games/hack/hack.rumors.c

   1 /* Copyright (c) Stichting Mathematisch Centrum, Amsterdam, 1985. */
   2 /* hack.rumors.c - version 1.0.3 */
   3 /* $FreeBSD: src/games/hack/hack.rumors.c,v 1.3 1999/11/16 02:57:10 billf Exp $ */
   4
   5 #include "hack.h"                       /* for RUMORFILE and BSD (index) */
   6 #define CHARSZ  8                       /* number of bits in a char */
   7 int n_rumors = 0;
   8 int n_used_rumors = -1;
   9 char *usedbits;
  10
  11 static void init_rumors(FILE *);
  12 static bool skipline(FILE *);
  13 static void outline(FILE *);
  14 static bool used(int);
  15
  16 static void
  17 init_rumors(FILE *rumf)
  18 {
  19         int i;
  20
  21         n_used_rumors = 0;
  22         while (skipline(rumf))
  23                 n_rumors++;
  24         rewind(rumf);
  25         i = n_rumors / CHARSZ;
  26         usedbits = alloc((unsigned)(i + 1));
  27         for (; i >= 0; i--)
  28                 usedbits[i] = 0;
  29 }
  30
  31 static bool
  32 skipline(FILE *rumf)
  33 {
  34         char line[COLNO];
  35
  36         for (;;) {
  37                 if (!fgets(line, sizeof(line), rumf))
  38                         return (0);
  39                 if (strchr(line, '\n'))
  40                         return (1);
  41         }
  42 }
  43
  44 static void
  45 outline(FILE *rumf)
  46 {
  47         char line[COLNO];
  48         char *ep;
  49
  50         if (!fgets(line, sizeof(line), rumf))
  51                 return;
  52         if ((ep = strchr(line, '\n')) != NULL)
  53                 *ep = 0;
  54         pline("This cookie has a scrap of paper inside! It reads: ");
  55         pline("%s", line);
  56 }
  57
  58 void
  59 outrumor(void)
  60 {
  61         int rn, i;
  62         FILE *rumf;
  63
  64         if (n_rumors <= n_used_rumors ||
  65             (rumf = fopen(RUMORFILE, "r")) == NULL)
  66                 return;
  67         if (n_used_rumors < 0)
  68                 init_rumors(rumf);
  69         if (!n_rumors)
  70                 goto none;
  71         rn = rn2(n_rumors - n_used_rumors);
  72         i = 0;
  73         while (rn || used(i)) {
  74                 skipline(rumf);
  75                 if (!used(i))
  76                         rn--;
  77                 i++;
  78         }
  79         usedbits[i / CHARSZ] |= (1 << (i % CHARSZ));
  80         n_used_rumors++;
  81         outline(rumf);
  82 none:
  83         fclose(rumf);
  84 }
  85
  86 static bool
  87 used(int i)
  88 {
  89         return (usedbits[i / CHARSZ] & (1 << (i % CHARSZ)));
  90 }