sys/src/cmd/fortune.c

   1 #include <u.h>
   2 #include <libc.h>
   3 #include <bio.h>
   4
   5 char choice[2048];
   6 char index[] = "/sys/games/lib/fortunes.index";
   7 char fortunes[] = "/sys/games/lib/fortunes";
   8
   9 void
  10 main(int argc, char *argv[])
  11 {
  12         int i;
  13         long offs;
  14         uchar off[4];
  15         int ix, nix;
  16         int newindex, oldindex;
  17         char *p;
  18         Dir *fbuf, *ixbuf;
  19         Biobuf *f, g;
  20
  21         newindex = 0;
  22         oldindex = 0;
  23         ix = offs = 0;
  24         if((f=Bopen(argc>1?argv[1]:fortunes, OREAD)) == 0){
  25                 print("Misfortune!\n");
  26                 exits("misfortune");
  27         }
  28         ixbuf = nil;
  29         if(argc == 1){
  30                 ix = open(index, OREAD);
  31                 if(ix>=0){
  32                         ixbuf = dirfstat(ix);
  33                         fbuf = dirfstat(Bfildes(f));
  34                         if(ixbuf == nil || fbuf == nil){
  35                                 print("Misfortune?\n");
  36                                 exits("misfortune");
  37                         }
  38                         if(ixbuf->length == 0){
  39                                 /* someone else is rewriting the index */
  40                                 goto NoIndex;
  41                         }
  42                         oldindex = 1;
  43                         if(fbuf->mtime > ixbuf->mtime){
  44                                 nix = create(index, OWRITE, 0666);
  45                                 if(nix >= 0){
  46                                         close(ix);
  47                                         ix = nix;
  48                                         newindex = 1;
  49                                         oldindex = 0;
  50                                 }
  51                         }
  52                 }else{
  53                         ix = create(index, OWRITE, 0666);
  54                         if(ix >= 0)
  55                                 newindex = 1;
  56                 }
  57         }
  58         if(oldindex){
  59                 seek(ix, truerand()%(ixbuf->length/sizeof(offs))*sizeof(offs), 0);
  60                 read(ix, off, sizeof(off));
  61                 Bseek(f, off[0]|(off[1]<<8)|(off[2]<<16)|(off[3]<<24), 0);
  62                 p = Brdline(f, '\n');
  63                 if(p){
  64                         p[Blinelen(f)-1] = 0;
  65                         strcpy(choice, p);
  66                 }else
  67                         strcpy(choice, "Misfortune!");
  68         }else{
  69 NoIndex:
  70                 Binit(&g, ix, 1);
  71                 srand(truerand());
  72                 for(i=1;;i++){
  73                         if(newindex)
  74                                 offs = Boffset(f);
  75                         p = Brdline(f, '\n');
  76                         if(p == 0)
  77                                 break;
  78                         p[Blinelen(f)-1] = 0;
  79                         if(newindex){
  80                                 off[0] = offs;
  81                                 off[1] = offs>>8;
  82                                 off[2] = offs>>16;
  83                                 off[3] = offs>>24;
  84                                 Bwrite(&g, off, sizeof(off));
  85                         }
  86                         if(lrand()%i==0)
  87                                 strcpy(choice, p);
  88                 }
  89         }
  90         print("%s\n", choice);
  91         exits(0);
  92 }