File name from file descriptor?

[Carsten Gaebler]

Carlos Ribeiro wrote:

> functionality depend a lot on the OS being used. Could you please tell us
> why do you *need* to make it work using file descriptors?

The problem is this: I have a script that is called like

./myscript.py < somefile

where somefile is a text file which may or may not be gzipped. To
determine whether or not the data is gzipped I read in one byte via the
gzip module. If that raises an exception I know the data is not gzipped.
But I'd miss the first byte if it is gzipped. Yes, I could store this byte
somewhere and then pass it around somehow, but ... you know? :-) So I'd
like to open a second 'instance' of the file for reading but I only have
sys.stdin's file descriptor.

cg.

> 
> At 14:03 22/06/01 +0200, Carsten Gaebler wrote:
> >Hi there!
> >
> >How can I determine a file's name if I only have the file descriptor?
> >os.fdopen(fd).name just returns '(fdopen)'.
> >