executable "wrapper" gui -- advice sought

[Grant Goodyear]

I'm in the process of writing an exceedingly simple gui that will take an
already existing binary executable and input text file (I don't want to
break the
working system!) and allow the user to modify the input arguments,
if desired, and then start the executable.  That part is straightforward.
What I'm not sure how to do is to capture the executable's std out as
it's generated.  My goal is to echo that output to a seperate window, and
also to use it to generate a periodically updated html "status report" so
that the program's progress can be monitored remotely.  Working
through the gui aspects isn't all that difficult, but I have _no_ idea how
to grab the executable's std out _while it is running_ and then have the
python gui do something (anything!) with that data.  Any advice?

Many thanks,
Grant Goodyear