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dumpgame.c revision 1.1 
      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[] = "@(#)dumpgame.c	4.6 (Berkeley) 6/1/90";
     36 #endif /* not lint */
     37 
     38 # include	"trek.h"
     39 
     40 /***  THIS CONSTANT MUST CHANGE AS THE DATA SPACES CHANGE ***/
     41 # define	VERSION		2
     42 
     43 struct dump
     44 {
     45 	char	*area;
     46 	int	count;
     47 };
     48 
     49 
     50 struct dump	Dump_template[] =
     51 {
     52 	(char *)&Ship,		sizeof (Ship),
     53 	(char *)&Now,		sizeof (Now),
     54 	(char *)&Param,		sizeof (Param),
     55 	(char *)&Etc,		sizeof (Etc),
     56 	(char *)&Game,		sizeof (Game),
     57 	(char *)Sect,		sizeof (Sect),
     58 	(char *)Quad,		sizeof (Quad),
     59 	(char *)&Move,		sizeof (Move),
     60 	(char *)Event,		sizeof (Event),
     61 	0
     62 };
     63 
     64 /*
     65 **  DUMP GAME
     66 **
     67 **	This routine dumps the game onto the file "trek.dump".  The
     68 **	first two bytes of the file are a version number, which
     69 **	reflects whether this image may be used.  Obviously, it must
     70 **	change as the size, content, or order of the data structures
     71 **	output change.
     72 */
     73 
     74 dumpgame()
     75 {
     76 	int			version;
     77 	register int		fd;
     78 	register struct dump	*d;
     79 	register int		i;
     80 
     81 	if ((fd = creat("trek.dump", 0644)) < 0)
     82 		return (printf("cannot dump\n"));
     83 	version = VERSION;
     84 	write(fd, &version, sizeof version);
     85 
     86 	/* output the main data areas */
     87 	for (d = Dump_template; d->area; d++)
     88 	{
     89 		write(fd, &d->area, sizeof d->area);
     90 		i = d->count;
     91 		write(fd, d->area, i);
     92 	}
     93 
     94 	close(fd);
     95 }
     96 
     97 
     98 /*
     99 **  RESTORE GAME
    100 **
    101 **	The game is restored from the file "trek.dump".  In order for
    102 **	this to succeed, the file must exist and be readable, must
    103 **	have the correct version number, and must have all the appro-
    104 **	priate data areas.
    105 **
    106 **	Return value is zero for success, one for failure.
    107 */
    108 
    109 restartgame()
    110 {
    111 	register int	fd;
    112 	int		version;
    113 
    114 	if ((fd = open("trek.dump", 0)) < 0 ||
    115 	    read(fd, &version, sizeof version) != sizeof version ||
    116 	    version != VERSION ||
    117 	    readdump(fd))
    118 	{
    119 		printf("cannot restart\n");
    120 		close(fd);
    121 		return (1);
    122 	}
    123 
    124 	close(fd);
    125 	return (0);
    126 }
    127 
    128 
    129 /*
    130 **  READ DUMP
    131 **
    132 **	This is the business end of restartgame().  It reads in the
    133 **	areas.
    134 **
    135 **	Returns zero for success, one for failure.
    136 */
    137 
    138 readdump(fd1)
    139 int	fd1;
    140 {
    141 	register int		fd;
    142 	register struct dump	*d;
    143 	register int		i;
    144 	int			junk;
    145 
    146 	fd = fd1;
    147 
    148 	for (d = Dump_template; d->area; d++)
    149 	{
    150 		if (read(fd, &junk, sizeof junk) != (sizeof junk))
    151 			return (1);
    152 		if ((char *)junk != d->area)
    153 			return (1);
    154 		i = d->count;
    155 		if (read(fd, d->area, i) != i)
    156 			return (1);
    157 	}
    158 
    159 	/* make quite certain we are at EOF */
    160 	return (read(fd, &junk, 1));
    161 }
    162