trek/dumpgame.c

   1 /*      $NetBSD: dumpgame.c,v 1.4 1995/04/24 12:25:54 cgd 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. All advertising materials mentioning features or use of this software
  16  *    must display the following acknowledgement:
  17  *      This product includes software developed by the University of
  18  *      California, Berkeley and its contributors.
  19  * 4. Neither the name of the University nor the names of its contributors
  20  *    may be used to endorse or promote products derived from this software
  21  *    without specific prior written permission.
  22  *
  23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  33  * SUCH DAMAGE.
  34  */
  35
  36 #ifndef lint
  37 #if 0
  38 static char sccsid[] = "@(#)dumpgame.c  8.1 (Berkeley) 5/31/93";
  39 #else
  40 static char rcsid[] = "$NetBSD: dumpgame.c,v 1.4 1995/04/24 12:25:54 cgd Exp $";
  41 #endif
  42 #endif /* not lint */
  43
  44 # include       "trek.h"
  45
  46 /***  THIS CONSTANT MUST CHANGE AS THE DATA SPACES CHANGE ***/
  47 # define        VERSION         2
  48
  49 struct dump
  50 {
  51         char    *area;
  52         int     count;
  53 };
  54
  55
  56 struct dump     Dump_template[] =
  57 {
  58         (char *)&Ship,          sizeof (Ship),
  59         (char *)&Now,           sizeof (Now),
  60         (char *)&Param,         sizeof (Param),
  61         (char *)&Etc,           sizeof (Etc),
  62         (char *)&Game,          sizeof (Game),
  63         (char *)Sect,           sizeof (Sect),
  64         (char *)Quad,           sizeof (Quad),
  65         (char *)&Move,          sizeof (Move),
  66         (char *)Event,          sizeof (Event),
  67         0
  68 };
  69
  70 /*
  71 **  DUMP GAME
  72 **
  73 **      This routine dumps the game onto the file "trek.dump".  The
  74 **      first two bytes of the file are a version number, which
  75 **      reflects whether this image may be used.  Obviously, it must
  76 **      change as the size, content, or order of the data structures
  77 **      output change.
  78 */
  79
  80 dumpgame()
  81 {
  82         int                     version;
  83         register int            fd;
  84         register struct dump    *d;
  85         register int            i;
  86
  87         if ((fd = creat("trek.dump", 0644)) < 0)
  88                 return (printf("cannot dump\n"));
  89         version = VERSION;
  90         write(fd, &version, sizeof version);
  91
  92         /* output the main data areas */
  93         for (d = Dump_template; d->area; d++)
  94         {
  95                 write(fd, &d->area, sizeof d->area);
  96                 i = d->count;
  97                 write(fd, d->area, i);
  98         }
  99
 100         close(fd);
 101 }
 102
 103
 104 /*
 105 **  RESTORE GAME
 106 **
 107 **      The game is restored from the file "trek.dump".  In order for
 108 **      this to succeed, the file must exist and be readable, must
 109 **      have the correct version number, and must have all the appro-
 110 **      priate data areas.
 111 **
 112 **      Return value is zero for success, one for failure.
 113 */
 114
 115 restartgame()
 116 {
 117         register int    fd;
 118         int             version;
 119
 120         if ((fd = open("trek.dump", 0)) < 0 ||
 121             read(fd, &version, sizeof version) != sizeof version ||
 122             version != VERSION ||
 123             readdump(fd))
 124         {
 125                 printf("cannot restart\n");
 126                 close(fd);
 127                 return (1);
 128         }
 129
 130         close(fd);
 131         return (0);
 132 }
 133
 134
 135 /*
 136 **  READ DUMP
 137 **
 138 **      This is the business end of restartgame().  It reads in the
 139 **      areas.
 140 **
 141 **      Returns zero for success, one for failure.
 142 */
 143
 144 readdump(fd1)
 145 int     fd1;
 146 {
 147         register int            fd;
 148         register struct dump    *d;
 149         register int            i;
 150         long                    junk;
 151
 152         fd = fd1;
 153
 154         for (d = Dump_template; d->area; d++)
 155         {
 156                 if (read(fd, &junk, sizeof junk) != (sizeof junk))
 157                         return (1);
 158                 if ((char *)junk != d->area)
 159                         return (1);
 160                 i = d->count;
 161                 if (read(fd, d->area, i) != i)
 162                         return (1);
 163         }
 164
 165         /* make quite certain we are at EOF */
 166         return (read(fd, &junk, 1));
 167 }