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