1 /* $NetBSD: dumpgame.c,v 1.15 2009/08/12 08:54:54 dholland Exp $ */
2
3 /*
4 * Copyright (c) 1980, 1993
5 * The Regents of the University of California. All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of the University nor the names of its contributors
16 * may be used to endorse or promote products derived from this software
17 * without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 */
31
32 #include <sys/cdefs.h>
33 #ifndef lint
34 #if 0
35 static char sccsid[] = "@(#)dumpgame.c 8.1 (Berkeley) 5/31/93";
36 #else
37 __RCSID("$NetBSD: dumpgame.c,v 1.15 2009/08/12 08:54:54 dholland Exp $");
38 #endif
39 #endif /* not lint */
40
41 #include <stdio.h>
42 #include <err.h>
43 #include <unistd.h>
44 #include <fcntl.h>
45 #include "trek.h"
46
47 /*** THIS CONSTANT MUST CHANGE AS THE DATA SPACES CHANGE ***/
48 #define VERSION 2
49
50 struct dump {
51 char *area;
52 int count;
53 };
54
55 static int readdump(int);
56
57
58 static struct dump Dump_template[] = {
59 { (char *)&Ship, sizeof (Ship) },
60 { (char *)&Now, sizeof (Now) },
61 { (char *)&Param, sizeof (Param) },
62 { (char *)&Etc, sizeof (Etc) },
63 { (char *)&Game, sizeof (Game) },
64 { (char *)Sect, sizeof (Sect) },
65 { (char *)Quad, sizeof (Quad) },
66 { (char *)&Move, sizeof (Move) },
67 { (char *)Event, sizeof (Event) },
68 { NULL, 0 }
69 };
70
71 /*
72 ** DUMP GAME
73 **
74 ** This routine dumps the game onto the file "trek.dump". The
75 ** first two bytes of the file are a version number, which
76 ** reflects whether this image may be used. Obviously, it must
77 ** change as the size, content, or order of the data structures
78 ** output change.
79 */
80
81 /*ARGSUSED*/
82 void
dumpgame(int v __unused)83 dumpgame(int v __unused)
84 {
85 int version;
86 int fd;
87 struct dump *d;
88 int i;
89
90 if ((fd = creat("trek.dump", 0644)) < 0) {
91 warn("cannot open `trek.dump'");
92 return;
93 }
94 version = VERSION;
95 write(fd, &version, sizeof version);
96
97 /* output the main data areas */
98 for (d = Dump_template; d->area; d++) {
99 write(fd, &d->area, sizeof d->area);
100 i = d->count;
101 write(fd, d->area, i);
102 }
103
104 close(fd);
105 }
106
107
108 /*
109 ** RESTORE GAME
110 **
111 ** The game is restored from the file "trek.dump". In order for
112 ** this to succeed, the file must exist and be readable, must
113 ** have the correct version number, and must have all the appro-
114 ** priate data areas.
115 **
116 ** Return value is zero for success, one for failure.
117 */
118
119 int
restartgame(void)120 restartgame(void)
121 {
122 int fd;
123 int version;
124
125 if ((fd = open("trek.dump", O_RDONLY)) < 0 ||
126 read(fd, &version, sizeof version) != sizeof version ||
127 version != VERSION ||
128 readdump(fd)) {
129 printf("cannot restart\n");
130 if (fd >= 0)
131 close(fd);
132 return (1);
133 }
134
135 close(fd);
136 return (0);
137 }
138
139
140 /*
141 ** READ DUMP
142 **
143 ** This is the business end of restartgame(). It reads in the
144 ** areas.
145 **
146 ** Returns zero for success, one for failure.
147 */
148
149 static int
readdump(int fd1)150 readdump(int fd1)
151 {
152 int fd;
153 struct dump *d;
154 int i;
155 long junk;
156
157 fd = fd1;
158
159 for (d = Dump_template; d->area; d++) {
160 if (read(fd, &junk, sizeof junk) != (sizeof junk))
161 return (1);
162 if ((char *)junk != d->area)
163 return (1);
164 i = d->count;
165 if (read(fd, d->area, i) != i)
166 return (1);
167 }
168
169 /* make quite certain we are at EOF */
170 return (read(fd, &junk, 1));
171 }
172