mkisofs question (ignore existing isofs?)

["Mick" <email_mick_groups@bigpond.com>]

Hi All,

I'mtrying to write a python script to wrap around mkisofs.  This works fine
if I want to use os.system(growisofs_command), but in this format the script
is blocking (ie doesn't return to me until the write is complete).  Another
(more preffered) option is to use popen2 to open the session,as this will
not block the script (ie I can poll for completion), but if the media is
dvd+rw AND is NOT virgin media, growisofs blits and an error and then
mini-formats the disc.

i've triedusing "dvd+rw-format /dev/dvd -lead-out"

But mkisofs still blits the error and countdown saying the disc contains an
isofs already..

this is an example of the output I get:
growisofs -dvd-compat -Z /dev/dvd -V DVD_TITLE -dvd-video
/movies/dvd.baks/BROTHER_BEA
R/
WARNING: /dev/dvd already carries isofs!
About to execute 'mkisofs -V DVD_TITLE -dvd-video
/movies/dvd.baks/BROTHER_BEAR/ | builtin_dd of=/de
v/dvd obs=32k seek=0'
Sleeping for 4 sec...

>From what I can gather, this countdown is breaking my script..  Is there a
flag to remove the countdown and just write over the existing data?

Mick