Determine sockets in use by python

[Jean-Paul Calderone]

On Sep 29, 4:08 pm, Jim Mellander <jmellan... at lbl.gov> wrote:
>
> On Wed, Sep 29, 2010 at 11:05 AM, Gary Herron <gher... at digipen.edu> wrote:
> > On 09/29/2010 09:50 AM, Jim Mellander wrote:
>
> >> Hi:
>
> >> I'm a newbie to python, although not to programming.  Briefly, I am
> >> using a binding to an external library used for communication in a
> >> client-server context, with the server in python.  Typically, I would
> >> set this up with event callbacks, and then enter a select loop, which,
> >> most the time idles and processes input events when the socket shows
> >> activity, kinda like:
>
> >> while True:
> >>     socket.select((my_socket),(),())
> >>     process_event()
>
> >> Unfortunately, the API does not expose the socket to the script level,
> >> and the developer recommends a busy loop:
>
> >> while True:
> >>     sleep(1)
> >>     process_event()
>
> >> which I hope to avoid, for many reasons.  If the socket can be exposed
> >> to the script level, then the problem would be solved.
>
> >> Failing that, it would be nice to be able to pythonically determine
> >> the sockets in use and select on those.  Does anyone have any
> >> suggestions on how to proceed?
>
> >> Thanks in advance
>
> > It's certain that any answer to this will depend on which operating system
> > you are using.  So do tell: What OS?
>
> Hi Gary:
>
> Certainly not windows....  I'm developing on OS/X but for production
> probably Linux and FreeBSD
>
> (I'm hoping for something a bit more portable than running 'lsof' and
> parsing the output, but appreciate any/all advice)
>

Linux has /proc/self/fd and OS X has /dev/fd.  Those both suppose you
have some way of determining which file descriptor corresponds to the
socket or sockets that the library is using, of course.  Vastly better
would be to convince the author to expose that information via a real
API.

Jean-Paul