games/trek/dumpgame.c

   1 /*      $NetBSD: dumpgame.c,v 1.14 2009/05/24 21:44:56 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 1.14 2009/05/24 21:44:56 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
  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
 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
 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 }