trek/dumpgame.c

   1 /*      $NetBSD: dumpgame.c,v 1.7 1999/09/08 21:45:32 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. 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 #include <sys/cdefs.h>
  37 #ifndef lint
  38 #if 0
  39 static char sccsid[] = "@(#)dumpgame.c  8.1 (Berkeley) 5/31/93";
  40 #else
  41 __RCSID("$NetBSD: dumpgame.c,v 1.7 1999/09/08 21:45:32 jsm Exp $");
  42 #endif
  43 #endif /* not lint */
  44
  45 #include <stdio.h>
  46 #include <err.h>
  47 #include <unistd.h>
  48 #include <fcntl.h>
  49 #include "trek.h"
  50
  51 /***  THIS CONSTANT MUST CHANGE AS THE DATA SPACES CHANGE ***/
  52 # define        VERSION         2
  53
  54 struct dump
  55 {
  56         char    *area;
  57         int     count;
  58 };
  59
  60 static int readdump __P((int));
  61
  62
  63 struct dump     Dump_template[] =
  64 {
  65         { (char *)&Ship,        sizeof (Ship) },
  66         { (char *)&Now,         sizeof (Now) },
  67         { (char *)&Param,       sizeof (Param) },
  68         { (char *)&Etc,         sizeof (Etc) },
  69         { (char *)&Game,        sizeof (Game) },
  70         { (char *)Sect,         sizeof (Sect) },
  71         { (char *)Quad,         sizeof (Quad) },
  72         { (char *)&Move,        sizeof (Move) },
  73         { (char *)Event,        sizeof (Event) },
  74         { NULL,                 0 }
  75 };
  76
  77 /*
  78 **  DUMP GAME
  79 **
  80 **      This routine dumps the game onto the file "trek.dump".  The
  81 **      first two bytes of the file are a version number, which
  82 **      reflects whether this image may be used.  Obviously, it must
  83 **      change as the size, content, or order of the data structures
  84 **      output change.
  85 */
  86
  87 /*ARGSUSED*/
  88 void
  89 dumpgame(v)
  90         int v __attribute__((__unused__));
  91 {
  92         int             version;
  93         int             fd;
  94         struct dump     *d;
  95         int             i;
  96
  97         if ((fd = creat("trek.dump", 0644)) < 0) {
  98                 warn("cannot open `trek.dump'");
  99                 return;
 100         }
 101         version = VERSION;
 102         write(fd, &version, sizeof version);
 103
 104         /* output the main data areas */
 105         for (d = Dump_template; d->area; d++)
 106         {
 107                 write(fd, &d->area, sizeof d->area);
 108                 i = d->count;
 109                 write(fd, d->area, i);
 110         }
 111
 112         close(fd);
 113 }
 114
 115
 116 /*
 117 **  RESTORE GAME
 118 **
 119 **      The game is restored from the file "trek.dump".  In order for
 120 **      this to succeed, the file must exist and be readable, must
 121 **      have the correct version number, and must have all the appro-
 122 **      priate data areas.
 123 **
 124 **      Return value is zero for success, one for failure.
 125 */
 126
 127 int
 128 restartgame()
 129 {
 130         int     fd;
 131         int             version;
 132
 133         if ((fd = open("trek.dump", O_RDONLY)) < 0 ||
 134             read(fd, &version, sizeof version) != sizeof version ||
 135             version != VERSION ||
 136             readdump(fd))
 137         {
 138                 printf("cannot restart\n");
 139                 close(fd);
 140                 return (1);
 141         }
 142
 143         close(fd);
 144         return (0);
 145 }
 146
 147
 148 /*
 149 **  READ DUMP
 150 **
 151 **      This is the business end of restartgame().  It reads in the
 152 **      areas.
 153 **
 154 **      Returns zero for success, one for failure.
 155 */
 156
 157 static int
 158 readdump(fd1)
 159 int     fd1;
 160 {
 161         int             fd;
 162         struct dump     *d;
 163         int             i;
 164         long                    junk;
 165
 166         fd = fd1;
 167
 168         for (d = Dump_template; d->area; d++)
 169         {
 170                 if (read(fd, &junk, sizeof junk) != (sizeof junk))
 171                         return (1);
 172                 if ((char *)junk != d->area)
 173                         return (1);
 174                 i = d->count;
 175                 if (read(fd, d->area, i) != i)
 176                         return (1);
 177         }
 178
 179         /* make quite certain we are at EOF */
 180         return (read(fd, &junk, 1));
 181 }