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 /* $DragonFly: src/games/hack/hack.rumors.c,v 1.3 2006/08/21 19:45:32 pavalos Exp $ */
   5
   6 #include "hack.h"                       /* for RUMORFILE and BSD (index) */
   7 #define CHARSZ  8                       /* number of bits in a char */
   8 int n_rumors = 0;
   9 int n_used_rumors = -1;
  10 char *usedbits;
  11
  12 static void init_rumors(FILE *);
  13 static bool skipline(FILE *);
  14 static void outline(FILE *);
  15 static bool used(int);
  16
  17 static void
  18 init_rumors(FILE *rumf)
  19 {
  20         int i;
  21
  22         n_used_rumors = 0;
  23         while (skipline(rumf))
  24                 n_rumors++;
  25         rewind(rumf);
  26         i = n_rumors / CHARSZ;
  27         usedbits = alloc((unsigned)(i + 1));
  28         for (; i >= 0; i--)
  29                 usedbits[i] = 0;
  30 }
  31
  32 static bool
  33 skipline(FILE *rumf)
  34 {
  35         char line[COLNO];
  36
  37         for (;;) {
  38                 if (!fgets(line, sizeof(line), rumf))
  39                         return (0);
  40                 if (strchr(line, '\n'))
  41                         return (1);
  42         }
  43 }
  44
  45 static void
  46 outline(FILE *rumf)
  47 {
  48         char line[COLNO];
  49         char *ep;
  50
  51         if (!fgets(line, sizeof(line), rumf))
  52                 return;
  53         if ((ep = strchr(line, '\n')) != 0)
  54                 *ep = 0;
  55         pline("This cookie has a scrap of paper inside! It reads: ");
  56         pline(line);
  57 }
  58
  59 void
  60 outrumor(void)
  61 {
  62         int rn, i;
  63         FILE *rumf;
  64
  65         if (n_rumors <= n_used_rumors ||
  66             (rumf = fopen(RUMORFILE, "r")) == NULL)
  67                 return;
  68         if (n_used_rumors < 0)
  69                 init_rumors(rumf);
  70         if (!n_rumors)
  71                 goto none;
  72         rn = rn2(n_rumors - n_used_rumors);
  73         i = 0;
  74         while (rn || used(i)) {
  75                 skipline(rumf);
  76                 if (!used(i))
  77                         rn--;
  78                 i++;
  79         }
  80         usedbits[i / CHARSZ] |= (1 << (i % CHARSZ));
  81         n_used_rumors++;
  82         outline(rumf);
  83 none:
  84         fclose(rumf);
  85 }
  86
  87 static bool
  88 used(int i)
  89 {
  90         return (usedbits[i / CHARSZ] & (1 << (i % CHARSZ)));
  91 }