| 1 | /* |
| 2 | * Copyright (c) 1980 Regents of the University of California. |
| 3 | * All rights reserved. The Berkeley software License Agreement |
| 4 | * specifies the terms and conditions for redistribution. |
| 5 | */ |
| 6 | |
| 7 | #ifndef lint |
| 8 | static char sccsid[] = "@(#)dumpgame.c 4.3 (Berkeley) %G%"; |
| 9 | #endif not lint |
| 10 | |
| 11 | # include "trek.h" |
| 12 | |
| 13 | /*** THIS CONSTANT MUST CHANGE AS THE DATA SPACES CHANGE ***/ |
| 14 | # define VERSION 2 |
| 15 | |
| 16 | struct dump |
| 17 | { |
| 18 | char *area; |
| 19 | int count; |
| 20 | }; |
| 21 | |
| 22 | |
| 23 | struct dump Dump_template[] = |
| 24 | { |
| 25 | (char *)&Ship, sizeof (Ship), |
| 26 | (char *)&Now, sizeof (Now), |
| 27 | (char *)&Param, sizeof (Param), |
| 28 | (char *)&Etc, sizeof (Etc), |
| 29 | (char *)&Game, sizeof (Game), |
| 30 | (char *)Sect, sizeof (Sect), |
| 31 | (char *)Quad, sizeof (Quad), |
| 32 | (char *)&Move, sizeof (Move), |
| 33 | (char *)Event, sizeof (Event), |
| 34 | 0 |
| 35 | }; |
| 36 | |
| 37 | /* |
| 38 | ** DUMP GAME |
| 39 | ** |
| 40 | ** This routine dumps the game onto the file "trek.dump". The |
| 41 | ** first two bytes of the file are a version number, which |
| 42 | ** reflects whether this image may be used. Obviously, it must |
| 43 | ** change as the size, content, or order of the data structures |
| 44 | ** output change. |
| 45 | */ |
| 46 | |
| 47 | dumpgame() |
| 48 | { |
| 49 | int version; |
| 50 | register int fd; |
| 51 | register struct dump *d; |
| 52 | register int i; |
| 53 | |
| 54 | if ((fd = creat("trek.dump", 0644)) < 0) |
| 55 | return (printf("cannot dump\n")); |
| 56 | version = VERSION; |
| 57 | write(fd, &version, sizeof version); |
| 58 | |
| 59 | /* output the main data areas */ |
| 60 | for (d = Dump_template; d->area; d++) |
| 61 | { |
| 62 | write(fd, &d->area, sizeof d->area); |
| 63 | i = d->count; |
| 64 | write(fd, d->area, i); |
| 65 | } |
| 66 | |
| 67 | close(fd); |
| 68 | } |
| 69 | |
| 70 | |
| 71 | /* |
| 72 | ** RESTORE GAME |
| 73 | ** |
| 74 | ** The game is restored from the file "trek.dump". In order for |
| 75 | ** this to succeed, the file must exist and be readable, must |
| 76 | ** have the correct version number, and must have all the appro- |
| 77 | ** priate data areas. |
| 78 | ** |
| 79 | ** Return value is zero for success, one for failure. |
| 80 | */ |
| 81 | |
| 82 | restartgame() |
| 83 | { |
| 84 | register int fd; |
| 85 | int version; |
| 86 | |
| 87 | if ((fd = open("trek.dump", 0)) < 0 || |
| 88 | read(fd, &version, sizeof version) != sizeof version || |
| 89 | version != VERSION || |
| 90 | readdump(fd)) |
| 91 | { |
| 92 | printf("cannot restart\n"); |
| 93 | close(fd); |
| 94 | return (1); |
| 95 | } |
| 96 | |
| 97 | close(fd); |
| 98 | return (0); |
| 99 | } |
| 100 | |
| 101 | |
| 102 | /* |
| 103 | ** READ DUMP |
| 104 | ** |
| 105 | ** This is the business end of restartgame(). It reads in the |
| 106 | ** areas. |
| 107 | ** |
| 108 | ** Returns zero for success, one for failure. |
| 109 | */ |
| 110 | |
| 111 | readdump(fd1) |
| 112 | int fd1; |
| 113 | { |
| 114 | register int fd; |
| 115 | register struct dump *d; |
| 116 | register int i; |
| 117 | int junk; |
| 118 | |
| 119 | fd = fd1; |
| 120 | |
| 121 | for (d = Dump_template; d->area; d++) |
| 122 | { |
| 123 | if (read(fd, &junk, sizeof junk) != (sizeof junk)) |
| 124 | return (1); |
| 125 | if ((char *)junk != d->area) |
| 126 | return (1); |
| 127 | i = d->count; |
| 128 | if (read(fd, d->area, i) != i) |
| 129 | return (1); |
| 130 | } |
| 131 | |
| 132 | /* make quite certain we are at EOF */ |
| 133 | return (read(fd, &junk, 1)); |
| 134 | } |