> > cron does not have that feature, but something like the old c-news
> > shell wrapper that got a lock, ran a program of some kind, and
> > destroyed the lock seems to be in order.  (for extra credit, give
> > it a command line option to either wait, or just die, if the lock
> > isn't gettable.)
>
> The lockfile program that comes with procmail is useful in shell
> scripts for manipulating lockfiles.

The shlock(1) program included in the base NetBSD system should also
be useful to tackle this task.

Regards,

- H=E5vard