games/ching/castching/castching.c

   1 /*      $NetBSD: castching.c,v 1.2 2008/07/20 01:03:21 lukem Exp $      */
   2
   3 /*
   4  * Copyright (c) 1988, 1993
   5  *      The Regents of the University of California.  All rights reserved.
   6  *
   7  * This code is derived from software contributed to Berkeley by
   8  * Guy Harris.
   9  *
  10  * Redistribution and use in source and binary forms, with or without
  11  * modification, are permitted provided that the following conditions
  12  * are met:
  13  * 1. Redistributions of source code must retain the above copyright
  14  *    notice, this list of conditions and the following disclaimer.
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in the
  17  *    documentation and/or other materials provided with the distribution.
  18  * 3. All advertising materials mentioning features or use of this software
  19  *    must display the following acknowledgement:
  20  *      This product includes software developed by the University of
  21  *      California, Berkeley and its contributors.
  22  * 4. Neither the name of the University nor the names of its contributors
  23  *    may be used to endorse or promote products derived from this software
  24  *    without specific prior written permission.
  25  *
  26  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  27  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  28  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  29  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  30  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  31  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  32  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  33  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  34  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  35  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  36  * SUCH DAMAGE.
  37  */
  38
  39 #include <sys/cdefs.h>
  40 #ifndef lint
  41 __COPYRIGHT("@(#) Copyright (c) 1988, 1993\
  42  The Regents of the University of California.  All rights reserved.");
  43 #endif /* not lint */
  44
  45 #ifndef lint
  46 #if 0
  47 static char sccsid[] = "@(#)ching.cno.c 8.1 (Berkeley) 5/31/93";
  48 #else
  49 __RCSID("$NetBSD: castching.c,v 1.2 2008/07/20 01:03:21 lukem Exp $");
  50 #endif
  51 #endif /* not lint */
  52
  53 /*
  54  * castching - Read a question, cast a change, and output the line
  55  * values to the standard output for processing by "printching".
  56  */
  57 #include <stdio.h>
  58 #include <stdlib.h>
  59 #include <time.h>
  60 #include <unistd.h>
  61 #include "ching.h"
  62
  63 static time_t now;              /* current time */
  64
  65 static unsigned seed;           /* seed for random number generator */
  66
  67 static int getquest(void);
  68 static unsigned getrand(void);
  69 static unsigned getrnum(void);
  70 static char *change(void);
  71
  72 static char string[6+1];        /* where the actual change string is put */
  73
  74 static int table[2][2][2] = {
  75         { { OYIN,  YYANG,}, { YYANG, YYIN,} },
  76         { { YYANG, YYIN,},  { YYIN,  OYANG,} },
  77 };
  78
  79 /*ARGSUSED*/
  80 int
  81 main(int argc, char **argv)
  82 {
  83         time(&now);
  84         /* randomize */
  85         seed = (int)now + getquest() + getgid() + getuid() + getpid();
  86         printf("%s\n", change());
  87         exit(0);
  88 }
  89
  90 /*
  91  * Hash the question by adding all the characters together.
  92  */
  93 static int
  94 getquest(void)
  95 {
  96         int result;
  97         int c;
  98
  99         result = 0;
 100         while ((c = getchar()) != EOF)
 101                 result += c;
 102         return(result);
 103 }
 104
 105 /*
 106  * Get a set of six lines making up a change.
 107  */
 108 static char *
 109 change(void)
 110 {
 111         int i;
 112
 113         for (i = 0; i < 6; i++)
 114                 string[i] = table[getrnum()&01][getrnum()&01][getrnum()&01] + '0';
 115         string[i] = '\0';
 116         return(string);
 117 }
 118
 119 /*
 120  * Get a number more random than what getrand() gives.
 121  */
 122 static unsigned
 123 getrnum(void)
 124 {
 125         return((getrand())>>(getrand()%17));
 126 }
 127
 128 /*
 129  * Get a random number.
 130  */
 131 static unsigned
 132 getrand(void)
 133 {
 134         return(seed = (seed*13077) + 6925);
 135 }