[Python-Dev] Pondering some changes to python.c...

Sean Reifschneider jafo-python-dev@tummy.com
Mon, 8 Apr 2002 23:36:29 -0600

On Mon, Apr 08, 2002 at 08:32:45PM -0400, Guido van Rossum wrote:
>This sounds awfully ill-defined.  Do you know how this is accomplished
>on various Unix variants besides Linux?  What if there's some platform

I got this mechanism by examining sendamil (which uses the ps output to
display various states).  Sendmail includes 6 mechanisms for setting the
process name:

   psstrings (a struct you can set argc/argv through)
   Apparently a SCO-specific mechanism which directly accesses kernel memory
   Overwriting the original argv[0]
   Setting argv[0] to point to a new buffer

I have no idea how "published" one should consider these interfaces...

>guaranteed to work as Linux is upgraded?  I'd hate to hear the
>complaints from users when they upgrade their kernel and find that it
>breaks Python, despite ABI compatibility promises.

Indeed.  It's small consolation that it would also break sendmail...

>What code would have a hold of argv, except main() which just calls

In the normal python interpreter, nothing.  My concern was more with a
system that embeddeds Python...  Which is why I'd lean more towards an
implementation which required an explicit initialization call to enable.
That would signal Python that the embedder knew of and condoned the
modification of the process string.

I'm torn between making it a build-time option in the SRPM (defaulting to
disabled) and just dropping it as "too contentious".  Sadly, the least
objectional way to make it happen is probably making it os.pstat() and
wrapping the pstat() system call on the platforms that have it.  "Sadly"
because Linux doesn't seem to be one of those platforms...

 If you don't have time to do it right, when will you ever find time to do
 it over?
Sean Reifschneider, Inimitably Superfluous <jafo@tummy.com>
tummy.com - Linux Consulting since 1995. Qmail, KRUD, Firewalls, Python