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      1 /*	$NetBSD: dumpgame.c,v 1.15 2009/08/12 08:54:54 dholland 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. Neither the name of the University nor the names of its contributors
     16  *    may be used to endorse or promote products derived from this software
     17  *    without specific prior written permission.
     18  *
     19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     29  * SUCH DAMAGE.
     30  */
     31 
     32 #include <sys/cdefs.h>
     33 #ifndef lint
     34 #if 0
     35 static char sccsid[] = "@(#)dumpgame.c	8.1 (Berkeley) 5/31/93";
     36 #else
     37 __RCSID("$NetBSD: dumpgame.c,v 1.15 2009/08/12 08:54:54 dholland Exp $");
     38 #endif
     39 #endif /* not lint */
     40 
     41 #include <stdio.h>
     42 #include <err.h>
     43 #include <unistd.h>
     44 #include <fcntl.h>
     45 #include "trek.h"
     46 
     47 /***  THIS CONSTANT MUST CHANGE AS THE DATA SPACES CHANGE ***/
     48 #define VERSION		2
     49 
     50 struct dump {
     51 	char	*area;
     52 	int	count;
     53 };
     54 
     55 static int readdump(int);
     56 
     57 
     58 static struct dump Dump_template[] = {
     59 	{ (char *)&Ship,	sizeof (Ship) },
     60 	{ (char *)&Now,		sizeof (Now) },
     61 	{ (char *)&Param,	sizeof (Param) },
     62 	{ (char *)&Etc,		sizeof (Etc) },
     63 	{ (char *)&Game,	sizeof (Game) },
     64 	{ (char *)Sect,		sizeof (Sect) },
     65 	{ (char *)Quad,		sizeof (Quad) },
     66 	{ (char *)&Move,	sizeof (Move) },
     67 	{ (char *)Event,	sizeof (Event) },
     68 	{ NULL,			0 }
     69 };
     70 
     71 /*
     72 **  DUMP GAME
     73 **
     74 **	This routine dumps the game onto the file "trek.dump".  The
     75 **	first two bytes of the file are a version number, which
     76 **	reflects whether this image may be used.  Obviously, it must
     77 **	change as the size, content, or order of the data structures
     78 **	output change.
     79 */
     80 
     81 /*ARGSUSED*/
     82 void
     83 dumpgame(int v __unused)
     84 {
     85 	int		version;
     86 	int		fd;
     87 	struct dump	*d;
     88 	int		i;
     89 
     90 	if ((fd = creat("trek.dump", 0644)) < 0) {
     91 		warn("cannot open `trek.dump'");
     92 		return;
     93 	}
     94 	version = VERSION;
     95 	write(fd, &version, sizeof version);
     96 
     97 	/* output the main data areas */
     98 	for (d = Dump_template; d->area; d++) {
     99 		write(fd, &d->area, sizeof d->area);
    100 		i = d->count;
    101 		write(fd, d->area, i);
    102 	}
    103 
    104 	close(fd);
    105 }
    106 
    107 
    108 /*
    109 **  RESTORE GAME
    110 **
    111 **	The game is restored from the file "trek.dump".  In order for
    112 **	this to succeed, the file must exist and be readable, must
    113 **	have the correct version number, and must have all the appro-
    114 **	priate data areas.
    115 **
    116 **	Return value is zero for success, one for failure.
    117 */
    118 
    119 int
    120 restartgame(void)
    121 {
    122 	int	fd;
    123 	int		version;
    124 
    125 	if ((fd = open("trek.dump", O_RDONLY)) < 0 ||
    126 	    read(fd, &version, sizeof version) != sizeof version ||
    127 	    version != VERSION ||
    128 	    readdump(fd)) {
    129 		printf("cannot restart\n");
    130 		if (fd >= 0)
    131 			close(fd);
    132 		return (1);
    133 	}
    134 
    135 	close(fd);
    136 	return (0);
    137 }
    138 
    139 
    140 /*
    141 **  READ DUMP
    142 **
    143 **	This is the business end of restartgame().  It reads in the
    144 **	areas.
    145 **
    146 **	Returns zero for success, one for failure.
    147 */
    148 
    149 static int
    150 readdump(int fd1)
    151 {
    152 	int		fd;
    153 	struct dump	*d;
    154 	int		i;
    155 	long			junk;
    156 
    157 	fd = fd1;
    158 
    159 	for (d = Dump_template; d->area; d++) {
    160 		if (read(fd, &junk, sizeof junk) != (sizeof junk))
    161 			return (1);
    162 		if ((char *)junk != d->area)
    163 			return (1);
    164 		i = d->count;
    165 		if (read(fd, d->area, i) != i)
    166 			return (1);
    167 	}
    168 
    169 	/* make quite certain we are at EOF */
    170 	return (read(fd, &junk, 1));
    171 }
    172