hack/hack.rumors.c

   1 /*      $NetBSD: hack.rumors.c,v 1.4 1997/10/19 16:58:55 christos Exp $ */
   2
   3 /*
   4  * Copyright (c) Stichting Mathematisch Centrum, Amsterdam, 1985.
   5  */
   6
   7 #include <sys/cdefs.h>
   8 #ifndef lint
   9 __RCSID("$NetBSD: hack.rumors.c,v 1.4 1997/10/19 16:58:55 christos Exp $");
  10 #endif                          /* not lint */
  11
  12 #include "hack.h"       /* for RUMORFILE and BSD (strchr) */
  13 #include "extern.h"
  14 #define CHARSZ  8               /* number of bits in a char */
  15 int             n_rumors = 0;
  16 int             n_used_rumors = -1;
  17 char           *usedbits;
  18
  19 void
  20 init_rumors(rumf)
  21         FILE           *rumf;
  22 {
  23         int             i;
  24         n_used_rumors = 0;
  25         while (skipline(rumf))
  26                 n_rumors++;
  27         rewind(rumf);
  28         i = n_rumors / CHARSZ;
  29         usedbits = (char *) alloc((unsigned) (i + 1));
  30         for (; i >= 0; i--)
  31                 usedbits[i] = 0;
  32 }
  33
  34 int
  35 skipline(rumf)
  36         FILE           *rumf;
  37 {
  38         char            line[COLNO];
  39         while (1) {
  40                 if (!fgets(line, sizeof(line), rumf))
  41                         return (0);
  42                 if (strchr(line, '\n'))
  43                         return (1);
  44         }
  45 }
  46
  47 void
  48 outline(rumf)
  49         FILE           *rumf;
  50 {
  51         char            line[COLNO];
  52         char           *ep;
  53         if (!fgets(line, sizeof(line), rumf))
  54                 return;
  55         if ((ep = strchr(line, '\n')) != 0)
  56                 *ep = 0;
  57         pline("This cookie has a scrap of paper inside! It reads: ");
  58         pline(line);
  59 }
  60
  61 void
  62 outrumor()
  63 {
  64         int             rn, i;
  65         FILE           *rumf;
  66         if (n_rumors <= n_used_rumors ||
  67             (rumf = fopen(RUMORFILE, "r")) == (FILE *) 0)
  68                 return;
  69         if (n_used_rumors < 0)
  70                 init_rumors(rumf);
  71         if (!n_rumors)
  72                 goto none;
  73         rn = rn2(n_rumors - n_used_rumors);
  74         i = 0;
  75         while (rn || used(i)) {
  76                 (void) skipline(rumf);
  77                 if (!used(i))
  78                         rn--;
  79                 i++;
  80         }
  81         usedbits[i / CHARSZ] |= (1 << (i % CHARSZ));
  82         n_used_rumors++;
  83         outline(rumf);
  84 none:
  85         (void) fclose(rumf);
  86 }
  87
  88 int
  89 used(i)
  90         int             i;
  91 {
  92         return (usedbits[i / CHARSZ] & (1 << (i % CHARSZ)));
  93 }