get number of open files in a process?

[Batutis, Ed]

> I'm still not convinced the approach here (of checking fds) is the right one
> to take - you have to have a very big reserve to not suddenly run out of fds,
> one would just limit amount of clients and, well, handle errors as they can
> pop up for reasons other than running out of fd slots.

I have a large reserve - usually more than 1000 fd slots. But occasionally something happens and the process runs out. There are a lot of different things going on in the process in terms of fd usage. So, finding the issue could be easier if I know when the number started rising to an unusual level. And I can possibly find the root cause more easily if I stop doing some things when this happens. I can monitor memory usage and CPU usage easily enough, but I could not figure out how to monitor fd usage. There are other approaches, yes. But I was looking for something simple but useful until additional effort could be expended on other approaches.

Thanks,

=Ed