Within "myscript.prl" instead of just printing and capturing STDOUT to $tmp_file, open it instead and write to it. You will want to checkout flock which may help prevent the overwriting problem. Still, if you have hundreds of thousands of processes/machines all trying to write to the same file, you are creating a huge bottleneck. What about running the command on each machine as you appear to want to do, but write it to a local temporary accumulation file. Then either retrieve each one, or send them to a common queue (on a periodic basis) where a second process can collate them into this one behemoth file you desire? Just a thought.

-THRAK
www.polarlava.com