That code doesn't work in real life, in spite of the fact that it was in an Animal Book. You can't flock a tied DBM, because some I/O has already happened before the flock is obtained, and not re-triggered once you have a flock.

You need to use a sentinel file before you tie and open. Super search here for sentinel, since I've mentioned it once or twice before. {grin}

-- Randal L. Schwartz, Perl hacker