[Python-Dev] Weird error handling in os._execvpe

Zack Weinberg zack@codesourcery.com
Thu, 1 Aug 2002 15:06:41 -0700

On Thu, Aug 01, 2002 at 03:27:43PM -0400, Guido van Rossum wrote:
> > 1. Make os.execvp[e] just call the C library's execvp[e]; it has to
> >    get this stuff right anyway.  We are already counting on it for
> >    execv - I would be surprised to find a system that had execv and
> >    not execvp, as long as PATH was a meaningful concept (it isn't, for
> >    instance, on classic MacOS).
> Probably agreed for execvpe().  All the non-env versions must call the
> env version because not all platforms have putenv, and there changes
> to os.environ don't get reflected in the process's environment.

execvp could be just

def execvp(file, args):
   return execvpe(file, args, environ)


> > 2. Enumerate all the platform-specific errno values for this failure
> >    mode, and check them all.  On Unix, ENOENT and arguably ENOTDIR.  I
> >    don't know about others.
> > 
> > 3. If we must do the temporary file thing, create a temporary
> >    _directory_; we control the contents of that directory, so we can
> >    be sure that the file name we choose does not exist.  Cleanup is
> >    messier than the other two possibilities.
> I like to agree with this, but I don't recall exactly why we ended up
> in this situation in the first place.  It's possible that it's an
> unnecessary sacrifice of a dead chicken, but it's also possible that
> there are platforms where this addressed a real need.  I'd like to
> think that it was because I didn't want to add more cruft to
> posixmodule.c (I've long given up on that :-).
> Can you post a patch to SF?  Then we can ask for volunteers to test it
> on various platforms.

I will write such a patch, however, I keep getting lost in the Python
source tree.  In addition to Modules/posixmodule.c, I would need to
update the nt, dos, os2, mac, ce, and riscos modules also, yes?  Where
are their sources kept?  I don't see an ntmodule.c, etc anywhere.