trek/dumpgame.c

   1 /*
   2  * Copyright (c) 1980 Regents of the University of California.
   3  * 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. All advertising materials mentioning features or use of this software
  14  *    must display the following acknowledgement:
  15  *      This product includes software developed by the University of
  16  *      California, Berkeley and its contributors.
  17  * 4. Neither the name of the University nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  */
  33
  34 #ifndef lint
  35 /*static char sccsid[] = "from: @(#)dumpgame.c  4.6 (Berkeley) 6/1/90";*/
  36 static char rcsid[] = "$Id: dumpgame.c,v 1.2 1993/08/01 18:50:39 mycroft Exp $";
  37 #endif /* not lint */
  38
  39 # include       "trek.h"
  40
  41 /***  THIS CONSTANT MUST CHANGE AS THE DATA SPACES CHANGE ***/
  42 # define        VERSION         2
  43
  44 struct dump
  45 {
  46         char    *area;
  47         int     count;
  48 };
  49
  50
  51 struct dump     Dump_template[] =
  52 {
  53         (char *)&Ship,          sizeof (Ship),
  54         (char *)&Now,           sizeof (Now),
  55         (char *)&Param,         sizeof (Param),
  56         (char *)&Etc,           sizeof (Etc),
  57         (char *)&Game,          sizeof (Game),
  58         (char *)Sect,           sizeof (Sect),
  59         (char *)Quad,           sizeof (Quad),
  60         (char *)&Move,          sizeof (Move),
  61         (char *)Event,          sizeof (Event),
  62         0
  63 };
  64
  65 /*
  66 **  DUMP GAME
  67 **
  68 **      This routine dumps the game onto the file "trek.dump".  The
  69 **      first two bytes of the file are a version number, which
  70 **      reflects whether this image may be used.  Obviously, it must
  71 **      change as the size, content, or order of the data structures
  72 **      output change.
  73 */
  74
  75 dumpgame()
  76 {
  77         int                     version;
  78         register int            fd;
  79         register struct dump    *d;
  80         register int            i;
  81
  82         if ((fd = creat("trek.dump", 0644)) < 0)
  83                 return (printf("cannot dump\n"));
  84         version = VERSION;
  85         write(fd, &version, sizeof version);
  86
  87         /* output the main data areas */
  88         for (d = Dump_template; d->area; d++)
  89         {
  90                 write(fd, &d->area, sizeof d->area);
  91                 i = d->count;
  92                 write(fd, d->area, i);
  93         }
  94
  95         close(fd);
  96 }
  97
  98
  99 /*
 100 **  RESTORE GAME
 101 **
 102 **      The game is restored from the file "trek.dump".  In order for
 103 **      this to succeed, the file must exist and be readable, must
 104 **      have the correct version number, and must have all the appro-
 105 **      priate data areas.
 106 **
 107 **      Return value is zero for success, one for failure.
 108 */
 109
 110 restartgame()
 111 {
 112         register int    fd;
 113         int             version;
 114
 115         if ((fd = open("trek.dump", 0)) < 0 ||
 116             read(fd, &version, sizeof version) != sizeof version ||
 117             version != VERSION ||
 118             readdump(fd))
 119         {
 120                 printf("cannot restart\n");
 121                 close(fd);
 122                 return (1);
 123         }
 124
 125         close(fd);
 126         return (0);
 127 }
 128
 129
 130 /*
 131 **  READ DUMP
 132 **
 133 **      This is the business end of restartgame().  It reads in the
 134 **      areas.
 135 **
 136 **      Returns zero for success, one for failure.
 137 */
 138
 139 readdump(fd1)
 140 int     fd1;
 141 {
 142         register int            fd;
 143         register struct dump    *d;
 144         register int            i;
 145         int                     junk;
 146
 147         fd = fd1;
 148
 149         for (d = Dump_template; d->area; d++)
 150         {
 151                 if (read(fd, &junk, sizeof junk) != (sizeof junk))
 152                         return (1);
 153                 if ((char *)junk != d->area)
 154                         return (1);
 155                 i = d->count;
 156                 if (read(fd, d->area, i) != i)
 157                         return (1);
 158         }
 159
 160         /* make quite certain we are at EOF */
 161         return (read(fd, &junk, 1));
 162 }