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