games/hack/hack.rumors.c

   1 /*      $NetBSD: hack.rumors.c,v 1.6 2009/06/07 18:30:39 dholland Exp $ */
   2
   3 /*
   4  * Copyright (c) 1985, Stichting Centrum voor Wiskunde en Informatica,
   5  * Amsterdam
   6  * All rights reserved.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions are
  10  * met:
  11  *
  12  * - Redistributions of source code must retain the above copyright notice,
  13  * this list of conditions and the following disclaimer.
  14  *
  15  * - 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  *
  19  * - Neither the name of the Stichting Centrum voor Wiskunde en
  20  * Informatica, nor the names of its contributors may be used to endorse or
  21  * promote products derived from this software without specific prior
  22  * written permission.
  23  *
  24  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
  25  * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
  26  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
  27  * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER
  28  * OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  29  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  30  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  31  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
  32  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
  33  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  34  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  35  */
  36
  37 /*
  38  * Copyright (c) 1982 Jay Fenlason <hack@gnu.org>
  39  * All rights reserved.
  40  *
  41  * Redistribution and use in source and binary forms, with or without
  42  * modification, are permitted provided that the following conditions
  43  * are met:
  44  * 1. Redistributions of source code must retain the above copyright
  45  *    notice, this list of conditions and the following disclaimer.
  46  * 2. Redistributions in binary form must reproduce the above copyright
  47  *    notice, this list of conditions and the following disclaimer in the
  48  *    documentation and/or other materials provided with the distribution.
  49  * 3. The name of the author may not be used to endorse or promote products
  50  *    derived from this software without specific prior written permission.
  51  *
  52  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
  53  * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
  54  * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL
  55  * THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  56  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  57  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
  58  * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
  59  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
  60  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
  61  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  62  */
  63
  64 #include <sys/cdefs.h>
  65 #ifndef lint
  66 __RCSID("$NetBSD: hack.rumors.c,v 1.6 2009/06/07 18:30:39 dholland Exp $");
  67 #endif                          /* not lint */
  68
  69 #include "hack.h"       /* for RUMORFILE and BSD (strchr) */
  70 #include "extern.h"
  71 #define CHARSZ  8               /* number of bits in a char */
  72
  73 static int n_rumors = 0;
  74 static int n_used_rumors = -1;
  75 static char *usedbits;
  76
  77 static void init_rumors(FILE *);
  78 static int skipline(FILE *);
  79 static void outline(FILE *);
  80 static int used(int);
  81
  82 static void
  83 init_rumors(FILE *rumf)
  84 {
  85         int             i;
  86         n_used_rumors = 0;
  87         while (skipline(rumf))
  88                 n_rumors++;
  89         rewind(rumf);
  90         i = n_rumors / CHARSZ;
  91         usedbits = (char *) alloc((unsigned) (i + 1));
  92         for (; i >= 0; i--)
  93                 usedbits[i] = 0;
  94 }
  95
  96 static int
  97 skipline(FILE *rumf)
  98 {
  99         char            line[COLNO];
 100         while (1) {
 101                 if (!fgets(line, sizeof(line), rumf))
 102                         return (0);
 103                 if (strchr(line, '\n'))
 104                         return (1);
 105         }
 106 }
 107
 108 static void
 109 outline(FILE *rumf)
 110 {
 111         char            line[COLNO];
 112         char           *ep;
 113         if (!fgets(line, sizeof(line), rumf))
 114                 return;
 115         if ((ep = strchr(line, '\n')) != 0)
 116                 *ep = 0;
 117         pline("This cookie has a scrap of paper inside! It reads: ");
 118         pline(line);
 119 }
 120
 121 void
 122 outrumor(void)
 123 {
 124         int             rn, i;
 125         FILE           *rumf;
 126         if (n_rumors <= n_used_rumors ||
 127             (rumf = fopen(RUMORFILE, "r")) == (FILE *) 0)
 128                 return;
 129         if (n_used_rumors < 0)
 130                 init_rumors(rumf);
 131         if (!n_rumors)
 132                 goto none;
 133         rn = rn2(n_rumors - n_used_rumors);
 134         i = 0;
 135         while (rn || used(i)) {
 136                 (void) skipline(rumf);
 137                 if (!used(i))
 138                         rn--;
 139                 i++;
 140         }
 141         usedbits[i / CHARSZ] |= (1 << (i % CHARSZ));
 142         n_used_rumors++;
 143         outline(rumf);
 144 none:
 145         (void) fclose(rumf);
 146 }
 147
 148 static int
 149 used(int i)
 150 {
 151         return (usedbits[i / CHARSZ] & (1 << (i % CHARSZ)));
 152 }