Subversion Repositories planix.SVN

#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";

void
main(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);
}