games/trek/dumpgame.c

   1 /*
   2  * Copyright (c) 1980, 1993
   3  *      The Regents of the University of California.  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  * @(#)dumpgame.c       8.1 (Berkeley) 5/31/93
  34  * $FreeBSD: src/games/trek/dumpgame.c,v 1.6 1999/11/30 03:49:46 billf Exp $
  35  * $DragonFly: src/games/trek/dumpgame.c,v 1.3 2006/09/07 21:19:44 pavalos Exp $
  36  */
  37
  38 #include <fcntl.h>
  39
  40 # include       "trek.h"
  41
  42 /***  THIS CONSTANT MUST CHANGE AS THE DATA SPACES CHANGE ***/
  43 # define        VERSION         2
  44
  45 struct dump
  46 {
  47         char    *area;
  48         int     count;
  49 };
  50
  51
  52 struct dump     Dump_template[] =
  53 {
  54         { (char *)&Ship,        sizeof (Ship)   },
  55         { (char *)&Now,         sizeof (Now)    },
  56         { (char *)&Param,       sizeof (Param)  },
  57         { (char *)&Etc,         sizeof (Etc)    },
  58         { (char *)&Game,        sizeof (Game)   },
  59         { (char *)Sect,         sizeof (Sect)   },
  60         { (char *)Quad,         sizeof (Quad)   },
  61         { (char *)&Move,        sizeof (Move)   },
  62         { (char *)Event,        sizeof (Event)  },
  63         { NULL,                 0               }
  64 };
  65
  66 static bool     readdump(int);
  67
  68 /*
  69 **  DUMP GAME
  70 **
  71 **      This routine dumps the game onto the file "trek.dump".  The
  72 **      first two bytes of the file are a version number, which
  73 **      reflects whether this image may be used.  Obviously, it must
  74 **      change as the size, content, or order of the data structures
  75 **      output change.
  76 */
  77
  78 void
  79 dumpgame(__unused int unused)
  80 {
  81         int                     version;
  82         int             fd;
  83         struct dump     *d;
  84         int             i;
  85
  86         if ((fd = creat("trek.dump", 0644)) < 0) {
  87                 printf("cannot dump\n");
  88                 return;
  89         }
  90         version = VERSION;
  91         write(fd, &version, sizeof version);
  92
  93         /* output the main data areas */
  94         for (d = Dump_template; d->area; d++)
  95         {
  96                 write(fd, &d->area, sizeof d->area);
  97                 i = d->count;
  98                 write(fd, d->area, i);
  99         }
 100
 101         close(fd);
 102 }
 103
 104
 105 /*
 106 **  RESTORE GAME
 107 **
 108 **      The game is restored from the file "trek.dump".  In order for
 109 **      this to succeed, the file must exist and be readable, must
 110 **      have the correct version number, and must have all the appro-
 111 **      priate data areas.
 112 **
 113 **      Return value is zero for success, one for failure.
 114 */
 115
 116 bool
 117 restartgame(void)
 118 {
 119         int     fd;
 120         int             version;
 121
 122         if ((fd = open("trek.dump", O_RDONLY)) < 0 ||
 123             read(fd, &version, sizeof version) != sizeof version ||
 124             version != VERSION ||
 125             readdump(fd))
 126         {
 127                 printf("cannot restart\n");
 128                 close(fd);
 129                 return (1);
 130         }
 131
 132         close(fd);
 133         return (0);
 134 }
 135
 136
 137 /*
 138 **  READ DUMP
 139 **
 140 **      This is the business end of restartgame().  It reads in the
 141 **      areas.
 142 **
 143 **      Returns zero for success, one for failure.
 144 */
 145
 146 static bool
 147 readdump(int fd1)
 148 {
 149         int             fd;
 150         struct dump     *d;
 151         int             i;
 152         long                    junk;
 153
 154         fd = fd1;
 155
 156         for (d = Dump_template; d->area; d++)
 157         {
 158                 if (read(fd, &junk, sizeof junk) != (sizeof junk))
 159                         return (1);
 160                 if ((char *)junk != d->area)
 161                         return (1);
 162                 i = d->count;
 163                 if (read(fd, d->area, i) != i)
 164                         return (1);
 165         }
 166
 167         /* make quite certain we are at EOF */
 168         return (read(fd, &junk, 1));
 169 }