>>>>That's fine, thanks again - I'll see your answer Saturday night. Let me know if you want to see the programs and log file.
>>>>There are only 2 prg and the log.
>>>
>>>
>>>This has gotten to a point where the only sensible answer I can give is
>>>(1) take it to iteration 500
>>>(2) Start coverage logging
>>>(3) let it do the iteration
>>>(4) stop coverage logging
>>>
>>>Then see which parts take a long time
>>
>>I've made a few changes in the write_log function and the time of execution is no longer increasing in my tests.
>
>
>Good - exit memory leak

If I can do better - I'd like to do better. I'll play with your fwrite idea.