BSD 4_3_Net_2 release

[unix-history] / usr / src / games / trek / dumpgame.c

/*
* Copyright (c) 1980 Regents of the University of California.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
*    notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
*    notice, this list of conditions and the following disclaimer in the
*    documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
*    must display the following acknowledgement:
*      This product includes software developed by the University of
*      California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
*    may be used to endorse or promote products derived from this software
*    without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/

#ifndef lint
static char sccsid[] = "@(#)dumpgame.c  4.6 (Berkeley) 6/1/90";
#endif /* not lint */

# include       "trek.h"

/***  THIS CONSTANT MUST CHANGE AS THE DATA SPACES CHANGE ***/
# define        VERSION         2

struct dump
{
       char    *area;
       int     count;
};


struct dump     Dump_template[] =
{
       (char *)&Ship,          sizeof (Ship),
       (char *)&Now,           sizeof (Now),
       (char *)&Param,         sizeof (Param),
       (char *)&Etc,           sizeof (Etc),
       (char *)&Game,          sizeof (Game),
       (char *)Sect,           sizeof (Sect),
       (char *)Quad,           sizeof (Quad),
       (char *)&Move,          sizeof (Move),
       (char *)Event,          sizeof (Event),
       0
};

/*
**  DUMP GAME
**
**      This routine dumps the game onto the file "trek.dump".  The
**      first two bytes of the file are a version number, which
**      reflects whether this image may be used.  Obviously, it must
**      change as the size, content, or order of the data structures
**      output change.
*/

dumpgame()
{
       int                     version;
       register int            fd;
       register struct dump    *d;
       register int            i;

       if ((fd = creat("trek.dump", 0644)) < 0)
               return (printf("cannot dump\n"));
       version = VERSION;
       write(fd, &version, sizeof version);

       /* output the main data areas */
       for (d = Dump_template; d->area; d++)
       {
               write(fd, &d->area, sizeof d->area);
               i = d->count;
               write(fd, d->area, i);
       }

       close(fd);
}


/*
**  RESTORE GAME
**
**      The game is restored from the file "trek.dump".  In order for
**      this to succeed, the file must exist and be readable, must
**      have the correct version number, and must have all the appro-
**      priate data areas.
**
**      Return value is zero for success, one for failure.
*/

restartgame()
{
       register int    fd;
       int             version;

       if ((fd = open("trek.dump", 0)) < 0 ||
           read(fd, &version, sizeof version) != sizeof version ||
           version != VERSION ||
           readdump(fd))
       {
               printf("cannot restart\n");
               close(fd);
               return (1);
       }

       close(fd);
       return (0);
}


/*
**  READ DUMP
**
**      This is the business end of restartgame().  It reads in the
**      areas.
**
**      Returns zero for success, one for failure.
*/

readdump(fd1)
int     fd1;
{
       register int            fd;
       register struct dump    *d;
       register int            i;
       int                     junk;

       fd = fd1;

       for (d = Dump_template; d->area; d++)
       {
               if (read(fd, &junk, sizeof junk) != (sizeof junk))
                       return (1);
               if ((char *)junk != d->area)
                       return (1);
               i = d->count;
               if (read(fd, d->area, i) != i)
                       return (1);
       }

       /* make quite certain we are at EOF */
       return (read(fd, &junk, 1));
}