get number of open files in a process?

[Jilles Tjoelker]

On Thu, Jan 21, 2016 at 07:44:01PM +0000, Batutis, Ed wrote:
> > However, the real question is what do you need this for.

> I would like to know when I am getting close to hitting the file
> handle limit. This is useful for two reasons: 1) if I run out of
> available file handles this will most likely cause my process to
> crash. If I start logging when the count begins to get dangerously
> high, then I might after the fact be able to determine what was going
> on to cause that. 2) Some handles are used by a user interface. It
> would be nice if the server could reject connections when the open
> handle count hit a critical threshold so the user interface doesn't
> become part of the problem - obscuring the actual underlying cause.

You can check the integer file descriptor that was just created, since
if the descriptor is N, at least N other descriptors must be active at
the same time. For example, if a new client's file descriptor is higher
than the limit minus some safety margin, reject the connection.

-- 
Jilles Tjoelker