freebsd-dev/games/trek/dumpgame.c
1999-11-30 03:50:02 +00:00

168 lines
4.2 KiB
C

/*
* Copyright (c) 1980, 1993
* The 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
#if 0
static char sccsid[] = "@(#)dumpgame.c 8.1 (Berkeley) 5/31/93";
#endif
static const char rcsid[] =
"$FreeBSD$";
#endif /* not lint */
#include <fcntl.h>
# 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;
int fd;
struct dump *d;
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()
{
int fd;
int version;
if ((fd = open("trek.dump", O_RDONLY)) < 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;
{
int fd;
struct dump *d;
int i;
long 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));
}