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         n_used_rumors = 0;
  22         while(skipline(rumf)) n_rumors++;
  23         rewind(rumf);
  24         i = n_rumors/CHARSZ;
  25         usedbits = (char *) alloc((unsigned)(i+1));
  26         for( ; i>=0; i--) usedbits[i] = 0;
  27 }
  28
  29 static bool
  30 skipline(FILE *rumf)
  31 {
  32 char line[COLNO];
  33         while(1) {
  34                 if(!fgets(line, sizeof(line), rumf)) return(0);
  35                 if(index(line, '\n')) return(1);
  36         }
  37 }
  38
  39 static void
  40 outline(FILE *rumf)
  41 {
  42 char line[COLNO];
  43 char *ep;
  44         if(!fgets(line, sizeof(line), rumf)) return;
  45         if((ep = index(line, '\n')) != 0) *ep = 0;
  46         pline("This cookie has a scrap of paper inside! It reads: ");
  47         pline(line);
  48 }
  49
  50 void
  51 outrumor(void)
  52 {
  53 int rn,i;
  54 FILE *rumf;
  55         if(n_rumors <= n_used_rumors ||
  56           (rumf = fopen(RUMORFILE, "r")) == NULL) return;
  57         if(n_used_rumors < 0) init_rumors(rumf);
  58         if(!n_rumors) goto none;
  59         rn = rn2(n_rumors - n_used_rumors);
  60         i = 0;
  61         while(rn || used(i)) {
  62                 skipline(rumf);
  63                 if(!used(i)) rn--;
  64                 i++;
  65         }
  66         usedbits[i/CHARSZ] |= (1 << (i % CHARSZ));
  67         n_used_rumors++;
  68         outline(rumf);
  69 none:
  70         fclose(rumf);
  71 }
  72
  73 static bool
  74 used(int i)
  75 {
  76         return(usedbits[i/CHARSZ] & (1 << (i % CHARSZ)));
  77 }