trek/dumpgame.c

   1 /*      $NetBSD: dumpgame.c,v 1.9 2004/01/27 20:30:31 jsm 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 1.9 2004/01/27 20:30:31 jsm 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 {
  52         char    *area;
  53         int     count;
  54 };
  55
  56 static int readdump(int);
  57
  58
  59 struct dump     Dump_template[] =
  60 {
  61         { (char *)&Ship,        sizeof (Ship) },
  62         { (char *)&Now,         sizeof (Now) },
  63         { (char *)&Param,       sizeof (Param) },
  64         { (char *)&Etc,         sizeof (Etc) },
  65         { (char *)&Game,        sizeof (Game) },
  66         { (char *)Sect,         sizeof (Sect) },
  67         { (char *)Quad,         sizeof (Quad) },
  68         { (char *)&Move,        sizeof (Move) },
  69         { (char *)Event,        sizeof (Event) },
  70         { NULL,                 0 }
  71 };
  72
  73 /*
  74 **  DUMP GAME
  75 **
  76 **      This routine dumps the game onto the file "trek.dump".  The
  77 **      first two bytes of the file are a version number, which
  78 **      reflects whether this image may be used.  Obviously, it must
  79 **      change as the size, content, or order of the data structures
  80 **      output change.
  81 */
  82
  83 /*ARGSUSED*/
  84 void
  85 dumpgame(v)
  86         int v __attribute__((__unused__));
  87 {
  88         int             version;
  89         int             fd;
  90         struct dump     *d;
  91         int             i;
  92
  93         if ((fd = creat("trek.dump", 0644)) < 0) {
  94                 warn("cannot open `trek.dump'");
  95                 return;
  96         }
  97         version = VERSION;
  98         write(fd, &version, sizeof version);
  99
 100         /* output the main data areas */
 101         for (d = Dump_template; d->area; d++)
 102         {
 103                 write(fd, &d->area, sizeof d->area);
 104                 i = d->count;
 105                 write(fd, d->area, i);
 106         }
 107
 108         close(fd);
 109 }
 110
 111
 112 /*
 113 **  RESTORE GAME
 114 **
 115 **      The game is restored from the file "trek.dump".  In order for
 116 **      this to succeed, the file must exist and be readable, must
 117 **      have the correct version number, and must have all the appro-
 118 **      priate data areas.
 119 **
 120 **      Return value is zero for success, one for failure.
 121 */
 122
 123 int
 124 restartgame()
 125 {
 126         int     fd;
 127         int             version;
 128
 129         if ((fd = open("trek.dump", O_RDONLY)) < 0 ||
 130             read(fd, &version, sizeof version) != sizeof version ||
 131             version != VERSION ||
 132             readdump(fd))
 133         {
 134                 printf("cannot restart\n");
 135                 close(fd);
 136                 return (1);
 137         }
 138
 139         close(fd);
 140         return (0);
 141 }
 142
 143
 144 /*
 145 **  READ DUMP
 146 **
 147 **      This is the business end of restartgame().  It reads in the
 148 **      areas.
 149 **
 150 **      Returns zero for success, one for failure.
 151 */
 152
 153 static int
 154 readdump(fd1)
 155 int     fd1;
 156 {
 157         int             fd;
 158         struct dump     *d;
 159         int             i;
 160         long                    junk;
 161
 162         fd = fd1;
 163
 164         for (d = Dump_template; d->area; d++)
 165         {
 166                 if (read(fd, &junk, sizeof junk) != (sizeof junk))
 167                         return (1);
 168                 if ((char *)junk != d->area)
 169                         return (1);
 170                 i = d->count;
 171                 if (read(fd, d->area, i) != i)
 172                         return (1);
 173         }
 174
 175         /* make quite certain we are at EOF */
 176         return (read(fd, &junk, 1));
 177 }