/*  * This file is part of the UCB release of Plan 9. It is subject to the license * terms in the LICENSE file found in the top-level directory of this * distribution and at http://akaros.cs.berkeley.edu/files/Plan9License. No * part of the UCB release of Plan 9, including this file, may be copied, * modified, propagated, or distributed except according to the terms contained * in the LICENSE file. */ #include <u.h>#include <libc.h>#include <bio.h> char choice[2048];char index[] = "/sys/games/lib/fortunes.index";char fortunes[] = "/sys/games/lib/fortunes"; voidmain(int argc, char *argv[]){	int i;	long offs;	uchar off[4];	int ix, nix;	int newindex, oldindex;	char *p;	Dir *fbuf, *ixbuf;	Biobuf *f, g; 	newindex = 0;	oldindex = 0;	ix = offs = 0;	if((f=Bopen(argc>1?argv[1]:fortunes, OREAD)) == 0){		print("Misfortune!\n");		exits("misfortune");	}	ixbuf = nil;	if(argc == 1){		ix = open(index, OREAD);		if(ix>=0){			ixbuf = dirfstat(ix);			fbuf = dirfstat(Bfildes(f));			if(ixbuf == nil || fbuf == nil){				print("Misfortune?\n");				exits("misfortune");			}			if(ixbuf->length == 0){				/* someone else is rewriting the index */				goto NoIndex;			}			oldindex = 1;			if(fbuf->mtime > ixbuf->mtime){				nix = create(index, OWRITE, 0666);				if(nix >= 0){					close(ix);					ix = nix;					newindex = 1;					oldindex = 0;				}			}		}else{			ix = create(index, OWRITE, 0666);			if(ix >= 0)				newindex = 1;		}	}	if(oldindex){		seek(ix, truerand()%(ixbuf->length/sizeof(offs))*sizeof(offs), 0);		read(ix, off, sizeof(off));		Bseek(f, off[0]|(off[1]<<8)|(off[2]<<16)|(off[3]<<24), 0);		p = Brdline(f, '\n');		if(p){			p[Blinelen(f)-1] = 0;			strcpy(choice, p);		}else			strcpy(choice, "Misfortune!");	}else{NoIndex:		Binit(&g, ix, 1);		srand(truerand());		for(i=1;;i++){			if(newindex)				offs = Boffset(f);			p = Brdline(f, '\n');			if(p == 0)				break;			p[Blinelen(f)-1] = 0;			if(newindex){				off[0] = offs;				off[1] = offs>>8;				off[2] = offs>>16;				off[3] = offs>>24;				Bwrite(&g, off, sizeof(off));			}			if(lrand()%i==0)				strcpy(choice, p);		}	}	print("%s\n", choice);	exits(0);}