the correct version number, and must have all the appro-
111 **	priate data areas.
112 **
113 **	Return value is zero for success, one for failure.
114 */
115 
116 bool
117 restartgame(void)
118 {
119 	int	fd;
120 	int		version;
121 
122 	if ((fd = open("trek.dump", O_RDONLY)) < 0 ||
123 	    read(fd, &version, sizeof version) != sizeof version ||
124 	    version != VERSION ||
125 	    readdump(fd))
126 	{
127 		printf("cannot restart\n");
128 		close(fd);
129 		return (1);
130 	}
131 
132 	close(fd);
133 	return (0);
134 }
135 
136 
137 /*
138 **  READ DUMP
139 **
140 **	This is the business end of restartgame().  It reads in the
141 **	areas.
142 **
143 **	Returns zero for success, one for failure.
144 */
145 
146 static bool
147 readdump(int fd1)
148 {
149 	int		fd;
150 	struct dump	*d;
151 	int		i;
152 	long			junk;
153 
154 	fd = fd1;
155 
156 	for (d = Dump_template; d->area; d++)
157 	{
158 		if (read(fd, &junk, sizeof junk) != (sizeof junk))
159 			return (1);
160 		if ((char *)junk != d->area)
161 			return (1);
162 		i = d->count;
163 		if (read(fd, d->area, i) != i)
164 			return (1);
165 	}
166 
167 	/* make quite certain we are at EOF */
168 	return (read(fd, &junk, 1));
169 }
170