intermachine flocking

[Simon Wistow]

We have a farm of machines which will have access to a file. We only 
want one of the machines accessing that file at once - if a process 
cannot get a lock on the file then it should exit immediately otherwise 
it shoudl write the necessary number of times to the file and then exit.

Of course flock() doesn't work across NFS. Is the only solution to this 
a flock daemon?

Simon