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
main(int argc,char * argv[])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 }
93